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.

PPARs in Neurodegenerative and Neuroinflammatory Pathways.

BACKGROUND: PPARs are lipid sensors activated by dietary lipids or their metabolites, mainly fatty acids and eicosanoids, that play critical roles in CNS biology, since brain has a very high lipid content and has the higher energetic metabolism in the body. METHODS: In neurodegenerative diseases in addition to metabolic impairment, also neuroinflammation is observed and PPARs are also closely linked to inflammatory processes. Several studies have revealed a complicated relationship between the innate immune response and tissue metabolism. RESULTS: In the brain, during pathological conditions, an alteration in metabolic status occurs, particularly involving glucose utilization and production, a condition which is generally related to metabolic changes. CONCLUSION: Taking into account the high expression of PPARs in the brain, this review will focus on the role of these transcription factors in CNS diseases.

Glycosilated nucleolin as marker for human gliomas.

Nucleolin is a multifunctional DNA and RNA binding protein involved in regulation of gene transcription, chromatin remodeling, RNA metabolism, and ribosomal RNA synthesis. Nucleolin seems to be over-expressed in highly proliferative cells and is involved in many aspect of gene expression: DNA recombination and replication, RNA transcription by RNA polymerase I and II, rRNA processing, mRNA stabilization, cytokinesis, and apoptosis. Although nucleolin is localized predominantly in the nucleolus, it has also been shown to be localized in a phosphorylated/glycolsilated form on the cell surface of different cells. Numerous articles dealing with surface nucleolin targeting for tumor therapy have been recently published. However, at present, no extensive informations are so far available for the presence of nucleolin in human gliomas. In the present work we investigated on the presence and localization of nucleolin in glioma on glioma specimens at different grade of malignancy and on primary glioma cell cultures derived by surgical resection, trying to correlate the presence of glycosilated membrane nucleolin with the malignancy grade. To this purpose an antibody produced by us against gp273 protein, demonstrated to recognized the glycosilated surface nucleolin, has been used. The results obtained demonstrate that surface nucleolin increase with the malignancy grade thus suggesting that it may constitute a histopathological marker for glioma grading and a possible tool for targeted therapy.

Hypoxia induces peroxisome proliferator-activated receptor α (PPARα) and lipid metabolism peroxisomal enzymes in human glioblastoma cells.

Glioblastoma multiforme (GBM) represents the most severe type of glioma, the most common brain tumor. Their malignancy shows a relationship with an increased proliferation and a poorly organized tumor vascularization, an event that leads to inadequate blood supply, hypoxic areas and at last to the formation of necrotic areas, a feature of glioblastoma. Hypoxic/necrotic tumors are more resistant to chemotherapy and radiation therapies, thus it is crucial to formulate new therapeutic approaches that can render these tumors more sensitive to the action of conventional therapies. It has been demonstrated that under hypoxia, gliomas accumulate lipid droplets and that this event is positively correlated with the degree of malignancy, glioblastoma being the most endowed with lipid droplets. We have previously demonstrated in ex vivo glioma specimens a grade-dependent lipid metabolism perturbation. Here we studied the lipid pathways and the presence of stemness markers in glioma primary cultures, obtained from surgical specimens of patients affected by glioma at different grade of malignancy, GBM primary cultures cultured under both hypoxic and normoxic conditions, as well as normal human astrocytes. The results obtained demonstrate that hypoxia plays a crucial role in regulating the expression of lipid metabolism peroxisomal enzymes, the lipid droplets accumulation as well as the transcription factor PPARα.

Biological effects of low frequency high intensity ultrasound application on ex vivo human adipose tissue.

In the present work the effects of a new low frequency, high intensity ultrasound technology on human adipose tissue ex vivo were studied. In particular, we investigated the effects of both external and surgical ultrasound-irradiation (10 min) by evaluating, other than sample weight loss and fat release, also histological architecture alteration as well apoptosis induction. The influence of saline buffer tissue-infiltration on the effects of ultrasound irradiation was also examined. The results suggest that, in our experimental conditions, both transcutaneous and surgical ultrasound exposure caused a significant weight loss and fat release. This effect was more relevant when the ultrasound intensity was set at 100 % (~2.5 W/cm², for external device; ~19-21 W/cm2, for surgical device) compared to 70 % (~1.8 W/cm² for external device; ~13-14 W/cm2 for surgical device). Of note, the effectiveness of ultrasound was much higher when the tissue samples were previously infiltrated with saline buffer, in accordance with the knowledge that ultrasonic waves in aqueous solution better propagate with a consequently more efficient cavitation process. Moreover, the overall effects of ultrasound irradiation did not appear immediately after treatment but persisted over time, being significantly more relevant at 18 h from the end of ultrasound irradiation. Evaluation of histological characteristics of ultrasound-irradiated samples showed a clear alteration of adipose tissue architecture as well a prominent destruction of collagen fibers which were dependent on ultrasound intensity and most relevant in saline buffer-infiltrated samples. The structural changes of collagen bundles present between the lobules of fat cells were confirmed through scanning electron microscopy (SEM) which clearly demonstrated how ultrasound exposure induced a drastic reduction in the compactness of the adipose connective tissue and an irregular arrangement of the fibers with a consequent alteration in the spatial architecture. The analysis of the composition of lipids in the fat released from adipose tissue after ultrasound treatment with surgical device showed, in agreement with the level of adipocyte damage, a significant increase mainly of triglycerides and cholesterol. Finally, ultrasound exposure had been shown to induce apoptosis as shown by the appearance DNA fragmentation. Accordingly, ultrasound treatment led to down-modulation of procaspase-9 expression and an increased level of caspase-3 active form.

Signal transduction pathways involved in PPARß/δ-induced neuronal differentiation.

Neuroblastomas are pediatric tumors originating from neuroblasts in the developing peripheral nervous system. The neurotrophin brain-derived neurotrophic factor (BDNF) is a key regulator of survival and differentiation of specific neuronal populations in the central and peripheral nervous system. Patients whose neuroblastoma tumors express high levels of BDNF and TrkB have an unfavorable prognosis. We have previously reported on the neuronal differentiating activity of peroxisome proliferator-activated receptors (PPAR)ß/δ natural and synthetic ligands by modulating BDNF/TrkB pathway, suggesting their potential use as new therapeutic strategies for neuroblastoma. The validation of new therapeutic agents implies the understanding of their mechanisms of action. Herein, we report the effects of activated-PPARß/δ on signal transduction pathways known to be involved in neuronal differentiation, such as ERK1,2 and BDNF pathways. The results obtained, using also PPARß/δ silencing, indicating a neuronal differentiating effect PPARß/δ-dependent through BDNF-P75-ERK1,2 pathways, further support a role for PPARß/δ in neuronal differentiation and pointing towards PPARß/δ as a modulator of pathways crucial for neuronal differentiation. These findings open new perspectives in the formulation of potential therapeutic approaches to be used as adjuvant treatment with the standard therapies.

Lipid metabolism impairment in human gliomas: expression of peroxisomal proteins in human gliomas at different grades of malignancy.

Gliomas are histologically graded by cellularity, cytological atypia, necrosis, mitotic figures, and vascular proliferation, features associated with biologically aggressive behaviour. However, abundant evidence suggests the presence of unrecognized, clinically relevant subclasses of the diffuse gliomas, both in respect to their underlying molecular phenotype and their clinical response to therapy. It is well-known that patient prognosis and therapeutic decisions rely on accurate pathological grading. Recently, it was reported that human gliomas accumulate lipid droplets during progression, suggesting a lipid metabolism impairment. Considering the crucial role of peroxisomes in lipid metabolism, in the present work we studied the expression profiles of proteins either exclusively localized to peroxisomes, such as peroxin14 (PEX14), peroxisomal membrane protein 70Kda (PMP70), acyl-CoA oxidase, thiolase, or partially associated to peroxisomes such as Hydroxymethylglutaryl-CoA reductase (HMGCoA-red) and peroxisomal-related proteins, namely PPARalpha, in human glioma specimens at different grades of malignancy. Moreover, Nile red staining of lipid droplets, thin layer chromatography (TLC) and proton nuclear magnetic resonance spectroscopy (NMR) were carried out in order to correlate the biochemical results with the lipid content of tumor tissues. The results obtained indicate that correlating the malignancy grade with the expression of peroxisomal genes and proteins, may constitute a sensitive tool to highlight possible subtypes not recognized by the classical histological techniques.

Neuronal response of peroxisomal and peroxisome-related proteins to chronic and acute Abeta injury.

The central role of peroxisomes in ROS and lipid metabolism and their importance in brain functioning are well established. The aim of this work was to study the modulation of peroxisomal and peroxisome-related proteins in cortical neurons in vitro challenged with chronic or acute Abeta treatment, in order to investigate whether peroxisomes represent one of the cellular target of Abeta in these cells. The expression of peroxisomal (PMP70, catalase, acyl-CoA oxidase and thiolase), peroxisome-related (PPARalpha, insulin-degrading enzyme) and anti-oxidant (SOD1, SOD2, GSTP1) proteins was studied. The results obtained, demonstrating an early upregulation of the peroxisomal proteins during the chronic challenge, followed by their dramatic impairment after acute challenge, suggest that peroxisomes represent one of the first line of defence against Abeta-mediated oxidative injury. Our results support the notion that substances able to activate PPARalpha and/or to induce peroxisomal proliferation may constitute a novel preventive and/or therapeutic tool against neurodegenerative diseases.

Biomolecular characterization of human glioblastoma cells in primary cultures: differentiating and antiangiogenic effects of natural and synthetic PPARgamma agonists.

Gliomas are the most commonly diagnosed malignant brain primary tumors. Prognosis of patients with high-grade gliomas is poor and scarcely affected by radiotherapy and chemotherapy. Several studies have reported antiproliferative and/or differentiating activities of some lipophylic molecules on glioblastoma cells. Some of these activities in cell signaling are mediated by a class of transcriptional factors referred to as peroxisome proliferator-activated receptors (PPARs). PPARgamma has been identified in transformed neural cells of human origin and it has been demonstrated that PPARgamma agonists decrease cell proliferation, stimulate apoptosis and induce morphological changes and expression of markers typical of a more differentiated phenotype in glioblastoma and astrocytoma cell lines. These findings arise from studies mainly performed on long-term cultured transformed cell lines. Such experimental models do not exactly reproduce the in vivo environment since long-term culture often results in the accumulation of further molecular alterations in the cells. To be as close as possible to the in vivo condition, in the present work we investigated the effects of PPARgamma natural and synthetic ligands on the biomolecular features of primary cultures of human glioblastoma cells derived from surgical specimens. We provide evidence that PPARgamma agonists may interfere with glioblastoma growth and malignancy and might be taken in account as novel antitumoral drugs.

PPARs Expression in Adult Mouse Neural Stem Cells: Modulation of PPARs during Astroglial Differentiaton of NSC.

PPAR isotypes are involved in the regulation of cell proliferation, death, and differentiation, with different roles and mechanisms depending on the specific isotype and ligand and on the differentiated, undifferentiated, or transformed status of the cell. Differentiation stimuli are integrated by key transcription factors which regulate specific sets of specialized genes to allow proliferative cells to exit the cell cycle and acquire specialized functions. The main differentiation programs known to be controlled by PPARs both during development and in the adult are placental differentiation, adipogenesis, osteoblast differentiation, skin differentiation, and gut differentiation. PPARs may also be involved in the differentiation of macrophages, brain, and breast. However, their functions in this cell type and organs still awaits further elucidation. PPARs may be involved in cell proliferation and differentiation processes of neural stem cells (NSC). To this aim, in this work the expression of the three PPAR isotypes and RXRs in NSC has been investigated.

PPARalpha mediates the effects of the pesticide methyl thiophanate on liver of the lizard Podarcis sicula.

The majority of environmental pollutants are potential peroxisomal proliferators which include a heterogeneous group of compounds known to determine massive peroxisomal proliferation and hepatocarcinogenesis in rodents. Peroxisomal proliferation is accompanied by the induction of the peroxisomal fatty acid beta-oxidation pathway mediated by a class of transcription factors named peroxisome proliferators activated receptors (PPARs). This phenomenon demonstrated also in ectotherm animals after exposition to environmental pollutants may be utilized as biomarker in environmental impact studies. In the present work we have tested the sensitivity to methyl thiophanate (TM) of the lizard Podarcis sicula in order to propose a biological model for monitoring the ecotoxicological effects of this pesticide on terrestrial sentinel species. The data obtained demonstrate that exposition to sub-lethal concentrations of TM leads to hepatocellular morphological changes and glycogen depletion, apoptosis, as well as probable peroxisomal proliferation attested by the increase of acyl-CoA oxidase (AOX). This effect seems to be mediated by the concomitant increase of PPARalpha. On the basis of these results we propose that also in Podarcis sicula, as just proposed for aquatic organisms, peroxisomal proliferation and AOX increase may be considered new biomarkers to evaluate pollution by organic compound in terrestrial environments.

PPARbeta agonists trigger neuronal differentiation in the human neuroblastoma cell line SH-SY5Y.

Neuroblastomas are pediatric tumors originating from immature neuroblasts in the developing peripheral nervous system. Differentiation therapies could help lowering the high mortality due to rapid tumor progression to advanced stages. Oleic acid has been demonstrated to promote neuronal differentiation in neuronal cultures. Herein we report on the effects of oleic acid and of a specific synthetic PPARbeta agonist on cell growth, expression of differentiation markers and on parameters responsible for the malignancy such as adhesion, migration, invasiveness, BDNF, and TrkB expression of SH-SY5Y neuroblastoma cells. The results obtained demonstrate that many, but not all, oleic acid effects are mediated by PPARbeta and support a role for PPARbeta in neuronal differentiation strongly pointing towards PPAR ligands as new therapeutic strategies against progression and recurrences of neuroblastoma.

Expression of peroxisome proliferator-activated receptors (PPARs) and retinoic acid receptors (RXRs) in rat cortical neurons.

Neuronal differentiation is a complex process involving the sequential expression of several factors. The important role of lipid molecules in brain development is well known. Many fatty acid cell signaling activities are mediated by peroxisome proliferator-activated receptors (PPARs). PPARs are ligand-activated transcription factors belonging to the steroid, thyroid and retinoid nuclear receptor superfamily. They are activated by fatty acids and their derivatives. Different isotypes of PPARs (alpha, beta/delta and gamma) have distinct physiological functions depending on their different ligand activation profiles and tissue distribution. PPARs have been involved in neural cell differentiation and death as well as in inflammation and neurodegeneration. Although PPARs have been described in neurons by in situ studies, the presence and possible modulation of these receptors during neuronal differentiation has not been explored yet. In this study we analyzed the expression of PPARs and of their heterodimeric partners, RXRs, in embryonic rat cortical neurons during their in vitro maturation. Our results demonstrate the presence of PPARs alpha, beta/delta and gamma and of RXRs beta and gamma. PPARalpha, beta/delta and gamma are differentially modulated during culture time suggesting that they may be involved in neuronal maturation. In particular, we point toward the PPARbeta/delta isotype as a key factor in neuronal differentiation.

Serum epidemiological trial on the prevalence of the anti-cytomegalovirus antibodies in patients under substitutive treatment with hemodialysis and CAPD.

The detection of IgG and IgM anti-cytomegalovirus is very important when movements of serum transaminases are noted in absence of positivity for virus of hepatitis in uremic patients on substitutive treatment; in our patients, we have noted a positivity of 67% for the IgG class. Cytomegalic infection must be taken into consideration for the high parenteral transmissibility in addition to the high grade of immunodepression of uremic patients.

The effects of reinforcement frequency and response requirements on the maintenance of behavior.

Six rats responded under fixed-interval and tandem fixed-interval fixed-ratio schedules of food reinforcement. Basic fixed-interval schedules alternated over experimental conditions with tandem fixed-interval fixed-ratio schedules with the same fixed-interval value. Fixed-interval length was varied within subjects over pairs of experimental conditions; the ratio requirement of the tandem schedules was varied across subjects. For both subjects with a ratio requirement of 10, overall response rates and running response rates typically were higher under the tandem schedules than under the corresponding basic fixed-interval schedules. For all subjects with ratio requirements of 30 or 60, overall response rates and running response rates were higher under the tandem schedules than under the corresponding basic fixed-interval schedules only with relatively short fixed intervals. At longer fixed intervals, higher overall response rates and running rates were maintained by the basic fixed-interval schedules than by the tandem schedules. These findings support Zeiler and Buchman's (1979) reinforcement-theory account of response strength as an increasing monotonic function of both the response requirement and reinforcement frequency. Small response requirements added in tandem to fixed-interval schedules have little effect on reinforcement frequency and so their net effect is to enhance responding. Larger response requirements reduce reinforcement frequency more substantially; therefore their net effect depends on the length of the fixed interval, which limits overall reinforcement frequency. At the longest fixed intervals studied in the present experiment, reinforcement frequency under the tandem schedules was sufficiently low that responding weakened or ceased altogether.