On the optical and electrical properties of rf and a.c. plasma polymerized aniline thin films

Polyaniline is a widely studied conducting polymer and is a useful material in its bulk and thin film form for many applications, because of its excellent optical and electrical properties. Pristine and iodine doped polyaniline thin films were prepared by a.c. and rf plasma polymerization techniques separately for the comparison of their optical and electrical properties. Doping of iodine was effected in situ. The structural properties of these films were evaluated by FTIR spectroscopy and the optical band gap was estimated from UV-vis-NIR measurements. Comparative studies on the structural, optical and electrical properties of a.c. and rf polymerization are presented here. It has been found that the optical band gap of the polyaniline thin films prepared by rf and a.c. plasma polymerization techniques differ considerably and the band gap is further reduced by in situ doping of iodine. The electrical conductivity measurements on these films show a higher value of electrical conductivity in the case of rf plasma polymerized thin films when compared to the a.c. plasma polymerized films. Also, it is found that the iodine doping enhanced conductivity of the polymer thin films considerably. The results are compared and correlated and have been explained with respect to the different structures adopted under these two preparation techniques

Fabrication of a quantum well heterostructure based on plasma polymerized aniline and its characterization using STM/STS

Two-dimensional electronic systems play a crucial role in modern electronics and offer a multitude of opportunities to study the fundamental phenomena at low dimensional physics. A quantum well heterostructure based on polyaniline (P) and iodine doped polyaniline (I) thin films were fabricated using radio frequency plasma polymerization on indium tin oxide coated glass plate. Scanning probe microscopy and scanning electron microscopy studies were employed to study the morphology and roughness of the polymer thin films. Local electronic density of states (LDOS) of the P–I–P heterostructures is probed using scanning tunnelling spectroscopy (STS). A step like LDOS is observed in the P–I–P heterostructure and is attributed to the quantum well confinement of electrons in the polymer heterostructure.

Studies on metal resistant bacteria in cochin estuary and its response towards antibiotics and silver nanoparticles

The Cochin estuary (CE), which is one of the largest wetland ecosystems, extends from Thanneermukkam bund in the south to Azhikode in the north. It functions as an effluent repository for more than 240 industries, the characteristics of which includes fertilizer, pesticide, radioactive mineral processing, chemical and allied industries, petroleum refining and heavy metal processing industries (Thyagarajan, 2004). Studies in the CE have been mostly on the spatial and temporal variations in the physical, chemical and biological characteristics of the estuary (Balachandran et al., 2006; Madhu et al., 2007; Menon et al., 2000; Qasim 2003;Qasim and Gopinathan 1969) . Although several monitoring programs have been initiated in the CE to understand the level of heavy metal pollution, these were restricted to trace metals distribution (Balachandran et al., 2005) or the influence of anthropogenic inputs on the benthos and phytoplankton (Madhu et al., 2007;Jayaraj, 2006). Recently, few studies were carried out on microbial ecology in the CE(Thottathil et al 2008a and b;Parvathi et al., 2009and 2011; Thomas et al., 2006;Chandran and Hatha, 2003). However, studies on metal - microbe interaction are hitherto not undertaken in this estuary. Hence, a study was undertaken at 3 sites with different level of heavy metal concentration tounderstand the abundance, diversity and mechanisms of resistance in metal resistant bacteria and its impact on the nutrient regeneration. The present work has also focused on the response of heavy metal resistant bacteria towards antibacterial agent’s antibiotics and silver nanoparticles

Adrenergic and muscarinic receptor subtypes functional regulation during diabetogenesis: Effect of curcumin and vitamin D3 pre-treatment

In the present study, the initial phase was directed to confirm the effects of curcumin and vitamin D3 in preventing or delaying diabetes onset by studying the blood glucose and insulin levels in the pre-treated and diabetic groups. Behavioural studies were conducted to evaluate the cognitive and motor function in experimental rats. The major focus of the study was to understand the cellular and neuronal mechanisms that ensure the prophylactic capability of curcumin and vitamin D3. To elucidate the mechanisms involved in conferring the antidiabetogenesis effect, we examined the DNA and protein profiles using radioactive incorporation studies for DNA synthesis, DNA methylation and protein synthesis. Furthermore the gene expression studies of Akt-1, Pax, Pdx-1, Neuro D1, insulin like growth factor-1 and NF-κB were done to monitor pancreatic beta cell proliferation and differentiation. The antioxidant and antiapoptotic actions of curcumin and vitamin D3 were examined by studying the expression of antioxidant enzymes - SOD and GPx, and apoptotic mediators like Bax, caspase 3, caspase 8 and TNF-α. In order to understand the signalling pathways involved in curcumin and vitamin D3 action, the second messengers, cAMP, cGMP and IP3 were studied along with the expression of vitamin D receptor in the pancreas. The neuronal regulation of pancreatic beta cell maintenance, proliferation and insulin release was studied by assessing the adrenergic and muscarinic receptor functional regulation in the pancreas, brain stem, hippocampus and hypothalamus. The receptor number and binding affinity of total muscarinic, muscarinic M1, muscarinic M3, total adrenergic, α adrenergic and β adrenergic receptor subtypes were studied in pancreas, brain stem and hippocampus of experimental rats. The mRNA expression of muscarinic and adrenergic receptor subtypes were determined using Real Time PCR. Immunohistochemistry studies using confocal microscope were carried out to confirm receptor density and gene expression results. Cell signalling alterations in the pancreas and brain regions associated with diabetogenesis and antidiabetogenesis were assessed by examining the gene expression profiles of vitamin D receptor, CREB, phospholipase C, insulin receptor and GLUT. This study will establish the anti-diabetogenesis activity of curcumin and vitamin D3 pre-treatment and will attempt to understand the cellular, molecular and neuronal control mechanism in the onset of diabetes.Administration of MLD-STZ to curcumin and vitamin D3 pre-treated rats induced only an incidental prediabetic condition. Curcumin and vitamin D3 pretreated groups injected with MLD-STZ exhibited improved circulating insulin levels and behavioural responses when compared to MLD-STZ induced diabetic group. Activation of beta cell compensatory response induces an increase in pancreatic insulin output and beta cell mass expansion in the pre-treated group. Cell signalling proteins that regulate pancreatic beta cell survival, insulin release, proliferation and differentiation showed a significant increase in curcumin and vitamin D3 pre-treated rats. Marked decline in α2 adrenergic receptor function in pancreas helps to relent sympathetic inhibition of insulin release. Neuronal stimulation of hyperglycemia induced beta cell compensatory response is mediated by escalated signalling through β adrenergic, muscarinic M1 and M3 receptors. Pre-treatment mediated functional regulation of adrenergic and cholinergic receptors, key cell signalling proteins and second messengers improves pancreatic glucose sensing, insulin gene expression, insulin secretion, cell survival and beta cell mass expansion in pancreas. Curcumin and vitamin D3 pre-treatment induced modulation of adrenergic and cholinergic signalling in brain stem, hippocampus and hypothalamus promotes insulin secretion, beta cell compensatory response, insulin sensitivity and energy balance to resist diabetogenesis. Pre-treatment improved second messenger levels and the gene expression of intracellular signalling molecules in brain stem, hippocampus and hypothalamus, to retain a functional neuronal response to hyperglycemia. Curcumin and vitamin D3 protect pancreas and brain regions from oxidative stress by their indigenous antioxidant properties and by their ability to stimulate cellular free radical defence system. The present study demonstrates the role of adrenergic and muscarinic receptor subtypes functional regulation in curcumin and vitamin D3 mediated anti-diabetogenesis. This will have immense clinical significance in developing effective strategies to delay or prevent the onset of diabetes.

Molekulare Mechanismen der cAMP-vermittelten Signaltransduktion

Zusammenfassung - Der sekundäre Botenstoff zyklisches Adenosinmonophosphat (cAMP) reguliert viele fundamentale zelluläre Prozesse wie Zellproliferation, Differenzierung, Energiemetabolismus und Genexpression. In eukaryotischen Zellen vermittelt die cAMP-abhängige Proteinkinase (PKA) die meisten biologischen Funktionen von cAMP. Die PKA besteht aus jeweils zwei regulatorischen (R) und katalytischen (C) Untereinheiten, die zusammen einen inaktiven Holoenzymkomplex bilden, der durch cAMP aktiviert wird. In dieser Arbeit wurde die Bindung von cAMP und cAMP-Analoga an die R Untereinheit der PKA unter funktionellen und mechanistischen Aspekten untersucht. Eine neue, auf Fluoreszenzpolarisation basierende Methode wurde entwickelt, um die Affinität von cAMP-Analoga in einem homogenen Ansatz schnell, reproduzierbar und nicht radioaktiv zu quantifizieren. Zur detaillierten Untersuchung des Bindungsmechanismus von cAMP und cAMP Analoga (Agonisten und Antagonisten) wurden thermodynamische Studien im direkten Vergleich mittels isothermaler Titrationskalorimetrie und kinetischen Analysen (Oberflächenplasmonresonanz, SPR) durchgeführt, wodurch thermodynamische Signaturen für das Bindungsverhalten der Nukleotide an die R Untereinheit der PKA erhalten werden konnten. Durch Interaktionsstudien an mutagenisierten R Untereinheiten wurde der intramolekulare Aktivierungsmechanismus der PKA in Bezug auf cAMP-Bindung, Holoenzymkomplex-Formierung und -Aktivierung untersucht. Die dabei erhaltenen Ergebnisse wurden mit zwei Modellen der cAMP-induzierten Konformationsänderung verglichen, und ein Aktivierungsmechanismus postuliert, der auf konservierten hydrophoben Aminosäuren basiert. Für in vivo Untersuchungen wurden zusammen mit Kooperationspartnern membranpermeable, fluoreszierende cAMP Analoga entwickelt, die Einblicke in die Dynamik der cAMP-Verteilung in Zellen erlauben. Neu entwickelte, Festphasen gebundene cAMP-Analoga (Agonisten und Antagonisten) wurden in einem (sub)proteomischen Ansatz dazu genutzt, natürliche Komplexe der R Untereinheit und des PKA-Holoenzyms aus Zelllysaten zu isolieren und zu identifizieren. Diese Untersuchungen fließen letztlich in einem systembiologischen Ansatz zusammen, der neue Einblicke in die vielschichtigen cAMP gesteuerten Netzwerke und Regulationsprozesse erlaubt.

Compositional evolution with mass transfer in closed systems

Evolution of compositions in time, space, temperature or other covariates is frequent in practice. For instance, the radioactive decomposition of a sample changes its composition with time. Some of the involved isotopes decompose into other isotopes of the sample, thus producing a transfer of mass from some components to other ones, but preserving the total mass present in the system. This evolution is traditionally modelled as a system of ordinary di erential equations of the mass of each component. However, this kind of evolution can be decomposed into a compositional change, expressed in terms of simplicial derivatives, and a mass evolution (constant in this example). A rst result is that the simplicial system of di erential equations is non-linear, despite of some subcompositions behaving linearly. The goal is to study the characteristics of such simplicial systems of di erential equa- tions such as linearity and stability. This is performed extracting the compositional dif ferential equations from the mass equations. Then, simplicial derivatives are expressed in coordinates of the simplex, thus reducing the problem to the standard theory of systems of di erential equations, including stability. The characterisation of stability of these non-linear systems relays on the linearisation of the system of di erential equations at the stationary point, if any. The eigenvelues of the linearised matrix and the associated behaviour of the orbits are the main tools. For a three component system, these orbits can be plotted both in coordinates of the simplex or in a ternary diagram. A characterisation of processes with transfer of mass in closed systems in terms of stability is thus concluded. Two examples are presented for illustration, one of them is a radioactive decay

Bacteriemia asociada a catéter epicutáneo en la unidad de cuidado intensivo neonatal de la Fundación Cardioinfantil

La bacteriemia asociada a catéter afecta a pacientes en las unidades de cuidado intensivo con una alta morbilidad, mortalidad y aumento de los costos al sistema de salud. Los recién nacidos son la población de más alto riesgo por el mayor uso de catéteres centrales. Objetivo: Caracterizar factores de riesgo para bacteriemia asociada a catéter en la Unidad de Cuidado Intensivo Neonatal de la Fundación Cardioinfantil entre 2005 - 2010 Materiales y método: Estudio descriptivo de corte transversal, incluyó todos los recién nacidos con diagnostico de bacteriemia asociada a catéter. Se analizó la información utilizando frecuencias y medidas de tendencia central. Resultados: Se encontraron 50 pacientes con diagnostico de bacteriemia asociada a catéter. 50% de género masculino, 52% con edad gestacional al nacimiento menor a 36 semanas y 24% con peso menor a 1500 gramos al momento de la inserción del catéter. La edad fue de 24.2 días al momento de la inserción del catéter. En el 66% de los pacientes el sitio de inserción fue el miembro superior, siendo el Sthaphylococcus Epidermidis el germen con el 50% de las bacteriemias. Conclusión: La bacteriemia asociada a catéter afecta paciente prematuros, de bajo peso sin diferencias en genero. La manipulación de dichos dispositivos, el sitio de inserción, el uso previo de antibióticos, la duración del catéter y el uso de nutrición parenteral son factores que están asociados al mayor riesgo de infección. Siendo el Staphylococcus Epidermidis el germen mas frecuente.

Eficacia de la limpieza corporal con clorhexidina en prevenir la sepsis neonatal en cuidado intensivo revisión sistemática

ANTECEDENTES. La mortalidad neonatal se debe principalmente a procesos infecciosos y a prematurez. Se ha sugerido que el lavado corporal total con clorhexidina podría reducir la mortalidad neonatal relacionada con infección. No existen revisiones sistemáticas que exploren la eficacia de esta intervención. Objetivo. Evaluar la eficacia y seguridad de la limpieza corporal total con clorhexidina en la prevención de las infecciones asociadas al cuidado de la salud en neonatos de alto riesgo hospitalizados en cuidado intensivo neonatal. Metodología. Se realizó una revisión sistemática de la literatura. La búsqueda se hizo a través de las bases de datos Medline, Embase, LilaCS, Cochrane library y el registro de ensayos clínicos del Instituto Nacional de Salud de Estados Unidos. Se incluyeron ensayos clínicos publicados en los últimos 15 años hasta el 30 de enero del 2015. Las variables cualitativas se estimaron mediante OR o RR con sus IC95%. Las variables cuantitativas mediante diferencias de promedios o diferencias estandarizadas de promedios con sus IC95%. Resultados: Se incluyeron 3 estudios en el análisis cualitativo y cuantitativo. No se encontró evidencia concluyente que permita recomendar el uso de la limpieza corporal total con clorhexidina en los recién nacidos hospitalizados en cuidado intensivo neonatal. Conclusión: No existe evidencia que permita concluir que la limpieza corporal total con clorhexidina al 0.25% es mejor respecto a otras intervenciones en la prevención de sepsis neonatal asociada al cuidado de la salud . Es una intervención segura sin efectos adversos significativos.

Natural resources, redistribution and Human capital formation

How do resource booms affect human capital accumulation? We exploit time and spatial variation generated by the commodity boom across local governments in Peru to measure the effect of natural resources on human capital formation. We explore the effect of both mining production and tax revenues on test scores, finding a substantial and statistically significant effect for the latter. Transfers to local governments from mining tax revenues are linked to an increase in math test scores of around 0.23 standard deviations. We find that the hiring of permanent teachers as well as the increases in parental employment and improvements in health outcomes of adults and children are plausible mechanisms for such large effect on learning. These findings suggest that redistributive policies could facilitate the accumulation of human capital in resource abundant developing countries as a way to avoid the natural resources curse.

Producció i caracterització de variants de la ribonucleasa pancreàtica humana dissenyades per a adquirir propietats citotòxiques

Amb la finalitat d'aprofundir en les bases moleculars de la citotoxicitat de les ribonucleases pancreàtiques, es van construir variants derivades de l'HP-RNasa seguint dues estratègies. En la primera, es van generar variants de l'enzim resistents a l'acció de l'inhibidor proteic de les ribonucleases (hRI), substituint residus implicats en la interfície de contacte entre la ribonucleasa i l'hRI. En la segona, es va addicionar el motiu RGD en regions de superfície de la proteïna implicades en la formació del complex amb l'hRI, a fi de promoure la seva interacció amb la membrana plasmàtica de les cèl·lules i a la vegada disminuir l'afinitat de les variants per l'hRI. Es va comprovar que només les variants portadores de substitucions múltiples adquirien la capacitat de resistència a l'hRI. L'estudi del percentatge d'inhibició de la síntesi proteica en cèl·lules incubades amb cadascuna de les variants va mostrar que només dues de les variants construïdes havien adquirit propietats citotòxiques. La citotoxicitat més elevada la va presentar una variant que no era resistent a l'hRI, amb valors que eren només entre 5 i 15 vegades inferiors als de l'onconasa. Aquest resultat demostrà que la sensibilitat a l'hRI no és necessàriament un paràmetre limitant per a la citotoxicitat de les ribonucleases. Cap de les variants que incorporava un motiu RGD presentà citotoxicitat, evidenciant que aquest motiu no és efectiu a fi de dotar les ribonucleases pancreàtiques de propietats citotòxiques. Es van estudiar les bases moleculars de la citotoxicitat de la variant més citotòxica. En primer lloc, l'anàlisi de la internalització per marcatge radioactiu d'aquesta variant en relació amb l'onconasa i amb altres variants de l'HP-RNasa no citotòxiques, va posar en evidència que només l'onconasa era internalitzada eficientment. Es descartava així la possibilitat que l'acció citotòxica de l'enzim estudiat fos conseqüència d'una major eficiència d'endocitosi. També es va comprovar que l'addició del motiu RGD no era capaç de promoure la internalització de les proteïnes amb més eficàcia. Per microscòpia confocal de fluorescència, les variants humanes només es van començar a detectar a l'interior de la cèl·lula a partir de les 24 h d'incubació. Totes les variants generades van presentar una eficiència catalítica superior al 50 % de l'activitat de la seva proteïna parental, PM5, indicant que probablement l'estructura del centre actiu no havia estat afectada de manera dràstica per les substitucions introduïdes. No obstant, en tots els casos es va produir una disminució en la termoestabilitat respecte a PM5. Aquest resultat indicà que la correlació descrita a la bibliografia entre l'increment de termoestabilitat i l'increment de citotoxicitat per les ribonucleases no sempre es compleix. Per microscòpia confocal es va comprovar que tant la proteïna més citotòxica, com una variant no citotòxica resistent a l'hRI, així com la proteïna parental, seguien la via de degradació lisosomal. Aquesta ruta de trànsit no va ser afectada per l'addició de drogues que alteren les vies de trànsit retrògrad (monensina i brefeldina A), però sí per l'addició de la bafilomicina A1, una droga que neutralitza el pH endosomal i que va actuar alentint el trànsit de les proteïnes als lisosomes. D'acord amb aquests resultats, els valors de citotoxicitat de les variants es van incrementar de manera significativa només en presència de bafilomicina A1, suggerint que les ribonucleases transloquen al citoplasma a partir d'algun punt de la via de trànsit endosomal. Es va comprovar que l'acció de la variant més citotòxica era deguda a que l'addició d'un segon motiu de tres Arg en PE5 dota a aquesta proteïna amb un senyal de transport nuclear. La fracció d'enzim que aconsegueix translocar al citoplasma a partir d'algun punt de la via endosomal previ als lisosomes, és conduït ràpidament al nucli de la cèl·lula per mitjà del mecanisme clàssic de transport actiu. Per la seva afinitat amb l'rRNA, l'enzim es concentra en el nuclèol, on probablement duu a terme la seva activitat catalítica. La interacció d'aquesta variant amb els receptors nucleocitoplasmàtics, les importines, impediria per altra banda el bloqueig de l'enzim per part de l'hRI. Els resultats obtinguts presenten una nova estratègia de disseny de ribonucleases citotòxiques, basada en l'addició de segments NLS a fi de promoure el transport nuclear dels enzims. Aquesta estratègia podria permetre superar limitacions que fins al moment han estat descrites com a limitants de la citotoxicitat de les ribonucleases pancreàtiques, com la sensibilitat a l'hRI o la baixa eficiència d'internalització.

Geochemical precursors to volcanic activity at Mount St. Helens, USA

The importance of the interplay between degassing and crystallization before and after the eruption of Mount St. Helens (Washington, USA) in 1980 is well established. Here, we show that degassing occurred over a period of decades to days before eruptions and that the manner of degassing, as deduced from geochemicai signatures within the magma, was characteristic of the eruptive style. Trace element (lithium) and short-lived radioactive isotope (lead-210 and radium-226) data show that ascending magma stalled within the conduit, leading to the accumulation of volatiles and the formation of lead-210 excesses, which signals the presence of degassing magma at depth.

The effect of aqueous diffusion on the fractionation of chlorine and bromine stable isotopes

Diffusive isotopic fractionation factors are important in order to understand natural processes and have practical application in radioactive waste storage and carbon dioxide sequestration. We determined the isotope fractionation factors and the effective diffusion coefficients of chloride and bromide ions during aqueous diffusion in polyacrylamide gel. Diffusion was determined as functions of temperature, time and concentration. The effect of temperature is relatively large on the diffusion coefficient (D) but only small on isotope fractionation. For chlorine, the ratio, D-35cl/D-37cl varied from 1.00128 +/- 0.00017 (1 sigma) at 2 degrees C to 1.00192 +/- 0.00015 at 80 degrees C. For bromine, D-79Br/D-81Br varied from 1.00098 +/- 0.00009 at 2 degrees C to 1.0064 +/- 0.00013 at 21 degrees C and 1.00078 +/- 0.00018 (1 sigma) at 80 degrees C. There were no significant effects on the isotope fractionation due to concentration. The lack of sensitivity of the diffusive isotope fractionation to anything at the most common temperatures (0 to 30 C) makes it particularly valuable for application to understanding processes in geological environments and an important natural tracer in order to understand fluid transport processes. (C) 2009 Elsevier Ltd. All rights reserved.

Restricted expression of NADPH oxidase/peroxidase gene (Duox) in zone VII of the ascidian endostyle

The ascidian Ciona intestinalis, a marine invertebrate chordate, is an emerging model system for developmental and evolutionary studies. The endostyle, one of the characteristic organs of ascidians, is a pharyngeal structure with iodine-concentrating and peroxidase activities and is therefore considered to be homologous to the follicular thyroid of higher vertebrates. We have previously reported that a limited part of the endostyle (zone VII) is marked by the expression of orthologs of the thyroid peroxidase (TPO) and thyroid transcription factor-2 (TTF-2/FoxE) genes. In this study, we have identified the Ciona homolog of NADPH oxidase/peroxidase (Duox), which provides hydrogen peroxide (H2O2) for iodine metabolism by TPO in the vertebrate thyroid. Expression patterns assessed by in situ hybridization have revealed that Ciona Duox (Ci-Duox) is predominantly expressed in the dorsal part of zone VII of the endostyle. Furthermore, two-color fluorescent in situ hybridization with Ci-Duox and Ciona TPO (CiTPO) has revealed that the ventral boundary of the Ci-Duox domain of expression is more dorsal than that of CiTPO. We have also characterized several genes, such as Ci-Fgf8/17/18, 5HT7, and Ci-NK4, which are predominantly expressed in the ventral part of zone VII, in a region complementary to the Ci-Duox expression domain. These observations suggest that, at the molecular level, zone VII has a complex organization that might have some impact on the specification of cell types and functions in this thyroid-equivalent element of the ascidian endostyle.

Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies

Objective: To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally Occurring radon gas. Design: Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer. Setting Nine European countries. Subjects 7148 cases Of lung cancer and 14 208 controls. Main outcome measures: Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic incite (Bq/m(3)) Of household air. Results: The mean measured radon concentration in homes of people in tire control group was 97 Bq/m(3), with 11% measuring > 200 and 4% measuring > 400 Bq/m(3). For cases of lung cancer the mean concentration was 104 Bq/m(3). The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m(3) increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m(3) increase in usual radon-that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P=0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m(3). The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m(3) would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers. Conclusions: Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.

Comparative expression analysis of transcription factor genes in the endostyle of invertebrate chordates

The endostyle of invertebrate chordates is a pharyngeal organ that is thought to be homologous with the follicular thyroid of vertebrates. Although thyroid-like features such as iodine-concentrating and peroxidase activities are located in the dorsolateral part of both ascidian and amphioxus endostyles, the structural organization and numbers of functional units are different. To estimate phylogenetic relationships of each functional zone with special reference to the evolution of the thyroid, we have investigated, in ascidian and amphioxus, the expression patterns of thyroid-related transcription factors such as TTF-2/MoxE4 and Pax2/5/8, as well as the forkhead transcription factors FoxQ1 and FoxA. Comparative gene expression analyses depicted an overall similarity between ascidians and amphioxus endostyles, while differences in expression patterns of these genes might be specifically related to the addition or elimination of a pair of glandular zones. Expressions of Ci-FoxE and BbFoxE4 suggest that the ancestral FoxE class might have been recruited for the formation of thyroid-like region in a possible common ancestor of chordates. Furthermore, coexpression of FoxE4, Pax2/5/8, and TPO in the dorsolateral part of both ascidian and amphioxus endostyles suggests that genetic basis of the thyroid function was already in place before the vertebrate lineage. (c) 2005 Wiley-Liss, Inc.