Long-wavelength supercontinuum generation in bismuth-silicate fibres

A broad smooth supercontinuum has been generated at long wavelengths in a highly-nonlinear bismuth silicate fibre pumping near the zero-dispersion wavelength of the cladding glass.     

Bioaccumulation of dioxin-like substances and selected brominated flame retardant congeners in the fat and livers of black pigs farmed within the Nebrodi Regional Park of Sicily

An observational study was designed to assess the bioaccumulation of polychlorodibenzodioxins (PCDD) and polychlorodibenzofurans (PCDF), dioxin-like polychlorobiphenyls (DL-PCB), and 13 selected polybromodiphenylethers (PBDE) in autochthonous pigs reared in the Nebrodi Park of Sicily (Italy). Perirenal fat and liver samples were drawn from animals representative of three different outdoor farming systems and from wild pigs and then analyzed for the chemicals mentioned previously. The highest concentrations of PCDD + PCDF and DL-PCB were detected in the fat (0.45 and 0.35 pg World Health Organization toxicity equivalents [WHO-TE] per g of fat base [FB], respectively) and livers (12.7 and 3.28 pg WHO-TE per g FB) of the wild group, whereas the free-ranging group showed the lowest levels (0.05 and 0.03 pg WHO-TE per g FB in fat and 0.78 and 0.27 pg WHO-TE per g FB in livers). The sum of PBDE congeners was highest in wild pigs (0.52 ng/g FB in fat and 5.64 ng/g FB in livers) and lowest in the farmed group (0.14 ng/g FB in fat and 0.28 ng/g FB in livers). The contamination levels in fat and livers of outdoor pigs had mean concentration values lower than those levels reported for intensively indoor-farmed animals. In wild pigs, bioaccumulation was associated with their free grazing in areas characterized by bush fires. The results of this study aid to emphasize the quality of the environment as a factor to guarantee food safety in typical processed pig meat products, specifically from outdoor and extensive Nebrodi farming systems.     

TMEM106B Acts as a Modifier of Cognitive and Motor Functions in Amyotrophic Lateral Sclerosis

The transmembrane protein 106B (TMEM106B) gene is a susceptibility factor and disease modifier of frontotemporal dementia, but few studies have investigated its role in amyotrophic lateral sclerosis. The aim of this work was to assess the impact of the TMEM106B rs1990622 (A–major risk allele; G–minor allele) on phenotypic variability of 865 patients with amyotrophic lateral sclerosis. Demographic and clinical features were compared according to genotypes by additive, dominant, and recessive genetic models. Bulbar onset was overrepresented among carriers of the AA risk genotype, together with enhanced upper motor neuron involvement and poorer functional status in patients harboring at least one major risk allele (A). In a subset of 195 patients, we found that the homozygotes for the minor allele (GG) showed lower scores at the Edinburgh Cognitive and Behavioral Amyotrophic Lateral Sclerosis Screen, indicating a more severe cognitive impairment, mainly involving the amyotrophic lateral sclerosis-specific cognitive functions and memory. Moreover, lower motor neuron burden predominated among patients with at least one minor allele (G). Overall, we found that TMEM106B is a disease modifier of amyotrophic lateral sclerosis, whose phenotypic effects encompass both sites of onset and functional status (major risk allele), motor functions (both major risk and minor alleles), and cognition (minor allele).     

Role of Tunneling Nanotubes in the Nervous System

Cellular communication and the transfer of information from one cell to another is crucial for cell viability and homeostasis. During the last decade, tunneling nanotubes (TNTs) have attracted scientific attention, not only as a means of direct intercellular communication, but also as a possible system to transport biological cargo between distant cells. Peculiar TNT characteristics make them both able to increase cellular survival capacities, as well as a potential target of neurodegenerative disease progression. Despite TNT formation having been documented in a number of cell types, the exact mechanisms triggering their formation are still not completely known. In this review, we will summarize and highlight those studies focusing on TNT formation in the nervous system, as well as their role in neurodegenerative diseases. Moreover, we aim to stress some possible mechanisms and important proteins probably involved in TNT formation in the nervous system.     

Characterization of furazolidone apical-related effects to human polarized intestinal cells

Neuron numbers in developing vertebrate organisms are regulated by the availability of growth factors which promote their survival. However, neuron survival may also be regulated by growth factors which promote rather than prevent cell death. This study examined the effects of bone morphogenetic proteins (BMPs) in inducing apoptosis of MAH cells, an immortalized sympathoadrenal progenitor cell line. Treatment of MAH cells with BMP2 or BMP4 killed the cells in a dose-dependent manner. By contrast, treatment with BMP7 or TGFbeta1 failed to affect survival, suggesting that induction of apoptosis is specific to the dpp subgroup of BMPs. Survival after treatment with BMP2 or BMP4 required addition of fibroblast growth factor (FGF) and nerve growth factor (NGF), indicating that BMP treatment made the neurons dependent upon an exogenous factor for survival. Several experimental observations suggested an apoptotic mechanism for BMP-induced death. After BMP2 treatment, the cells progressively shrank and became pyknotic. Further, there was prominent endonucleosomic cleavage of DNA (laddering) as well as TUNEL staining. Moreover, BMP-induced death was inhibited by the caspase inhibitor z-VAD and was partially prevented by the endonuclease inhibitor aurintricarboxylic acid. These observations suggest that neuron numbers may be regulated by factors which promote death and that exposure to such factors may be a signal for the development of dependence upon other growth factors for survival.     

Antitumor activity of bax and p53 naked gene transfer in lung cancer: in vitro and in vivo analysis

In vitro and in vivo data have demonstrated that virus-mediated p53 gene transfer can induce active cell death and lung tumor regression. In contrast, the therapeutic potential of bax, another apoptosis-inducing gene, has not been described. We compared p53 and bax cytotoxic effects by transient transfection of an average of 25 +/- 5% of the H-322 and H-358 bronchioloalveolar carcinoma cell lines in vitro. Under these conditions, bax expression killed 70 to 90% of the transfected cells whereas p53 killed only 40% of them. The killing activity of both genes involved apoptosis, as shown by TUNEL staining. Surprisingly, BrdU incorporation indicated that the cells that did resist Bax toxicity were blocked in the pre-S phase of the cell cycle, a result expected for p53 only. In vivo, repeated injections of naked DNA encoding Bax or p53 inhibited the growth of 4-mm preestablished H-322 tumors in nude mice. Growth retardation only, and not inhibition, was observed in H-358, a poorly transfectable and rapidly growing tumor. These results indicate that Bax and p53 share a similar, strong antitumor activity in vivo, even if the former is a more potent inducer of apoptosis in vitro.     

Influence of breast- and formula-feeding on plasma cholesterol precursor sterols throughout the first year of life

We evaluated endogenous cholesterol synthesis and plasma lipid profile longitudinally from birth to 1 year old in infants who were exclusively breast-fed (n = 19) or formula-fed (n = 19) for the first 4 months of life. At 1 and 4 months of age, breast-fed infants had higher plasma total and low-density lipoprotein cholesterol and apolipoprotein B levels than formula-fed infants, whereas plasma mevalonate and lanosterol levels were not different between the two study groups.     

Recasting modified nodal analysis to improve reliability in numerical circuit Simulation

Modified nodal analysis (MNA) can be considered as the most adopted method in circuit simulation programs. Once node equations were written and complemented with those from the current controlled branches, a nonlinear system of algebraic and/or differential equations is obtained. In general, by using linear multistep integration methods, differential equations are recast as nonlinear algebraic ones, which are solved through the Newton method at each integration time step. While computer precision is not an issue in most situations, some specific but frequent cases yield ill-conditioned or singular matrices even in originally well posed circuits. This drawback can occur in different situations namely in presence of strongly nonlinear elements and/or when very small integration time steps are used. In the second case, very large conductances in the companion model of capacitors can introduce roundoff errors. In this paper, a transformation of the MNA that overcomes these problems is proposed. It is based on a suitable recombination of equations and electrical variables of the conventional MNA and it can be easily implemented in a circuit simulator.     

Proinflammatory cytokines regulate antigen-independent T-cell activation by two separate calcium-signaling pathways in multiple sclerosis patients

OBJECTIVE: The study examined the prevalence of low birth weight among biracial infants of black and white parents, by region of the United States. METHODS: Using the national linked live birth-death infant file for 1991, low birth weight (<2,500 g) was examined among 50,980 biracial singleton infants according to parental race (black mother-white father vs. white mother-black father). RESULTS: Nationally, the rate of low birth weight was 31% higher in the black mother-white father group (8.4%) than in the white mother-black father group (6.4%). The difference was smaller in the Northeast, reflecting a high rate (9.8%) for biracial infants of Puerto-Rican white mothers. The difference in the West was larger (75%), due to both a high rate in the black mother-white father group (9.1%) and a low rate for the white mother-black father group (5.2%), and persisted after controlling for parental education and a variety of maternal risk factors. CONCLUSIONS: Further studies are needed to identify the maternal factors involved in the regional differences in the prevalence of low birth weight among biracial infants.