Chromosomal fragile sites FRA3B and FRA16D show correlated expression and association with failure of apoptosis in lymphocytes from patients with thyroid cancer

It has been suggested that common fragile sites (cFSs) are related to cancer development. This appears to be the case for FRA3B and FRA16D, localized in two tumor-suppressor genes (FHIT and WWOX, respectively) that are altered by deletions or loss of heterozygosity (LOH) in many cancers. The features responsible for fragility have not yet been identified. Furthermore, it is still unclear whether instability at these regions causes chance deletions and loss of function of the associated genes, or whether the gene function itself is related to the appearance of fragility. In this study, we analyzed cFS expression in lymphocytes from 20 healthy or thyroid cancer-affected subjects exposed to radiation after the Chernobyl accident. The same cells were examined for apoptosis, a principal function of both the FHIT and WWOX genes. Exceptionally elevated chromosome fragility was observed, particularly in cancer patients, affecting FRA3B, FRA16D, and a cluster of less highly expressed cFSs; levels of chromosome fragility were found to be correlated among these cFSs. Interestingly, most expressed cFSs were sites of LOH reported for thyroid tumors; moreover, cells with the highest fragility also had a reduced ability to undergo apoptosis. These findings reveal previously unknown genetic interactions affecting fragile loci, suggestive of a shared function inside mitotic cells. Attenuation of checkpoint control and apoptosis resistance seem to be the cell phenotypes associated with unusual chromosome fragility. We propose that breakage at specific cFS could derive from early epigenetic events at loci involved in radiation carcinogenesis. This article contains supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.     

A simple and inexpensive light source for research in visual neuroscience

Investigating the properties of light responsive neurons and their networks requires appropriate control of stimulus parameters, such as intensity, spectral composition, spatial and temporal profile. In the present paper, we describe how to build a simple, versatile and low-cost light source for use in visual neuroscience. The light source is a InGaN-based ultrabright light-emitting diode (LED), which may generate conventional light flashes as well as a variety of time varying stimuli to be used in quantitative studies of the visual system. In particular, with this instrument one may generate light stimuli sinusoidally modulated in time at frequencies ranging from 0.05 to 50 Hz, with less than 1% harmonic distortion at a contrast exceeding 85%. The relationship between applied voltage and energy emitted by the source is linear over an intensity range that exceeds 4.5 log-units, up to the full suppression of the light-sensitive currents in mammalian rods. The light source has minimal space requirement and does not generate appreciable radiating heat and hum, allowing its use for single cell work "in vitro" as well as for "in vivo" recording of the electroretinogram (ERG).     

Optically active polymers bearing side‐chain photochromic moieties: synthesis and chiroptical properties of methacrylic homopolymers with pendant trans‐azobenzene chromophores bound through L‐leucine,L‐valine and L‐proline amino acid spacers

Novel optically active monomers, based on different L ‐amino acid residues such as trans‐(S)‐4‐(2‐methacryloylamino‐3‐methylbutanoylamino)azobenzene, trans‐(S)‐4‐(2‐methacryloylamino‐4‐methylpentanoylamino)azobenzene and trans‐(S)‐4‐(N‐methacryloyl‐2‐pyrrolidinoylamino)azobenzene, have been prepared and homopolymerized by free radical initiation. Circular dichroism spectra of the resulting polymers, as compared with those of the corresponding low molecular weight analogues, purposely synthesized, allow one to suggest that the macromolecules assume in solution achiral or chiral conformations with a prevailing screw sense, depending on the bulkiness and rigidity of the L ‐amino acid residue present in the side chains. The role of intra‐ and/or inter‐molecular hydrogen bonding between side‐chain amido groups along the backbone and the structural requirements of the chiral groups in determining the macromolecular arrangement is also discussed.     

Influence of the ratio of particulate autogenous bone graft/platelet‐rich plasma on bone healing in critical‐size defects: A histologic and histometric study in rat calvaria

The purpose of this study was to analyze histomorphometrically the influence of the ratio of particulate autogenous bone (AB) graft/platelet‐rich plasma (PRP) on bone healing in surgically created critical‐size defects (CSD) in rat calvaria. Fifty rats were divided into five groups: Group C (control), Group AB, Group AB/PRP‐50, Group AB/PRP‐100, and Group AB/PRP‐150. A 5‐mm diameter critical‐size defect was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group AB, the defect was filled with 0.01 mL of AB graft. In Groups AB/PRP‐50, AB/PRP‐100, and AB/PRP‐150, the defects were filled with 0.01 mL of AB graft combined with 50, 100, and 150 µL of PRP, respectively. All animals were euthanized at 30 days postoperative. Histomorphometry, using image analysis software, and histology analyses were performed. New Bone Area (NBA) and the remaining bone graft particles area (RPA) were calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for analysis. No defect completely regenerated with bone. Group AB/PRP‐50 (41.78 ± 13.48%) had a significantly greater NBA than Groups C (19.29 ± 5.11%), AB (27.43 ± 10.90%) or AB/PRP‐150 (19.17 ± 8.45%) (p < 0.05). No significant differences were observed between groups AB/PRP‐50 and AB/PRP‐100 or among groups AB, AB/PRP‐100, and AB/PRP‐150 with regard to NBA (p > 0.05). Group AB/PRP‐150 (31.59 ± 3.22%) had a significantly greater RPA than Groups AB (19.09 ± 5.21%), AB/PRP‐50 (17.33 ± 4.43%), and AB/PRP‐100 (19.72 ± 3.62%) (p < 0.001). No significant differences were observed among groups AB, AB/PRP‐50, and AB/PRP‐100 with regard to RPA (p > 0.05). The ratio AB graft/PRP influences bone healing in surgically created CSD in rat calvaria. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:468–473, 2010     

Lifetime rhythmicity and mania as correlates of suicidal ideation and attempts in mood disorders

BACKGROUND: The aim of this study is to establish to what degree variation in lifetime experience of rhythmicity and manic-hypomanic features correlates with suicidality in individuals with mood disorders and other major psychiatric diagnoses and in a comparison group of controls. METHOD: Suicidal ideation and attempts were investigated in a clinical sample, including 77 patients with schizophrenia, 60 with borderline personality disorder, 61 with bipolar disorder, 88 with unipolar depression, and 57 with panic disorder, and in a comparison group of 102 controls. Using information derived from the diagnostic interview and a self-report assessment of mood spectrum symptoms, subjects were assigned to 3 categories according to the maximum level of suicidality achieved in the lifetime (none, ideation/plans, and suicide attempts). The association of categorical and continuous variables with suicidality levels was investigated using multinomial logistic regression models. RESULTS: Suicidal ideation and plans were more common in unipolar depression (50%) and bipolar disorder (42.4%) than in borderline personality disorder (30%), whereas the reverse was true for suicidal attempts. In each of the study groups, the number and the type of mood spectrum items endorsed, including depressive and manic-hypomanic items and rhythmicity and vegetative symptoms, were associated with increased levels of suicidality. CONCLUSIONS: Our results suggest that the assessment of lifetime rhythmicity and manic-hypomanic features may be clinically useful to identify potential suicide attempters in high-risk groups.     

Apolipoprotein B is a new target of the GDNF/RET and ET‐3/EDNRB signalling pathways

Background GDNF/RET and Endothelin‐3 (ET‐3)/EDNRB regulate survival, differentiation, migration, and proliferation of neural crest‐derived cells. Although several RET and EDNRB signalling mediators have been characterized, most of the genes targeted by these two pathways are still largely unknown. We focused our study on apolipoprotein B (APOB) as a novel target gene of the RET and EDNRB pathways, based on previous data obtained using a Caenorhabditis elegans strain mutant for the homologue of mammalian ECE1. Methods Molecular and cellular studies of Apob were performed in the murine Neuro2a cells, an in vitro model for studying neural crest‐derived cell development, along with a mouse knock‐in for the Hirschsprung‐associated mutation Ret^C620R. Silencing for Apob and Ret has been performed via shRNA. Key Results GDNF/RET and ET‐3/EDNRB cooperated in inducing neuronal differentiation resulting in Apob activation in Neuro2a cell line. Apob expression was downregulated in mouse embryos homozygous for the Ret^C620R mutation and presenting a severe Hirschsprung phenotype. Ret silencing prevented Apob expression increase. MAPK P38 kinase activation evoked Apob expression via GDNF/RET signalling in Neuro2a cells. A p53‐dependent repressor element in Apob promoter resulted in a reduced Apob expression. Silencing of Apob reduced HuD protein expression. Conclusions & Inferences Apob is a novel downstream target of the RET/EDNRB pathways with a role in neuronal survival and maintenance, as indicated by its effect on HuD expression. Our data provide a conceptual framework to investigate and establish the role of APOB gene in severe gut dysmotility.     

Thermal Ablation of Lung Tissue: In Vivo Experimental Comparison of Microwave and Radiofrequency

This study was designed to compare feasibility, safety, and effectiveness of microwave (MW) ablation versus radiofrequency (RF) ablation of lung tissue in a rabbit model. Twenty New Zealand White rabbits were submitted to MW (n = 10, group A) or RF ablation (n = 10, group B). The procedures were performed with a prototype MW ablation device with a 1.6-cm radiating section antenna (Valleylab MW Ablation System) and with a 2-cm exposed-tip RF electrode (Cool-tip RF Ablation System). At immediate computed tomography increase in density, maximum diameters (D1–D3) of ablation zones were measured and ablation volume was calculated. Histopathologic assessment was performed 3 and 7 days after the procedure. Technical success was achieved in nine of 10 rabbits in each group. One death occurred in group B. Complications included pneumothorax (group A, n = 4; group B, n = 4), abscess (group A, n = 1; group B, n = 1), and thoracic wall burn (group A, n = 4). No significant differences were demonstrated in attenuation increase (P = 0.73), dimensions (P = 0.28, 0.86, 0.06, respectively, comparing D1–D3) and volume (P = 0.17). At histopathology, ablation zones were similar, with septal necrosis, edema, hemorrhage, and peripheral lymphocytic infiltrate. Complete thrombosis of more than 90% of vessels up to 2 mm in diameter was depicted at the periphery of the ablation zone in group A specimens. In group B specimens, complete thrombosis was depicted in 20% of vessels. Feasibility and safety of MW and RF ablation are similar in a lung rabbit model. MW ablation produces a greater damage to peripheral small vessels inducing thrombosis.