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1

Incentivos para atraer y retener personal de salud de zonas rurales del Per?: un estudio cualitativo  

PubMed Central

El objetivo fue identificar incentivos de atracción y retención en zonas rurales y distantes de Ayacucho, Perú. Fueron realizadas entrevistas en profundidad con 80 médicos, enfermeras, obstetras y técnicos (20 por grupo) de las zonas más pobres y con 11 funcionarios. No existen políticas sistemáticas de atracción y retención de personal de salud en Ayacucho. Los principales incentivos, en orden de importancia, fueron mejoras salariales, oportunidades de formación y capacitación, estabilidad laboral y nombramiento, mejoras en infraestructura y equipos, e incremento del personal. Se mencionaron también mejoras en la vivienda y alimentación, mayor cercanía con la familia y reconocimiento por el sistema de salud. Existen coincidencias y singularidades entre los distintos grupos sobre los incentivos clave para estimular el trabajo rural, que deben considerarse al diseñar políticas públicas. Las iniciativas del Estado deben comprender procesos rigurosos de monitoreo y evaluación, para asegurar que las mismas tengan el impacto deseado.

Huicho, Luis; Canseco, Francisco Diez; Lema, Claudia; Miranda, J. Jaime; Lescano, Andres G.

2014-01-01

2

RELACIÓN SUELO-ÁRBOL Y FACTORES DE SITIO, EN PLANTACIONES JÓVENES DE TECA (Tectona grandis), EN LA ZONA OESTE DE LA CUENCA DEL CANAL DE PANAMÁ  

Microsoft Academic Search

Recibido: 07\\/12\\/04 Aceptado: 01\\/03\\/05 RE SU MEN Mediante la utilización de un muestreo factorial estratificado con 4 repeticiones (3x3x4) se seleccionaron 36 parcelas permanentes de medición en plantaciones de teca en la zona oeste de la cuenca del Canal de Panamá. En la estratifi- cación se emplearon como criterios el incremento medio anual (IMA) en altura total y la pendiente

Manuel Mollinedo; Luis Ugalde; Alfredo Alvarado; Jean Mark Verjans; Luis Carles Rudy

2005-01-01

3

BASES PARA EL MANEJO INTEGRADO DEL RECURSO LANGOSTA (Panulirus argus) EN LA ZONA COSTERA SUR DE PINAR DEL RÍO. I. FACTORES AMBIENTALES  

Microsoft Academic Search

A study of management of costal areas in the western gulf of Batabanó, southern coast of Pinar del Río province, is presented in three parts: environmental factors, socio economical factors and integrated management. Main characteristics of natural factors are analyzed, such as river supply of water to the coast, water temperature, salinity, dissolved oxygen, turbidity, ph, nutrients and organic nitrogen

Roberto Piñeiro; Rafael Puga; Gaspar González-Sansón

4

The zona pellucida "receptors".  

PubMed

Binding of mammalian sperm to the zona pellucida and the induction of the acrosome reaction are prerequisites for successful oocyte fertilization. In the mouse model, the zona pellucida consists of three sulfated glycoproteins, ZP1, ZP2, and ZP3. Zona pellucida proteins are secreted to form a filamentous zona matrix in which ZP2 and ZP3 complex into co-polymers cross-linked by ZP1. ZP3 is the ligand for primary sperm binding and important for the induction of the acrosome reaction. The zona pellucida glycoprotein ZP2 is also crucially involved in the process of fertilization. Previous reports suggest that ZP2 mediates secondary binding of spermatozoa and that cleavage of ZP2 by proteases released through cortical granule reaction causes zona "hardening" and thus prevents polyspermy. Human and mouse ZP2 proteins differ in the primary structure as derived from cDNA clones. We designed an immunological approach to search for ZP2 domains with functional relevance. Antisera were generated against synthetic peptides derived (a) from ZP2 amino acid sequences that are homologous in human and mouse ZP2 amino acid sequences (AS ZP2-20) or (b) from human ZP2 amino acid sequences that differ from the mouse ZP2 sequence (AS ZP2-26). Immunochemical studies with microbisected bovine zonae pellucidae demonstrated that both antisera, AS ZP2-20 and AS ZP2-26, specifically detected ZP2 protein. Using the competition-hemizona-assay, sperm binding to antibody treated bovine hemizonae pellucidae were compared with control hemizonae (given as hemizona index). Antiserum AS ZP2-20 significantly inhibited binding of spermatozoa to test hemizonae (p < 0.0001), whereas treatment of hemizonae with AS ZP2-26 did not influence sperm-egg interaction. Our results show that antibodies against ZP2 peptides react with bovine zonae pellucidae and can be used as markers for ZP2. Furthermore, AS ZP2-20 identifies a ZP2 epitope that is possibly of functional relevance for sperm-egg interaction. PMID:9361810

Hinsch, E; Hägele, W; Schill, W B; Hinsch, K D

1997-01-01

5

Zonas francas en Colombia: beneficios tributarios en el impuesto de renta  

Microsoft Academic Search

Este documento presenta la medición de los beneficios en el impuesto de renta otorgados a las empresas que operan en las zonas francas, los cuales están representados por una tarifa diferencial del 15% y, hasta el año 2010, por una deducción especial por inversión en activos fijos. Así mismo, el documento incluye el cálculo del aporte de estas empresas al

Jorge Ramos F; Karen Rodríguez Z

6

Zona Pellucida Induced Acrosome Reaction, Sperm Morphology, and Sperm–Zona Binding Assessments Among Subfertile Men  

Microsoft Academic Search

Purpose: The study aimed to evaluate the relationship between the zona pellucida induced acrosome reaction (ZIAR) and (i) percentage normal spermatozoa as well as (ii) sperm–zona pellucida binding potential among men referred for a routine semen analysis.

H. S. Bastiaan; R. Menkveld; S. Oehninger; D. R. Franken

2002-01-01

7

Zona hardening, zona drilling and assisted hatching: new achievements in assisted reproduction.  

PubMed

Prior to fertilization, the zona pellucida surrounding the mammalian oocyte acts as a species-specific sperm barrier and is involved in sperm binding. After fertilization, the zona plays a role in blocking polyspermic fertilization, it protects the integrity of the preimplantation embryo during early embryonic development, and also helps its oviductal transport. Zona hardening occurs naturally after fertilization in order to ensure this threefold function. A combination of lysins produced by the cleaving embryo or the uterus and physical expansion then reduces the zona thickness in preparation for hatching. Zona hardening, although not readily quantifiable, may also be induced by in vitro culture and by in vivo aging. Indeed, prolonged exposure of human oocytes and embryos to artificial culture conditions seems to impair their ability to implant. Implantation rates are also inversely correlated with advanced female age. Recently, failure of the embryonic zona pellucida to rupture following blastocyst expansion has been put forward as a possible contributing factor in implantation failure. In order to help embryos escape from their zonae during blastocyst expansion, different types of assisted hatching have been developed. Zona drilling involves the creation of an opening in the zona with acidified medium, whereas zona slitting is carried out in the same manner as partial zona dissection. In zona thinning, the zona is just made thinner over a certain area without a hole or a slit being created. More recently, laser-assisted hatching has been introduced. In vitro studies with both mouse and human embryos have indicated that an artificial gap in the zona pellucida significantly improves the hatching ability of blastocysts grown in vitro as compared to non-micromanipulated embryos. However, the clinical relevance of assisted hatching within an assisted reproduction program remains controversial and elusive. Very few randomized studies are available. Most reports are of retrospective analyses which report either no differences in implantation and pregnancy rates between assisted hatching and control embryos or better results after assisted hatching. Five randomized controlled studies suggest that assisted hatching - of no benefit to the overall patient population - might be of value in increasing embryo implantation rates only in selected cases. No further evidence exists for an age-related benefit from assisted hatching in patients with advanced maternal age. PMID:10729729

De Vos, A; Van Steirteghem, A

2000-01-01

8

La evaluación de la reducción de amenazas en el Parque Natural de la Zona Volcánica de la Garrotxa (Girona)  

Microsoft Academic Search

En aquest article, s’hi presenta la metodologia i els resultats derivats de l’aplicació d’una adaptació del denominat model d’avaluació de la reducció d’amenaces (Threat Reduction Assesment) en el Parc Natural de la Zona Volcànica de la Garrotxa (PNZVG). S’hi pretén valorar l’efectivitat de la gestió a partir del grau de reducció de les amenaces en el PNZVG. L’estudi es va

Fernando Abarquero Zorrilla; Josep Vila Subirós

2010-01-01

9

Mouse zona pellucida genes and glycoproteins  

Microsoft Academic Search

The zona pellucida (ZP) is a thick extracellular coat that surrounds all mammalian eggs. The ZP plays important roles during oogenesis, fertilization, and preimplantation development. The mouse ZP consists of only three glycoproteins, called ZP1, ZP2, and ZP3. All three glycoproteins are essential structural components of the ZP. Additionally, ZP3 serves as a primary sperm receptor and acrosome reaction-inducer, and

P. M. Wassarman; L. Jovine; E. S. Litscher

2004-01-01

10

Interaction of sperm with the zona pellucida during fertilization.  

PubMed

In order to achieve fertilization sperm cells, first need to successfully interact with the zona pellucida. To this end, the sperm surface is extensively remodeled during capacitation and the resulting sperm cells also possess hyperactivated motility. Together, this serves to mediate optimal recognition of the zona pellucida in the oviduct or after in vitro fertilization incubations (primary zona pellucida binding). When the sperm cell attaches to the zona pellucida, it will be triggered to undergo the acrosome reaction which allows the hyperactivated motile sperm cell to drill through the zona pellucida (secondary zona pellucida binding coinciding with sequential local zona pellucida digestion and rebinding). After successful zona penetration, some sperm cells may enter the perivitelline space. This delaying strategy of the oocyte allows only one sperm cell at a given time to bind and fuse with the oocyte (fertilization) and thus minimizes the risk of polyspermy. The fertilization fusion between the oocyte and the first sperm cell is immediately followed by a polyspermic fertilization block, in which the content of the oocyte's cortical granules is released into the perivitelline space. The cortical reaction blocks further sperm-oocyte fusion either by sticking at the oolemma or by the induction of a biochemical reaction of the zona pellucida (zona pellucida hardening). The cortical reaction thus blocks sperm-zona pellucida binding and/or sperm-zona pellucida penetration. This review summarizes the current understanding of sperm-zona pellucida interactions in relation to mammalian fertilization. The lack of knowledge about sperm-zona pellucida binding in ruminants will be critically discussed. PMID:21755679

Gadella, B M

2010-01-01

11

Viscoelastic characterization of mouse zona pellucida.  

PubMed

The viscoelastic properties of the zona pellucida (ZP), which is the extracellular coat surrounding an oocyte/embryo, are evaluated in this study. Previous studies demonstrate that ZP mechanical properties change during oocyte maturation, fertilization, and early embryo development, but linear pure elastic models currently being used do not satisfy the time-dependent mechanical behavior of the ZP. In this paper, nonlinear viscoelastic characterization was performed using the Hunt-Crossley model and the newly developed vision-based nanoforce estimation method. The results show that viscoelasticity is a physical property of the ZP that exhibits hysteresis. The stiffness and viscosity parameters simultaneously increase following fertilization, causing the stiffness and viscosity of the embryo ZP (ten samples) to be 2.57-fold and 4.44-fold greater, respectively, than that of the oocyte ZP (eleven samples). This behavior well describes the noncovalently cross-linked filamentous structure of the ZP, supporting zona hardening during fertilization as a mechanically relevant event. PMID:23212311

Kim, Jungsik; Kim, Jung

2013-02-01

12

Fourier Transform Infrared Spectroscopic Analysis of the Intact Zona Pellucida of the Mammalian Egg: Changes in the Secondary Structure of Bovine Zona Pellucida Proteins During Fertilization  

Microsoft Academic Search

The zona pellucida is the acellular transparent envelope surrounding the mammalian oocyte. An analysis of the changes in the structures of zona pellucida proteins is essential for understanding the molecular mechanisms underlying the im- portant physiological roles of the zona during fertilization and preimplantation. The hardening of the zona caused by the structural changes during fertilization is generally accepted to

MASAYUKI NARA; NAOTO YONEZAWA; TAKESHI SHIMADA; KAZUYA TAKAHASHI; MASARU TANOKURA; FUMIAKI YUMOTO; HIROYUKI NAKAGAWA; KAZUYO OHASHI; MINORU NAKANO

13

Valoración económica del ruido: una aplicación a través del método de transferencia de beneficios  

Microsoft Academic Search

Este artículo tiene como objetivo realizar una aproximación a la valoración económica de los beneficios de la reducción del ruido generado por infraestructuras de telecomunicaciones en cuatro zonas urbanas del área metropolitana de la ciudad de Medellín (Colombia). Así, mediante el método de transferencia de beneficios, en un horizonte a perpetuidad, se obtuvo un valor económico de $79,40 millones para

Francisco Javier Correa Restrepo; Juan David Osorio Múnera; Bernardo Andrés Patiño Valencia

2011-01-01

14

Fourier transform infrared spectroscopic analysis of the intact zona pellucida of the mammalian egg: changes in the secondary structure of bovine zona pellucida proteins during fertilization.  

PubMed

The zona pellucida is the acellular transparent envelope surrounding the mammalian oocyte. An analysis of the changes in the structures of zona pellucida proteins is essential for understanding the molecular mechanisms underlying the important physiological roles of the zona during fertilization and preimplantation. The hardening of the zona caused by the structural changes during fertilization is generally accepted to be responsible for blocking polyspermy. In this study, we analyzed changes in the secondary structure of the zona during fertilization by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy. The predominance of beta-sheet structure in porcine ovarian egg zona proteins in water was ascertained using FTIR spectra. Alpha-helix structure was also present. The attenuated total reflection (ATR)-FTIR spectrum of intact, unsolubilized porcine zonae pellucidae from ovarian eggs indicated that the zona proteins in the native zona pellucida also have beta-structure as the main constituent. Attenuated total reflection-FTIR spectroscopy of intact bovine zona pellucida obtained from ovarian and fertilized eggs at the blastocyst stage revealed that the beta-structure content increased during fertilization. Furthermore, a reduction of the thickness of the zona during fertilization was observed using transmission electron microscopy. Therefore, the change in the zona architecture that causes hardening of the zona during fertilization is accompanied by changes in the secondary structure of the zona proteins. PMID:16446492

Nara, Masayuki; Yonezawa, Naoto; Shimada, Takeshi; Takahashi, Kazuya; Tanokura, Masaru; Yumoto, Fumiaki; Nakagawa, Hiroyuki; Ohashi, Kazuyo; Hamano, Seizo; Nakano, Minoru

2006-02-01

15

Mechanical properties of zona pellucida hardening.  

PubMed

We have investigated the changes in the mechanical properties of the zona pellucida (ZP), a multilayer glycoprotein coat that surrounds mammalian eggs, that occur after the maturation and fertilization process of the bovine oocyte by using atomic force spectroscopy. The response of the ZP to mechanical stress has been recovered according to a modified Hertz model. ZP of immature oocytes shows a pure elastic behavior. However, for ZPs of matured and fertilized oocyte, a transition from a purely elastic behavior, which occurs when low stress forces are applied, towards a plastic behavior has been observed. The high critical force necessary to induce deformations, which supports the noncovalent long interaction lifetimes of polymers, increases after the cortical reaction. Atomic force microscopy (AFM) images show that oocyte ZP surface appears to be composed mainly of a dense, random meshwork of nonuniformly arranged fibril bundles. More wrinkled surface characterizes matured oocytes compared with immature and fertilized oocytes. From a mechanical point of view, the transition of the matured ZP membrane toward fertilized ZP, through the hardening process, consists of the recovery of the elasticity of the immature ZP while maintaining a plastic transition that, however, occurs with a much higher force compared with that required in matured ZP. PMID:19471918

Papi, Massimiliano; Brunelli, Roberto; Sylla, Lakamy; Parasassi, Tiziana; Monaci, Maurizio; Maulucci, Giuseppe; Missori, Mauro; Arcovito, Giuseppe; Ursini, Fulvio; De Spirito, Marco

2010-05-01

16

Mechanical property characterization of mouse zona pellucida.  

PubMed

Previous intracytoplasmic sperm injection (ICSI) studies have indicated significant variation in ICSI success rates among different species. In mouse ICSI, the zona pellucida (ZP) undergoes a "hardening" process at fertilization in order to prevent subsequent sperm from penetrating. There have been few studies investigating changes in the mechanical properties of mouse ZP post fertilization. To characterize mouse ZP mechanical properties and quantitate the mechanical property differences of the ZP before and after fertilization, a microelectromechanical systems-based multiaxis cellular force sensor has been developed. A microrobotic cell manipulation system employing the multiaxis cellular force sensor is used to conduct mouse ZP force sensing, establishing a quantitative relationship between applied forces and biomembrane structural deformations on both mouse oocytes and embryos. An analytical biomembrane elastic model is constructed to describe biomembrane mechanical properties. The characterized elastic modulus of embryos is 2.3 times that of oocytes, and the measured forces for puncturing embryo ZP are 1.7 times those for oocyte ZP. The technique and model presented in this paper can be applied to investigations into the mechanical properties of other biomembranes, such as the plasma membrane of oocytes or other cell types. PMID:15376919

Sun, Yu; Wan, Kai-Tak; Roberts, Kenneth P; Bischof, John C; Nelson, Bradley J

2003-12-01

17

SISTEMA REMOTO DE ADQUISICIÓN PARA EL CONTROL DEL RUIDO AMBIENTAL CON FPGA Y FPAA  

Microsoft Academic Search

RESUMEN Este artículo propone el diseño de un sistema de adquisición de datos con componentes digitales y analógicos microelectrónicos reconfigurables, como son el FPGA (Field Programmable Gate Array) y el FPAA (Field Programmable Analog Array), para monitorear y analizar la contaminación por ruido ambiental. Este prototipo obtiene los datos del ruido de una zona vial (zona centro de una ciudad)

A. Castillo Atoche; J. Vázquez Castillo; V. Sanchez Huerta; P. Del Río Dawn

18

Acrosome reaction of mouse epididymal sperm on oocyte zona pellucida.  

PubMed

To improve assessment of the acrosome reaction of mouse epididymal sperm, we employed anti-Izumo1 antibody instead of antibodies against acrosomal proteins. The acrosomal states among acrosome-intact, spontaneously acrosome-reacted, truly acrosome-reacted, and probably dead and/or membrane-damaged sperm were clearly distinguished by combined application of anti-Izumo1 antibody, DNA dye Hoechst 33342, and monoclonal antibody MN7 to paraformaldehyde-fixed sperm. When the acrosome reaction of capacitated epididymal sperm on the oocyte zona pellucida was examined using anti-Izumo1 antibody, approximately 20% of sperm bound onto the zona pellucida were acrosome-reacted 30 min after insemination. We also observed the moment of the acrosome reaction of live sperm on the zona pellucida by time-lapse monitoring using fluorescein isothiocyanate-conjugated anti-Izumo1 antibody. PMID:17135711

Yamashita, Misuzu; Yamagata, Kazuo; Tsumura, Keiko; Nakanishi, Tomoko; Baba, Tadashi

2007-04-01

19

Laser zona dissection using short-pulse ultraviolet lasers  

NASA Astrophysics Data System (ADS)

The interaction of pulsed ultraviolet radiation with the zona pellucida of human oocytes which had failed to fertilize in standard IVF cycles, was investigated. Two lasers were studied: a 100 ps pulsed Nd:YAG with a nonlinear crystal emitting light at 266 nm, and a 15 ns XeCl excimer laser with 308 nm radiation. Incisions in the zona were made by aiming the beam tangentially to the oocyte. The results indicate superior, high precision performance by the excimer laser creating trenches as narrow as 1 micrometers and as shallow as 1 micrometers . The incision size was found to be sensitive to the laser's energy and to the position of the microscope's objective focal plane, but relatively insensitive to the laser pulse repetition rate. Once the minimum spot size was defined by the system parameters, the laser beam was used to curve out any desired zona shape. This laser microsurgery technique as applied to partial zone dissection or zona drilling could prove very useful as a high-precision, non-contact method for treatments of low fertilization rate and for enhancing embryo implantation rates in patients undergoing IVF treatments.

Neev, Joseph; Tadir, Yona; Ho, Peter D.; Whalen, William E.; Asch, Richardo H.; Ord, Teri; Berns, Michael W.

1992-06-01

20

Laser zona pellucida thinning--an alternative approach to assisted hatching  

Microsoft Academic Search

BACKGROUND: The purpose of this study was to assess the efficacy and hatching characteristics of in-vitro cultured human embryos subjected to laser zona pellucida thinning. METHOD: Zona thinning was performed on 110 embryos using a non-contact 1.48 µm diode laser and the hatch rate in vitro was compared with 42 control embryos. Variation of zona thickness and degree of zona

D. A. Blake; A. S. Forsberg; B. R. Johansson; M. Wikland

2001-01-01

21

Scintigraphy of normal mouse ovaries with monoclonal antibodies to ZP-2, the major zona pellucida protein  

SciTech Connect

The zona pellucida is an extracellular glycocalyx, made of three sulfated glycoproteins, that surrounds mammalian oocytes. Parenterally administered monoclonal antibodies specific for ZP-2, the most abundant zona protein, localize in the zona pellucida. When labeled with iodine-125, these monoclonal antibodies demonstrate a remarkably high target-to-nontarget tissue ratio and provide clear external radioimaging of ovarian tissue.

East, I.J.; Keenan, A.M.; Larson, S.M.; Dean, J.

1984-08-31

22

Prognostic value of various spermatological attributes as predictors of zona binding and zona penetration of buffalo (Bubalus bubalis) semen.  

PubMed

Twenty-four ejaculates from six (four ejaculates each) Surti buffalo bulls aged 4-8 years were used to assess various attributes of spermatozoa influencing the zona-binding and zona-penetration tests. Ejaculates from each bulls were subjected to in vitro sperm--zona binding and sperm--zona penetration tests (four replicates per bull) using immature buffalo oocytes. The average number of spermatozoa bound per oocyte was 27.79 +/- 5.90. The average number of spermatozoa penetrated per oocyte was 3.35 +/- 0.64. The average number of zona-bound and -penetrated spermatozoa differed significantly between animals. Significant difference (p < 0.05) was observed between the plasmalemma integrity as assessed by eosin--nigrosin stain and hypo-osmotic swelling (HOS) test. Furthermore, the percentage of cells positive for the HOS test, i.e. functional membrane integrity (51.25 +/- 2.32) was significantly (p < 0.05) higher than hypo-osmotic swelling-Giemsa (HOS-G) test, i.e. the subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (42.87 +/- 4.56). The HOS test had significant correlations with plasmalemma integrity as measured by the vital stain, eosin--nigrosin (r = 0.85, p < 0.05). The HOS-G test also had significant correlation with plasmalemma integrity measured by vital stains such as eosin--nigrosin (r = 0.90, p < 0.05) and fluorogenic stains [carboxyfluorescein diacetate (CFDA) and propidium iodide (PI); r = 0.92, p < 0.01] and HOS test (r = 0.93), acrosomal integrity (r = 0.86, p < 0.05) and mitochondrial membrane potential (r = 0.99, p < 0.01). The plasmalemma integrity (fluorogenic stain), functional membrane integrity (HOS test), subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (HOS-G test) and mitochondrial membrane potential had significant (p < 0.05) correlation with sperm zona binding and penetration. The present study indicates that these parameters could represent important determinants of sperm quality influencing zona binding and penetration. PMID:18673329

Selvaraju, S; Ghosh, J; Ravindra, J P

2009-02-01

23

The practical side of immunocontraception: zona proteins and wildlife.  

PubMed

With shrinking habitat, the humane control of certain wildlife populations is relevant. The contraceptive vaccine based on native porcine zona pellucida (PZP) has been applied to various wildlife populations for 20 years. Prominent efforts include wild horses, urban deer, zoo animals and African elephants, among others. This approach has been successful in managing entire populations and to date, no significant debilitating short- or long-term health effects have been documented. PMID:19850355

Kirkpatrick, J F; Rowan, A; Lamberski, N; Wallace, R; Frank, K; Lyda, R

2009-12-01

24

Proteasomal interference prevents zona pellucida penetration and fertilization in mammals.  

PubMed

The ubiquitin-proteasome pathway has been implicated in the penetration of ascidian vitelline envelope by the fertilizing spermatozoon (Sawada et al., Proc Natl Acad Sci U S A 2002; 99:1223-1228). The present study provides experimental evidence demonstrating proteasome involvement in the penetration of mammalian zona pellucida (ZP). Using porcine in vitro fertilization as a model, penetration of ZP was completely inhibited by specific proteasomal inhibitors MG-132 and lactacystin. Three commercial rabbit sera recognizing 20S proteasomal core subunits beta-1i, beta-2i, alpha-6, and beta-5 completely blocked fertilization at a very low concentration (i.e., diluted 1/2000 to 1/8000 in fertilization medium). Neither proteasome inhibitors nor antibodies had any effects on sperm-ZP binding and acrosome exocytosis in zona-enclosed oocytes or on fertilization rates in zona-free oocytes, which were highly polyspermic. Consistent with a possible role of ubiquitin-proteasome pathway in ZP penetration, ubiquitin and various alpha and beta type proteasomal subunits were detected in boar sperm acrosome by specific antibodies, immunoprecipitated and microsequenced by MALDI-TOF from boar sperm extracts. Antiubiquitin-immunoreactive substrates were detected on the outer face of ZP by epifluorescence microscopy. This study therefore provides strong evidence implicating the ubiquitin-proteasome pathway in mammalian fertilization and zona penetration. This finding opens a new line of acrosome/ZP research because further studies of the sperm acrosomal proteasome can provide new tools for the management of polyspermia during in vitro fertilization and identify new targets for contraceptive development. PMID:15253927

Sutovsky, Peter; Manandhar, Gaurishankar; McCauley, Tod C; Caamaño, Jose Nestor; Sutovsky, Miriam; Thompson, Winston E; Day, Billy N

2004-11-01

25

Hyperactivation of capacitated human sperm correlates with the zona pellucida-induced acrosome reaction of zona pellucida-bound sperm  

Microsoft Academic Search

BACKGROUND: The aim of this study was to determine the relationship between human sperm hyperactivation (HA), sperm-zona pellucida (ZP) binding and the ZP-induced acrosome reaction (AR) of ZP-bound sperm in vitro. METHODS: Sperm samples from 129 infertile men were studied. Motile sperm (2 3 106) selected by Pure sperm were incubated with four oocytes in 1 ml human tubal fluid

D. Y. Liu; M. L. Liu; G. N. Clarke; H. W. G. Baker

2007-01-01

26

Viscous forces are predominant in the zona pellucida mechanical resistance  

NASA Astrophysics Data System (ADS)

The zona pellucida (ZP) is a multilayer glycoprotein spherical shell surrounding mammalian eggs. The ZP's mechanical response plays a crucial role in mammalian fertilization and is a parameter commonly adopted in ``in vitro fertilization'' to characterize the oocytes quality. While it is assumed that ZP mechanical response is purely elastic, here we prove that dissipative forces cannot be neglected. Physiologically, this evidence implies that an increase in the spermatozoa motility can induce dramatic changes on the ZP reaction force turning ZP shell in an impenetrable barrier leading to fertility impairments.

Papi, Massimiliano; Maiorana, Alessandro; Douet, Cécile; Maulucci, Giuseppe; Parasassi, Tiziana; Brunelli, Roberto; Goudet, Ghylène; De Spirito, Marco

2013-01-01

27

'ZP domain' of human zona pellucida glycoprotein-1 binds to human spermatozoa and induces acrosomal exocytosis  

Microsoft Academic Search

BACKGROUND: The human egg coat, zona pellucida (ZP), is composed of four glycoproteins designated as zona pellucida glycoprotein-1 (ZP1), -2 (ZP2), -3 (ZP3) and -4 (ZP4) respectively. The zona proteins possess the archetypal 'ZP domain', a signature domain comprised of approximately 260 amino acid (aa) residues. In the present manuscript, attempts have been made to delineate the functional significance of

Anasua Ganguly; Pankaj Bansal; Tripti Gupta; Satish K Gupta

2010-01-01

28

Zona-free embryo culture: is it a viable option to improve pregnancy rates?  

PubMed

Sporadic reports published during the previous decade have documented pregnancies achieved with transfer of zona-free human embryos. Although the overall efficiency seems to be good and some authors have suggested systematic application for special infertility problems, there have been only a few attempts to compare the benefits of zona-free embryo culture and transfer with the traditional approach using zona-intact embryos. So far, the majority of instances in which zona-free culture has been applied have occurred accidentally. This review summarizes the known functions of the zona pellucida, analyses natural and artificial situations where its function is compromised, including zona hardening and difficult hatching that seem to be related to in-vitro embryo culture, and discusses possible methods and timing for artificial zona removal. With the availability of in-vitro systems capable of replacing important functions of the zona pellucida, routine use of zona-free culture for the whole in-vitro period, after or even before fertilization, is a realistic possibility with potential additional benefits. Based on the increasing amount of animal studies, a systematic comparison is suggested that may eventually diminish the handicaps of the in-vitro situation and lead to simplification of manipulations as well as higher success rates after embryo transfer. PMID:20466592

Vajta, Gábor; Rienzi, Laura; Bavister, Barry D

2010-07-01

29

Effect of capacitation of stallion sperm with polyvinylalcohol or bovine serum albumin on penetration of bovine zona-free or partially zona-removed equine oocytes1  

Microsoft Academic Search

Experiments were conducted to study effects of macromolecules on stallion sperm capacita- tion and fertilization as determined by penetration of bovine zona-free and equine partially zona-removed oo- cytes. Stallion sperm were capacitated in TYH medium (modified Krebs-Ringer bicarbonate) supplemented with either 1 mg\\/mL of polyvinylalcohol (PVA) or 4 mg\\/ mL of BSA. Capacitation was induced with 8 bromoade- nosine cyclic

Y. H. Choi; F. C. Landim-Alvarenga; G. E. Seidel Jr; E. L. Squires

2003-01-01

30

Complexin-I-deficient sperm are subfertile due to a defect in zona pellucida penetration  

Microsoft Academic Search

Upon adhesion to the zona pellucida, sperm undergo regulated exocytosis of the acrosome. Although it is necessary for sperm to penetrate the zona pellucida and fertilize an egg, the acrosomal membrane fusion process is poorly understood. Complexins I and II are small, cytosolic proteins that bind to a complex of proteins termed the soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex

Longmei Zhao; Kerstin Reim; David J Miller

2008-01-01

31

EFFECT ON SURVIVAL OF MICROMANIPULATING THE ZONA PELLUCIDA OF BOVINE EMBRYOS  

Microsoft Academic Search

Lopatáfiová M., L. Hol?, A. Vinkler: Effect on Survival of Micromanipulating the Zona Pellucida of Bovine Embryos. Acta Vet. Brno 2001, 70: 49-56. Day 7 bovine embryos collected from superovulated cows were subjected to standard incision in the zona pellucida before subsequent in vitro culture for 72 h or direct transfer. The aim of this simple microsurgical treatment of fresh

M. LOPATÁ; L. HOL; A. VINKLER

2001-01-01

32

Disulfide formation in bovine zona pellucida glycoproteins during fertilization: evidence for the involvement of cystine cross-linkages in hardening of the zona pellucida.  

PubMed

The time for solubilization of the bovine zona pellucida in a hypotonic buffer containing 5% (v/v) beta-mercaptoethanol and 7 mol urea l-1 increased by 10% after fertilization. Coupling with a specific fluorescent thiol probe, monobromobimane (mBBr), was markedly greater in the zona pellucida of ovarian eggs compared with fertilized eggs, indicating that the cysteine residues in the zona pellucida of unfertilized eggs are oxidized to cystines during fertilization. After endo-beta-galactosidase digestion to remove N-acetyllactosamine repeats of the carbohydrate chains, three zona pellucida glycoproteins (ZPA, ZPB and ZPC) coupled with the fluorescent bimane groups were fractionated efficiently by reverse-phase HPLC. Estimation of bimane groups in the three components and SDS-PAGE revealed that intramolecular disulfide bonds in ZPA and intra- and intermolecular disulfide bonds in ZPB were formed during fertilization, but oxidation of cysteine residues in ZPC was low. Specific proteolysis of ZPA during fertilization was also observed. These results indicate that the formation of disulfide linkages together with specific proteolysis result in the construction of a rigid zona pellucida structure, which is responsible for hardening of the zona pellucida. PMID:10690208

Iwamoto, K; Ikeda, K; Yonezawa, N; Noguchi, S; Kudo, K; Hamano, S; Kuwayama, M; Nakano, M

1999-11-01

33

Nanoscale characterization of the biomechanical hardening of bovine zona pellucida.  

PubMed

The zona pellucida (ZP) is an extracellular membrane surrounding mammalian oocytes. The so-called zona hardening plays a key role in fertilization process, as it blocks polyspermy, which may also be caused by an increase in the mechanical stiffness of the ZP membrane. However, structural reorganization mechanisms leading to ZP's biomechanical hardening are not fully understood yet. Furthermore, a correct estimate of the elastic properties of the ZP is still lacking. Therefore, the aim of the present study was to investigate the biomechanical behaviour of ZP membranes extracted from mature and fertilized bovine oocytes to better understand the mechanisms involved in the structural reorganization of the ZP that may lead to the biomechanical hardening of the ZP. For that purpose, a hybrid procedure is developed by combining atomic force microscopy nanoindentation measurements, nonlinear finite element analysis and nonlinear optimization. The proposed approach allows us to determine the biomechanical properties of the ZP more realistically than the classical analysis based on Hertz's contact theory, as it accounts for the nonlinearity of finite indentation process, hyperelastic behaviour and material heterogeneity. Experimental results show the presence of significant biomechanical hardening induced by the fertilization process. By comparing various hyperelastic constitutive models, it is found that the Arruda-Boyce eight-chain model best describes the biomechanical response of the ZP. Fertilization leads to an increase in the degree of heterogeneity of membrane elastic properties. The Young modulus changes sharply within a superficial layer whose thickness is related to the characteristic distance between cross-links in the ZP filamentous network. These findings support the hypothesis that biomechanical hardening of bovine ZP is caused by an increase in the number of inter-filaments cross-links whose density should be higher in the ZP inner side. PMID:22675161

Boccaccio, Antonio; Frassanito, Maria Cristina; Lamberti, Luciano; Brunelli, Roberto; Maulucci, Giuseppe; Monaci, Maurizio; Papi, Massimiliano; Pappalettere, Carmine; Parasassi, Tiziana; Sylla, Lakamy; Ursini, Fulvio; De Spirito, Marco

2012-11-01

34

Nanoscale characterization of the biomechanical hardening of bovine zona pellucida  

PubMed Central

The zona pellucida (ZP) is an extracellular membrane surrounding mammalian oocytes. The so-called zona hardening plays a key role in fertilization process, as it blocks polyspermy, which may also be caused by an increase in the mechanical stiffness of the ZP membrane. However, structural reorganization mechanisms leading to ZP's biomechanical hardening are not fully understood yet. Furthermore, a correct estimate of the elastic properties of the ZP is still lacking. Therefore, the aim of the present study was to investigate the biomechanical behaviour of ZP membranes extracted from mature and fertilized bovine oocytes to better understand the mechanisms involved in the structural reorganization of the ZP that may lead to the biomechanical hardening of the ZP. For that purpose, a hybrid procedure is developed by combining atomic force microscopy nanoindentation measurements, nonlinear finite element analysis and nonlinear optimization. The proposed approach allows us to determine the biomechanical properties of the ZP more realistically than the classical analysis based on Hertz's contact theory, as it accounts for the nonlinearity of finite indentation process, hyperelastic behaviour and material heterogeneity. Experimental results show the presence of significant biomechanical hardening induced by the fertilization process. By comparing various hyperelastic constitutive models, it is found that the Arruda–Boyce eight-chain model best describes the biomechanical response of the ZP. Fertilization leads to an increase in the degree of heterogeneity of membrane elastic properties. The Young modulus changes sharply within a superficial layer whose thickness is related to the characteristic distance between cross-links in the ZP filamentous network. These findings support the hypothesis that biomechanical hardening of bovine ZP is caused by an increase in the number of inter-filaments cross-links whose density should be higher in the ZP inner side.

Boccaccio, Antonio; Frassanito, Maria Cristina; Lamberti, Luciano; Brunelli, Roberto; Maulucci, Giuseppe; Monaci, Maurizio; Papi, Massimiliano; Pappalettere, Carmine; Parasassi, Tiziana; Sylla, Lakamy; Ursini, Fulvio; De Spirito, Marco

2012-01-01

35

Studies on zona hardening in rat oocytes that are matured in vitro in a serum-free medium.  

PubMed

The present study confirms that zona pellucidae of rat oocytes became resistant to chymotrypsin digestion (zona hardening) after undergoing in vitro maturation (IVM) in a serum-free medium. However, zona hardening did not occur when empty zonae without oocytes were cultured in the same IVM conditions, suggesting that oocyte-derived factor(s) is responsible for zona hardening in oocytes matured in the serum-free medium. Zona hardening occurred primarily after dictyate oocytes were cultured for 6-8 hours in the IVM medium without serum. Zona hardening could be prevented or alleviated if oocytes were cultured in the IVM medium containing bovine foetal calf serum, a soybean trypsin inhibitor, or beta-mercaptoethanol, and in vitro fertilization rates for such oocytes were normal. Possible mechanisms of the phenomenon of zona hardening in oocytes matured in serum-free conditions are discussed in relation to its possible relevance to the cortical reaction and the physiological block to polyspermy. PMID:2015089

Zhang, X; Rutledge, J; Armstrong, D T

1991-03-01

36

Effect of capacitation of stallion sperm with polyvinylalcohol or bovine serum albumin on penetration of bovine zona-free or partially zona-removed equine oocytes.  

PubMed

Experiments were conducted to study effects of macromolecules on stallion sperm capacitation and fertilization as determined by penetration of bovine zona-free and equine partially zona-removed oocytes. Stallion sperm were capacitated in TYH medium (modified Krebs-Ringer bicarbonate) supplemented with either 1 mg/mL of polyvinylalcohol (PVA) or 4 mg/mL of BSA. Capacitation was induced with 8 bromoadenosine cyclic monophosphate (8BrcAMP; 0.5 mM) alone or in combination with 0.1 microM of ionomycin. Intraspecies gametes were co-incubated in TYH/PVA or TYH/BSA for 18 to 20 h. For zona-free bovine oocytes, penetration rate (35%) with the combination of 8BrcAMP and ionomycin in PVA-containing medium was higher (P < 0.05) than any treatment in BSA-containing medium (5 to 6%). A similar study was conducted using equine oocytes with partially removed zonae. Sperm capacitated and used for in vitro fertilization (IVF) in PVA-containing medium had higher penetration rates (P < 0.01) than sperm in BSA-containing medium (54 vs. 11%). The effect of equine preovulatory follicular fluid on bovine oocyte penetration was assessed. Bovine oocytes were matured in tissue culture medium-199 with 0, 20, 50, or 100% equine preovulatory follicular fluid, and 1 IU/mL of equine chorionic gonadotropin. Stallion sperm were treated with 8BrcAMP + ionomycin in PVA- or BSA-containing media. The penetration rates of bovine zona-free oocytes by stallion sperm were again higher with PVA (47%) than BSA (18%; P < 0.01). Penetration rates of oocytes matured in 100% follicular fluid were higher (P < 0.05) than for oocytes matured with 0% follicular fluid. The effects of equine follicular fluid and PVA/BSA during sperm capacitation on standard bovine IVF were examined. Culture of bovine oocytes with equine follicular fluid did not affect oocyte maturation or penetration rates after IVF. Bovine sperm capacitated with heparin in PVA-containing medium yielded lower (P < 0.05) fertilization rates than those capacitated in BSA-containing medium when incubated with both zona-intact and zona-free bovine oocytes. In summary, PVA was superior to BSA for ionophore-induced capacitation of equine sperm for penetration of zona-free bovine oocytes or partially zona-removed equine oocytes, but not for standard bovine IVF with bovine sperm. Zona-free bovine oocytes may be useful for assaying in vitro capacitation and fertilization of stallion sperm. PMID:12926790

Choi, Y H; Landim-Alvarenga, F C; Seidel, G E; Squires, E L

2003-08-01

37

A new method for preparation of pure zonae pellucidae in large quantities from porcine ovaries.  

PubMed

A new method for preparation of large quantities of zona substance in pure form from porcine ovaries has been described. In addition to the previously reported techniques of glass wool treatment and sieving by saran meshes, the following three significant improvements have been introduced: disruption of ovaries by an electric machine equipped with two multi-needed disks, which resulted in a considerably accelerated recovery of follicular oocytes with a high yield; low-speed centrifugation at 170 X g for 15 s was found to be an obligatory step to eliminate light particulate material from the crude oocyte suspension; use of 50% sucrose solution in discontinuous density gradient centrifugation permitted complete separation of homogeneous samples at two stages of the final preparation of zona-encased oocytes or of oocyte-free zonae. Microscopic examination revealed no contaminating components in the zona preparation. With this method 93 mg of lyophilized zona preparation were obtained from 24 553 porcine ovaries. Analysis of a solubilized zona substance by Sephacryl S-200 column chromatography showed the presence of two major glycoproteins which could not be separated completely from each other. By analysis of the two components with SDS-PAGE, only a single, but broad, band of glycoprotein was found, indicating the successful isolation of a major component(s) from porcine zonae. PMID:7196952

Noda, Y; Mori, T; Takai, I; Kohda, H; Nishimura, T

1981-07-01

38

Beneficial effect of long zona dissection on frozen-thawed blastocysts at a young age  

Microsoft Academic Search

Aim  To assess the appropriateness of assisted hatching using long zona dissection of human frozen-thawed blastocysts at the time\\u000a of warming, especially in women over 35 years of age or with repeated implantation failures.\\u000a \\u000a \\u000a \\u000a Methods  Of 177 frozen-thawed blastocyst transfer cycles, 89 control cycles had an intact zona and 88 cycles had assisted hatching\\u000a using long zona dissection of human thawed blastocyst

Setsuko Yamamoto; Michiko Umeki; Mioko Kodoma; Teruhiro Hamano; Fujiyo Matsusita

2007-01-01

39

Welcome to Zona Land: Education in Physics and Mathematic  

NSDL National Science Digital Library

Zona Land, created by Ed Zobel, is a science and mathematics resource site for students and teachers. The site illustrates mathematical and physical principles by the use of Java applets and VRML simulations. The Science section contains the Physics Department (mechanics, waves and light), EZ Graph, and EZ Evaluator. EZ Graph allows the user to view the graph of a desired function. Evaluator is an online calculator that has trigonometric capabilities. The Mathematics section has four subject areas plus the Graph and Evaluator tools. Graph Paper allows the user to examine the effects of different scales on pre-designed linear, cubic, quadratic, and sine functions. The Function Institute begins with an optional tour of the definition of a function. Also available at the Institute are graphs of linear and polynomial functions. The Geometry Section has three areas of resources: Common Shapes, Fractals, and Coordinate Geometry. Trigonometry Realms has a simple yet comprehensive introduction to trigonometry. Help is available for all of the different resource applications.

Zobel, Edward A.

1998-01-01

40

State-dependent gating of sensory inputs by zona incerta.  

PubMed

We have previously shown that the GABAergic nucleus zona incerta (ZI) suppresses vibrissae-evoked responses in the posterior medial (POm) thalamus of the rodent somatosensory system. We proposed that this inhibitory incerto-thalamic pathway regulates POm responses during different behavioral states. Here we tested the hypothesis that the cholinergic reticular activating system, implicated in regulating states of arousal, modulates ZI activity. We show that stimulation of brain stem cholinergic nuclei (laterodorsal tegmental and pedunculopontine tegmental) results in suppression of spontaneous firing of ZI neurons. Iontophoretic application of the cholinergic agonist carbachol to ZI neurons suppresses both their spontaneous firing and their vibrissae-evoked responses. We also found that carbachol application to an in vitro slice preparation suppresses spontaneous firing of neurons in the ventral sector of ZI (ZIv). Finally, we demonstrate that the majority of ZIv neurons contain parvalbumin and project to POm. Based on these results, we present the state-dependent gating hypothesis, which states that differing behavioral states-regulated by the brain stem cholinergic system-modulate ZI activity, thereby regulating the response properties of higher-order nuclei such as POm. PMID:16775205

Trageser, Jason C; Burke, Kathryn A; Masri, Radi; Li, Ying; Sellers, Larisa; Keller, Asaf

2006-09-01

41

Loss of Zona Pellucida Binding Proteins in the Acrosomal Matrix Disrupts Acrosome Biogenesis and Sperm Morphogenesis  

Microsoft Academic Search

Zona pellucida binding protein 1 (ZPBP1), a spermatid and spermatozoon protein that localizes to the acrosome, was originally identified in pigs and named for its binding to the oocyte zona pellucida. In an in silico search for germ cell-specific genes, Zpbp1 and its novel paralog, Zpbp2, were discovered and confirmed to be expressed only in the testes in both mice

Yi-Nan Lin; Angshumoy Roy; Wei Yan; Kathleen H. Burns; Martin M. Matzuk

2007-01-01

42

Involvement of carbohydrates in the hardening of the zona pellucida of mouse oocytes.  

PubMed

The effect of lectins with different saccharide specificity (ConA, LCA, DBA, WGA and PNA) on enzymatic digestion of the zona pellucida (ZP) of mouse oocytes was studied. All lectins tested, except PNA, induced ZP hardening with different degrees of efficiency. Moreover, extensive ZP digestion with mixed exoglycosidase prevented "spontaneous" ZP hardening. These observations suggest that changes of the carbohydrate moieties can be involved in the hardening of the zona pellucida of mouse oocytes. PMID:1934081

Dolci, S; Bertolani, M V; Canipari, R; De Felici, M

1991-07-01

43

Immunological identification of zona pellucida 2 (ZP2) protein in human oocytes.  

PubMed

The ZP2 protein is a zona pellucida glycoprotein that plays a major role in fertilization. It mediates secondary binding of spermatozoa and is one of the proteins that are involved in zona 'hardening'. ZP2 proteins were identified in various mammalian zonae pellucidae. Their primary structures are highly conserved as revealed by cDNA cloning. Antisera were used against synthetic peptides generated either against a ZP2 amino acid that is homologous in human and mouse ZP2 amino acid sequences (AS ZP2-20) or antibodies against a synthetic human ZP2 peptide (AS ZP2-26). Immunoblots showed that antiserum AS ZP2-20 and AS ZP2-26 strongly recognized human ZP2 protein with an apparent molecular mass of about 72 kDa; both antisera reacted with a minor immunoreactive polypeptide at 96 kDa. In human ovary sections, both antisera revealed immunoreactivity to human zonae pellucidae. Immuno-electron microscopy demonstrated an equal distribution of ZP2 throughout the human zona pellucida. Considerable amounts of immunoreactive material were observed in the ooplasm; some ramification-like extensions of zona pellucida antigen were found close to cells surrounding the oocyte. Our results indicate that antisera against synthetic ZP2 peptides can be used as specific markers for the identification of ZP2 protein in human oocytes. PMID:9739427

Hinsch, E; Hägele, W; van der Ven, H; Oehninger, S; Schill, W B; Hinsch, K D

1998-01-01

44

Changes in the properties and composition of zona pellucida of pigs during fertilization in vitro.  

PubMed

Several hundred fertilized pig eggs were prepared by an in vitro fertilization (IVF) technique in which follicular phase ovarian eggs were matured in vitro to metaphase II before incubation with capacitated epididymal spermatozoa for 12 h at 39 degrees C. Parthenogenetic eggs were also prepared by stimulation of the mature eggs with an electric pulse. The zonae were solubilized with 0.2% pronase/phosphate-buffered saline (PBS) or lactic acid/PBS. The time taken for solubilization was 30-40% shorter than for unfertilized eggs, indicating that zona hardening was induced during fertilization. At the same time, the sperm receptor activity of the zona was reduced. Electrophoretic analyses of zona glycoproteins from the ovarian, mature and fertilized eggs revealed that the amount of 90 kDa proteins decreased substantially during fertilization. This fraction could barely be detected in the zonae from parthenogenetic eggs. However, modification with a fluorescent probe showed that the general architecture of the zona remained unchanged during fertilization. These results suggest that the minor 90 kDa proteins are specifically degraded by the protease(s) released from the oocyte at fertilization, thereby leading to the block to polyspermy. PMID:1518000

Hatanaka, Y; Nagai, T; Tobita, T; Nakano, M

1992-07-01

45

Sodium deficiency regulates rat adrenal zona glomerulosa gene expression.  

PubMed

Aldosterone is the primary adrenocortical hormone regulating sodium retention, and its production is under the control of the renin-angiotensin-aldosterone system (RAAS). In vitro, angiotensin II can induce aldosterone production in adrenocortical cells without causing cell proliferation. In vivo, a low-sodium diet activates the RAAS and aldosterone production, at least in part, through an expansion of the adrenal zona glomerulosa (zG) layer. Although these mechanisms have been investigated, RAAS effects on zG gene expression have not been fully elucidated. In this study, we took an unbiased approach to define the complete list of zG transcripts involved in RAAS activation. Adrenal glands were collected from 11-week old Sprague-Dawley rats fed either sodium-deficient (SDef), normal sodium (NS), or high-sodium (HS) diet for 72 hours, and laser-captured zG RNA was analyzed on microarrays containing 27 342 probe sets. When the SDef transcriptome was compared with NS transcriptome (SDef/NS comparison), only 79 and 10 probe sets were found to be up- and down-regulated more than two-fold in SDef, respectively. In SDef/HS comparison, 201 and 68 probe sets were up- and down-regulated in SDef, respectively. Upon gene ontology (GO) analysis of these gene sets, we identified three groups of functionally related GO terms: cell proliferation-associated (group 1), response to stimulus-associated (group 2), and cholesterol/steroid metabolism-associated (group 3) GO terms. Although genes in group 1 may play a critical role in zG layer expansion, those in groups 2 and 3 may have important functions in aldosterone production, and further investigations on these genes are warranted. PMID:24422541

Nishimoto, Koshiro; Harris, Ruth B S; Rainey, William E; Seki, Tsugio

2014-04-01

46

Effects of porcine zona pellucida immunocontraceptives in zoo felids.  

PubMed

Methods of contraception are necessary for management of zoo felids; however, the most commonly used contraceptive (melengestrol acetate implant) is associated with serious adverse reactions with long-term use. Porcine zona pellucida (pZP) vaccines are promising as contraceptives, but their safety in zoo felids has not been tested. pZP vaccine was administered to 27 female felids representing 10 species, including African lion (Panthera leo), Asian leopard (P. pardus), jaguar (P. onca), tiger (P. tigris), snow leopard (P. uncia), cougar (Felis concolor), Siberian lynx (F. lynx), Canada lynx (F. canadensis), serval (F. serval), and bobcat (F. rufus), in 15 facilities. Over 6 wk, each animal received three i.m. injections of 65 microg pZP with Freund's complete adjuvant (FCA), Freund's incomplete adjuvant, or carbopol as the adjuvant. Behavioral signs of estrus were seen in 14 of the vaccinated felids. An unacceptably high incidence of adverse reactions was seen including injection site swelling, lameness, limb swelling, or abscessation (or all) in five felids after injection with FCA as the initial adjuvant. Adverse behavioral signs, including increased irritability and aggression, were seen in four felids. Six of the felids were assayed for antibodies against pZP during the 12 mo after vaccination; all showed antibody production. Antibody levels appeared to peak 1-4 mo after vaccination began, although elevated antibody levels persisted in two animals for > 12 mo after the first injection. All vaccinated felids were ovariohysterectomized 3-13 mo after vaccination. Folliculogenesis was present in all treated animals, and there was no histopathologic evidence of inflammatory damage to ovaries. Contraceptive efficacy was not specifically evaluated in this study; however, two of the three felids housed with an intact male became pregnant during the study, one of which gave birth to healthy cubs. PMID:15526881

Harrenstien, Lisa A; Munson, Linda; Chassy, Lisa M; Liu, Irwin K M; Kirkpatrick, Jay F

2004-09-01

47

Capacitation-dependent reorganization of microdomains in the apical sperm head plasma membrane: Functional relationship with zona binding and the zona-induced acrosome reaction  

Microsoft Academic Search

For sperm to successfully fertilize an oocyte, it needs to pass through certain steps prior to, during and after initial recognition of the zona pellucida (ZP). During capacitation, the surface of the sperm head becomes remodelled, priming it to bind to the ZP and subsequently to undergo the ZP-induced acrosome reaction. During capacitation, sperm ZP-binding proteins are ordered in functional

A. Boerke; P. S. Tsai; N. Garcia-Gil; I. A. Brewis; B. M. Gadella

2008-01-01

48

Development and quality of porcine parthenogenetically activated embryos after removal of zona pellucida.  

PubMed

The need of the zona pellucida (ZP) for in vitro development is controversial because it might be an obstacle to hatching of the blastocyst. This study investigated the development and quality of porcine parthenogenetically activated (PA) embryos by observation of the developmental kinetics, the developmental percentages, the frequency of apoptosis, and robustness after removal of the ZP by pronase. Three experiments were made between zona-free PA embryos and zona-intact embryos: (1) determination of the timing of developmental stages using time-lapse observations for 6 days; (2) determination of developmental percentages and occurrence of apoptosis on Day 6 and Day 7 (Time of PA, Day 0); and (3) investigation of the robustness of embryos using vitrification on Day 4. The developmental kinetics showed that there was a general trend for zona-free PA embryos to develop faster than zona intact PA embryos at all developmental stages, but the difference was only significant at the five-cell stage. When compared with development of zona-intact embryos, ZP removal decreased the overall blastocyst percentage (83.9 ± 2.0 vs. 72.5 ± 2.9, respectively) and especially the percentage of good morphology (grades 1 and 2 combined) blastocysts (69.5 ± 2.0 vs. 55.7 ± 2.4, respectively). However, the process showed a significant decrease in apoptosis indicating an increased embryonic quality. Still, the survival percentage of porcine PA embryos after vitrification was dramatically decreased after ZP removal at all observation times (P < 0.05). In conclusion, removal of the zona pellucida might improve the embryonic quality by accelerating the speed of embryonic development and decreasing the number of apoptotic cells in blastocysts even though developmental percentages and embryonic robustness might be decreased. PMID:23602082

Li, Rong; Liu, Ying; Pedersen, Hanne Skovsgaard; Kragh, Peter M; Callesen, Henrik

2013-07-01

49

Indicadores de riesgo y de gestión del riesgo de los desastres: resultados para Nicaragua  

Microsoft Academic Search

Los desastres naturales han repercutido en las perspectivas de desarrollo de muchos de los países de América Latina y el Caribe. Nicaragua está al frente de esta infortunada realidad, estando localizada en una de las zonas del mundo más propensa a amenazas naturales. Con el fin de apoyar a Nicaragua es reducir su vulnerabilidad frente a las amenazas y las

Omar D. Cardona

2007-01-01

50

Fetal calf serum increased the zona pellucida penetrability of rat oocytes matured in vitro.  

PubMed

We examined the effect of fetal calf serum (FCS) on meiotic division, subsequent fertilization, and first cleavage to the 2-cell stage of rat oocytes during in vitro maturation. FCS had no effect on the nuclear progression from dictiate to metaphase of the second maturation in vitro and, FCS had no effect on the first cleavage to the 2-cell stage of fertilized oocytes. However, FCS efficiently increased penetration rate of oocytes and shortened the time required for dissolution of the zona pellucida by alpha-chymotrypsin. These results showed that FCS did not affect cytoplasmic maturation necessary for oocytes to develop to the 2-cell stages. We found that FCS only affects the zona pellucida and does not affect the nucleus or cytoplasm of rat oocytes. FCS may prevent hardening of the zona pellucida. PMID:2244475

Fujii, Y; Yoshioka, T; Sasaki, J

1990-08-01

51

Mouse zona pellucida dynamically changes its elasticity during oocyte maturation, fertilization and early embryo development.  

PubMed

A change in the elasticity of mouse zona pellucida was quantitatively evaluated during oocyte maturation, fertilization and early embryo development. Young's modulus of zona pellucida of germinal vesicle (GV), metaphase-II (MII), pronuclear (PN), 2cell, 4cell, 8cell, morulae (M) and early blastocyst (EB) stages was measured using a micro tactile sensor (MTS) and a chamber exclusively designed for the measurement. The MTS has very high sensitivity and a deformation of only 5 microm was sufficient to calculate the Young's modulus and the oocyte/embryo maintained its original spherical shape during the measurement. The Young's modulus of GV, MII, PN, 2cell, 4cell, 8cell, M and EB was 22.8+/-10.4 kPa (n=30), 8.26+/-5.22 kPa (n=74), 22.3+/-10.5 kPa (n=66), 13.8+/-3.54 kPa (n=41), 12.6+/-3.34 kPa (n=19), 5.97+/-4.97 kPa (n=6), 1.88+/-1.34 kPa (n=8) and 3.39+/-1.86 kPa (n=4), respectively. Experimental results clearly demonstrated that the mouse zona pellucida hardened following fertilization. Interestingly, once the zona pellucida hardened at the PN stage, it gradually softened as the embryo developed (i.e. it was found that the zona hardening is a transient phenomenon). Furthermore, the zona pellucida of the GV oocyte was as hard as that of the PN embryo and became soft as it matured to the MII stage. In addition, the safety of the MTS measurement for oocytes and embryos was discussed both theoretically and experimentally. PMID:17257374

Murayama, Yoshinobu; Mizuno, Jinji; Kamakura, Hirokazu; Fueta, Yoichi; Nakamura, Hiroko; Akaishi, Kazuyuki; Anzai, Ken; Watanabe, Akihiko; Inui, Hiroaki; Omata, Sadao

2006-11-01

52

Porcine sperm-zona binding ability as an indicator of fertility  

PubMed Central

The escalated use of artificial insemination in swine has increased the importance of determining fertility of a semen sample before it is used. Multiple laboratory assays have been developed to assess fertilizing potential but they have yielded inconsistent results. This experiment sought to determine the relationship between in vitro competitive zona binding ability and in vivo fertility based on heterospermic inseminations and paternity testing. The zona pellucida binding ability and fertility of sperm from 15 boars was assessed by comparing sperm from one boar with sperm from other individual boars in a pair-wise fashion using four ejaculates. The relationship of zona binding ability to the mean number of piglets sired per litter for each boar as well as historic fertility data (litter size and farrowing rate) was assessed. The in vitro competition assay consisted of labeling sperm from each boar of the pair with a different fluorophore and incubating an equal number of sperm from each boar in the same droplet with porcine oocytes. The competitive assay was highly effective in ranking boars by zona binding ability (R2 = 0.94). Paternity testing using microsatellite markers was used to determine the mean number of piglets sired per litter for each boar during heterospermic inseminations. The pairwise heterospermic insemination assay was effective in ranking boar fertility (R2 = 0.59). Using historical data from these boars, average litter size and farrowing rate were correlated (r = 0.81, p < 0.001). However, zona binding ability was not significantly correlated with historic farrowing rate data or historic average litter size. Boar sperm zona binding ability was also not correlated significantly with the mean number of piglets sired per litter following heterospermic insemination. But the number of piglets sired by each boar was related to a combination of zona binding ability, sperm motility, normal morphology, acrosomal integrity, and the presence of distal droplets (R2 = 0.70). These results suggest that zona binding ability is not an accurate predictor of fertilizing ability when used alone; however, when coupled with other sperm assessments, fertility may be predicted successfully.

Collins, E. D.; Flowers, W. L.; Shanks, R. D.; Miller, D. J.

2008-01-01

53

Tracking diffusion of GM1 gangliosides and zona pellucida binding molecules in sperm plasma membranes following cholesterol efflux.  

PubMed

The molecules on mammalian spermatozoa that mediate recognition and binding to the zona pellucida of the egg are still not understood. Current concepts favour their assembly into multimolecular complexes in the plasma membrane in response to cholesterol efflux, an important step during sperm capacitation. Here, we track in real time diffusion of cross-linked clusters containing zona-binding molecules and GM1 gangliosides in the plasma membrane of live boar spermatozoa before and after cholesterol reduction. Both GM1 gangliosides and zona-binding molecules partition into a low density Triton X100 resistant phase suggesting their association with lipid rafts. Initially, GM1 and zona-binding molecules localize to the apical ridge on the acrosome but following cholesterol efflux with methyl-beta-cyclodextrin, clusters containing zona-binding molecules diffuse randomly over the acrosomal domain. Diffusing clusters of either type do not access the postacrosome. Spermatozoa agglutinated head-to-head show contact-induced coalescence of GM1 gangliosides (but not zona-binding molecules) suggestive of a specific mechanosensitive response. Thus, cholesterol efflux initiates diffusion (and possibly formation) of novel lipid raft-like structures containing zona-binding molecules over the sperm acrosome. We hypothesise that in combination with contact coalescence, these mechanisms concentrate important molecules to the appropriate site on the sperm surface to mediate zona binding. PMID:20060391

Jones, Roy; Howes, Elizabeth; Dunne, Paul D; James, Peter; Bruckbauer, Andreas; Klenerman, David

2010-03-15

54

Zona pellucida drilling by a 1.48-um laser: influence on the biomechanics of the hatching process  

Microsoft Academic Search

Efficient and well controlled laser drilling of the zona pellucida of mouse eggs has been demonstrated recently using a 1.48 micrometers laser diode. The zona pellucida openings (5 - 10 micrometers ) can be obtained within the culture dish in an either tangential or more poleward irradiation in respect to the spherical egg structure. Zone drilling is achieved at a

Klaus Rink; Laurent Descloux; Guy P. Delacretaz; Alfred Senn; Dorotha Nocera; Marc Germond

1996-01-01

55

Timing of zona pellucida formation in the tammar wallaby ( Macropus eugenii) and brushtail possum ( Trichosurus vulpecula)  

Microsoft Academic Search

The zona pellucida (ZP) is an extracellular coat that surrounds the mammalian egg, and serves as the primary recognition site for fertilizing spermatozoa. The timetable of ZP formation was examined in two marsupials, the tammar wallaby (Macropus eugenii) and the brushtail possum (Trichosurus vulpecula) using conventional histological methods, immunofluorescence and electron microscopy. Ovaries from tammar wallaby pouch young less than

K. E Mate

1998-01-01

56

Harmful effects of anti-zona pellucida antibodies in folliculogenesis, oogenesis, and fertilization  

Microsoft Academic Search

The zona pellucida (ZP) is an extracellular matrix that surrounds the mammalian oocyte and plays an important role in normal folliculogenesis and fertilization. Because of its strong immunogenicity and its possible relation with premature ovarian failure, we conducted the present study to examine whether or not anti-ZP antibodies impaired folliculogenesis. Mouse preantral follicles were cultured with anti-ZP antibodies to evaluate

Giannina Calongos; Akiko Hasegawa; Shinji Komori; Koji Koyama

2009-01-01

57

Local production and action of adrenomedullin in the rat adrenal zona glomerulosa  

Microsoft Academic Search

This study was designed to investigate the synthesis and action of adrenomedullin in the rat adrenal gland. The results obtained fromin situhybridization and immunocyto- chemical studies suggest that adrenomedullin is synthesized not only in the medulla, but also within the zona glomeru- losa of the rat adrenal cortex. Findings from in situ hybrid- ization and binding studies also suggested that

S Kapas; A Martinez; F Cuttitta; J P Hinson

1998-01-01

58

Distinct subtypes of zona pellucida morphology reflect canine oocyte viability and cumulus-oocyte complex quality.  

PubMed

The aim of this study was to analyze surface morphology of the zona pellucida (ZP) and assess its relationship with oocyte viability, cumulus-oocyte complex (COC) quality, and oocyte donor age in dogs. Canine ovaries were sliced to release COCs for use in three experiments. In Experiment 1, oocytes from high-quality (grade I) COCs were viewed with scanning electron microscopy to visualize the zona surface. Four zonae, classified as types I, II, III, and IV, were detectable on high-quality oocytes. Most (95.5%) dog donors had oocytes with two or three ZP types. The ZP type I had a smooth compact surface with few pores. The ZP type II was less compact with many distinct circular or elliptical pores. The ZP type III had a rough surface with folds and many irregular shaped pores and hollows. The ZP type IV also had a rough surface with folds, but in addition, stringy filaments obscured the pores and hollows. The frequency of ZP type I in the oocyte population was low (2.7%), whereas ZP types II, III, and IV each occurred in approximately one-third of the oocyte population. In Experiment 2, oocytes from high-quality COCs were stained with propidium iodide (PI) before scanning electron microscopy to investigate the relationship of oocyte viability with ZP morphology. In Experiment 3, oocytes were collected from low-quality (grade 2) and high-quality (grade 1) COCs to investigate the role of COC quality on zona structure. Zonae types I and II were characteristic of PI-positive (dead) oocytes and oocytes from low-quality COCs, whereas ZP types III and IV were prevalent on PI-negative (living) oocytes and oocytes from high-quality COCs. We concluded that the heterogeneous ZP surface underwent structural rearrangements related to oocyte viability and COC quality. This warrants further investigation into ZP structure and may be useful for canine-assisted reproduction. PMID:23790239

Lunn, Matthew O; Wright, Shirley J

2013-09-15

59

Immunoglobulin to zona pellucida 3 mediates ovarian damage and infertility after contraceptive vaccination in mice.  

PubMed

Antibodies reactive with the ovarian glycoprotein zona pellucida (ZP) have been linked with human female infertility. Anti-fertility vaccines that target ZP antigens have been utilized to restrict pest animal populations and their efficacy is associated with ovary-specific antibody induction. However, the necessity for zona pellucida-specific antibody in mediating infertility has not been examined in vivo. A recombinant mouse cytomegalovirus vaccine encoding murine zona pellucida 3 that induces rapid and complete infertility in BALB/c mice has been produced. The onset of infertility is temporally related to the presence of antibody sequestered into ovarian follicles and binding to the ZP of infected mice and the loss of mature follicles. When this vaccine was inoculated into immunoglobulin-deficient BALB/c mice with a null mutation in the immunoglobulin mu chain gene Igh-6, fertility was unaffected. Passive transfer of serum containing ZP3 antibodies also elicited transient infertility. Electron microscopy of ovarian tissue collected from ZP3-immunized immunocompetent mice demonstrated significant focal thinning of the zona pellucida (ZP) with reduced length and concentration of transzonal processes and many oocytes displayed evidence of injury. None of these changes were found in vaccinated immunoglobulin-deficient mice. These data confirm that ZP3-reactive antibody is necessary and sufficient to induce autoimmune-mediated follicular depletion and fertility suppression following the inoculation of this vaccine, and suggest that this is due to impaired zona pellucida formation. These findings have relevance in understanding the etiology of autoimmune ovarian disease in woman where anti-ZP antibodies are likely to have a causal role in infertility. PMID:20382503

Lloyd, Megan L; Papadimitriou, John M; O'Leary, Sean; Robertson, Sarah A; Shellam, Geoffrey R

2010-08-01

60

Most fertilizing mouse spermatozoa begin their acrosome reaction before contact with the zona pellucida during in vitro fertilization  

PubMed Central

To fuse with oocytes, spermatozoa of eutherian mammals must pass through extracellular coats, the cumulus cell layer, and the zona pellucida (ZP). It is generally believed that the acrosome reaction (AR) of spermatozoa, essential for zona penetration and fusion with oocytes, is triggered by sperm contact with the zona pellucida. Therefore, in most previous studies of sperm–oocyte interactions in the mouse, the cumulus has been removed before insemination to facilitate the examination of sperm–zona interactions. We used transgenic mouse spermatozoa, which enabled us to detect the onset of the acrosome reaction using fluorescence microscopy. We found that the spermatozoa that began the acrosome reaction before reaching the zona were able to penetrate the zona and fused with the oocyte's plasma membrane. In fact, most fertilizing spermatozoa underwent the acrosome reaction before reaching the zona pellucida of cumulus-enclosed oocytes, at least under the experimental conditions we used. The incidence of in vitro fertilization of cumulus-free oocytes was increased by coincubating oocytes with cumulus cells, suggesting an important role for cumulus cells and their matrix in natural fertilization.

Jin, Mayuko; Fujiwara, Eiji; Kakiuchi, Yasutaka; Okabe, Masaru; Satouh, Yuhkoh; Baba, Shoji A.; Chiba, Kazuyoshi; Hirohashi, Noritaka

2011-01-01

61

Indomethacin delays zona-shedding and implantation in the ovariectomized progesterone-treated hamster.  

PubMed

Pregnant hamsters were ovariectomized on Day 2 (Day 1 = sperm positive) and given progesterone replacement therapy daily (200 microgram sc in sesame oil). Either 2 or 4 mg indomethacin (Indo) given on Day 3 and early Day 4 delayed shedding of the zona pellucida and the onset of implantation on Day 4. One mg Indo administered on Day 3 was only partially effective. By Day 5, approximately half of the hamsters receiving either 2 or 4 mg Indo exhibited implantation sites whereas all controls and hamsters receiving 1 mg Indo had sites. At the dosages used, estradiol cypionate, histamine, prostacyclin and prostaglandin E2 did not overcome the effects of Indo. The results indicate that Indo interferes with zona shedding and implantation of blastocysts in the ovariectomized-progesterone treated hamster. PMID:7146454

Terranova, P F; Dey, S A

1982-08-01

62

Lessons from the gene expression pattern of the rat zona glomerulosa  

PubMed Central

We recently identified hundreds of transcripts with differential expression in rat zona glomerulosa (zG) and zona fasciculata. Although the genes up-regulated in the zG may be playing important roles in aldosterone production, the relationship between most of these genes and aldosterone production has not been uncovered. Because aldosterone, in the presence of a high sodium diet, is now considered a significant cardiovascular risk factor, in this review we performed gene ontology and pathway analyses on the same microarray data to better define the genes that may influence zG function. Overall, we identified a number of genes that may be involved in aldosterone production through transforming growth factor ? (TGF-?), WNT, calcium, potassium, and ACTH signaling pathways. The list of genes we present in the current report may become an important tool for researchers working on primary aldosteronism and aldosterone-related cardiovascular diseases.

Nishimoto, Koshiro; Rainey, William E.; Bollag, Wendy B.; Seki, Tsugio

2013-01-01

63

Structure and Function of the Proteins of the Mammalian Zona pellucida  

Microsoft Academic Search

The zona pellucida (ZP) is the extracellular matrix that plays important roles in sperm-egg interaction. The ZP is composed of three major glycoproteins that exhibit heterogeneity due to extensive post-translational modifications including glycosylation and sulfation. Because of these modifications the nomenclature of ZP proteins from different species based on electrophoretic mobilities has been confusing. As the cDNAs and genes encoding

S. V. Prasad; S. M. Skinner; C. Carino; N. Wang; J. Cartwright; B. S. Dunbar

2000-01-01

64

Cytochemical demonstration of modification of carbohydrates in the mouse zona pellucida during folliculogenesis  

Microsoft Academic Search

In the present study, lectin-gold cytochemistry and antibodies against ZP2 and ZP3 glycoproteins were used to investigate\\u000a the oligosaccharide content of mouse ovarian zona pellucida (ZP) during follicular development. The entire thickness of the\\u000a ZP and several organelles of the oocyte (cortical granules, Golgi apparatus, and vesicular aggregates) were reactive to RCA-I,\\u000a DSA, AAA, WGA, MAA, and LFA throughout follicular

Manuel Avilés; Majid El-Mestrah; Louay Jaber; María Teresa Castells; José Ballesta; Frederick W. K. Kan

2000-01-01

65

Isolated ZP-N domains constitute the N-terminal extensions of Zona Pellucida proteins  

Microsoft Academic Search

Zona Pellucida (ZP) domains have been found in a wide variety of extracellular proteins, in which they play essential role for polymer- ization. They are shared by the ZP proteins, which constitute the extracellular coat of animal eggs. Except from ZP3, constituting the primary sperm receptor, the ZP proteins possess, in addition to their C-terminal ZP domains, N-terminal extensions, which

Isabelle Callebaut; Jean Paul Mornon; Philippe Monget

2007-01-01

66

Immunolocalization of zona pellucida antigens in the ovarian follicle of dogs, cats, horses and elephants  

Microsoft Academic Search

A comparative evaluation of the location of immunoreactive porcine zona pellucida (pZP) glycoproteins was performed with polyclonal rabbit anti-pZP antibodies on ovarian sections of the dog, cat, horse, and elephant. For this, formalin (light microscopy) and glutaraldehyde (transmission electron microscopy [TEM]) fixed ovarian sections were incubated with antibodies raised against highly purified pZP. Staining patterns were determined with diaminobenzidine (DAB)

M. R. Barber; S. M. Lee; W. L. Steffens; M. Ard; R. A. Fayrer-Hosken

2001-01-01

67

Frequency of defective sperm-zona pellucida interaction in severely teratozoospermic infertile men  

Microsoft Academic Search

BACKGROUND: The frequency of defective sperm-zona pellucida (ZP) interaction in teratozoospermic infertile men was investigated. METHODS: Sperm-ZP binding and the ZP-induced acrosome reaction (ZPIAR) were per- formed in 125 infertile men with <5% of their sperm with normal morphology (strict criteria), but with a sperm count >203106\\/ml and total motility >30% in semen. Oocytes that failed to fertilize in clinical

Yi Liu; H. W. Gordon Baker

2003-01-01

68

Protein kinase C plays an important role in the human zona pellucida- induced acrosome reaction  

Microsoft Academic Search

To investigate the involvement of protein kinases in signal transduction in the human zona pellucida (ZP)- induced acrosome reaction (AR), the effects of protein kinase (PK) activators, dibutyryl cAMP (PKA) and cGMP (PKG), phorbol 12-myristate 13-acetate (PMA, PKC), and the PKC inhibitor, staurosporine were studied. Sperm samples were obtained from normozoospermic men with normal sperm-ZP binding. Oocytes were obtained from

D. Y. Liu; H. W. G. Baker

1997-01-01

69

Zona pellucida filtration of structurally abnormal spermatozoa and reduced fertilization in teratospermic cats  

Microsoft Academic Search

Zona pellucida (ZP) penetration, in vitro fertilization, embryo development, and the morphology of fertilizing sperm were examined through use of normospermic (> 60% structurally normal sperm\\/ejaculate) versus teratospermic (< 40% structurally normal sperm\\/ejaculate) ejaculates from domestic cats. In addition, the effect of swim-up processing on sperm-oocyte interaction was compared with that of simple sperm washing. Normospermic and teratospermic ejaculates were

J. G. Howard; A. M. DONOGHUE; L. A. JOHNSTON; D. E. WILDT

1993-01-01

70

Ability of Catalonian donkey sperm to penetrate zona pellucida-free bovine oocytes matured in vitro  

Microsoft Academic Search

An experiment was designed to study the interaction between fresh\\/frozen-thawed donkey spermatozoa and zona pellucida (ZP)-free bovine oocytes in an attempt to develop a model for assessing cryopreserved Catalonian donkey sperm function. Semen from five donkeys was collected using an artificial vagina. Sperm motility and viability were immediately assessed and the semen sample cryopreserved. Sperm viability and motility were then

E. Taberner; R. Morató; T. Mogas; J. Miró

2010-01-01

71

Effect of IVF and laser zona dissection on DNA methylation pattern of mouse zygotes  

Microsoft Academic Search

In vitro fertilization (IVF) and zona pellucida laser microdissection-facilitated IVF (Laser-IVF) are presently routine procedures\\u000a in human assisted reproduction. The safety of these methods at the epigenetic level is not fully understood. Studies on mouse\\u000a Laser-IVF embryos provide evidence that the use of Laser-IVF leads to reduced birth rate, indicating a potential harm of this\\u000a technique for the embryo. Hence,

Dominika D. Peters; Konstantin Lepikhov; Karsten Rodenacker; Susan Marschall; Auke Boersma; Peter Hutzler; Hagen Scherb; Jörn Walter; Martin Hrabé de Angelis

2009-01-01

72

Body mass index is not associated with sperm-zona pellucida binding ability in subfertile males  

PubMed Central

Lifestyle factors, such as weight and nutritional status may affect male fertility, including sperm fertilization ability. The objective of this retrospective study was to evaluate the association between body mass index (BMI) and sperm–zona pellucida binding ability assessed according to the zona binding (ZB) test, which has been described to be a relevant diagnostic tool for the prediction of in vitro fertilization (IVF) ability. Three hundred and six male patients from couples diagnosed with primary idiopathic or mild male factor infertility were included. Correlations between BMI and semen parameters according to ZB test indices were assessed, together with frequencies of positive and negative tests across the BMI categories. In this selected population, BMI was not related to conventional semen parameters or sperm quality assessed according to the ability of spermatozoa to bind to the zona pellucida. The previously described poor outcomes of IVF procedures in cases of male obesity could be due to other sperm defects, such as alterations of sperm capacitation or acrosome reaction. The link between male BMI and biological outcomes during IVF procedures, such as fertilization rates, should be further evaluated.

Sermondade, Nathalie; Dupont, Charlotte; Faure, Celine; Boubaya, Marouane; Cedrin-Durnerin, Isabelle; Chavatte-Palmer, Pascale; Sifer, Christophe; Levy, Rachel

2013-01-01

73

Body mass index is not associated with sperm-zona pellucida binding ability in subfertile males.  

PubMed

Lifestyle factors, such as weight and nutritional status may affect male fertility, including sperm fertilization ability. The objective of this retrospective study was to evaluate the association between body mass index (BMI) and sperm-zona pellucida binding ability assessed according to the zona binding (ZB) test, which has been described to be a relevant diagnostic tool for the prediction of in vitro fertilization (IVF) ability. Three hundred and six male patients from couples diagnosed with primary idiopathic or mild male factor infertility were included. Correlations between BMI and semen parameters according to ZB test indices were assessed, together with frequencies of positive and negative tests across the BMI categories. In this selected population, BMI was not related to conventional semen parameters or sperm quality assessed according to the ability of spermatozoa to bind to the zona pellucida. The previously described poor outcomes of IVF procedures in cases of male obesity could be due to other sperm defects, such as alterations of sperm capacitation or acrosome reaction. The link between male BMI and biological outcomes during IVF procedures, such as fertilization rates, should be further evaluated. PMID:23770940

Sermondade, Nathalie; Dupont, Charlotte; Faure, Céline; Boubaya, Marouane; Cédrin-Durnerin, Isabelle; Chavatte-Palmer, Pascale; Sifer, Christophe; Lévy, Rachel

2013-09-01

74

Thermal effects in laser-assisted pre-embryo zona drilling  

NASA Astrophysics Data System (ADS)

Diode lasers ((lambda) equals 1480 nm) are used with in vitro fertilization to dissect the zone pellucida (shell) of pre- embryos. A focused laser beam is applied in vitro to form a channel or trench in the zona pellucida. The procedure is used to facilitate biopsy or as a promoter of embryo hatching. We present examples and measurements of zona pellucida ablation using animal models. In using the laser it is vital not to damage pre-embryo cells, e.g., by overheating. In order to define safe regimes we have derived some thermal side effects of zona pellucida removal. The temperature profile in the beam and vicinity is predicted as function of laser pulse duration and power. In a crossed- beam experiment a HeNe laser probe is used to detect the temperature-induced change in the refractive index of an aqueous solution, and estimate local thermal gradient. We find that the diode laser beam produces superheated water approaching 200 degree(s)C on the beam axis. Thermal histories during and following the laser pulse are given for regions in the neighborhood of the beam. We conclude that an optimum regime exists with pulse duration

Douglas-Hamilton, Diarmaid H.; Conia, Jerome D.

2001-04-01

75

Changes to the meiotic spindle and zona pellucida of mature mouse oocytes following different cryopreservation methods.  

PubMed

This study is to investigate the change of morphology of the meiotic spindle and the extent of zona hardening relating to the morphological survival and developmental competence of thawed oocytes. Four- to 8-week-old female mice (C57BL/6) primed with an intraperitoneal injection of pregnant mare's serum gonadotropin and human chorionic gonadotropin. Cryopreserved oocytes using two protocols: vitrificaton using ethylene glycol (EG) and slow freezing using propanediol (PROH). The freezing oocytes were thawed and were fertilized and subsequently cultured in vitro. Spindle/chromosome imagery, dissolution of zona pellucida, and post-thawing survival and development were comparable between two groups. The vitrification cryopreservation method proved to be better than the slow-freezing protocol when comparing the frequency of normal-shaped spindle development post-thawing. The difference in the time required for the dissolution of the zona pellucida under treatment of pronase that was determined to exist between the two cryopreservation methods was statistically significant (P<0.005). The survival rate of post-thawed mature oocytes was significantly greater for the vitrification group than it was for the slow-freezing cryopreservation group (P=0.005). The vitrification cryopreservation of mature murine oocytes would appear to be more satisfactory than the slow controlled-rate freezing method as regards the post-thawing oocyte survival and also the incidence of the normal spindle apparatus in the ooplasm. PMID:17434695

Ko, Chiu-Sung; Ding, Dah-Ching; Chu, Ta-Wei; Chu, Yung-Ning; Chen, I-Ching; Chen, Wei-Hwa; Wu, Gwo-Jang

2008-05-01

76

Zona pellucida modifications in the mouse in the absence of oocyte activation.  

PubMed

Mouse oocytes arrested in metaphase II exhibit zona hardening and a reduced fertilization rate after exposure to the cryoprotectant dimethylsulfoxide (Johnson J, In Vitro Fertil Embryo Transfer 6:168-175, 1989) but do not undergo parthenogenetic activation (Johnson and Pickering, Development 100:313-324, 1987). This paper shows that dimethylsulfoxide causes proteolytic modification of the zona pellucida glycoprotein ZP2 and inhibition of sperm binding. These effects of dimethylsulfoxide are caused by premature exocytosis of the cortical granules, a process that is initiated usually on fertilization. A model for the mechanism of action of dimethylsulfoxide is proposed based on the combined effects of cytoskeletal modification and osmotic shock. The presence of serum before and during the exposure to dimethylsulfoxide was found to reduce significantly these deleterious effects on the mouse zona pellucida without inhibiting the cortical granule release. These results highlight the suitability of dimethylsulfoxide as a tool to study the mechanisms leading to cortical granule release. Use of dimethylsulfoxide allows the separation of oocyte parthenogenetic activation from cortical granule release, and addition of serum allows separation of cortical granule release from the action of the cortical granule contents. Their use allows a dissection of the mechanisms underlying each of these three related events. PMID:2064782

Vincent, C; Turner, K; Pickering, S J; Johnson, M H

1991-04-01

77

Developmental competence of equine oocytes: impacts of zona pellucida birefringence and maternally derived transcript expression.  

PubMed

In the present study, equine oocytes were classified into groups of presumably high and low developmental competence according to cumulus morphology, as well as oocyte ability to metabolise brilliant cresyl blue (BCB) stain. All oocytes were evaluated individually in terms of morphometry, zona pellucida birefringence (ZPB) and relative abundance of selected candidate genes. Oocytes with an expanded cumulus (Ex), representing those with presumably high developmental competence, had a significantly thicker zona (18.2 vs 17.3µm) and a significantly higher ZPB (64.6 vs 62.1) than oocytes with a compacted cumulus (Cp). Concurrently, oocytes classified as highly developmentally competent (BCB+) had a significantly thicker zona (18.8 vs 16.1µm) and significantly higher ZPB (63.1 vs 61.3) compared with oocytes classified as having low developmental competence. Expression of TFAM, STAT3 and CKS2 was significantly higher in Ex compared with Cp oocytes, whereas expression of COX1, ATPV6E and DNMT1 was lower. Together, the data reveal that developmentally competent equine oocytes are larger in size, have higher ZPB values and exhibit a typical genetic signature of maternally derived transcripts compared with oocytes with lower in vitro developmental competence. PMID:23622680

Mohammadi-Sangcheshmeh, Abdollah; Held, Eva; Rings, Franca; Ghanem, Nasser; Salilew-Wondim, Dessie; Tesfaye, Dawit; Sieme, Harald; Schellander, Karl; Hoelker, Michael

2014-03-01

78

Induction of cultured bovine adrenocortical zona glomerulosa cell 17-hydroxylase activity by ACTH.  

PubMed

The induction of steroid 17-hydroxylase activity was examined in primary cultures of bovine adrenocortical zona glomerular cells. 17-Hydroxylase activity was determined by assaying the metabolism of [3H]pregnenolone to [3H]17-hydroxypregnenolone by high performance liquid chromatography (HPLC). Conversion of [3H]pregnenolone to [3H] progesterone and [3H]17-hydroxypregnenolone to [3H]17-hydroxyprogesterone was prevented by the addition of cyanoketone, an inhibitor of 3 beta-hydroxysteroid dehydrogenase. ACTH increased adrenal zona glomerulosa 17-hydroxylase activity 55-fold to 1750 pmoles/10(4) cells/2 h, an activity equivalent to that of ACTH-treated zona fasciculata cells. Maximal induction was seen after 4 days exposure to ACTH. The dose of ACTH which gave half-maximal induction was 0.25 nM. Previously, ACTH had been demonstrated to suppress bovine glomerulosa conversion of deoxycorticosterone to aldosterone by a steroid-induced oxygen-derived free radical process that was prevented by antioxidants. This process resulted in loss of the terminal cytochrome P-450 enzyme involved in aldosterone biosynthesis. However, induction of 17-hydroxylase activity is not affected by antioxidants or the addition of steroids, e.g. cortisol. ACTH-mediated induction of bovine zone glomerulosa 17-hydroxylase activity and suppression of glomerulosa aldosterone production results in effective conversion of functional glomerulosa cells to functional fasciculata cells. The actions of ACTH on glomerulosa 17-hydroxylase activity support the hypothesis of a steroid-induced functional zonation of the adrenal cortex. PMID:6301909

Crivello, J F; Gill, G N

1983-04-01

79

The zona pellucida of the koala (Phascolarctos cinereus): its morphogenesis and thickness  

PubMed Central

In this study the ultrastructural organization of the koala oocyte and the thickness of the surrounding extracellular coat, the zona pellucida, has been determined to ascertain whether there is coevolution of the morphology of the female gamete with that of the highly divergent male gamete that is found in this marsupial species. Ovaries from several adult koalas were obtained and prepared for transmission electron microscopy. Oocytes in large tertiary follicles were somewhat smaller than those of most other marsupials, although their ultrastructural organization appeared similar and included many yolk vesicles. The zona pellucida surrounding the oocytes in tertiary follicles was approximately 8 µm thick and thus is of similar thickness to that of some eutherian mammals but at least twice as thick as that of most marsupial species so far studied. The results indicate that the koala oocyte is unusually small for a marsupial species whereas the zona pellucida is, by contrast, much thicker. How this relates to sperm–egg interaction at the time of fertilization has yet to be determined.

Chapman, Jamie A; Leigh, Christopher M; Breed, William G

2006-01-01

80

Development of an optimized zona-free method of somatic cell nuclear transfer in the goat.  

PubMed

The purpose of this study was to develop an improved zona-free method of goat somatic cell nuclear transfer (SCNT) that has both ease of operation and efficiency. The main steps involved were: (1) optimization of in vitro oocyte maturation, (2) parthenogenetic activation of zona-free oocytes, (3) SCNT of zona-free anaphase II-telophase II (AII-TII) oocytes that subverted the need for long term UV-exposure of the oocytes, and (4) in vitro culture of groups of cloned embryos in wells in a highly efficient continuous serum-free embryo medium to the blastocyst stage before transfer to the recipients. Percentages of transgenic blastocyst production were 22.3 and 33.1% for adult and fetal cell lines, respectively. After transfer of cloned and transgenic blastocysts, 28.6 and 36.4% of the recipients were confirmed pregnant and 75 and 33.3% of the pregnancies resulted in the delivery of viable offspring, respectively. To our knowledge, this is the first report of successful live and survived birth of cloned and transgenic offspring through a whole procedure of in vitro oocyte maturation and embryo development to the blastocyst stage, and in this study the in vitro efficiencies of cloned and transgenic embryo production were higher than the available reports. PMID:21473692

Nasr-Esfahani, M H; Hosseini, S M; Hajian, M; Forouzanfar, M; Ostadhosseini, S; Abedi, P; Khazaie, Y; Dormiani, K; Ghaedi, K; Forozanfar, M; Gourabi, H; Shahverdi, A H; Vosough, A D; Vojgani, H

2011-04-01

81

Tracking diffusion of GM1 gangliosides and zona pellucida binding molecules in sperm plasma membranes following cholesterol efflux  

Microsoft Academic Search

The molecules on mammalian spermatozoa that mediate recognition and binding to the zona pellucida of the egg are still not understood. Current concepts favour their assembly into multimolecular complexes in the plasma membrane in response to cholesterol efflux, an important step during sperm capacitation. Here, we track in real time diffusion of cross-linked clusters containing zona-binding molecules and GM1 gangliosides

Roy Jones; Elizabeth Howes; Paul D. Dunne; Peter James; Andreas Bruckbauer; David Klenerman

2010-01-01

82

Evaluation of bovine zona pellucida characteristics in polarized light as a prognostic marker for embryonic developmental potential.  

PubMed

It has previously been demonstrated that zona pellucida imaging of human oocytes using polarized light microscopy is a clinically applicable method for the noninvasive assessment of oocyte quality. This study was designed to investigate whether zona pellucida characteristics of bovine oocytes and zygotes in polarized light may similarly serve as a useful marker for developmental competence in bovine reproductive biotechnologies. Zona birefringence intensity parameters of 2862 oocytes/zygotes were objectively evaluated with an automatic analysis system and correlated with oocyte/zygote quality. In detail, immature oocytes of good quality assessed with brilliant cresyl blue staining showed significantly lower zona birefringence than poor-quality counterparts (P<0.001). After in vitro maturation and classification according to maturational status, the birefringence intensity parameters were significantly different in those oocytes that reached metaphase II compared with arrested stages (P<0.001). Following either parthenogenetic activation or IVF with subsequent in vitro culture in a well-of-the-well system until day 9, superior development as determined by cleavage, blastocyst formation, and hatching ability was associated with lower zona birefringence intensity parameters. When early zygote-stage embryos were selected and assorted in groups based on zona birefringence (high/medium/low), the group of embryos derived from high-birefringence zygotes displayed a significantly compromised developmental potential compared with low-birefringence zygotes. These results clearly show that developmentally competent bovine oocytes/zygotes exhibit lower zona birefringence intensity parameters. Therefore, birefringence imaging of zona pellucida is a suitable technique to predict bovine preimplantation embryo development. PMID:21415090

Koester, M; Mohammadi-Sangcheshmeh, A; Montag, M; Rings, F; Schimming, T; Tesfaye, D; Schellander, K; Hoelker, M

2011-06-01

83

Composición y propiedades cerámicas de las pizarras de la Zona Centro Ibérica del Macizo Ibérico Meridional (Norte de Jaén, España)  

Microsoft Academic Search

Composition and ceramic properties of shales from the Central-Iberican Zone of Southern Iberian Massif (Northern Jaen, Spain) The suitability of shale materials from the Iberian Massif in the Jaén province (Spain) to make ceramic materials has been eva- luated. The main components of these shales are illite, kaolinite, quartz and feldspars, with lesser amounts of chlorite, pyro- phyllite, paragonite and

M. VÁZQUEZ; J. PARRAS

84

'ZP domain' of human zona pellucida glycoprotein-1 binds to human spermatozoa and induces acrosomal exocytosis  

PubMed Central

Background The human egg coat, zona pellucida (ZP), is composed of four glycoproteins designated as zona pellucida glycoprotein-1 (ZP1), -2 (ZP2), -3 (ZP3) and -4 (ZP4) respectively. The zona proteins possess the archetypal 'ZP domain', a signature domain comprised of approximately 260 amino acid (aa) residues. In the present manuscript, attempts have been made to delineate the functional significance of the 'ZP domain' module of human ZP1, corresponding to 273-551 aa fragment of human ZP1. Methods Baculovirus-expressed, nickel-nitrilotriacetic acid affinity chromatography purified 'ZP domain' of human ZP1 was employed to assess its capability to bind and subsequently induce acrosomal exocytosis in capacitated human spermatozoa using tetramethyl rhodamine isothiocyanate conjugated Pisum sativum Agglutinin in absence or presence of various pharmacological inhibitors. Binding characteristics of ZP1 'ZP domain' were assessed employing fluorescein isothiocyanate (FITC) labelled recombinant protein. Results SDS-PAGE and immunoblot characterization of the purified recombinant protein (both from cell lysate as well as culture supernatant) revealed a doublet ranging from ~35-40 kDa. FITC- labelled 'ZP domain' of ZP1 binds primarily to the acrosomal cap of the capacitated human spermatozoa. A dose dependent increase in acrosomal exocytosis was observed when capacitated sperm were incubated with recombinant 'ZP domain' of human ZP1. The acrosome reaction mediated by recombinant protein was independent of Gi protein-coupled receptor pathway, required extra cellular calcium and involved both T- and L-type voltage operated calcium channels. Conclusions Results described in the present study suggest that the 'ZP domain' module of human ZP1 has functional activity and may have a role during fertilization in humans.

2010-01-01

85

Effects of dehydroepiandrosterone on aldosterone release in rat zona glomerulosa cells  

Microsoft Academic Search

The present study was to investigate the effects and action mechanisms of dehydroepiandrosterone (DHEA) on steroidogenesis\\u000a in rat adrenal zona glomerulosa cells (ZG). ZG cells were incubated with DHEA in the presence or absence of angiotensin II\\u000a (AngII), a high concentration of potassium, 8-Br-cAMP, forskolin, 25-OH-cholesterol, pregnenolone, progesterone, deoxycorticosterone,\\u000a corticosterone, A23187, or cyclopiazonic acid (CPA) at 37°C for 1 h. The

Ling-Ling Chang; Wan-Song Alfred Wun; Paulus S. Wang

2008-01-01

86

Human sperm bind to the N-terminal domain of ZP2 in humanized zonae pellucidae in transgenic mice  

PubMed Central

Fertilization requires taxon-specific gamete recognition, and human sperm do not bind to zonae pellucidae (ZP1–3) surrounding mouse eggs. Using transgenesis to replace endogenous mouse proteins with human homologues, gain-of-function sperm-binding assays were established to evaluate human gamete recognition. Human sperm bound only to zonae pellucidae containing human ZP2, either alone or coexpressed with other human zona proteins. Binding to the humanized matrix was a dominant effect that resulted in human sperm penetration of the zona pellucida and accumulation in the perivitelline space, where they were unable to fuse with mouse eggs. Using recombinant peptides, the site of gamete recognition was located to a defined domain in the N terminus of ZP2. These results provide experimental evidence for the role of ZP2 in mediating sperm binding to the zona pellucida and support a model in which human sperm–egg recognition is dependent on an N-terminal domain of ZP2, which is degraded after fertilization to provide a definitive block to polyspermy.

Baibakov, Boris; Boggs, Nathan A.; Yauger, Belinda; Baibakov, Galina

2012-01-01

87

Laser assisted zona thinning technique has no beneficial effect on the ART outcomes of two different maternal age groups  

PubMed Central

Purpose Laser assisted zona thinning is a technique used for facilitating embryo’s hatching process and is commonly used for the embryos of poor prognosis patients with advanced maternal age, repeated implantation failures, poor embryo quality or thick zona pellucida. The aim of this study was to investigate the effect of zona thinning on both good or poor prognosis patients of two different age groups. Methods We investigated two different age groups (group 1: <35 years and group 2: ?35 years ) and compared the effect of assisted zona thinning (groups 1A and 2A) versus not-thinned controls (groups 1B and 2B) in both groups. Results The clinical pregnancy rates were 57% and 56% in groups 1A and 1B (p?=?0.86), 43% and 38% in groups 2A and 2B (p?=?0.59) respectively. Conclusions Our results suggest that laser assisted zona thinning of day 3 embryos has no beneficial effect on clinical pregnancy and implantation outcomes.

Atvar, Ozhan; Vanlioglu, Omer Faruk

2010-01-01

88

Contraceptive vaccines based on the zona pellucida glycoproteins for dogs and other wildlife population management.  

PubMed

Zona pellucida (ZP) glycoproteins, by virtue of their critical role in fertilization, have been proposed as candidate antigens for the development of contraceptive vaccines. In this review, the potential of a ZP-based contraceptive vaccine for the management of wildlife population, with special reference to street dogs, is discussed. Immunization of various animal species, including female dogs, with native porcine ZP led to inhibition of fertility, which was associated with the ovarian dysfunction. Immunization of female dogs with Escherichia coli-expressed recombinant dog ZP glycoprotein-3 (ZP3) either coupled to diphtheria toxoid or expressed as fusion protein with 'promiscuous' T non-B-cell epitope of tetanus toxoid also led to inhibition of fertility. To improve the contraceptive efficacy of ZP-based contraceptive vaccine, various groups are working on improving the immunogen, use of DNA vaccine as prime-boost strategy, and delivering the zona proteins/peptides presented on either virus-like particles or entrapped in microsphere. Host-specific live vectors such as ectromelia virus and cytomegalovirus have also been used to deliver mouse ZP3 in mice. Various studies show the enormous potential of the ZP-based vaccine for the management of wildlife population, where permanent sterilization may be desirable. PMID:21501280

Gupta, Satish K; Srinivasan, Villuppanoor A; Suman, Pankaj; Rajan, Sriraman; Nagendrakumar, Singanallur B; Gupta, Neha; Shrestha, Abhinav; Joshi, Pooja; Panda, Amulya K

2011-07-01

89

Ovastacin, a cortical granule protease, cleaves ZP2 in the zona pellucida to prevent polyspermy  

PubMed Central

The mouse zona pellucida is composed of three glycoproteins (ZP1, ZP2, and ZP3), of which ZP2 is proteolytically cleaved after gamete fusion to prevent polyspermy. This cleavage is associated with exocytosis of cortical granules that are peripherally located subcellular organelles unique to ovulated eggs. Based on the cleavage site of ZP2, ovastacin was selected as a candidate protease. Encoded by the single-copy Astl gene, ovastacin is an oocyte-specific member of the astacin family of metalloendoproteases. Using specific antiserum, ovastacin was detected in cortical granules before, but not after, fertilization. Recombinant ovastacin cleaved ZP2 in native zonae pellucidae, documenting that ZP2 was a direct substrate of this metalloendoprotease. Female mice lacking ovastacin did not cleave ZP2 after fertilization, and mouse sperm bound as well to Astl-null two-cell embryos as they did to normal eggs. Ovastacin is a pioneer component of mouse cortical granules and plays a definitive role in the postfertilization block to sperm binding that ensures monospermic fertilization and successful development.

Burkart, Anna D.; Xiong, Bo; Baibakov, Boris; Jimenez-Movilla, Maria

2012-01-01

90

Análisis descriptivo del tamaño relativo del gasto del gobierno chileno  

Microsoft Academic Search

En este trabajo se examina el tamaño relativo del Gobierno chileno a través de una comparación internacional con valores equivalentes de otros países. Adicionalmente hay un análisis similar para dos componentes importantes del gasto público: educación y salud. El gasto del Gobierno de Chile, valor en torno del 20% (PIB), está junto al tercio inferior de países que poseen un

Eduardo Engel; Patricio Meller; Claudio Bravo

1998-01-01

91

Role of acidification elicited by sialylation and sulfation of zona glycoproteins during oocyte maturation in porcine sperm-zona pellucida interactions.  

PubMed

The porcine zona pellucida (ZP) undergoes biochemical changes during the final phase of maturation prior to fertilization. The present study was conducted to elucidate whether the acidification of ZP glycoproteins during porcine oocyte maturation influences sperm-ZP interactions. Two-dimensional gel electrophoresis clearly demonstrated that ZP acidification occurred in accordance with the sialylation and sulfation of ZP glycoproteins in oocytes matured for 44 h. The increases in the incidences of sperm penetration and polyspermy with the progress of the IVM culture period were significantly suppressed by ZP desialylation on treatment with neuraminidase as a consequence of reductions in the number of sperm bound to ZPs and the acrosome reaction (AR) in ZP-bound sperm (P<0.05). In contrast, the blocking of ZP sulfation by NaClO(3) treatment during IVM markedly reduced the incidence of polyspermy with no inhibitory effect on penetration, but the number of sperm bound to ZPs and the rate of AR-inducing sperm were decreased to the same level as in desialylated oocytes. The results indicate that ZP sulfation influences sperm-ZP interactions in a ZP sialylation-independent manner. Moreover, sialylation and sulfation were not associated with a protective proteolytic modification of the ZP matrix before fertilization. These findings suggest that ZP acidification elicited by the sialylation and sulfation of ZP glycoproteins during oocyte maturation contributes to the porcine ZP acquiring the capacity to accept sperm. PMID:21897057

Lay, Khin Mar; Oshiro, Ryuko; Arasaki, Chiemi; Ashizawa, Koji; Tatemoto, Hideki

2011-12-01

92

Effects of fetuin on zona pellucida hardening, fertilization and embryo development in cattle.  

PubMed

Mammalian oocytes can undergo spontaneous meiotic maturation when they are liberated from their follicles and cultured in vitro; however, the zona pellucida (ZP) becomes resistant to chymotrypsin digestion, or hardens, when spontaneous maturation occurs in serum-free medium. Schroeder et al. [Biol. Reprod. 43 (1990) 891] described that fetuin, a component of fetal calf serum (FCS), inhibits ZP hardening during oocyte maturation. The aim of this experiment was to study the effect of the presence of cumulus cells and addition of hormones to maturation media on bovine zona hardening and embryo development in medium with and without fetuin. In Experiment I, different concentrations of fetuin were added to the maturation medium. The time necessary for digestion of 50% of the ZP (d50) was not different when oocytes were matured in presence of 10% FCS, 1mg/ml polyvinyl alcohol (PVA), or 4, 1 and 0.25mg/ml of fetuin; cleavage rates were also similar. However, significantly more blastocysts (P<0.05) were formed when FCS was used compared to PVA and 0.25mg/ml of fetuin. In Experiment II, we examined the influence of the presence of cumulus cells and hormones during the maturation of oocytes in media with PVA, BSA, FCS and fetuin. The d50 was significantly higher (P<0.05) when oocytes were matured in presence of cumulus cells. The cleavage rate of cumulus-intact oocytes was similar for all groups. However, when oocytes were partially stripped before maturation, the cleavage rate was significantly higher (P<0.05) when FCS or fetuin was used. In both stripped and non-stripped groups, significantly more blastocysts (P<0.05) were formed when oocytes were matured with FCS compared to BSA and PVA. These results indicate that zona hardening, as described for mouse and human oocytes, does not have a large effect on bovine cumulus-intact oocytes. Apparently fetuin can be used as a substitute for FCS during bovine oocyte maturation, since it leads to similar developmental rates as FCS in intact and partially stripped oocytes. PMID:12047927

Landim-Alvarenga, F C; Boyazoglu, S E A; Carvalho, L R; Choi, Y H; Squires, E L; Seidel, G E

2002-06-17

93

Specific activation requirements of zona-free sheep oocytes before and after somatic cell nuclear transfer.  

PubMed

In this study, the effect of the steps involved in zona-free somatic cell nuclear transfer (SCNT) on oocyte transcripts was investigated in sheep. To establish the reliable combined electrical-chemical activation for zona-free oocytes, oocytes were first exposed to an electrical pulse and then treated with 18 chemical activation regimens designed through modifying duration and concentration of ionomycin and 6-dimethyl aminopurine (6-DMAP), which is routinely used for SCNT. Electrofusion-mediated nuclear transfer significantly reduced transcript abundances of CCNB1, POU5F1, NPM2, GMMN, and CX43 compared to intact oocytes. Maximum parthenogenetic blastocyst development was obtained when oocytes were submitted to electric pulse and then to (1) 5??M ionomycin for 5 or 2.5?min, both followed by 2?h of incubation with 6-DMAP (41.7±1.1, and 42.4±1.4%, respectively), (2) 5??M ionomycin for 1?min+6-DMAP for 4?h (43.1±1.4%), and (3) 2.5??M ionomycin for 1?min+6-DMAP for 2?h (42.4±1.4%), with significant differences compared to all the other groups. Statistical assessment of interactions between duration and concentration of ionomycin and duration of 6-DMAP exposure revealed that (1) concentration of ionomycin may be a more important factor than its duration, (2) both a long exposure period and a low concentration of ionomycin had marked decreasing effects on parthenogenetic development of zona-free oocytes, and (3) high duration of exposure to 6-DMAP can reduce parthenogenetic development. Despite an activation preference of parthenogenetic oocytes, a significantly higher rate of cloned blastocyst development was observed when reconstructed oocytes were activated with 5??M ionomycin for 5?min rather than 2.5??M ionomycin for 1?min (8.8±2.5 vs. 1.25±2.2%). These results suggested that SCNT steps have determining effects on oocyte transcripts and activation preferences of the reconstituted oocytes compared to intact counterparts. In this sense, reconstituted oocytes may need a higher concentration of ionomycin for a longer period than intact oocytes. PMID:23713434

Hajian, M; Kiani, M; Hosseini, M S; Ostadhosseini, S; Forouzanfar, M; Afrough, M; Nasr-Esfahani, M H

2013-06-01

94

Tracking down the ZP domain: From the mammalian zona pellucida to the molluscan vitelline envelope.  

PubMed

Oocytes from virtually all organisms are surrounded by at least one coat. This specialized extracellular matrix, called the zona pellucida (ZP) in mammals and the vitelline envelope (VE) in nonmammals, has a structural function and plays essential roles in oogenesis, fertilization, and early development. During the last 15 years, compelling evidence has accumulated that all ZP/VE subunits polymerize using a conserved sequence, the ZP domain, so that the basic structural features of egg coat matrices have been maintained through evolution. Moreover, ZP domains have been identified in many other polymeric extracellular proteins from eukaryotes. This review compares the ultrastructure and molecular composition of egg coats from mollusc to human, suggests a common mechanism for assembly of ZP/VE proteins, and discusses alternative models of how these could be arranged within filaments. PMID:16944418

Monné, Magnus; Han, Ling; Jovine, Luca

2006-09-01

95

Microestructura y propiedades mecánicas de conductores protónicos de alta temperatura crecidos por fusión de zona flotante  

Microsoft Academic Search

Se han estudiado conductores protónicos de alta temperatura (CPAT) fabricados por fusión de zona flotante asistida por láser (SrCe 0.9Y0.1O3-?, SrCe0.8Y0.2O3-?, SrZr0.9Y0.1O3-?, SrZr0.8Y0.2O3-?, Sr3(Ca1.18Nb1.82)O9-? y SrTi0.95Sc0.05O3-?). La caracterización microestructural se ha realizado mediante Microscopía Electrónica de Barrido y Transmisión (MEB, MET). Los materiales tienen una estructura celular, con células de anchuras entre 10-50 µm y regiones intercelulares superiores a 1

M. J. López RobLedo; A. SA

96

Specific antibodies to porcine zona pellucida detected by quantitative radioimmunoassay in both fertile and infertile women  

SciTech Connect

The specific radioimmunoassay system was developed for the titration of the antibodies to porcine zona pellucida (ZP) in human sera by using /sup 125/I-labeled purified porcine ZP as antigen, which is known to have cross-reactivity with human ZP. The antibodies in human sera were detected in 3 of 11 (27%) women with unexplained infertility, in 16 of 48 (33%) amenorrheic patients, in 4 of 12 (33%) fertile women, and in 3 of 10 (30%) men. Moreover, antibody titers in infertile women were no higher than those in fertile women and in men. These results seem to suggest that the antibodies in human sera that cross-react with porcine ZP may not be an important factor in causing infertility in women.

Kurachi, H.; Wakimoto, H.; Sakumoto, T.; Aono, T.; Kurachi, K.

1984-02-01

97

Sperm penetration to the zona pellucida of an oocyte: a computational model incorporating acrosome reaction.  

PubMed

For fertilisation to occur, a spermatozoon needs to cross the zona pellucida (ZP), which is a glycoprotein layer surrounding the oocyte. Crossing the ZP requires an acrosome reaction (AR) where enzymes released from the spermatozoon head locally digest and soften the ZP so that the spermatozoon can penetrate deeper. Here, a biomechanical sperm-oocyte interaction model that considers the AR using the finite element method was formulated. This modelling is used to determine which of the following factors directly contribute to the crossing of the ZP: local ZP softening by AR, sperm head shape, ZP hardening elsewhere than in the AR site, ZP thickness and sperm hyperactivation (more flagellar beating). It has been found that an AR softening the ZP to over one-tenth of its basal stiffness is important for successful sperm penetration, and that 'sharper' heads have a biomechanical advantage in penetrating deeper. The approach is promising for understanding this exciting stage of reproduction. PMID:23477851

Kozlovsky, Pavel; Gefen, Amit

2013-10-01

98

Effects of fetuin on zona pellucida hardening and fertilizability of equine oocytes matured in vitro.  

PubMed

In vitro fertilization (IVF) has had poor success in the horse, a situation related to low rates of sperm penetration through the zona pellucida (ZP). Zona pellucida hardening (ZPH) is seen in mouse and rat oocytes cultured in serum-free medium. The hardened ZP is refractory to sperm penetration. Fetuin, a component of fetal calf serum, inhibits ZPH and allows normal fertilization rates in oocytes cultured in the absence of serum. We evaluated whether fetuin is present in horse serum and follicular fluid (FF) and whether fetuin could inhibit ZPH in equine oocytes matured in vitro, thus increasing sperm penetration during IVF. The presence of fetuin in equine serum and FF was confirmed by immunoblotting. Oocytes submitted to in vitro maturation (IVM) in medium containing fetuin were used for ZPH assay or IVF. Intracytoplasmic sperm injection (ICSI) was carried out as a control procedure. The presence of fetuin during IVM did not affect the rate of maturation to metaphase II. Maturation of oocytes in the presence of fetuin reduced ZPH in a dose-dependent manner. After both IVF and ICSI, there was no significant difference in oocyte fertilization between fetuin-treated and untreated oocytes. The fertilization rate was significantly higher after ICSI than after IVF, both in fetuin-treated and in untreated oocytes. In conclusion, fetuin reduced ZPH in equine oocytes but did not improve sperm penetration during IVF. This implies that, in the horse, "spontaneous" ZPH is unlikely to be the major factor responsible for inhibiting sperm penetration in vitro. PMID:10411537

Dell'Aquila, M E; De Felici, M; Massari, S; Maritato, F; Minoia, P

1999-08-01

99

Zona pellucida solubility and cortical granule complements in human oocytes following assisted reproductive techniques.  

PubMed

In this study the solubility to alpha-chymotrypsin of the zona pellucida (ZP) of human oocytes and polyploid embryos obtained during various clinical procedures of assisted fertilisation (IVF, ICSI, cyropreservation) was evaluated. The aim of the study was to determine whether changes in ZP solubility occur during such procedures and whether abnormal solubility could be likened to fertilisation failure. Correlation between ZP solubility and cortical granule (CG) density was also studied. The results showed that ZP solubility varied considerably among germinal vesicle or metaphase oocytes obtained from different subjects, but was essentially identical for the oocyte cohort obtained from individual women. On the basis of ZP solubility metaphase oocytes were subdivided into two classes: class I, average ZP dissolution time +/- SE = 24.1+/-0.9 min, n = 28; and class II, 46.7+/-2.0 min, n = 13. Prolonged ZP dissolution times of metaphase oocytes were significantly correlated with a low in vitro fertilisation rate in sibling oocytes. The zonae of fertilised eggs (polyploid embryos) showed long solubilisation times (IVF: 45.3+/-3.4 min, n = 18; ICSI: 48.9+/-2.7 min, n = 19). ZP solubility of oocytes that failed to fertilise was intermediate between that of class I metaphase oocytes and embryos (unfertilised IVF: 33.0+/-2.7 min, n = 13; unfertilised ICSI: 43.0+/-2.4 min, n = 9). A moderate spontaneous ZP hardening occurred when metaphase oocytes were cultured for 24 h. Finally, cryopreservation of unfertilised oocytes caused hardening of their ZP, with dissolution times that were comparable to those found in fertilised eggs (49.5+/-2.3 min, n = 10). In most cases, an inverse correlation was found between ZP dissolution time and CG density (longer solubilisation times corresponding to lower CG density). ZP hardening caused by cryopreservation, however, was not associated with a significant reduction in CG density in most of the oocytes examined. PMID:11508739

Manna, C; Rienzi, L; Greco, E; Sbracia, M; Rahman, A; Poverini, R; Siracusa, G; De Felici, M

2001-08-01

100

Phosphorus in agroforestry systems : a contribution to sustainable agriculture in the Zona da Mata of Minas Gerais, Brazil  

Microsoft Academic Search

The Zona da Mata is a region situated in the domain of the Atlantic Coastal Rainforest in the southeast of the state of Minas Gerais, Brazil. This domain stretches along the Brazilian coast from north to south and ranks among the top five of the 25 biodiversity hotspots, the richest and the most threatened reservoirs of plant and animal life

I. M. Cardoso

2002-01-01

101

A family of genes encoding zona pellucida (ZP) domain proteins is expressed in various epithelial tissues during Drosophila embryogenesis  

Microsoft Academic Search

Zona pellucida (ZP) domain proteins have been identified in various species from worms to humans. Most of the characterized ZP family members are secreted or remain anchored to the plasma membrane where they play a structural role and\\/or act as receptors. In humans, several ZP proteins attracted attention because of their abundant expression in certain organs and their relation to

Anna Ja?wi?ska; Markus Affolter

2004-01-01

102

Effects of White Blood Cells on the In Vitro Penetration of Zona-free Hamster Eggs by Human Spermatozoa  

Microsoft Academic Search

The presence of white blood cells in semen has been associated with male infertility. Previous studies indi- cate that pyospermia occurs in conjunction with de- creases in sperm motility, number of normal sperm forms, and penetration rates in the zona-free hamster egg sperm penetration assay. We have evaluated the relationship of seminal white blood cells and sperm function, as reflected

DONALD K. MARUYAMA; RALPH W. HALE; B. JANE ROGERS

103

Adherence of bovine viral diarrhea virus to bovine oocytes and embryos with a hardened zona pellucida cultured in vitro.  

PubMed

The purpose of this study was to investigate the adherence of bovine viral diarrhea virus (BVDV) to bovine mature, or immature, cumulus-free oocytes and to in vitro fertilized embryos, maintained in vitro in a ligated bovine oviduct to allow for the hardening of the zona pellucida. Incubation of the oocytes and embryos in the oviduct for 5 h caused hardening of the zona pellucida as measured by resistance to pronase digestion (which increased from approximately 3 min to 7 h; P > 0.001). However, there was no difference between the number of infected oocytes and embryos (n = 965 in 193 samples) following experimental exposure to BVDV regardless of whether or not they were previously incubated in the oviduct (P > 0.05). It was concluded that the modification of the proteolytic resistance properties of the zona pellucida during in vitro oviductal incubation did not influence the adherence of BVDV to zona pellucida of oocytes or in vitro fertilized embryos. PMID:12528828

Bielanski, A; Lutze-Wallace, Cheryl L; Nadin-Davis, S

2003-01-01

104

Release of tissue-type plasminogen activator by activated rat eggs and its possible role in the zona reaction.  

PubMed

The resumption of meiosis results in synthesis of tissue-type plasminogen activator (tPA) in the rat and mouse oocytes (Haurte et al., Cell 43:551-558, 1985). The present study demonstrates that freshly ovulated rat oocytes released their tPA into the surrounding medium upon in vitro activation by sperm penetration or treatment with a calcium ionophore. The presence of a neutralizing monoclonal anti-tPA antibody during in vitro activation by the calcium ionophore inhibited the activation-induced zona hardening and also preserved the ability of the oocyte to be penetrated by sperm subsequent to activation. Rat oocytes undergo zona hardening during in vitro maturation in the absence of serum, presumably as a result of spontaneous cortical granule release, based on findings in mice and hamsters. In the present study, the anti-tPA antibody prevented the zona hardening and enhanced partition by spermatozoa of rat oocytes that were matured in vitro without serum. Collectively, the observations reported have suggest a possible role of tPA released during the cortical granule reaction in the zona reaction, which contributes to the block to polyspermy. PMID:1515147

Zhang, X; Rutledge, J; Khamsi, F; Armstrong, D T

1992-05-01

105

A prospective randomized study to assess the benefit of partial zona pellucida digestion before frozen-thawed embryo transfers  

Microsoft Academic Search

BACKGROUND: Assisted hatching (AH) in fresh embryo transfer (ET) could be associated with increased implanta- tion rates. However, very few prospective randomized studies have specifically addressed the issue of AH during frozen- thawed embryo transfers (FET) cycles, those that have reported controversial results. The aim of this study was to evaluate the benefit of an enzymatic zona pellucida treatment of

C. Sifer; A. Sellami; C. Poncelet; P. Kulski; B. Martin-Pont; J. Bottero; R. Porcher; I. Cedrin-Durnerin; J. N. Hugues; J. P. Wolf

2006-01-01

106

Cryopreservation of oocytes and embryos: use of a mouse model to investigate effects upon zona hardness and formulate treatment strategies in an in-vitro fertilization programme.  

PubMed

Mouse oocytes and embryos were obtained following ovulation induction of (C57B16 x CBA) F1 animals. Zonae pellucidae were exposed to alpha-chymotrypsin in phosphate-buffered medium (PB1) supplemented with 3 mg/ml bovine serum albumin upon a heated stage (37 degrees C) and were observed constantly through an inverted microscope. The endpoint of the bioassay was the limits of the zona no longer being seen clearly at x 200 magnification, and the time taken for each zona to dissolve was recorded. A dose-dependent response in dissolution time was clearly seen, with 1% alpha-chymotrypsin being chosen as the routine working solution. Cryopreservation of 2-cell mouse embryos using propanediol did not cause zona hardening but induced a small and significant softening, as gauged by the time taken for zona dissolution (2181 +/- 167 versus 1864 +/- 82 s). Zona hardening was not suspected to occur after the freezing of human embryos as there was no difference in implantation rates per embryo for in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment cycles between fresh [IVF: 63/644 (9.7%); ICSI: 51/330 (15.5%)] and frozen embryos [IVF: 36/458 (7.9%); ICSI: 18/112 (16.1%)]. Conversely, significant hardening of the zonae of mature oocytes was seen following cryopreservation (747 +/- 393 s) compared with freshly ovulated oocytes (151 +/- 68 s). It is concluded that (i) the freezing of murine oocytes with propanediol results in zona hardening, implying a possible benefit of ICSI after the cryopreservation of human oocytes, and (ii) the cryopreservation of embryos is not associated with zona hardening or reduced implantation, making microdissection of the zona in such cases generally unwarranted. PMID:9262294

Matson, P L; Graefling, J; Junk, S M; Yovich, J L; Edirisinghe, W R

1997-07-01

107

Descripción de la zona de alta difusión en un modelo bidimensional para hojas de corriente  

NASA Astrophysics Data System (ADS)

Los modelos bidimensionales para describir hojas de corriente de alta simetría no suministran una descripción detallada de las regiones donde la difusión es considerablemente importante. Tal es el caso de los modelos desarrollados en la década del '60 por Sweet, Parker, Petschek y Sonnerup. En esta comunicación presentamos una solución de las ecuaciones MHD en el entorno del origen, construyendo series bidimensionales para todas las magnitudes físicas involucradas. Valiéndonos de la alta simetría y de las características del problema, logramos reducir el número de coeficientes a calcular. Utilizamos un programa autoconsistente para extender el cálculo a regiones vecinas con difusión moderada o despreciable.

Montero, M. F.; Paola, C. A.; Platzeck, A. M.

108

Atlas del Genoma del Cáncer  

Cancer.gov

Es posible que haya más de 200 tipos diferentes de cáncer y muchos subtipos más, cada uno de estos causado por errores en el ADN que desencadenan el crecimiento descontrolado de las células. La identificación de los cambios en el conjunto completo de ADN de cada tipo de cáncer, su genoma, y el entendimiento de cómo interactúan dichos cambios para impulsar el proceso de la enfermedad sentarán las bases de una era individualizada de tratamiento del cáncer.

109

Instantánea del cáncer infantil  

Cancer.gov

Información sobre la incidencia y mortalidad del cáncer en los niños, tendencias en el financiamiento del NCI para la investigación del cáncer infantil; así como ejemplos de actividades y adelantos en la investigación relevantes para esta población.

110

Improved fertilization and implantation rates after non-touch zona pellucida microdrilling of mouse oocytes with a 1.48 microm diode laser beam.  

PubMed

The safety of microdrilling the zona pellucida of mouse oocytes with a 1.48 microm diode laser has been investigated by determining the ability of mouse oocytes to fertilize in vitro and develop in vivo. Mice born after transfer of control and zona pellucida-microdrilled embryos into foster mothers were submitted to anatomical and immunohistochemical investigations, and their aptitude to breed was assessed in two subsequent generations. Decoronization of the oocytes with hyaluronidase induced a reduction of the fertilization and implantation rates, which was attributed to a zona hardening phenomenon. After laser zona pellucida microdrilling, these rates were restored to those obtained with embryos derived from untreated oocyte-cumulus complexes. Pups derived from zona pellucida microdrilled embryos were comparable with those obtained from control embryos, confirming the lack of deleterious effects of the laser treatment. In conclusion, the 1.48 microm diode laser allows safe microdrilling of the zona pellucida of mouse oocytes after decoronization with hyaluronidase. Based on the health of the F2 generation and the lack of neuroanatomical and neurochemical differences, we concluded that this technology may be investigated in the human, particularly when the zona pellucida represents the main impediment for fertilization or embryo hatching. PMID:8671388

Germond, M; Nocera, D; Senn, A; Rink, K; Delacretaz, G; Pedrazzini, T; Hornung, J P

1996-05-01

111

Association between embryonic loss and damage to the zona pellucida by invasive micromanipulation during oviductal transfer of early-stage embryos in pigs.  

PubMed

The aim of this study was to examine the impact of zona pellucida damage, which might arise during somatic cell nuclear transfer (SCNT), on the development and survival of transferred embryos. The zonae pellucidae of in vitro matured oocytes were either punctured with 8- to 10-microm square-ended nuclear injection pipettes and piezo pulses or slit with 35- to 40-microm enucleation pipettes. Intact oocytes were used as controls. These oocytes were electroactivated to induce parthenogenesis and transferred to the oviducts of estrus-synchronized recipient gilts. After 5 to 7 days, the recipient uteri were flushed to collect embryos, and embryonic development (morula-blastocyst stage embryos/collected embryos) and survival (viable embryos/collected embryos) were determined. In total, 221 zona-punctured, 129 zona-slitted and 57 intact embryos were transplanted into four, two and two gilts, respectively. The efficiency of embryo recovery was similar in all groups (64.3 to 79.1%). However, the zona-penetrated and incised embryos exhibited unstable development and survival compared with the controls; development and survival of the control embryos were 94.7 and 87.7%, whereas those of the zona-punctured embryos were 69.0 and 47.9% (P<0.01) and those of the zona-slit embryos were 64.7 and 50.0% (P<0.01). Cells with large foci that appeared to be macrophage giant cells were observed at the surface or inside the degenerated zona-damaged embryos. These results indicate that the recipient's immune response to damage to the zona pellucida may impair embryonic development after transplantation to the oviduct. This may be one of the factors causing the reduced efficiency of live progeny production by SCNT. PMID:17598954

Ueno, Satoshi; Kurome, Mayuko; Tomii, Ryo; Hiruma, Katsumi; Saitoh, Hitoshi; Nagashima, Hiroshi

2007-10-01

112

Fetuin inhibits zona pellucida hardening and conversion of ZP2 to ZP2f during spontaneous mouse oocyte maturation in vitro in the absence of serum.  

PubMed

The zona pellucida of mouse oocytes becomes resistant to chymotrypsin digestion, or "hardened", when spontaneous maturation occurs in serum-free medium (De Felici and Siracusa, Gam Res 1982; 6:107). The hardened zona pellucida is refractory to sperm penetration, thus preventing fertilization. Conversion of the zona pellucida glycoprotein ZP2 to ZP2f by a protease from precociously released oocyte cortical granules appears to be a major contributory factor of zona pellucida hardening (Ducibella et al., Dev Biol 1990; 137:46). Fetal bovine serum (FBS) prevents zona hardening and the ZP2 to ZP2f conversion during oocyte maturation in vitro (Downs et al., Gam Res 1986; 15:115; Ducibella et al., Dev Biol 1990; 137:46). This study was conducted to determine whether fetuin, a major glycoprotein constituent of FBS and a protease inhibitor, could prevent zona pellucida hardening during murine oocyte maturation in serum-free medium. Commercially available preparations of fetuin purified by three different methods were all active in inhibiting zona pellucida hardening in a concentration-dependent manner. Further chromatographic purification of one of these preparations indicated that the activity preventing zona pellucida hardening was associated specifically with fetuin. Fetuin also inhibited the conversion of ZP2 to ZP2f in a concentration-dependent manner during oocyte maturation in serum-free medium. Moreover, oocytes that matured in serum-free medium containing fetuin could be fertilized and could undergo preimplantation development to the blastocyst stage. These results indicate that fetuin, a component of FBS, inhibits zona pellucida hardening during oocyte maturation, and suggest that fetuin acts by preventing the proteolytic conversion of ZP2 to ZP2f by precociously released cortical granules. PMID:1705446

Schroeder, A C; Schultz, R M; Kopf, G S; Taylor, F R; Becker, R B; Eppig, J J

1990-11-01

113

Role of intra-acrosomal antigenic molecules acrin 1 (MN7) and acrin 2 (MC41) in penetration of the zona pellucida in fertilization in mice.  

PubMed

In this study the role of two intra-acrosomal molecules, acrin 1 (MN7) and acrin 2 (MC41), during in vitro fertilization (IVF) was examined. The pertinent monoclonal antibodies mMN7 and mMC41 specifically recognize a 90 kDa protein (acrin 1) localized to the entire acrosome and a 200 kDa protein (acrin 2) localized to the cortex region of the anterior acrosome, respectively. Experiments were designed to assess the effects of mMN7 and mMC41 on fertilization in mice using TYH medium containing mMN7 or mMC41 at 0.0, 0.025, 0.05 and 0.1 mg ml-1. Under these conditions, capacitated spermatozoa inseminated the cumulus-invested oocytes. Acrosome-reacted spermatozoa inseminated the zona pellucida-free oocytes. The antibodies had no effect on sperm motility and primary binding to the zona pellucida, but significantly inhibited the rate of fertilization of zona pellucida-intact oocytes in a dose-dependent manner. A significantly small number of spermatozoa remained attached to the zona pellucida at 5 h after insemination in the presence of mMC41. mMC41 and mMN7 antibodies did not affect the fertilization rate of zona pellucida-free oocytes. Confocal laser scanning microscopy with indirect immunofluorescence traced the effect of the monoclonal antibodies on the zona pellucida-induced acrosome reaction, and revealed that mMN7 prevented completion of acrosomal matrix dispersal, whereas mMC41 did not affect the acrosome reaction. mMC41 appeared to inhibit secondary binding or some biochemical steps on the zona pellucida after the acrosome reaction but before penetration of the zona pellucida. Thus, the intra-acrosomal antigenic molecules acrin 1 and acrin 2 are essential for distinct events before sperm penetration of the zona pellucida in mice. PMID:10645241

Saxena, D K; Tanii, I; Yoshinaga, K; Toshimori, K

1999-09-01

114

Some certainty for the "zone of uncertainty"? Exploring the function of the zona incerta.  

PubMed

The zona incerta (ZI), first described over a century ago by Auguste Forel as a "region of which nothing certain can be said," forms a collection of cells that derives from the diencephalon. To this day, we are still not certain of the precise function of this "zone of uncertainty" although many have been proposed, from controlling visceral activity to shifting attention and from influencing arousal to maintaining posture and locomotion. In this review, I shall outline the recent advances in the understanding of the structure, connectivity and functions of the ZI. I will then focus on a possible and often neglected global role for the ZI, one that links its diverse functions together. In particular, I aim to highlight the idea that the ZI forms a primal center of the diencephalon for generating direct responses (visceral, arousal, attention and/or posture-locomotion) to a given sensory (somatic and/or visceral) stimulus. With this global role in mind, I will then address recent results indicating that abnormal ZI activity manifests in clinical symptoms of Parkinson disease. PMID:15561420

Mitrofanis, J

2005-01-01

115

A hybrid characterization framework to determine the visco-hyperelastic properties of a porcine zona pellucida.  

PubMed

The zona pellucida (ZP) is a specialized extracellular matrix surrounding the developing oocyte. This thick matrix consists of various types of glycoprotein that play different roles in the fertilization process. Nowadays, several techniques are available for assessing ZP's mechanical response. The basic assumption behind these methods is that the ZP behaves like an elastic body: hence, dissipative forces are neglected and Young's modulus remains unaffected by probe dynamics. However, dissipative forces are strongly regulated by the slippage of ZP chains past one another while reaction forces related to elastic deformations (driven by the ability of each chain to stretch) depend on the ZP structure (i.e. number of cross-links and distances between knots). Although viscous reaction forces generated by the ZP are one of the main factors regulating sperm transit, their peculiar behaviour along the ZP structure remains poorly understood and rarely investigated. In order to overcome this limitation, a novel visco-hyperelastic model describing the porcine ZP reaction forces generated by nanoindentations at different probe rates is developed and verified in this study. Visco-hyperelastic parameters of porcine ZP membranes are determined by means of a hybrid characterization framework combining atomic force microscopy nanoindentation measurements, nonlinear finite-element analysis and nonlinear optimization. Remarkably, it is possible to separate the contributions of hyperelastic and viscous terms to ZP mechanical response and evaluate the error made in the determination of ZP mechanical properties if viscous effects were not considered. PMID:24748956

Boccaccio, A; Lamberti, L; Papi, M; De Spirito, M; Douet, C; Goudet, G; Pappalettere, C

2014-04-01

116

Identification of bovine embryos cultured in groups by attachment of barcodes to the zona pellucida.  

PubMed

The low number of oocytes collected from unstimulated donors by ovum pick-up means that embryos produced from each individual female have to be cultured individually or in very small groups. However, it has been demonstrated that single-embryo culture is less efficient than embryo culture in groups. To overcome this limitation, we developed a direct embryo-tagging system, which allows the collective culture of embryos from different origins whilst preserving their pedigree. Presumptive bovine zygotes were tagged with eight wheat-germ agglutinin biofunctionalised polysilicon barcodes attached to the outer surface of the zona pellucida (ZP). Four different barcodes were used to encode groups of 20-25 embryos, which were then cultured in the same drop. Cleavage, Day-7 and Day-8 blastocysts and barcode retention rates were assessed. In addition, Day-7 blastocysts were vitrified and warmed. Barcode attachment to the ZP of bovine embryos affected neither in vitro embryo development nor post-warming survival of the tagged embryos. All the embryos maintained barcodes attached until Day 8 of culture (3.63±0.37 barcodes per embryo) and could be identified. In conclusion, identification of embryos by barcodes attached to the ZP is feasible and will allow the culture of embryos from different donors in the same drop. PMID:24942183

Novo, Sergi; Morató, Roser; Penon, Oriol; Duran, Sara; Barrios, Leonardo; Nogués, Carme; Plaza, José Antonio; Pérez-García, Luisa; Mogas, Teresa; Ibáñez, Elena

2014-06-01

117

Vitellogenin and zona radiata proteins as biomarkers of endocrine disruption in peregrine falcon (Falco peregrinus).  

PubMed

The aim of this study was to test a specific method for the detection of Vitellogenin (Vtg) and Zona Radiata Proteins (Zrp) in plasma from peregrine falcon (Falco peregrinus) as specific biomarkers for the evaluation of the effects of endocrine disruptors. The method was assayed with different peregrine falcon individuals (including mature and immature birds of both sexes) from a Spanish population being studied in terms of their contamination with organochlorine compounds with endocrine disrupting properties. This study shows that mouse anti bird Vtg monoclonal antibody ND3C3 (Biosense) seems to be the most specific antibody in binding plasmatic lipoproteins in peregrine falcon when compared to other anti Vtg antibodies. Rabbit anti salmon Zrp polyclonal antibodies O146 (Biosense) show cross-reactivity with Zrp in the samples studied. These preliminary results confirm the applicability of both of these diagnostic tools assayed (induction of Vtg and Zrp) in detecting exposure to Endocrine Disrupting Chemicals (EDCs) in this species. The increase of Vtg and Zrp detected in male specimens suggest a potential hazard to EDCs in the peregrine falcon which represents a species still affected by organochlorine compounds, and in particular those with estrogenic activity. PMID:17223181

Jiménez, Begoña; Mori, Gabriele; Concejero, Miguel A; Merino, Rubén; Casini, Silvia; Fossi, María Cristina

2007-04-01

118

[Soluble expression, purification and immunoreactive identification of mouse zona pellucida 3 fusion protein].  

PubMed

Mammalian zona pellucida 3(ZP3) plays an important role in the induction of capacitating sperm acrosome reaction. In this study, we obtained the soluble mZP3 fusion protein and identified its immunoreactivity. mZP3 cDNA was cloned into plasmid pMAL-p2x, and the recombinant plasmid was transformed into Escherichia coli BL21. To get the soluble mZP3 fusion protein, we tried to optimize the expression conditions, including additives, IPTG concentrations, temperatures and induction duration. Then, Western blotting and ELISA were used to identify the immunoreactivity of the purified protein. Based on the optimization experiments, we concluded that the best soluble expression conditions for the mZP3 fusion protein involved incubation to an A600 of 0.6, addition of glucose to a final concentration of 0.02 mol/L, addition of IPTG to a final concentration of 0.6 mmol/L and then further incubation for 4 h at 25 degrees C. Western blotting and ELISA showed that the mZP3 fusion protein retained immunoreactivity. The fusion protein can be used as solubility antigens for developing the immunocontraception vaccines of mZP3 and detecting the immune effects of the vaccine. PMID:19938453

Sun, Meiyu; Ma, Zhenghai; Li, Yongxin; Lü, Tao; Chen, Kaixu; Zhang, Fuchun

2009-08-01

119

Zona Pellucida Domain-Containing Protein ?-Tectorin is Crucial for Zebrafish Proper Inner Ear Development  

PubMed Central

Background The zona pellucida (ZP) domain is part of many extracellular proteins with diverse functions from structural components to receptors. The mammalian ?-tectorin is a protein of 336 amino acid residues containing a single ZP domain and a putative signal peptide at the N-terminus of the protein. It is 1 component of a gel-like structure called the tectorial membrane which is involved in transforming sound waves into neuronal signals and is important for normal auditory function. ?-Tectorin is specifically expressed in the mammalian and avian inner ear. Methodology/Principal Findings We identified and cloned the gene encoding zebrafish ?-tectorin. Through whole-mount in situ hybridization, we demonstrated that ?-tectorin messenger RNA was expressed in the otic placode and specialized sensory patch of the inner ear during zebrafish embryonic stages. Morpholino knockdown of zebrafish ?-tectorin affected the position and number of otoliths in the ears of morphants. Finally, swimming behaviors of ?-tectorin morphants were abnormal since the development of the inner ear was compromised. Conclusions/Significance Our results reveal that zebrafish ?-tectorin is specifically expressed in the zebrafish inner ear, and is important for regulating the development of the zebrafish inner ear. Lack of zebrafish ?-tectorin caused severe defects in inner ear formation of otoliths and function.

Yang, Chung-Hsiang; Cheng, Chia-Hsiung; Chen, Gen-Der; Liao, Wei-Hao; Chen, Yi-Chung; Huang, Kai-Yun; Hwang, Pung-Pung; Hwang, Sheng-Ping L.; Huang, Chang-Jen

2011-01-01

120

Zona occludens-2 protects against podocyte dysfunction induced by ADR in mice.  

PubMed

Zona occludens-2 (ZO-2) is a protein present at the tight junction and nucleus of epithelial cells. ZO-2 represses the transcription of genes regulated by the Wnt/?-catenin pathway. This pathway plays a critical role in podocyte injury and proteinuria. Here, we analyze whether the overexpression of ZO-2 in the glomerulus, by hydrodynamics transfection, prevents podocyte injury mediated by the Wnt/?-catenin pathway in the mouse model of adriamycin (ADR) nephrosis. By immunofluorescence and immunogold electron microscopy, we show that ZO-2 is present in mice glomerulus, not at the slit diaphragms where nephrin concentrates, but in the cytoplasm and at processes of podocytes. Our results indicate that in the glomeruli of mice treated with ADR, ZO-2 overexpression increases the amount of phosphorylated ?-catenin, inhibits the expression of the transcription factor snail, prevents nephrin and podocalyxin loss, reduces podocyte effacement and massive fusions, restrains proteinuria, and supports urea and creatinine clearance. These results suggest that ZO-2 could be a new target for the regulation of hyperactive Wnt/?-catenin signaling in proteinuric kidney diseases. PMID:23034938

Bautista-García, Pablo; Reyes, José L; Martín, Dolores; Namorado, María C; Chavez-Munguía, Bibiana; Soria-Castro, Elizabeth; Huber, Otmar; González-Mariscal, Lorenza

2013-01-01

121

Fucosyl neoglycoprotein binds to mouse epididymal spermatozoa and inhibits sperm binding to the egg zona pellucida.  

PubMed

Glycan epitopes of cellular glycoconjugates act as versatile biochemical signals, and this sugar coding plays an important role in cell-to-cell recognition processes. In this study, our aims were to determine the distribution of sperm receptors with activity for fucosyl- and galactosyl glycans and to address whether monosugar neoglycoproteins functionally mimic the binding between zona pellucida (ZP) glycoproteins and spermatozoa. In mouse epididymal spermatozoa with intact acrosomes, fucopyranosyl bovine serum albumin (BSA-Fuc) bound to the segment of the acrosome, the equatorial segment, and the postacrosome region of the sperm head. Galactosyl BSA (BSA-Gal) binding activity was similar to that of BSA-Fuc, but was weaker. In acrosome-reacted spermatozoa treated with the Ca(2+) ionophore A23187, BSA-zuc binding was lost in the apical segment of the acrosome but remained in the equatorial segment and postacrosome regions. BSA-Gal binding to the equatorial region was increased. In the presence of 2.5 ?g ml(-1) BSA-Fuc, in vitro sperm-ZP binding was significantly decreased, indicating that fucosyl BSA functionally mimics ZP glycoproteins during sperm-egg ZP interactions. At the same concentration, BSA-Gal was not effective. Fucosyl BSA that efficiently inhibited the sperm-ZP binding can mimic the ZP glycoconjugate and has potential for use as a sperm fertility control agent in mouse. PMID:22998388

Oh, Y S; Ahn, H S; Gye, M C

2013-12-01

122

Estimating Young's modulus of zona pellucida by micropipette aspiration in combination with theoretical models of ovum.  

PubMed

The zona pellucida (ZP) is the spherical layer that surrounds the mammalian oocyte. The physical hardness of this layer plays a crucial role in fertilization and is largely unknown because of the lack of appropriate measuring and modelling methods. The aim of this study is to measure the biomechanical properties of the ZP of human/mouse ovum and to test the hypothesis that Young's modulus of the ZP varies with fertilization. Young's moduli of ZP are determined before and after fertilization by using the micropipette aspiration technique, coupled with theoretical models of the oocyte as an elastic incompressible half-space (half-space model), an elastic compressible bilayer (layered model) or an elastic compressible shell (shell model). Comparison of the models shows that incorporation of the layered geometry of the ovum and the compressibility of the ZP in the layered and shell models may provide a means of more accurately characterizing ZP elasticity. Evaluation of results shows that although the results of the models are different, all confirm that the hardening of ZP will increase following fertilization. As can be seen, different choices of models and experimental parameters can affect the interpretation of experimental data and lead to differing mechanical properties. PMID:19828504

Khalilian, Morteza; Navidbakhsh, Mahdi; Valojerdi, Mojtaba Rezazadeh; Chizari, Mahmoud; Yazdi, Poopak Eftekhari

2010-04-01

123

Identification of potential oviductal factors responsible for zona pellucida hardening and monospermy during fertilization in mammals.  

PubMed

Oviduct fluid increases the time required for digestion of the zona pellucida (ZP) by proteolytic enzymes (ZP hardening). This effect has been associated with levels of monospermy after in vitro fertilization (IVF) in the pig and cow, but the possible existence of a directly proportional relationship between hardening and monospermy remains unknown. To investigate whether variations in hardening of different oviductal fluids (OFs) are correlated with variations in levels of monospermy after IVF, porcine oocytes were incubated with three batches of OFs known to produce different ZP hardening effects (3, 7, and 25 min); after IVF, monospermy levels were 0%, 14.58% ± 5.14%, and 35.14% ± 7.95%, respectively. These results could partially explain the lack of polyspermy found during in vivo fertilization in pigs (with a hardened oviductal ZP) compared with levels found during IVF (with no hardened ZP). Using the bovine model, OF was fractionated by heparin affinity chromatography, and the hardening effect on the ZP was tested for each fraction obtained from a linear gradient of sodium chloride concentration. The highest effect was obtained with the fraction eluted with 0.4 M sodium chloride. Fractions with high-level or low-level effects were processed by on-chip electrophoresis and high-performance liquid chromatography-tandem mass spectrometry. A list of potential proteins responsible for this effect includes OVGP1 and members of the HSP and PDI families. PMID:23863406

Mondéjar, Irene; Martínez-Martínez, Irene; Avilés, Manuel; Coy, Pilar

2013-09-01

124

Estimating Young's modulus of zona pellucida by micropipette aspiration in combination with theoretical models of ovum  

PubMed Central

The zona pellucida (ZP) is the spherical layer that surrounds the mammalian oocyte. The physical hardness of this layer plays a crucial role in fertilization and is largely unknown because of the lack of appropriate measuring and modelling methods. The aim of this study is to measure the biomechanical properties of the ZP of human/mouse ovum and to test the hypothesis that Young's modulus of the ZP varies with fertilization. Young's moduli of ZP are determined before and after fertilization by using the micropipette aspiration technique, coupled with theoretical models of the oocyte as an elastic incompressible half-space (half-space model), an elastic compressible bilayer (layered model) or an elastic compressible shell (shell model). Comparison of the models shows that incorporation of the layered geometry of the ovum and the compressibility of the ZP in the layered and shell models may provide a means of more accurately characterizing ZP elasticity. Evaluation of results shows that although the results of the models are different, all confirm that the hardening of ZP will increase following fertilization. As can be seen, different choices of models and experimental parameters can affect the interpretation of experimental data and lead to differing mechanical properties.

Khalilian, Morteza; Navidbakhsh, Mahdi; Valojerdi, Mojtaba Rezazadeh; Chizari, Mahmoud; Yazdi, Poopak Eftekhari

2010-01-01

125

Antibodies to Two ZP3 B Cell Epitopes Affect Zona Pellucida Assembly  

PubMed Central

Mouse zona pellucida (ZP) proteins are synthesized in developing oocytes and assembled into ZP after their secretion. This study has investigated whether anti-ZP3 antibodies affect ZP assembly. Peptides CP2 and CP3 were used to elicit antibodies to two ZP3 B cell epitopes, ZP3(335–342) and ZP3(171–180). Ovulated eggs from mice immunized with a mixture of CP2/CP3 showed an abnormal ZP; importantly, the ZP completely dissolved both in vitro and in vivo 12 hours after ovulation. Although CP3 immunization resulted also in abnormal ZP, the ZP did not dissociate. Binding of antibodies to the ZP prior to oocyte maturation was requisite, as in vitro incubation of ovulated eggs in combination with the two antibodies failed to induce ZP dissolution. Electron microscopic observation further demonstrated a significant abnormality in ZP structure in CP2/CP3-immunized mice, especially in mature follicles, suggesting that B cell epitopes may be involved in ZP assembly. Though antibody elicited by CP2 has been shown to inhibit fertilization, we show now that antibody induced by CP3 had no effect on fertility. However, immunization with CP3/CP2 resulted in a significantly lower fertility rate than CP2 alone. This suggests that infertility in these mice may be due to an unstable ZP structure. Our model provides a useful tool to study ZP assembly and its structure beyond molecular biology method.

Borillo, Jason; Coonrod, Scott A.; Wu, Jean; Zhou, Cindy; Lou, Yahuan

2008-01-01

126

Detection of angiotensin II binding to single adrenal zona glomerulosa cells by confocal Raman microspectroscopy  

NASA Astrophysics Data System (ADS)

We developed a confocal Raman microspectroscopic technique to study ligand-receptor bindings in single cells using Raman-labeled ligands and surface-enhanced Raman scattering (SERS). The adrenal zona glomerulosa (ZG) cells were used as a model in this study. ZG cells have a high density of angiotensin II (AII) receptors on the cellular membrane. There are two identified subtypes of AII receptors,namely AT1 and AT2 receptors. AII is a peptidic hormone, which upon binding to its receptors, stimulates the release of aldosterone from ZG cells. The cellular localization of these receptors subtypes was detected in single ZG cells by using immunocomplexation of receptors with specific antibodies and confocal Raman microspectroscopy. In the binding study, we used biotin-labeled AII to bind to its receptors in ZG cells. Then, avidin and Raman-labeled AII. The binding was measure directly on the single ZG cells. The results showed that the binding was displaced with unlabeled AII and specific AII antagonists. This is a rapid and sensitive technique for detection of cellular ligand bindings as well as antagonists screening in drug discovery.

McCoy, Michael J.; Habermann, Timothy J.; Hanke, Craig J.; Adar, Fran; Campbell, William B.; Nithipatikom, Kasem

1999-04-01

127

Evidence for extracellular, but not intracellular, generation of angiotensin II in the rat adrenal zona glomerulosa  

SciTech Connect

Based on the observation that high levels of renin and angiotensin II (Ang II) are found in the adrenal zona glomerulosa (ZG), it has been postulated that Ang II is formed intracellularly by the renin-converting enzyme cascade in this tissue. To test this hypothesis, the authors examined renin-angiotensin system components in subcellular fractions of the rat adrenal ZG. Renin activity and immunoreactive-Ang II (IR-Ang II) were observed in vesicular fractions but were not colocalized. In addition, angiotensinogen, angiotensin I, and converting enzyme were not observed in the renin or IR-Ang II-containing vesicular fractions. These data do not support the hypothesis that Ang II is formed intracellularly within the renin-containing vesicles of the ZG. Rather, since modulatable renin release from adrenal ZG slices was observed and renin activity was found in dense vesicular fractions (33-39% sucrose), it is likely that Ang II formation in the ZG is extracellular and initiated by the release of vesicular renin. In ZG lysomal fractions {sup 125}I-labeled Ang II was degraded to {sup 125}I-labeled des-(Phe{sup 8})Ang II. Since Ang II antibodies do not recognize des-(Phe{sup 8})Ang II, these finding explain why IR-Ang II in the ZG is due predominantly to Ang II and not to its C-terminal immunoreactive fragments.

Urata, H.; Khosla, M.C.; Bumpus, M.; Husain, A. (Research Institute of the Cleveland Clinic Foundation, OH (USA))

1988-11-01

128

Single sperm cryopreservation on cryoloops: an alternative to hamster zona for freezing individual spermatozoa.  

PubMed

Methodology enabling cryopreservation of individual spermatozoa in extreme cases of oligozoospermia would tremendously benefit patients. This study explores the use of a nylon loop for cryopreservation of small quantities of spermatozoa, and also describes a novel technique for freezing individual spermatozoa with this cryoloop. Experiments were conducted to compare sperm recovery and viability after cryopreservation in conventional vials versus on the cryoloops. Discarded human sperm specimens with varying parameters were utilized. The study also examines two different glycerolbased cryoprotectants, with and without test yolk buffer. For single sperm cryopreservation, 5-10 spermatozoa were selected and loaded onto cryoloops with the aid of a microscope and micromanipulation equipment. Sperm function testing was performed on both human and bovine spermatozoa frozen on cryoloops. Microquantities of spermatozoa frozen on cryoloops exhibited overall motility and viability parameters similar to control samples frozen in cryovials. Individually selected spermatozoa cryopreserved on loops were easily recovered and post-thaw motility was generally good. Sperm function testing demonstrated that both human and bovine spermatozoa cryopreserved on loops were able to undergo sperm head decondensation when injected into oocytes. Cryoloops may be an excellent alternative to hamster zonae for cryopreserving small numbers of human spermatozoa. PMID:15257818

Desai, Nina N; Blackmon, Heather; Goldfarb, James

2004-07-01

129

Humoral immune responses in brushtail possums ( Trichosurus vulpecula) induced by bacterial ghosts expressing possum zona pellucida 3 protein  

Microsoft Academic Search

The introduced common brushtail possum (Trichosurus vulpecula) is a major pest in New Zealand and immunocontraceptive vaccines are being developed for biocontrol of possum populations, with bacterial ghosts (BGs) being evaluated as a means of oral delivery. Recombinant BGs expressing possum zona pellucida 3 protein (ZP3) as an L? membrane-anchored protein (ZP3-L?) or as an S-layer SbsA-fusion protein (MBP-SbsA-ZP3) were

Xianlan Cui; Janine A. Duckworth; Petra Lubitz; Frank C. Molinia; Christoph Haller; Werner Lubitz; Phil E. Cowan

2010-01-01

130

Porcine oocyte zona pellucida M(r) 55,000 glycoproteins: identification of O-glycosylated domains.  

PubMed

The distribution of O-linked oligosaccharides on the M(r) 55,000 glycoproteins, ZP3 alpha and ZP3 beta, of the porcine oocyte zona pellucida was examined. Purified preparations of endo-beta-galactosidase digested ZP3 alpha and ZP3 beta were reduced and carboxamidomethylated and digested with trypsin. When the trypsin digests were mapped by HPLC, each glycoprotein yielded only one N-acetylgalactosamine containing glycopeptide. Purification of the O-glycopeptides was achieved by a two-step protocol. Tryptic digests were applied to jacalin-agarose and specifically-bound O-glycopeptides (alpha OGP and beta OGP) were eluted with buffer containing 50 mM alpha-methylgalactoside as the haptenic sugar. Further purification of each O-glycopeptide was accomplished by reverse phase HPLC. Purified O-glycopeptides were characterized with respect to amino acid and carbohydrate compositions and sequenced by automated Edman degradation; alpha OGP was a 41-residue glycopeptide with three O-linked sugar chains. Sequence comparisons revealed a 75% identity between alpha OGP and a corresponding segment of rabbit rec55 zona protein; beta OGP was a 25-residue glycopeptide characterized by the presence of one N-linked and five O-linked sugar chains and a trypsin-resistant internal arginine residue. Sequence alignments revealed an 80% or greater identity between beta OGP and internal peptides of mouse, hamster and human ZP3 zona proteins. These studies demonstrate that in the case of ZP3 alpha and ZP3 beta, the pig homologues of rabbit rec55 and mouse ZP3, respectively, O-linked oligosaccharides are confined within delimited domains rather than widely dispersed on the polypeptide backbone. Such clustering of O-linked oligosaccharides may represent an essential determinant of the structure and biological activity of zona proteins. PMID:1418987

Yurewicz, E C; Pack, B A; Sacco, A G

1992-10-01

131

Characterization of cell surface polypeptides of unfertilized, fertilized, and protease-treated zona-free mouse eggs  

SciTech Connect

The polypeptide composition of unfertilized, fertilized, and protease-treated zona-free mouse eggs was evaluated in this study. Zona-free eggs were radioiodinated by an Iodogen-catalyzed reaction. Light microscopic autoradiography of egg sections revealed that labeling was restricted to the cell surface. Labeled eggs were solubilized, and cell surface polypeptides were identified by one-dimensional SDS polyacrylamide gel electrophoresis and autoradiography. The unfertilized egg demonstrated 8-10 peptides that incorporated {sup 125}I, with major bands observed at approximately 145-150, 94, and 23 kilodaltons (kD). Zona-free eggs fertilized in vitro and then radiolabeled demonstrated several new bands in comparison to unfertilized eggs, with a major band appearing at approximately 36 kD. Treatment of radiolabeled unfertilized eggs with either trypsin or chymotrypsin (1 mg/ml for 5-20 min) caused enzyme-specific modifications in labeled polypeptides. Trypsin (T) treatment resulted in time-dependant modification of the three major peptides at 145-150, 94, and 23 kD. Chymotrypsin (CT) treatment, in contrast, was associated with loss or modification of the 94 kD band, with no apparent effect on either the 145-150 or 23 kD band. Taken together with previous data indicating that T or CT egg treatment interferes with sperm-egg attachment and fusion, these results suggest a possible role for the 94 kD protein in sperm-egg interaction.

Boldt, J.; Gunter, L.E.; Howe, A.M. (Medical College of Georgia, Augusta (USA))

1989-05-01

132

Use of fetal bovine serum to protect against zona hardening during preparation of mouse oocytes for cryopreservation.  

PubMed

Addition of 20% fetal bovine serum (FBS) to media used for cryopreservation does not reduce the premature release of cortical granules but does prevent their action on the zona pellucida and thereby prevents zona hardening. In this paper, it is shown that the washing period required for removal of FBS is less than 12 min for cumulus-free oocytes and between 150 and 170 min for cumulus-intact oocytes. When these washing periods are observed after exposure of oocytes to the cryoprotectant dimethylsulphoxide (DMSO; 1.5 M) in the presence of 20% FBS, a subsequent exposure to calcium ionophore A23187 or a second exposure to 1.5 M DMSO both lead to zona hardening. This result suggests that sufficient cortical granules remain to elicit a block to polyspermy at fertilization. Oocytes, which had been exposed to DMSO and FBS and then washed free of both, were fertilized in vitro; the incidence of polyspermy was not found to be elevated over the level found in controls. PMID:1587950

George, M A; Johnson, M H; Vincent, C

1992-03-01

133

Políticas del sitio web  

Cancer.gov

En el sitio web del NCI se proporcionan enlaces a otros sitios web con fines informativos y para conveniencia del público. Si el usuario selecciona un sitio web externo, saldrá del sitio web del NCI y estará sujeto a las políticas de privacidad y seguridad de dicho sitio.

134

Coberturas de vacunación neumocócica en menores de 2 años en 2 zonas de Almería capital  

Microsoft Academic Search

ObjectivesIn 2001 the conjugate pneumococcal vaccine (pcv7) was marketed in Spain (74.96 € per dose), although it is subsidised for high risk groups. This could lead to restrictions in socially deprived sections of the population. Paediatricians in the Virgen del Mar Health Centre and the Puche Clinic recommend the vaccine for children of less than 2 years of age. The

E. Ramos Salas; F. J. Diez Delgado; M. Salazar Agullo; F. M. Ramos Pleguezuelos

2008-01-01

135

Gonadotropin-releasing hormone-stimulated sperm binding to the human zona is mediated by a calcium influx.  

PubMed

The mechanism by which GnRH increases sperm-zona pellucida binding in humans was investigated in this study. We tested whether GnRH increases sperm-zona binding in Ca(2+)-free medium and in the presence of Ca(2+) channel antagonists. We also examined the GnRH effect on the intracellular free Ca(2+) concentration ([Ca(2+)](i)). Sperm treatment with GnRH increased sperm-zona binding 300% but only when Ca(2+) was present in the medium. In Ca(2+)-free medium or in the presence of 400 nM nifedipine, 80 microM diltiazem, or 50 microM verapamil, GnRH did not influence sperm-zona binding. GnRH increased the [Ca(2+)](i) in the sperm in a dose-dependent manner. The maximum effect was reached with 75 nM GnRH. The GnRH-induced increase in [Ca(2+)](i) was fast and transient, from a basal [Ca(2+)](i) of 413 +/- 22 nM to a peak value of 797 +/- 24 nM. The GnRH-induced increase in [Ca(2+)](i) was entirely due to a Ca(2+) influx from the extracellular medium because the increase in [Ca(2+)](i) was blocked by the Ca(2+) chelator EGTA and by the Ca(2+) channel antagonists nifedipine and diltiazem. These antagonists, however, were not able to inhibit the progesterone-activated Ca(2+) influx. On the contrary, T-type calcium channel antagonists pimozide and mibefradil did not affect GnRH-activated Ca(2+) influx but inhibited the progesterone-activated Ca(2+) influx. Finally, the GnRH-induced Ca(2+) influx was blocked by two specific GnRH antagonists, Ac-D-Nal(1)-Cl-D-Phe(2)-3-Pyr-D-Ala(3)-Arg(5)-D-Glu(AA)(6)-GnRH and Ac-(3,4)-dehydro-Pro(1),-p-fluoro-D-Phe(2), D-Trp(3,6)-GnRH. These results suggest that GnRH increases sperm-zona binding via an elevation of [Ca(2+)](i) through T-type, voltage-operated calcium channels. PMID:10906075

Morales, P; Pizarro, E; Kong, M; Kerr, B; Ceric, F; Vigil, P

2000-08-01

136

Binding of Sperm to the Zona Pellucida Mediated by Sperm Carbohydrate-Binding Proteins is not Species-Specific in vitro between Pigs and Cattle  

PubMed Central

Carbohydrates are candidates for the basis of species-selective interaction of gametes during mammalian fertilization. In this study, we sought to clarify the roles of sugar residues in the species-selective, sperm–oocyte interaction in pigs and cattle. Acrosome-intact porcine and bovine sperm exhibited their strongest binding affinities for ?-Gal and ?-Man residues, respectively. Porcine-sperm specificity changed from ?-Gal to ?-Man after the acrosome reaction, while bovine-sperm specificity did not. Binding of acrosome-intact and acrosome-reacted sperm decreased after trypsinization, indicating that the carbohydrate-binding components are proteins. While immature oocytes bound homologous sperm preferentially to heterologous sperm, oocytes matured in vitro bound similar numbers of homologous and heterologous sperm. Lectin staining revealed the aggregation of ?-Man residues on the outer surface of the porcine zona during maturation. In both species, zona-free, mature oocytes bound homologous sperm preferentially to heterologous sperm. The lectin-staining patterns of the zona pellucida and zona-free oocytes coincided with the carbohydrate-binding specificities of acrosome-intact and acrosome-reacted sperm, respectively, supporting the involvement of carbohydrates in gamete recognition in pigs and cattle. These results also indicate that sperm-zona pellucida and sperm–oolemma bindings are not strictly species-specific in pigs and cattle, and further suggest that sperm penetration into the zona and/or fusion with oolemma may be species-specific between pigs and cattle.

Takahashi, Kazuya; Kikuchi, Kazuhiro; Uchida, Yasuomi; Kanai-Kitayama, Saeko; Suzuki, Reiichiro; Sato, Reiko; Toma, Kazunori; Geshi, Masaya; Akagi, Satoshi; Nakano, Minoru; Yonezawa, Naoto

2013-01-01

137

Significance of egg's zona pellucida glycoproteins in sperm-egg interaction and fertilization.  

PubMed

Mammalian fertilization is a highly programmed process by which sperm and egg unite to form a zygote, a cell with somatic chromosome numbers. To fertilize an egg, the capacitated (acrosome-intact) spermatozoa recognize and bind to the egg's extracellular glycocalyx coat, the zona pellucida (ZP). The tight and irreversible binding of the opposite gametes in the mouse and many other species studied, including man, results in the opening of Ca2+ channels on sperm plasma membrane (PM) and influx of Ca2+. The transient rise in Ca2+ and other second messengers, such as cAMP and IP3, initiates a cascade of signaling events that elevate sperm pH and triggers the fusion of the sperm PM and underlying outer acrosomal membrane at multiple sites (induction of the acrosomal reaction). The fusion of the two membranes results in the exocytosis of acrosomal contents at the site of sperm-egg adhesion. The hydrolytic action of the acrosomal enzymes (glycohydrolases, proteinases, esterases, sulfatases etc), released at the site of sperm-egg adhesion, along with the enhanced thrust generated by the hyperactivated spermatozoon, are important factors that regulate the penetration of the ZP and the fusion of the acrosome-reacted spermatozoon with the egg. Evidence accumulated over the past two decades strongly suggests that glycan units of the ZP have a significant role in the recognition and adhesion of the opposite gametes and induction of the AR. In this review article, we intend to highlight well programmed molecular events that results in the sperm-egg adhesion and fertilization. Our intention is also to discuss the increasing controversy on the role of ZP glycan chains in sperm-egg interactions. PMID:25020059

Abou-Haila, A; Bendahmane, M; Tulsiani, D R

2014-08-01

138

Does women's age influence zona pellucida birefringence of metaphase ?? oocytes in in-vitro maturation program?  

PubMed Central

Background: In vitro maturation (IVM) is a promising treatment option for certain infertile women. Nowadays, with the aid of PolScope, it has become possible to evaluate zona pellucida (ZP) characteristics as a parameter of oocyte quality. Moreover, quality of oocytes can be influenced by many factors, such as patient’s age. The PolScope system is a non-invasive technique to assess birefringent structures such as the meiotic spindle and ZP in living oocytes. Objective: The aim was to determine the influence of the woman's age on ZP birefringence, a sign of oocyte quality, and morphology of in-vitro matured human oocytes using non-invasive polarized light (PolScope) microscopy. Materials and Methods: ZP birefringence and morphology were determined in 105 retrieved oocytes from 58 women undergoing ICSI in two age groups (?30 years and <30 years). The immature oocytes were selected and after IVM, the quality of metaphase ?? (MII) oocytes was assessed. The oocytes abnormalities were classified as intracytoplasmic and extracytoplasmic abnormalities. Results: Oocyte maturation rates were significantly reduced in ?30 year’s women (56%) in comparison with other age group (80.7%). In addition, the ZP birefringence was significantly higher in MII oocytes in the younger group compared with the older group (76.2% vs. 38.1%; p=0.00). Following morphologic assessment, the rates of oocytes with extracytoplasmic (p=0.02) and both abnormalities (extra- and intracytoplasmic) (p=0.01) were higher in aged versus the younger women. Conclusion: There was a positive relationship between advanced maternal age with decreased ZP birefringence and oocyte morphological quality in in-vitro matured human oocytes.

Omidi, Marjan; Khalili, Mohammad Ali; Nahangi, Hossein; Ashourzadeh, Sareh; Rahimipour, Marzieh

2013-01-01

139

Zona pellucida birefringence and meiotic spindle visualisation of human oocytes are not influenced by IVM technology.  

PubMed

The aim of the present study was to investigate the relationship between the presence of the meiotic spindle and zona pellucida (ZP) birefringence with morphology of in vivo- and in vitro-matured human oocytes. Germinal vesicles (n=47) and MI (n=38) oocytes obtained from stimulated ovaries of patients undergoing intracytoplasmic sperm injection (ICSI) underwent IVM. Using a PolScope (OCTAX PolarAID; Octax, Herbon, Germany), the presence of spindles and ZP birefringence was assessed in both in vivo-matured (n=56) and IVM (n=56) oocytes. In addition, the morphology of each matured oocyte was evaluated microscopically. There were insignificant differences for ZP birefringence and meiotic spindle between the in vivo-matured and IVM MII oocytes. Subanalysis revealed that the rates of morphologically abnormal oocytes did not differ significantly between the two groups, except in the case of irregular shape (P=0.001), refractile body (P=0.001) and fragmented polar body (P=0.03), which were higher in IVM oocytes. In the case of in vivo-matured oocytes, a significantly higher percentage of oocytes with intracytoplasmic and both intra- and extracytoplasmic abnormalities have a low birefringent ZP (P=0.007 and P=0.02, respectively). There was no relationship between morphological abnormalities and spindle detection. The findings suggest that clinical IVM is a safe technology that maintains the high maturation rate and integrity of oocytes. In addition, the use of the non-invasive PolScope is recommended for the detection of oocytes most suitable for ICSI. PMID:23544843

Omidi, Marjan; Khalili, Mohammad Ali; Ashourzadeh, Sareh; Rahimipour, Marzieh

2014-03-01

140

Adrenocortical cells of the zona reticularis normally express HLA-DR antigenic determinants.  

PubMed Central

A distinct population of normal human adrenocortical cells from adult glands spontaneously express HLA-DR, and occasionally also HLA-DQ, antigenic determinants in vivo and in vitro, as detected by immunofluorescence techniques using monoclonal antibodies on frozen tissue sections, primary cultures, and viable cell suspensions. In vivo, these antigenic determinants were found to be confined to the compact-type cells in the zona reticularis. In vitro, the adrenocortical identity of these HLA-DR+ cells was conclusively established by the characteristic change in their morphologic features induced by ACTH1-24 and by the simultaneous detection of tissue-specific adrenal autoantigens in double-label immunofluorescence staining. The cell surface expression of HLA-DR determinants by compact cells persisted in culture for several weeks and was not significantly affected by treatment with ACTH1-24. On the other hand, fetal adrenocortical cells of both transient and definitive zones were invariably negative for the expression of these HLA Class II antigenic determinants. Because normal human adrenocortical cells also express on their surface the molecules which constitute specific autoantigens in autoimmune adrenalitis, these findings argue against the notion that an ectopic HLA-DR expression associated with an otherwise "silent" autoantigen might trigger an organ-specific autoimmune response against endocrine cells. In addition, the expression of HLA-DR determinants by viable normal reticularis cells provides a readily detectable surface marker which may allow the physical separation of this population for studies in vitro. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Khoury, E. L.; Greenspan, J. S.; Greenspan, F. S.

1987-01-01

141

Mapping of Minimal Motifs of B-Cell Epitopes on Human Zona Pellucida Glycoprotein-3  

PubMed Central

The human zona pellucida glycoprotein-3 (hZP3) by virtue of its critical role during fertilization has been proposed as a promising candidate antigen to develop a contraceptive vaccine. In this direction, it is imperative to map minimal motifs of the B cell epitopes (BCEs) so as to avoid ZP-specific oophoritogenic T cell epitopes (TCEs) in the ZP3-based immunogens. In this study, based on known results of mapping marmoset and bonnet monkey ZP3 (mstZP3 and bmZP3), two predictable epitopes23–30??and??301–320 on hZP3 were first confirmed and five minimal motifs within four epitopes on hZP3 were defined using serum to recombinant hZP3a22–176 or hZP3b177–348 as well as a biosynthetic peptide strategy. These defined minimal motifs were QPLWLL23–28 for hZP323–30, MQVTDD103–108 for hZP393–110, EENW178–181 for hZP3172–190, as well as SNSWF306–310 and EGP313–315 for hZP3301–320, respectively. Furthermore, the antigenicity of two peptides for hZP3172–187 and hZP3301–315 and specificity of the antibody response to these peptides were also evaluated, which produced high-titer antibodies in immunized animals that were capable of reacting to ZP on human oocytes, r-hZP3b177–348 protein, as well as r-hZP3172–190, r-hZP3303–310, and r-hZP3313–320 epitope peptides fused with truncated GST188 protein.

Xu, Wan-Xiang; He, Ya-Ping; Wang, Jian; Tang, Hai-Ping; Shi, Hui-Juan; Sun, Xiao-Xi; Ji, Chao-Neng; Gu, Shao-Hua; Xie, Yi

2012-01-01

142

Contraceptive potential of porcine and feline zona pellucida A, B and C subunits in domestic cats.  

PubMed

Feral cat populations are a major problem in many urban regions throughout the world, threatening biodiversity. Immunocontraception is considered as an alternative and a more humane means to control overpopulation of pest animals than current methods including trapping, poisoning and shooting. In this study, we evaluate porcine zona pellucida (ZP) polypeptide (55 kDa) and feline ZP A, B and C subunits expressed by plasmid vectors as candidate vaccines against fertility in the female domestic cat. Cats were injected subcutaneously with three doses of the ZP vaccines. Vaccinated cats were compared with naïve cats for ZP-antibody response, ovarian histology and fertility after mating. Vaccination with native porcine ZP 55 kDa polypeptide induced anti-porcine ZP antibodies detected by ELISA. However, these antibodies did not cross-react with feline ZP as assessed by immunohistochemistry and no effect on fertility in vivo was observed after mating. However, vaccination of cats with feline ZPA or feline ZPB+C DNA vectors elicited circulating antibodies specific for feline ZP as assessed by ELISA, with reactivity to native feline ZP in ovarian follicles in situ. Vaccination with feline ZPA and ZPB+C DNA did not elicit changes in ovarian histology. Although sample sizes were small, conception rates in mated females were 25 and 20% in the ZPA and ZPB+C vaccinated groups respectively, compared with 83% in the control group. We conclude that feline ZPA and ZPB+C subunits are potential candidate antigens for immunocontraceptive vaccines in the domestic cat. PMID:19279201

Eade, Joyce A; Roberston, Ian D; James, Cassandra M

2009-06-01

143

Dextran vitrification media prevents mucin coat and zona pellucida damage in rabbit embryo.  

PubMed

Vitrification of embryos is being increasingly important for cryopreservation in mammals. However, damage and toxicity has to be reduced even more. The composition of cryoprotective medium used to immerse the embryos affects viability and developmental potential. The aim of this work was to assess the effect of the Polyvinylalcohol-PVA- and Dextran addition to vitrification media on the in vitro development of rabbit embryos from superovulated and non-superovulated females. Superovulation group were treated intramuscularly with 25 IU rhFSH. The vitrification media contained the same permeable cryoprotectans (Ethylene Glycol-ET- and Dimethyl Sulfoxide-Me?SO-) and different macromolecules (PVA and Dextran) in different combinations. There was a significantly higher proportion of embryos without damages in mucin coat or zona pellucida after warming (undamaged embryos) in the control than in the superovulation group (95.8% vs. 83.2%, respectively). The proportion of undamaged embryos was significantly affected by the vitrification solution composition. The rate of undamaged embryos after warming in media containing 20% Me?SO was significantly lower in media supplemented with PVA than in media with dextran (67.3 vs. 93.8, respectively). However, the proportion of undamaged embryos for the medium supplemented with dextran was similar for media with 15 or 20% Me?SO. In conclusion, the addition of dextran to the vitrification media improve the preservation of rabbit embryos and permits to reduce the amount of Me?SO for vitrification. Additionally, in vitro developmental ability of undamaged embryos were not affected by superovulation treatment nor vitrification media. PMID:20708233

Viudes De Castro, M P; Cortell, C; Vicente, J S

2010-12-01

144

Proacrosin-deficient mice and zona pellucida modifications in an experimental model of multifactorial infertility.  

PubMed

In humans, male and female partners contribute more or less equally to the infertility problem. In approximately 20% of infertile couples, the concurrence of male and female factors is suggested to be responsible for infertility. Neither of these factors are known nor is there a model system to prove this assumption. We present such a model system in the mouse, in which the lack of acrosin in the male and modifications of the zona pellucida (ZP) in the female result in a significant reduction of the fertilization rate in vitro. We generated mice carrying a deletion in the proline-rich region (PRR) of the proacrosin gene, resulting in the absence of proacrosin in the homozygous PRR(-/-) male mouse. Under normal conditions, sperm from the proacrosin-deficient mice are still capable of ZP penetration and fertilization. In this study, modifications of the ZP of oocytes after superovulation were achieved by treatment with dimethylsulphoxide or aroclor-1254 or by in-vitro ageing. It is known that under these conditions, a time-dependent hardening of the ZP occurs. The rates of fertilization in vitro of treated and aged oocytes using sperm from PRR(-/-) mice were found to be significantly reduced when compared with those reached with wild-type sperm. The relevance of the acrosin status and ZP condition for fertilization success were further substantiated by the finding that the fertilization rate with PRR(-/-) sperm is affected by the thickness of the ZP. Our results demonstrate that the lack of acrosin in sperm in combination with modifications to the ZP can affect fertility and can be an experimental model for the study of unexplained infertility in human couples in which both male- and female-derived factors are suggested to be the underlying causes. PMID:11994540

Nayernia, Karim; Adham, Ibrahim M; Shamsadin, Rahman; Müller, Christian; Sancken, Ulrich; Engel, Wolfgang

2002-05-01

145

Evaluation of Zona Pellucida Function for Sperm Penetration During In Vitro Fertilization in Pigs  

PubMed Central

Abstract In porcine oocytes, the function of the zona pellucida (ZP) with regard to sperm penetration or prevention of polyspermy is not well understood. In the present study, we investigated the effects of the ZP on sperm penetration during in vitro fertilization (IVF). We collected in vitro-matured oocytes with a first polar body (ZP+ oocytes). Some of them were freed from the ZP (ZP? oocytes) by two treatments (pronase and mechanical pipetting), and the effects of these treatments on sperm penetration parameters (sperm penetration rate and numbers of penetrated sperm per oocyte) were evaluated. There was no evident difference in the parameters between the two groups. Secondly, we compared the sperm penetration parameters of ZP+ and ZP? oocytes using frozen-thawed epididymal spermatozoa from four boars. Sperm penetration into ZP+ oocytes was found to be accelerated relative to ZP? oocytes. Thirdly, we evaluated the sperm penetration of ZP+ and ZP? oocytes at 1?10 h after IVF (3 h gamete co-incubation). The proportions of oocytes penetrated by sperm increased significantly with time in both groups; however, the number of penetrated sperm per oocyte did not increase in ZP? oocytes. Finally, we performed IVF using ZP? oocytes divided into control (3 h) and prolonged gamete co-incubation (5 h) groups. Greater numbers of sperm penetrated in the 5 h group than in the control group. These results suggest that the ZP and oolemma are not competent factors for prevention of polyspermy in our present porcine IVF system. However, it appears that ZP removal is one of the possibilities for reducing polyspermic penetration in vitro in pigs.

TANIHARA, Fuminori; NAKAI, Michiko; KANEKO, Hiroyuki; NOGUCHI, Junko; OTOI, Takeshige; KIKUCHI, Kazuhiro

2013-01-01

146

Two subunits of the 55 K porcine zona pellucida glycoprotein family are immunologically distinct  

SciTech Connect

The 55K glycoprotein family (ZP3) of the porcine zona pellucida is comprised of two subunits of 46 K and 45 K which can be resolved by endo-..beta..-galactosidase digestion of ZP3 followed by reversed phase HPLC on Vydac C4 resin. Gel electrophoresis revealed that the 46 K component (EBDG..cap alpha..) is approx. 95% pure and the 45 K component (EBGD..beta..) is 100% pure. In the present study, these two subunits were evaluated immunologically by RIA. Under similar reaction protocols (chloramine-T iodination procedure) comparable specific activities were obtained for EBGD..cap alpha.. (33.06 +/- 7.5 ..mu..ci/..mu..gm), EBGD..beta.. (30.45 +/- 1.6) and ZP3 (26.3 +/- 1.3). Antibody (Ab) titration studies revealed that EBGD..cap alpha.. and ..beta.. are potent immunogens and /sup 125/I-EBGD..cap alpha.. showed minimal cross reactivity to EBGD..beta..-Ab (8% bound at 1:500 dilution), whereas, /sup 125/I-EBGD..beta.. showed a greater degree of cross reactivity to EBGD..cap alpha..-Ab (23% bound at 1:500 dilution). Maximum binding for the two labeled antigens against homologous Abs (1:500) was > 60%. Dose response studies revealed that in the /sup 125/I-EBGD..cap alpha.. vs EBGD..cap alpha.. -Ab system, the 50% intercept was 3.25 +/- 0.32 ng for EBGD..cap alpha.. and 472.43 +/- 30.26 ng for EBGD..beta.. (p < 0.01), whereas, in the /sup 125/I-EBGD..beta.. vs EBGD..beta..-Ab system the 50% intercept was 3.51 +/- 0.58 for EBGD..beta.. and 166.77 +/- 49.20 for EBGD..cap alpha.. (p < 0.01). No significant differences were observed in the slopes of the dose response curves. It is concluded that the two subunits of ZP3 possess distinct immunologic characteristics as evaluated by RIA.

Subramanian, M.G.; Yurewicz, E.C.; Sacco, A.G.

1986-03-01

147

Ability of Catalonian donkey sperm to penetrate zona pellucida-free bovine oocytes matured in vitro.  

PubMed

An experiment was designed to study the interaction between fresh/frozen-thawed donkey spermatozoa and zona pellucida (ZP)-free bovine oocytes in an attempt to develop a model for assessing cryopreserved Catalonian donkey sperm function. Semen from five donkeys was collected using an artificial vagina. Sperm motility and viability were immediately assessed and the semen sample cryopreserved. Sperm viability and motility were then reassessed immediately after thawing. The motion characteristics of the fresh and frozen-thawed spermatozoa were determined using a computer-assisted sperm analysis system. In vitro-matured cow oocytes were inseminated with different percent live donkey sperm (high (>60%) or low (<40%) viability donkey sperm). After 18h of co-incubation, the oocytes were fixed, stained with 4',6-diamidino-2-phenylindole (DAPI) and examined for sperm penetration, the number of penetrated spermatozoa per oocyte, and male pronucleus formation. Frozen-thawed spermatozoa from high viability semen showed significantly lower VCL, VAP and mean ALH values than did high viability fresh spermatozoa. In contrast, frozen-thawed spermatozoa of low viability had significantly higher velocity values than fresh spermatozoa of low viability. A significant positive correlation (P<0.01) was detected between percentage fertilization and viability (r=0.84), and between percentage fertilization and certain CASA parameters (VAP, r=0.56; VCL, r=0.61 and mean ALH, r=0.68). Fresh or frozen-thawed high viability spermatozoa penetrated 90.1% and 85.4% of bovine oocytes respectively. Lower rates of penetration were observed for fresh and frozen-thawed low viability spermatozoa (34% and 22.5% respectively). The donkey spermatozoa were able to fuse with the oolema and even to decondense and form the male pronucleus (85-94%). Larger numbers of penetrated spermatozoa per oocyte were recorded when high viability sperm samples were used, whether fresh (3.02 vs. 1.12 for low viability sperm) or frozen-thawed (3.41 vs. 1.47). Consequently, low viability sperm samples showed higher percentages of monospermic penetration (91.17% and 61.97% for fresh and frozen-thawed sperm samples respectively). These findings suggest that bovine oocytes provide a useful model for assessing the penetration potential of frozen-thawed donkey sperm. PMID:19748750

Taberner, E; Morató, R; Mogas, T; Miró, J

2010-04-01

148

Bovine oocyte quality in relation to ultrastructural characteristics of zona pellucida, polyspermic penetration and developmental competence.  

PubMed

In the present study, the effect of bovine oocyte quality related to ultrastructural characteristics of zona pellucida (ZP), polyspermic penetration and embryo developmental competence was evaluated. Cumulus-oocyte complexes were punctioned from 453 ovaries, classified as 1, 2, 3 and 4 according to their morphological aspect, matured for 24 h and then divided into two groups. In group A, oocytes were fixed in 2.5% glutaraldehyde and 0.1 m sodium cacodylate and examined under a scanning electron microscope. Photomicrographs were taken and ZP's pores were evaluated in squares of 6.4-microm width. In group B, oocytes were fertilized in vitro. After 48 h, non-cleaved oocytes were fixed for polyspermy evaluation. On days 7, 9 and 10, embryos were classified as developed (blastocysts and hatched blastocysts). Results showed that quality 1 oocytes revealed a ZP pore diameter of 0.50 +/- 0.07 microm, which was smaller than the observed on oocytes of quality 2 (0.83 +/- 0.10 microm), quality 3 (1.02 +/- 0.22 microm) and quality 4 (1.38 +/- 0.59 microm) (p < or = 0.05). For In Vitro Fertilization (IVF), results showed that embryos originating from oocytes classed as 3 and 4 had lower cleavage rate (68.4% and 43.8%) than those belonging to class 1 and 2 (79.5% and 69.3%) (p < or = 0.05). None oocyte classified as 3 and 4 developed to hatch blastocysts, while for oocytes belonging to quality 1 and 2, these values were, respectively, 15.2% and 12.5%. Concerning polyspermy, oocytes class 1 and 2 had lower polyspermic penetration than those belonging to class 3 and 4 (respectively 4.1%, 4.5%, 11.1% and 9.8%, for class 1, 2, 3 and 4). In conclusion, the present study demonstrated that oocytes with low qualities result in lower developmental competence and with high percentage of polyspermy after IVF, which can be the result of the ZP structure such as the number and the pore's diameter. PMID:18484959

Santos, P; Chaveiro, A; Simões, N; Moreira da Silva, F

2008-12-01

149

Evaluation of zona pellucida birefringence intensity during in vitro maturation of oocytes from stimulated cycles  

PubMed Central

Background This study evaluated whether there is a relationship between the zona pellucida birefringence (ZP-BF) intensity and the nuclear (NM) and cytoplasmic (CM) in vitro maturation of human oocytes from stimulated cycles. Results The ZP-BF was evaluated under an inverted microscope with a polarizing optical system and was scored as high/positive (when the ZP image presented a uniform and intense birefringence) or low/negative (when the image presented moderate and heterogeneous birefringence). CM was analyzed by evaluating the distribution of cortical granules (CGs) throughout the ooplasm by immunofluorescence staining. CM was classified as: complete, when CG was localized in the periphery; incomplete, when oocytes presented a cluster of CGs in the center; or in transition, when oocytes had both in clusters throughout cytoplasm and distributed in a layer in the cytoplasm periphery Nuclear maturation: From a total of 83 germinal vesicle (GV) stage oocytes, 58 of oocytes (69.9%) reached NM at the metaphase II stage. From these 58 oocytes matured in vitro, the high/positively scoring ZP-BF was presented in 82.7% of oocytes at the GV stage, in 75.8% of oocytes when at the metaphase I, and in 82.7% when oocytes reached MII. No relationship was observed between NM and ZP-BF positive/negative scores (P = 0.55). These variables had a low Pearson's correlation coefficient (r = 0.081). Cytoplasmic maturation: A total of 85 in vitro-matured MII oocytes were fixed for CM evaluation. Forty-nine oocytes of them (57.6%) showed the complete CM, 30 (61.2%) presented a high/positively scoring ZP-BF and 19 (38.8%) had a low/negatively scoring ZP-BF. From 36 oocytes (42.3%) with incomplete CM, 18 (50%) presented a high/positively scoring ZPBF and 18 (50%) had a low/negatively scoring ZP-BF. No relationship was observed between CM and ZP-BF positive/negative scores (P = 0.42). These variables had a low Pearson's correlation coefficient (r = 0.11). Conclusions The current study demonstrated an absence of relationship between ZP-BF high/positive or low/negative score and nuclear and cytoplasmic in vitro maturation of oocytes from stimulation cycles.

2011-01-01

150

Calcium-free vitrification reduces cryoprotectant-induced zona pellucida hardening and increases fertilization rates in mouse oocytes.  

PubMed

Despite the success of embryo cyropreservation, routine oocyte freezing has proved elusive with only around 200 children born since the first reported birth in 1986. The reason for the poor efficiency is unclear, but evidence of zona pellucida hardening following oocyte freezing indicates that current protocols affect oocyte physiology. Here we report that two cryoprotectants commonly used in vitrification procedures, dimethyl sulfoxide (DMSO) and ethylene glycol, cause a large transient increase in intracellular calcium concentration in mouse metaphase II (MII) oocytes comparable to the initial increase triggered at fertilization. Removal of extracellular calcium from the medium failed to affect the response exacted by DMSO challenge, but significantly reduced the ethylene glycol-induced calcium increase. These results suggest that the source of the DMSO-induced calcium increase is solely from the internal calcium pool, as opposed to ethylene glycol that causes an influx of calcium across the plasma membrane from the external medium. By carrying out vitrification in calcium-free media, it was found that zona hardening is significantly reduced and subsequent fertilization and development to the two-cell stage significantly increased. Furthermore, such calcium-free treatment appears not to affect the embryo adversely, as shown by development rates to the blastocyst stage and cell number/allocation. Since zona hardening is one of the early activation events normally triggered by the sperm-induced calcium increases observed at fertilization, it is possible that other processes are negatively affected by the calcium rise caused by cryoprotectants used during oocyte freezing, which might explain the current poor efficiency of this technique. PMID:16388009

Larman, Mark G; Sheehan, Courtney B; Gardner, David K

2006-01-01

151

Instantánea del cáncer colorrectal  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer colorrectal; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

152

Use of fetal bovine serum substitutes for the protection of the mouse zona pellucida against hardening during cryoprotectant addition.  

PubMed

The addition of 20% fetal bovine serum (FBS) to media used for mouse oocyte cryopreservation prevents hardening of the zona pellucida that otherwise can occur due to premature release of cortical granule contents (George et al., Hum. Reprod., 7, 401-412, 1992). Protection of human oocytes would ideally be achieved by using a human macromolecular source or a more defined bovine source than total FBS. Here we investigate whether FBS can be replaced by human serum, human cord serum, human serum albumin or fetuin, the major protein component of FBS. Only fetuin was found to be effective. PMID:7507131

George, M A; Johnson, M H

1993-11-01

153

5HT 7 receptor subtype as a mediator of the serotonergic regulation of luteinizing hormone release in the zona incerta  

Microsoft Academic Search

5-Hydroxytryptamine (5-HT) and the 5-HT1A\\/7 receptor agonist (+)-8-hydroxy-2-(di-n-propylamino) tetralinHBr (8-OH-DPAT), injected into the zona incerta (an area in the dorsal hypothalamus) of the female rat, inhibit the release of luteinizing hormone (LH) and the effects of both are blocked by the 5-HT2\\/7 receptor antagonist, ritanserin. As both 8-OH-DPAT and ritanserin have moderate activity at the 5-HT7 receptor subtype, the possibility

Arif Siddiqui; Mahmoud Abu-Amara; Cyrielle Aldairy; James J. Hagan; Catherine Wilson

2004-01-01

154

Moléculas orgánicas obtenidas en simulaciones experimentales del medio interestelar.  

NASA Astrophysics Data System (ADS)

Las nubes moleculares son regiones de formación de estrellas, con temperaturas cinéticas entre 10-50 K y densidades de 103-106 átomos cm-3. Su materia está formada por gas y polvo interestelar. Estas partículas de polvo están cubiertas por una fina capa de hielo, de unos 0.01 ?m, que contiene H2O y a menudo CO, CO2, CH3OH y NH3. El hielo es presumiblemente irradiado por fotones ultravioleta y rayos cósmicos en las zonas poco profundas de las nubes moleculares y las regiones circunestelares. En un sistema de vacío, P ˜ 10-7 mbar, simulamos la deposición de hielo a partir de 10 K y la irradiación ultravioleta por medio de una lámpara de descarga de hidrógeno activada con microondas. La evolución del hielo se observa por medio de un espectrómetro infrarrojo. De este modo es posible determinar la composición del hielo observado en el medio interestelar y predecir la presencia de moléculas aún no detectadas en el espacio, que han sido producto del procesamiento del hielo en nuestros experimentos. También es posible calentar el sistema hasta temperatura ambiente para sublimar el hielo depositado. Cuando el hielo ha sido previamente irradiado, se observa un residuo compuesto por moléculas orgánicas complejas, algunas prebióticas, como varios ácidos carboxílicos, aminas, amidas, ésteres y en menor proporción moléculas heterocíclicas y aminoácidos. Algunas de estas moléculas podrían detectarse en estado gaseoso por medio de observaciones milimétricas y de radio. También podrían estar presentes en el polvo cometario, cuyo análisis químico está planeado por las misiones Stardust y Rosetta. Mientras tanto, nuestro grupo está llevando a cabo el análisis de partículas de polvo interplanetario (IDPs), algunas de las cuales pueden ser de origen cometario. Al igual que ocurre con los productos obtenidos por irradiación del hielo en nuestros experimentos, algunas IDPs son ricas en material orgánico que contiene oxígeno.

Muñoz-Caro, Guillermo Manuel

155

Impact of the size of zona pellucida thinning area on vitrified-warmed cleavage-stage embryo transfers: a prospective, randomized study  

Microsoft Academic Search

Purpose  The aim of this study was to determine if the size of zona pellucida thinning area by laser assisted hatching could affect\\u000a the rates of pregnancy and implantation for vitrified-warmed embryo transfers at the cleavage-stage.\\u000a \\u000a \\u000a \\u000a Methods  A total of 120 vitrified-warmed cleavage-stage embryo transfers were randomly assigned to either quarter or half of zona pellucida\\u000a thinning group.\\u000a \\u000a \\u000a \\u000a Results  The rates of clinical

Kenichiro Hiraoka; Kaori Hiraoka; Toshitaka Horiuchi; Tomoyo Kusuda; Shinichiro Okano; Masayuki Kinutani; Kazuo Kinutani

2009-01-01

156

Boletín del Instituto Nacional del Cáncer - 16 de enero 2013  

Cancer.gov

El Boletín del Instituto Nacional del Cáncer ha suspendido su publicación a partir del 16 de enero de 2013. El archivo del Boletín, que cuenta con todas las ediciones publicadas desde 2009 a 2013, permanecerá a disposición de los lectores en el sitio web del NCI.

157

Effect of in vitrofertilization medium on the acrosome reaction, cortical reaction, zona pellucida hardening and in vitro development in pigs.  

PubMed

Physiological events at the time of fertilization of pig oocytes may differ in vitro depending on the in vitro fertilization (IVF) medium. This hypothesis was tested by in vitro maturation of pig oocytes for 44 h in NCSU-37 medium and thereafter fertilization with frozen-thawed ejaculated spermatozoa. Three different IVF media (TCM-199, Tyrode's albumin lactate pyruvate (TALP) and Tris-buffered medium (TBM)) were used. For the acrosome reaction test, spermatozoa were incubated for 0-150 min in the three IVF media, and the proportion of live acrosome-reacted and acrosome-intact cells was determined by fluorescein isothiocyanate-labelled peanut agglutinin (FITC-PNA) and propidium iodide (PI) staining. The cortical granule density of oocytes was evaluated by confocal microscopy, 2.5 and 5.0 h after culture in each medium in the presence or absence of spermatozoa. Zona pellucida resistance to pronase digestion was also determined in the same groups. The percentages of penetration, monospermy, male pronucleus formation, cleavage and blastocyst formation, and the number of cells per blastocyst after culture were determined. The results indicate that the acrosome reaction occurred much faster in TBM than in TCM-199 or TALP medium. Continuous cortical granule synthesis was observed in the three media when oocytes were incubated in the absence of spermatozoa. The presence of spermatozoa triggered the cortical reaction in a large proportion of oocytes fertilized in TCM-199 and TALP media. On the basis of the duration of pronase digestion, the zona pellucida of oocytes incubated in TCM-199 was harder (407.7 +/- 35.5 s) than that of oocytes cultured in TALP (235.4 +/- 18.2 s) or TBM (189.1 +/- 16.8 s). No zona pellucida hardening was noted in oocytes after insemination in any of the media. The percentages of penetration and cleavage were higher in oocytes cultured in TCM-199 and TALP than in TBM. The percentage of monospermy was higher in TCM-199 and TBM than in TALP. No effect of the medium was shown on the percentage of blastocyst formation or on the number of cells per blastocyst. In conclusion, the results highlight how differently the fertilization events take place in each IVF medium and how far these IVF media still are from achieving biological properties of gametes close to those observed in the physiological setting. PMID:12141941

Coy, P; Gadea, J; Romar, R; Matás, C; García, E

2002-08-01

158

Immunogenicity of zona pellucida glycoprotein-3 and spermatozoa YLP(12) peptides presented on Johnson grass mosaic virus-like particles.  

PubMed

For safer and effective immunocontraception, zona (ZP3) and spermatozoa specific (YLP(12)) peptides have been presented on virus-like particles (VLPs) derived from Johnson grass mosaic virus coat protein. Immunization of FvB/cJ female mice with VLPs presenting YLP(12)-ZP3 fusion peptide and a physical mixture of VLPs presenting either YLP(12) or ZP3 epitope led to generation of specific antibody responses and a significant reduction in litters born per mice (p<0.005). Significant curtailment of fertility was also observed in animals immunized with adjuvnated ZP3 and YLP(12) synthetic peptides. These results suggest that VLPs can be used to present gamete epitopes for immunocontraception. PMID:19428905

Choudhury, Sangeeta; Kakkar, Varsha; Suman, Pankaj; Chakrabarti, Kausiki; Vrati, Sudhanshu; Gupta, Satish K

2009-05-14

159

Atrial natriuretic factor R sub 1 receptor from bovine adrenal zona glomerulosa: Purification, characterization, and modulation by amiloride  

SciTech Connect

The atrial natriuretic factor (ANF) R{sub 1} receptor from bovine adrenal zona glomerulosa was solubilized with Triton X-100 and purified 13,000-fold, to apparent homogeneity, by sequential affinity chromatography on ANF-agarose and steric exclusion high-performance liquid chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining of the purified receptor preparation in the absence or presence of dithiothreitol revealed a single protein band of M{sub r} 130,000. Affinity cross-linking of {sup 125}I-ANF to the purified receptor resulted in the labeling of the M{sub r} 130,000 band. The purified receptor bound ANF with a specific activity of 6.8 nmol/mg of protein, corresponding to a stoichiometry of 0.9 mol of ANF bound/mol of M{sub r} 130,000 polypeptide. Starting with 500 g of adrenal zona glomerulosa tissue, the authors obtained more than 500 pmol of purified receptor with an overall yield of 9%. The purified receptor showed a typical ANF-R{sub 1} pharmacological specificity similar to that of the membrane-bound receptor. The homogeneous M{sub r} 130,000 receptor protein displayed high guanylate cyclase activity (1.4 {mu}mol of cyclic GMP formed min{sup {minus}1} (mg of protein){sup {minus}1}) which was not stimulated by ANF. This finding supports the notion that the ANF binding and the guanylate cyclase activities are intrinsic components of the same polypeptide. Finally, the purified ANF-R{sub 1} receptor retained its sensitivity to modulation by amiloride, suggesting the presence of an allosteric binding site for amiloride on the receptor protein.

Meloche, S.; Ong, H.; De Lean, A. (Clinical Research Institute of Montreal, Quebec (Canada) Univ. of Montreal, Quebec (Canada)); McNicoll, M.; Liu, B. (Clinical Research Institute of Montreal, Quebec (Canada))

1988-10-18

160

Hardening of the zona pellucida of unfertilized eggs can reduce polyspermic fertilization in the pig and cow.  

PubMed

One of the proposed mechanisms of polyspermy block is an increased resistance of the zona pellucida (ZP) to proteolytic digestion (ZP hardening) as a consequence of cortical granule exocytosis that occurs soon after fertilization. However, evidence is available that the zonae pellucidae of freshly ovulated pig and cow oocytes harden considerably before fertilization. It was thought that such pre-fertilization ZP hardening could be involved in the control of polyspermy, and its lack in the oocytes matured in vitro could be one of the reasons for the extremely high incidence of polyspermy in pig in vitro fertilization (IVF). To test this hypothesis, two different types of cross-linking reagents were employed and their effects on ZP hardening and IVF efficiency were examined. The sulfhydryl-reactive cross-linkers produced a slight hardening of ZP (P<0.001) of treated oocytes compared with control oocytes, and totally inhibited sperm penetration into pig oocytes after IVF. In the cow, sperm penetration into eggs was reduced to 10%. It is proposed that formation of disulfide bonds in ZP or blocking of SH groups in the oocyte plasma membrane proteins prevents sperm penetration. An amine-reactive cross-linker was then assayed and produced strong ZP hardening, increasing the incidence of monospermy in both pig and cow oocytes after fertilization. When the cross-linker concentration was optimized, a 45% improvement for pig IVF efficiency was reached. It is proposed that the observed physiological ZP hardening is a mechanism to control polyspermy, differentially affecting various mammalian species and can be imitated by the use of amine-reactive cross-linkers during IVF. PMID:18159080

Coy, Pilar; Grullon, Luis; Canovas, Sebastian; Romar, Raquel; Matas, Carmen; Aviles, Manuel

2008-01-01

161

The opening of maitotoxin-sensitive calcium channels induces the acrosome reaction in human spermatozoa: differences from the zona pellucida.  

PubMed

The acrosome reaction (AR), an absolute requirement for spermatozoa and egg fusion, requires the influx of Ca²(+) into the spermatozoa through voltage-dependent Ca²(+) channels and store-operated channels. Maitotoxin (MTx), a Ca²(+)-mobilizing agent, has been shown to be a potent inducer of the mouse sperm AR, with a pharmacology similar to that of the zona pellucida (ZP), possibly suggesting a common pathway for both inducers. Using recombinant human ZP3 (rhZP3), mouse ZP and two MTx channel blockers (U73122 and U73343), we investigated and compared the MTx- and ZP-induced ARs in human and mouse spermatozoa. Herein, we report that MTx induced AR and elevated intracellular Ca²(+) ([Ca²(+)](i)) in human spermatozoa, both of which were blocked by U73122 and U73343. These two compounds also inhibited the MTx-induced AR in mouse spermatozoa. In disagreement with our previous proposal, the AR triggered by rhZP3 or mouse ZP was not blocked by U73343, indicating that in human and mouse spermatozoa, the AR induction by the physiological ligands or by MTx occurred through distinct pathways. U73122, but not U73343 (inactive analogue), can block phospholipase C (PLC). Another PLC inhibitor, edelfosine, also blocked the rhZP3- and ZP-induced ARs. These findings confirmed the participation of a PLC-dependent signalling pathway in human and mouse zona protein-induced AR. Notably, edelfosine also inhibited the MTx-induced mouse sperm AR but not that of the human, suggesting that toxin-induced AR is PLC-dependent in mice and PLC-independent in humans. PMID:20835262

Chávez, Julio C; de Blas, Gerardo A; de la Vega-Beltrán, José L; Nishigaki, Takuya; Chirinos, Mayel; González-González, María Elena; Larrea, Fernando; Solís, Alejandra; Darszon, Alberto; Treviño, Claudia L

2011-01-01

162

Tyrosine phosphorylation on capacitated human sperm tail detected by immunofluorescence correlates strongly with sperm-zona pellucida (ZP) binding but not with the ZP-induced acrosome reaction  

Microsoft Academic Search

BACKGROUND: Protein tyrosine phosphorylation (TP) of human sperm is related to sperm capacitation and zona pellucida (ZP) binding. The aim of this study was to determine whether the TP of capacitated sperm is a useful marker for the ability of sperm to bind to the ZP and undergo the ZP-induced acrosome reaction (AR). METHODS: Semen samples were obtained from 115

D. Y. Liu; G. N. Clarke; H. W. G. Baker

2005-01-01

163

Structure of the cumulus matrix and zona pellucida in the golden hamster: A new view of sperm interaction with oocyte-associated extracellular matrices  

Microsoft Academic Search

Hamster oocyte-cumulus complexes (OCC), with and without sperm, were structurally analyzed by light- and electron microscopy using freeze substitution. This method has yielded a clear picture of the extracellular oocyte investments, the cumulus cell matrix and the zona pellucida. The cumulus matrix has an overall homogeneous fibrillar structure which appears to attach to cumulus cells at their filopodial extensions. The

Ashley I. Yudin; Gary N. Cherr; David F. Katz

1988-01-01

164

Effect of chronic administration of methamphetamine on the responsiveness of substantia nigra zona reticulata neurons to GABA or a GABA agonist in rats  

Microsoft Academic Search

The effects of chronic administration of methamphetamine on the responsiveness of neurons of the substantia nigra zona reticulata (SNR) to gammaaminobutyric acid (GABA) or to a GABA receptor agonist were examined. Neuronal activity was recorded from the SNR of rats that had been pretreated twice daily, for 6 consecutive days, with saline or with 5 mg\\/kg methamphetamine. Intravenous administration of

Katsuo Kamata; Tsutomu Kameyama

1986-01-01

165

PRIMER REPORTE SOBRE FOTOSENSIBILIZACION CAUSADA POR Pithomices chartarum EN BORREGOS PASTOREANDO Brachiaria brizantha. EN LA ZONA CENTRO DEL ESTADO DE TAMAULIPAS  

Microsoft Academic Search

RESUMEN: La creciente explosión demográfica, sobre todo en los países subdesarrollados, como lo es México, se han dado a la tarea de aumentar los productos alimentarios de origen animal por citar un ejemplo, la explotación de ovinos, mismo que a su vez se buscan nuevas alternativas para su alimentación, sobre todo con costos mínimos, por ello la utilización de recursos

O. S. Escamilla Gallegos; P. Zárate Fortuna; M. Rodríguez Morales; J. García Jiménez; M. González

166

Application of a zona pellucida binding assay (ZBA) in the domestic cat benefits from the use of in vitro matured oocytes  

PubMed Central

Background Zona pellucida binding assays (ZBAs) have proven useful in determining the fertilising ability of spermatozoa in several species. Most ZBAs use fresh or salt-stored oocytes collected from fresh ovaries but because ovaries are not easy to obtain on a regular basis, chilled and frozen-thawed ovaries have been tested, with varying results. The present study tested the hypothesis that cat spermatozoa, either fresh or frozen-thawed, can bind to homologous zona pellucida of oocytes retrieved from frozen-thawed queen ovaries to a similar extent as they can bind to the zona pellucida of fresh, in vitro matured oocytes. Methods Ovaries were collected from queens after routine ovario-hysterectomy and either stored in NaCl at -20°C until use (treatment animals), or used fresh (controls). Cumulus-oocyte complexes (COCs) were retrieved by ovarian slicing from either source and used directly (immature oocytes from frozen-thawed ovaries; treatment animals) or after in vitro maturation (IVM) (fresh ovaries; controls) for 24 hours in TCM 199, supplemented with 1 IU hCG/mL and 0.5 IU eCG/mL and 0.5% bovine serum albumin (BSA). The oocytes were incubated for 4 hours in 5% CO2 in air at 38°C and 100% humidity in the presence of 5 × 106 fresh or frozen-thawed spermatozoa/mL. Representative samples of oocytes were processed for scanning electron microscopy (SEM). Results Both fresh and frozen-thawed spermatozoa bound to the in vitro matured zona pellucida but significantly fewer, or no, spermatozoa bound to frozen-thawed, immature zona pellucida (P < 0.001). Also, more fresh spermatozoa than frozen-thawed spermatozoa bound to the zona pellucida (P < 0.001). The zona pellucida surface differed in morphology (SEM), with in vitro matured oocytes showing a dense surface with few fenestrations in contrast to their frozen-thawed, immature counterparts, where fenestrations were conspicuously larger. Conclusion In conclusion, under the conditions of the present study, immature oocytes recovered from ovaries frozen immersed in NaCl at -20°C are less suitable for use in feline ZBA.

Hermansson, Ulrika; Axner, Eva; Holst, Bodil Strom

2007-01-01

167

La teoria del pendolo  

Microsoft Academic Search

Il silenzio era tale che, ascoltando attentamente, si sarebbe potuto udire la voce dell'anima. Era proprio questo il motivo per cui Galileo si alzava ogni mattina di buon ora per dire le sue orazioni innanzi al maestoso altare del duomo. Guardava a lungo le volte intorno a lui cercando con lo sguardo la perfezione del creato e poi, con l'ambiguità

Di Claudio Chillemi

168

Evaluación del desempeño integral del sector transporte  

Microsoft Academic Search

Las organizaciones hoy por hoy buscan aplicar un sistema de indicadores que evalúe la gestión y el desempeño del sector transporte en materia económica, social, ambiental e integral, con el fin de garantizar a las partes interesadas una información confiable sobre los resultados de desempeño frente al desarrollo sostenible, que facilite el ingreso a mercados nacionales e internacionales a partir

Clara Inés Pardo Martínez

2007-01-01

169

Boletín del Instituto Nacional del Cáncer - 07-20-2010  

Cancer.gov

El doctor Harold Varmus, acompañado de su esposa Constance Casey (centro), presta juramento como director del NCI ante la Secretaria del Departamento de Salud y Servicios Humanos, Kathleen Sebelius, el lunes 12 de julio. (Foto cortesía de Chris Smith) El 12 de julio, el doctor Harold Varmus prestó juramento ante la Secretaria del Departamento de Salud y Servicios Humanos de los Estados Unidos, Kathleen Sebelios, como el decimocuarto director del Instituto Nacional del Cáncer.

170

Hojas informativas del NCI  

Cancer.gov

La colección de hojas informativas del NCI trata de una variedad de temas relacionados con el cáncer. Las hojas informativas se revisan y ponen al día de acuerdo a las investigaciones más recientes sobre el cáncer.

171

Il problema del litio.  

NASA Astrophysics Data System (ADS)

Contents: 1. Introduzione. 2. La nucleosintesi del Big Bang. 3. Il litio nelle stelle di popolazione II. 4. I modelli stellari standard. 5. Il litio negli ammassi aperti. 6. Meccanismi di distruzione "non standard". 7. I modelli non-standard applicati alla popolazione II. 8. L'evoluzione Galattica del litio. 9. Quali stelle producono litio? 10. Il litio come elemento chiave per dare un nome agli oggetti stellari più minuscoli. 11. Conclusioni.

D'Antona, F.

1995-03-01

172

Amenazas comerciales del Acuerdo Can-Mercosur para los sectores productivos del Valle del Cauca  

Microsoft Academic Search

El Acuerdo de Complementación Económica, suscrito entre la Comunidad Andina (CAN) y el Mercado Común del Sur (MERCOSUR), marca un avance hacia una integración económica y política más profunda en América Latina. Por tal razón, el objetivo del presente artículo es identificar los sectores del Valle del Cauca que revelan desventajas competitivas relativas, por lo que se pueden ver potencialmente

Lya Paola Sierra Suárez; José Tomás Peláez Soto

2008-01-01

173

EL DESARROLLO DEL PENSAMIENTO CRÍTICO DEL ESTUDIANTE. UNA FINALIDAD EDUCATIVA PENDIENTE DEL ÁREA CURRICULAR ESTUDIOS SOCIALES  

Microsoft Academic Search

Esta investigación tuvo como objetivo determinar las características del proceso instruccional en la tercera etapa del nivel de Educación Básica que contribuyen al desarrollo del pensamiento crítico del estudiante para satisfacer el imperativo legal vigente desde julio de 1980, particularmente para el área curricular Estudios Sociales. Durante cuatro años escolares en dos instituciones educativas que ofrecen el precitado nivel se

Haydée Páez

174

Espectroscopia del Cometa Halley  

NASA Astrophysics Data System (ADS)

Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.

Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.

1987-05-01

175

Expression of two zona pellucida genes is regulated by 17?-ethinylestradiol in adult rare minnow Gobiocypris rarus.  

PubMed

Zona pellucida (ZP) proteins are glycoproteins synthesized in liver, ovary or in both tissues in fish. In the present study, we aimed to determine the responsiveness of ZP2 and ZP3 to 17?-ethinylestradiol (EE2) in adult rare minnow Gobiocypris rarus. The full length of ZP3 cDNA was firstly characterized and its tissue distribution revealed that ZP3 mRNA was predominantly expressed in ovary of G. rarus. The gene expression profiles of ZP2, ZP3 and vitellogenin (VTG) were analyzed in gonad and liver of adult G. rarus exposed to EE2 at 1, 5, 25, and 125 ng/L for 3 and 6 days. The results show that ZP2 is more sensitive than ZP3 in gonads of both genders, and VTG in liver is extremely sensitive to EE2 in male fish. However, at lower concentrations (1 and 5 ng/L), the ZP2 in testes shows higher responsiveness to EE2 compared with VTG in rare minnow. The 5' flanking regions of ZP2 and ZP3 were isolated and the comparison of transcription factors in the regions of ZP2 and ZP3 suggested that the disparity for the responsiveness of ZP2 and ZP3 to EE2 could partly be a result of differential cis-elements such as oocyte-specific protein (Osp1) binding sites or/and sex-determining region Y (SRY) binding site. PMID:23603245

Yuan, Cong; Zhang, Yingying; Hu, Guojun; Li, Meng; Zheng, Yao; Gao, Jiancao; Yang, Yanping; Zhou, Ying; Wang, Zaizhao

2013-06-01

176

Traditional intracytoplasmic sperm injection provides equivalent outcomes compared with human zona pellucida-bound selected sperm injection.  

PubMed

Summary The capability of human zona pellucida (ZP) to bind selectively to normal functional sperm with normal chromatin has been reported widely in the literature. The aim of this study was to evaluate whether ZP-binding sperm selection may represent a method to retrieve superior spermatozoa for intracytoplasmic sperm injection (ICSI). Patients were divided into two groups: a ZP-ICSI and a conventional ICSI group. In the ZP-ICSI group, spermatozoa for injection were selected after ZP-sperm incubation and spermatozoa that were tightly bound to the ZP were used for ICSI (ZP-ICSI). Clinical outcomes of ZP-ICSI were compared with the outcomes of traditional scientist-selected sperm injection (conventional ICSI). Results did not show any significant difference in fertilization, pregnancy, implantation and take-home-baby rates between conventional ICSI and ZP-ICSI. However, when data relative to patients who received ZP-ICSI were analyzed, an interesting result was observed: higher sperm concentration and morphology correlated with higher ZP-sperm binding. Additionally, patients with higher ZP-sperm binding seem to have improved pregnancy and take-home-baby rates. In conclusion, this study shows that ZP-ICSI is not a superior method compared with conventional ICSI. However, clinical ICSI outcomes were apparently improved in the presence of good ZP-sperm binding. We therefore speculate that sperm competence to ICSI could be reduced when the sperm's ability to bind the ZP is impaired. PMID:23659189

Casciani, Valentina; Minasi, Maria Giulia; Fabozzi, Gemma; Scarselli, Filomena; Colasante, Alessandro; Lobascio, Anna Maria; Greco, Ermanno

2013-05-01

177

Capacitation in the presence of methyl-?-cyclodextrin results in enhanced zona pellucida-binding ability of stallion spermatozoa.  

PubMed

While IVF has been widely successful in many domesticated species, the development of a robust IVF system for the horse remains an elusive and highly valued goal. A major impediment to the development of equine IVF is the fact that optimised conditions for the capacitation of equine spermatozoa are yet to be developed. Conversely, it is known that stallion spermatozoa are particularly susceptible to damage arising as a consequence of capacitation-like changes induced prematurely in response to semen handling and transport conditions. To address these limitations, this study sought to develop an effective system to both suppress and promote the in vitro capacitation of stallion spermatozoa. Our data indicated that the latter could be achieved in a bicarbonate-rich medium supplemented with a phosphodiesterase inhibitor, a cyclic AMP analogue, and methyl-?-cyclodextrin, an efficient cholesterol-withdrawing agent. The populations of spermatozoa generated under these conditions displayed a number of hallmarks of capacitation, including elevated levels of tyrosine phosphorylation, a reorganisation of the plasma membrane leading to lipid raft coalescence in the peri-acrosomal region of the sperm head, and a dramatic increase in their ability to interact with heterologous bovine zona pellucida (ZP) and undergo agonist-induced acrosomal exocytosis. Furthermore, this functional transformation was effectively suppressed in media devoid of bicarbonate. Collectively, these results highlight the importance of efficient cholesterol removal in priming stallion spermatozoa for ZP binding in vitro. PMID:24194571

Bromfield, Elizabeth G; Aitken, R John; Gibb, Zamira; Lambourne, Sarah R; Nixon, Brett

2014-02-01

178

Pertussis toxin treatment does not block inhibition by atrial natriuretic factor of aldosterone secretion in cultured bovine zona glomerulosa cells  

SciTech Connect

The authors have previously reported that atrial natriuretic factor (ANF) potently inhibits PGE or forskolin-stimulation aldosterone secretion in bovine zona glomerulosa (ZG) by acting through specific high affinity receptors. In order to evaluate the functional role of the regulatory protein N/sub i/ and the inhibition of adenylate cyclase activity (AC) in ZG, the authors have studied the effect of treatment with PT on inhibition by ANF of aldosterone production. Primary cultures of ZG were treated for 18 hours in serum-free F12 medium with (0-100 ng/ml PT). No effect of PT pretreatment was observed either on basal, PGE-stimulated or ANF-inhibited levels of steroidogenesis. When membranes prepared from control ZG were ADP-ribosylated with (/sup 32/P) NAD in the presence of PT, two toxin-specific bands with 39 Kd and 41 Kd were documented on SDS gel. Cell pretreatment with as low as 1 ng/ml drastically reduced further labelling of these two bands while higher doses completely abolished them. Since PT treatment covalently modifies completely the toxin substrate without altering ANF inhibition of adrenal steroidogenesis, the authors conclude that N/sub i/ is not involved in the mode of action of ANF on aldosterone production.

De Lean, A.; Cantin, M.

1986-03-05

179

[Oral immunization of Lugurus lugurus with the plasmid nanoemulsion of zona pellucida 3 to enhance infertility effects].  

PubMed

Immunocontraceptive technology is beginning to attract more attention for the control of wild mouse or other pest animals. Oral vaccination of animals and man, to provide effective mucosal and/or systemic immunity, is a good delivery system, but it remains poor bioavailablity, one of the most promising strategies to improve the oral delivery relies on polymeric nanoparticles carriers to encapsulate vaccine. Nanoemulsion was used as the carriers of oral immunization of Lugurus Lugurus zona pellucida 3, the immune response and antifertility potential of this vaccine is valuated. Nanoemulsion-encapsulated plasmid pcDNA3.0-Aat-COMP-lzp3-C3d3 (pACLC DNA vaccine) was prepared and evaluated the encapsulation efficiency by anion exchange chromatography. The mice were orally delivered with nanoemulsion-encapsulated plasmid, to detect specific IgG in serum and IgA in vaginal fluid by indirect ELISA, and to perform fertility experiment, to do histological analysis of immunized mice ovary. The results showed that the specific IgG and IgA antibody is elicited, the fertility rate is deceased at a certain extent. In conclusion, it is feasible that nanoemulsion is used as the carriers of oral immunization. PMID:19697700

Zhang, Ai Lian; Zhuang, Shu Zhen; Wu, Dao Cheng; Li, Yi Jie; Zhang, Fu Chun

2009-06-01

180

Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus in Patients with Parkinson's Disease: Effects on Voice Intensity  

PubMed Central

Deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with Parkinson's disease (PD) affects speech inconsistently. Recently, stimulation of the caudal zona incerta (cZi-DBS) has shown superior motor outcomes for PD patients, but effects on speech have not been systematically investigated. The aim of this study was to compare the effects of cZi-DBS and STN-DBS on voice intensity in PD patients. Mean intensity during reading and intensity decay during rapid syllable repetition were measured for STN-DBS and cZi-DBS patients (eight patients per group), before- and 12 months after-surgery on- and off-stimulation. For mean intensity, there were small significant differences on- versus off-stimulation in each group: 74.2 (2.0)?dB contra 72.1 (2.2)?dB (P = .002) for STN-DBS, and 71.6 (4.1)?dB contra 72.8 (3.4)?dB (P = .03) for cZi-DBS, with significant interaction (P < .001). Intensity decay showed no significant changes. The subtle differences found for mean intensity suggest that STN-DBS and cZi-DBS may influence voice intensity differently.

Lundgren, Sofie; Saeys, Thomas; Karlsson, Fredrik; Olofsson, Katarina; Blomstedt, Patric; Linder, Jan; Nordh, Erik; Zafar, Hamayun; van Doorn, Jan

2011-01-01

181

Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus in Patients with Parkinson's Disease: Effects on Diadochokinetic Rate  

PubMed Central

The hypokinetic dysarthria observed in Parkinson's disease (PD) affects the range, speed, and accuracy of articulatory gestures in patients, reducing the perceived quality of speech acoustic output in continuous speech. Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) and of the caudal zona incerta (cZi-DBS) are current surgical treatment options for PD. This study aimed at investigating the outcome of STN-DBS (7 patients) and cZi-DBS (7 patients) in two articulatory diadochokinesis tasks (AMR and SMR) using measurements of articulation rate and quality of the plosive consonants (using the percent measurable VOT metric). The results indicate that patients receiving STN-DBS increased in articulation rate in the Stim-ON condition in the AMR task only, with no effect on production quality. Patients receiving cZi-DBS decreased in articulation rate in the Stim-ON condition and further showed a reduction in production quality. The data therefore suggest that cZi-DBS is more detrimental for extended articulatory movements than STN-DBS.

Karlsson, Fredrik; Unger, Elin; Wahlgren, Sofia; Blomstedt, Patric; Linder, Jan; Nordh, Erik; Zafar, Hamayun; van Doorn, Jan

2011-01-01

182

Effect of the size of zona pellucida opening on hatching in the common marmoset monkey (Callithrix jacchus) embryo.  

PubMed

The use of the common marmoset monkey in biomedical research has increased recently, and further attention has been devoted to this model after the successful production of transgenic marmosets. To extend genetic engineering approaches to widespread biomedical research fields, efficient prolonged in vitro culturing of embryo development is necessary. We aimed to evaluate the effects of the size of the zona pellucida opening on promoting the hatching process in the marmoset embryo. Piezo-microdrilling of a 6-?m opening in eight embryos resulted in four partially hatched embryos and one hatched embryo after 5 days of culture. Piezo-microdrilling a 20-?m opening in 11 embryos resulted in nine partial hatchings and no hatched embryos. Piezo-scraping an 80-?m opening in six embryos resulted in no partially hatched embryos and five hatched embryos. These results suggest that an 80-?m opening, rather than 6-?m or 20-?m openings, is suitable to complete the hatching process in the marmoset embryo. PMID:24000827

Ishibashi, Hidetoshi; Motohashi, Hideyuki H; Kumon, Mami; Yamamoto, Kazuhiro; Okada, Hironori; Okada, Takashi; Seki, Kazuhiko

2013-11-01

183

Frequency of disordered zona pellucida (ZP)-induced acrosome reaction in infertile men with normal semen analysis and normal spermatozoa-ZP binding  

Microsoft Academic Search

Results of zona pellucida (ZP)-induced acrosome reaction (AR) are reported for 186 normospermic men with unexplained infertility and compared with 34 normal fertile men and 54 patients with disordered ZP-induced AR (DZPIAR) diagnosed after failure of standard IVF. For each ZP-induced AR test, four oocytes that failed to fertilize in IVF were incubated for 2 h with 2106\\/ml motile spermatozoa.

Yi Liu; Gary N. Clarke; Mirjana Martic; Claire Garrett; H. W. Gordon Baker

184

Interference of antisperm antibodies with the induction of the acrosome reaction by zona pellucida (ZP) and its relationship with the inhibition of ZP binding  

Microsoft Academic Search

Objective: To determine whether antisperm antibodies can interfere with the induction of the acrosome reaction (AR) by the zona pellucida (ZP) and whether this interference also can occur in the absence of an inhibitory effect on ZP binding.Design: Prospective in vitro study.Setting: A tertiary care center, the Andrologic Clinic, University of L'Aquila.Patient(s): Sera from 12 infertile patients with high titers

Felice Francavilla; Rossella Romano; Riccardo Santucci; Virginia Marrone; Giuliana Properzi; Giovanni Ruvolo

1997-01-01

185

Interference with the 19S proteasomal regulatory complex subunit PSMD4 on the sperm surface inhibits sperm-zona pellucida penetration during porcine fertilization  

Microsoft Academic Search

Proteolysis of ubiquitinated sperm and oocyte proteins by the 26S proteasome is necessary for the success of mammalian fertilization,\\u000a including but not limited to acrosomal exocytosis and sperm-zona pellucida (ZP) penetration. The present study examined the\\u000a role of PSMD4, an essential non-ATPase subunit of the proteasomal 19S regulatory complex responsible for proteasome-substrate\\u000a recognition, in sperm-ZP penetration during porcine fertilization in

Young-Joo Yi; Gaurishankar Manandhar; Miriam Sutovsky; Shawn W. Zimmerman; V?ra Jonáková; Fred W. van Leeuwen; Richard Oko; Chang-Sik Park; Peter Sutovsky

2010-01-01

186

Expression patterns of Brx1 ( Rieg gene), Sonic hedgehog, Nkx2.2, Dlx1 and Arx during zona limitans intrathalamica and embryonic ventral lateral geniculate nuclear formation  

Microsoft Academic Search

The Brx1 homeobox gene has been isolated and shown to be expressed in the zona limitans intrathalamica (ZLI) of the mouse embryo. Brx1 is a member of the Brx gene family and comprises the genes for Brx1a and Brx1b, which differ in the sequence in the region located on the 5?-terminal side of the homeobox. The complete amino acid sequences

Kunio Kitamura; Hirohito Miura; Masako Yanazawa; Toshio Miyashita; Kentaro Kato

1997-01-01

187

Zona pellucida thickness variation and occurrence of visible mononucleated blastomeres in preembryos are associated with a high pregnancy rate in IVF treatment  

Microsoft Academic Search

Purpose: The ability of six morphological criteria (embryo development rate, fragmentation, regularity of blastomere shape, equality\\u000a of blastomere size, zona pellucida thickness variation [ZPTV], and visible mononucleated blastomeres [VMBs]) to predict pregnancy\\u000a in IVF treatment cycles was evaluated.\\u000a \\u000a \\u000a Methods: In order to select a homogeneous study group, 85 consecutive nulliparous couples with single tubal infertility undergoing\\u000a their first IVF treatment

Måns Palmstierna; Daniel Murkes; György Csemiczky; Ola Andersson; Håkan Wramsby

1998-01-01

188

Olig2 Lineage Cells Generate GABAergic Neurons in the Prethalamic Nuclei, Including the Zona Incerta, Ventral Lateral Geniculate Nucleus and Reticular Thalamic Nucleus  

Microsoft Academic Search

Neuronal differentiation is a crucial event during neural development. Recent studies have characterized the development of the diencephalon; however, the origins of the primarily GABAergic prethalamic nuclei, including the zona incerta (ZI), ventral lateral geniculate nucleus (vLG) and reticular thalamic nucleus (RT), remain unclear. Here we characterize Olig2 lineage cells in the developing prethalamus using mice in which tamoxifen-induced recombination

Naoko Inamura; Katsuhiko Ono; Hirohide Takebayashi; Bernard Zalc; Kazuhiro Ikenaka

2011-01-01

189

Boletín del Instituto Nacional del Cáncer  

Cancer.gov

No se puede negar que vivimos en una comunidad global, en la que los eventos de una ciudad o país pueden tener graves consecuencias para los residentes de otra ciudad o país a miles de kilómetros de distancia. Ya sea la pandemia del virus H1N1, los recientes disturbios en Irán o la recesión económica mundial, es evidente que esta interconectividad trae consigo retos importantes. Pero también puede crear oportunidades sin precedentes, en particular aquellas que podrían mejorar sustancialmente la salud pública.

190

Platelet activating factor improves the in vitro penetration of zona free hamster eggs by buffalo (Bubalus bubalis) spermatozoa.  

PubMed

Twelve buffalo bulls of Murrah breed, selected on the basis of their conception rates, were classified into low-, moderate- and high-fertility groups. Frozen semen was thawed and treated with 200 microM platelet activating factor (PAF) for 15 min at 37 degrees C and 5% CO2. In both treated and control (no PAF) semen samples (five replicates per bull), the following were assessed: motility, acrosome reaction (AR) evaluation (for 10 replicates of each bull), and zona-free hamster oocyte penetration test--to determine aspects of fertilization in vitro, viz., sperm attached per ovum (SA/O), fertilization percent (FP), fertilization index (FI), and polyspermic ova (PO). There was an effect of group (P < 0.01) on all parameters; all except motility were increased by PAF treatment. However, the group X treatment interaction was not significant for any parameter. The overall mean values of motility, AR, SA/O, FP, FI, and PO, for controls, treated spermatozoa and (net change) were: 42.89 +/- 0.85, 36.65 +/- 0.85, (-6.24); 28.94 +/- 0.46, 61.44 +/- 0.58, (32.50); 126 +/- 2, 145 +/- 2, (19); 74.21 +/- 1.59, 89.11 +/- 1.18, (14.90); 0.79 +/- 0.02, 1.10 +/- 0.03, (0.31) and 5.22 +/- 1.22, 21.69 +/- 1.88, (16.47)%, respectively. In conclusion, PAF significantly increased the AR and other aspects of fertilization, despite a small reduction in motility. PMID:15763101

Kumar, Subodh; Sharma, Arjava

2005-04-01

191

Raman microspectroscopy as a non-invasive tool to assess the vitrification-induced changes of ovine oocyte zona pellucida.  

PubMed

Cryopreservation-induced modifications of zona pellucida (ZP) have been explored to a lesser extent compared to other oocyte compartments. Different methods have been applied to identify ZP changes, but most of them are invasive and measure only few properties of ZP. Raman microspectroscopy (RMS) is a powerful technique for studying the molecular composition of cells but to date few studies have been performed on the oocytes using this method. The aim of the present study is to investigate the structural modifications of ZP of vitrified/warmed in vitro matured ovine oocytes by means of RMS. Cumulus-oocyte complexes were recovered from the ovaries of slaughtered adult sheep, matured in vitro and vitrified following the Minimum Essential Volume method using cryotops. ZPs of vitrified/warmed oocytes (VITRI), were exposed to vitrification solutions but not cryopreserved (CPA-exp) and untreated oocytes (CTR) were analyzed by RMS. We focused our analysis on the ZP protein and carbohydrate components by analyzing the 1230-1300 cm(-1) amide III region and the 1020-1140 cm(-1) spectral range in RMS spectra, respectively. The spectral profiles in the ranges of proteins and carbohydrates were comparable between CTR and CPA-exp ZPs, whereas VITRI ZPs showed a significantly altered protein secondary structure characterized by an increase in ?-sheet content and a decrease in the ?-helix content. A significant modification of the carbohydrate components was also observed. This study demonstrates that vitrification of ovine oocytes induces biochemical changes of ZP related to the secondary structure of proteins and carbohydrate residues. Cryoprotectants do not strongly alter the molecular composition of ZP which is affected mainly by cooling. Raman technology offers a powerful and non-invasive tool to assess molecular modifications induced by cryopreservation in oocytes. PMID:22387147

Bogliolo, Luisa; Ledda, Sergio; Innocenzi, Plinio; Ariu, Federica; Bebbere, Daniela; Rosati, Irma; Leoni, Giovanni Giuseppe; Piccinini, Massimo

2012-06-01

192

Connexin 43 Interacts with Zona Occludens-1 and -2 Proteins in a Cell Cycle Stage-specific Manner*  

PubMed Central

Gap junction channels play an important role in cell growth control, secretion and embryonic development. Gap junctional communication and channel assembly can be regulated by protein-protein interaction with kinases and phosphatases. We have utilized tandem mass spectrometry (MS/MS) sequence analysis as a screen to identify proteins from cell lysates that interact with the C-terminal cytoplasmic region of connexin 43 (Cx43). MS/MS analysis of tryptic fragments yielded several proteins including zona occludens-1 (ZO-1), a structural protein previously identified to interact with Cx43, and ZO-2, a potential novel interacting partner. We confirmed the interaction of ZO-2 with Cx43 by using a combination of fusion protein “pull down,” co-immunoprecipitation, and co-localization experiments. We show that the C-terminal region of Cx43 is necessary for interaction with the PDZ2 domain of ZO-2. Far Western analysis revealed that ZO-2 can directly bind to Cx43 independent of other interacting partners. Immunofluorescence studies indicate that both ZO-1 and ZO-2 can co-localize with Cx43 within the plasma membrane at apparent gap junctional structures. We examined Cx43 interaction with ZO-1 and ZO-2 at different stages of the cell cycle and found that Cx43 had a strong preference for interaction with ZO-1 during G0, whereas ZO-2 interaction occurred approximately equally during G0 and S phases. Since essentially all of the Cx43 in G0 cells is assembled into Triton X-100-resistant junctions, Cx43-ZO-1 interaction may contribute to their stability.

Singh, Deepika; Solan, Joell L.; Taffet, Steven M.; Javier, Ronald; Lampe, Paul D.

2012-01-01

193

Molecular characterization and expression pattern of three zona pellucida 3 genes in the Chinese sturgeon, Acipenser sinensis.  

PubMed

Chinese sturgeon (Acipenser sinensis) is a rare and endangered species and also an important resource for the sturgeon aquaculture industry. SMART cDNAs were synthesized from the ovary of A. sinensis, and the full-length cDNAs of three zona pellucida glycoprotein 3 genes (the new gene named AsZP3) were cloned and sequenced. AsZP3.1, AsZP3.2, and AsZP3.3 were 1,388 base pairs (bp), 1,288, and 1,290 bp in length, respectively, and they could be translated into proteins with 440, 394, and 398 amino acids, respectively. High level of amino acids sequence identity was seen between AsZP3.2 and AsZP3.3 (about 82%), but they share low identity with AsZP3.1 (26 and 23%, respectively). The AsZP3.1 has 42-50% amino acids sequence identity values with other fish and lower values with higher vertebrates (38%); AsZP3.2 and AsZP3.3 shared about 30-44% sequence identity with higher vertebrates and other fish. RT-PCR analysis indicated that AsZP3.1 displayed a wide tissue distribution at the mRNA levels including liver, kidney, spleen, heart, and ovary, but AsZP3.2 and AsZP3.3 mRNAs were expressed exclusively in the gonad. All three AsZP3 mRNAs were not detected during embryogenesis and early larval development; furthermore, they were not detected in the gonads of 1- and 2-year-old Chinese sturgeons. All three AsZP3 mRNAs were detected in the testes of 3-year-old males and in the ovaries of 4- and 5-year-old female Chinese sturgeons. PMID:21072685

Chuang-Ju, Li; Qi-Wei, Wei; Xi-Hua, Chen; Li, Zhou; Hong, Cao; Fang, Gan; Jian-Fang, Gui

2011-09-01

194

Pruebas de Papanicolaou y del virus del papiloma humano (VPH)  

Cancer.gov

Hoja informativa que describe los exámenes selectivos de detección del cáncer de cérvix, los cuales incluyen la prueba de Papanicolaou y la prueba de los virus del papiloma humano. La hoja informativa incluye también información acerca de las pautas de exámenes de detección del cáncer de cérvix.

195

Instantánea del cáncer de esófago  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de esófago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

196

Instantánea del cáncer de próstata  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de próstata; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

197

Instantánea del cáncer de estómago  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de estómago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

198

Instantánea del sarcoma de Kaposi  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma de Kaposi; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

199

Instantánea del cáncer de tiroides  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de tiroides; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

200

Instantánea del cáncer de ovario  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de ovario; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

201

Instantánea del cáncer de endometrio  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de endometrio; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

202

Instantánea del cáncer de vejiga  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de vejiga; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

203

Instantánea del cáncer de riñón  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de riñón; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

204

Instantánea del cáncer de páncreas  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de páncreas; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

205

Instantánea del cáncer de pulmón  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de pulmón; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

206

Zona Land: Energy  

NSDL National Science Digital Library

This item is a tutorial on work and energy designed and maintained by a high school physics teacher. Topics include kinetic and potential energy, spring potential energy, GPE, heat and temperature, and nuclear energy. The author uses an entertaining blend of text and interactive simulations to engage the student. NOTE: The full potential of this resource cannot be viewed without a VRML plug-in. This item is part of a larger collection of physics and mathematics resources by the author.

Zobel, Edward

2007-10-23

207

Zona Land: Waves  

NSDL National Science Digital Library

This item is a tutorial on the fundamentals of waves. Topics include wave properties and phenomena, types of waves, wave interference, and more. The section on interference includes simple animations of constructive and destructive interference, which can be played in slow motion to allow users to visualize the phenomena before attempting more difficult wave simulations.

Zobel, Edward

2009-03-22

208

Coculturing cumulus oocyte complexes with denuded oocytes alters zona pellucida ultrastructure in in vitro matured bovine oocytes.  

PubMed

Oocyte quality is a key factor affecting success of in vitro embryo production in cattle. Improving the microenvironment of oocytes during in vitro maturation (IVM) can increase developmental rate and embryo quality. Therefore, the objective was to determine whether denuded oocytes (DO) affect embryo development and ultrastructure of the zona pellucida (ZP) in in vitro matured bovine oocytes. Intact immature cumulus-oocytes complexes (COC) obtained from a local abattoir or by ovum pick-up (OPU) were cocultured with and without abattoir-obtained DO at a COC:DO ratio of 1:5. After IVM, DO were removed and intact DO were either fertilized or observed by scanning electron microscopy. Blastocyst quality was evaluated using a TUNEL assay. The ZP pore size decreased after IVM in COC + DO coculture, regardless of their origin (OPU, 310.5 ± 92.5 vs. 428.9 ± 148.5 nm; abattoir, 317.5 ± 68.5 vs. 358.9 ± 128.5 nm; P < 0.05; mean values ± standard deviation). Moreover, the number of ZP pores in OPU COC + DO and COC + DO was greater than those in OPU COC and COC (control) groups (56 ± 4 and 55 ± 7 vs. 50 ± 6 and 42 ± 4; P < 0.05). The rate of blastocyst development in COC + DO and OPU COC + DO groups was greater those in control and OPU COC groups (36.6% and 55.5% vs. 28.1% and 40.0%; P < 0.05). Moreover, the total cell numbers of blastocysts in COC + DO group exceeded that of control (132.91 ± 30.90 vs. 115.44 ± 24.95; P < 0.05), with no significant between OPU COC + DO and OPU COC groups (139.31 ± 42.51 vs. 137.00 ± 61.34). In conclusion, in vitro embryo development competence and quality improved when oocytes were cocultured with DO. Furthermore, there more, but smaller, ZP pores. PMID:24084231

Choi, Byung-Hyun; Bang, Jae-Il; Jin, Jong-In; Kim, Seong-Su; Jo, Hyun-Tae; Deb, Gautam Kumar; Ghanem, Nasser; Cho, Kyu-Woan; Kong, Il-Keun

2013-12-01

209

Fecal 20-oxo-pregnane concentrations in free-ranging African elephants (Loxodonta africana) treated with porcine zona pellucida vaccine.  

PubMed

Because of overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. In this regard, the potential use of the porcine zona pellucida (pZP) vaccine as an effective means for population control is explored. While potential effects of pZP treatment on social behavior of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. In this study, ovarian activity of free-ranging, pZP-treated African elephant females was monitored noninvasively for 1 yr at Thornybush Private Nature Reserve, South Africa, by measuring fecal 5?-pregnan-3?-ol-20-on concentrations via enzyme immunoassay. A total of 719 fecal samples from 19 individuals were collected over the study period, averaging 38 samples collected per individual (minimum, maximum: 16, 52). Simultaneously, behavioral observations were made to record the occurrence of estrous behavior for comparison. Each elephant under study showed 5?-pregnan-3?-ol-20-on concentrations rising above baseline at some period during the study indicating luteal activity. Average 5?-pregnan-3?-ol-20-on concentrations were 1.61 ± 0.46 ?g/g (mean ± SD). Within sampled females, 42.9% exhibited estrous cycles within the range reported for captive African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average estrous cycle duration was 14.72 ± 0.85 wk. Estrous behavior coincided with the onset of the luteal phase and a subsequent rise in 5?-pregnan-3?-ol-20-on concentrations. Average 5?-pregnan-3?-ol-20-on levels positively correlated with rainfall. No association between average individual 5?-pregnan-3?-ol-20-on concentrations or cyclicity status with age or parity were detected. Earlier determination of efficacy was established via fecal hormone analysis with no pregnancies determined 22 mo post-treatment and onward. Results indicate the presence of ovarian activity amongst pZP-treated female African elephants in 2 yr after initial immunization. Further study should now be aimed toward investigating the long-term effects of pZP vaccination on the reproductive function of female African elephants. PMID:22444560

Ahlers, M J; Ganswindt, A; Münscher, S; Bertschinger, H J

2012-07-01

210

Do age and extended culture affect the architecture of the zona pellucida of human oocytes and embryos?  

PubMed

Advanced female age and extended in vitro culture have both been implicated in zona pellucida (ZP) hardening and thickening. This study aimed to determine the influence of (i) the woman's age and (ii) prolonged in vitro culture of embryos on ZP thickness and density using non-invasive polarized light (LC-PolScope) microscopy. ZP thickness and density (measured as retardance) were determined in oocytes, embryos and blastocysts in women undergoing intracytoplasmic sperm injection (ICSI) in two age groups (older, > 38 years; younger, < or = 38 years). A total of 193 oocytes from 29 patients were studied. The younger group contained 100 oocytes and the older group 93 oocytes. The ZP was significantly thicker in metaphase II oocytes in the older group compared with the younger group (mean +/- SD: 24.1 +/- 2.5 microm vs 23.1 +/- 3.3 microm; p = 0.01) but ZP density was equal (2.8 +/- 0.7 nm). By day 2 of culture, embryos from the two groups had similar ZP thickness (22.2 +/- 2.2 microm vs 21.7 +/- 1.6 microm; p = 0.28) and density (2.9 +/- 0.7 nm vs 2.8 +/- 0.8 nm; p = 0.57). For the embryos cultured to blastocyst (older: n = 20; younger: n = 18) ZP thickness was similar in the two groups (19.2 +/- 2.7 microm vs 19.1 +/- 5.0 microm; p = 0.8) but thinner than on day 2. The older group had significantly denser ZP than the younger group (4.2 +/- 0.5 nm vs 3.3 +/- 1.0 nm, p < 0.01). Blastocysts from both groups had significantly denser ZP than their corresponding day 2 embryos (older: 4.2 +/- 0.5 nm vs 2.9 +/- 0.7 nm, p < 0.001; younger: 3.3 +/- 1.0 nm vs 2.8 +/- 0.8 nm, p = 0.013). It is concluded that there is little relationship between ZP thickness and its density as measured by polarized light microscopy. While ZP thickness decreases with extended embryo culturing, the density of the ZP increases. ZP density increases in both age groups with extended culture and, interestingly, more in embryos from older compared with younger women. PMID:16700974

Kilani, Suha S; Cooke, Simon; Kan, Andrew K; Chapman, Michael G

2006-02-01

211

Relation between physical properties of the zona pellucida and viability of bovine embryos after slow-freezing and vitrification.  

PubMed

In vitro-produced bovine morulae/blastocyst embryos (n = 119) were slow-frozen and vitrified and the physical alterations of the zona pellucida (ZP) was observed by scanning electron microscopy (SEM) to find an explanation for the loss of developmental capacity of the embryos after freezing/thawing. A control group was provided, in which embryos (n = 38) were neither frozen nor vitrified. Embryos were in vitro-cultured in a standard CO2 Heraeus incubator and their viability was assessed 24 and 48 h after the start of culture, evaluating their morphological aspect. After 24 h of culture, embryo survival rate for slow-freezing/thawed (n = 23), vitrified/thawed (n = 20) and control embryos (n = 20) was 39, 27 and 90%, and 35, 14 and 65% after 48 h of culture, respectively. For evaluation of physical changes occurring in ZP, 20 embryos were slow-frozen, 18 were vitrified and 18 were used as control. All embryos were fixed, dried and examined under an SEM. Embryo's diameter, as well as the number of pores and their diameter was measured in squares of 6.4 microm width. We observed that, on average, the diameter of the embryos (92.26 +/- 10.15 microm) did not differ significantly among all embryos. As far as the diameter of the pores in the outer surface of the ZP is concerned, the results revealed a significant difference (P < 0.05) between control (0.48 +/- 0.0025 microm), slow-frozen (0.34 +/- 0.0007 microm) and vitrified (0.27 +/- 0.0006 microm) embryos. For the number of pores, statistical differences (p < 0.05) were observed between control and vitrified embryos (45.4 +/- 7.3 vs 38.2 +/- 8.2). It is possible that ZP functions as a barrier which is positive when dealing with pathogens, but is harmful when nutrients were supplied from the outside, especially at 48 h of culture. Results indicate that the steps of cryopreservation cause alterations in ZP, with irreversible damage on the further developmental competence of bovine embryos. PMID:15943693

Moreira da Silva, F; Metelo, R

2005-06-01

212

The immune response and fertility of koalas (Phascolarctos cinereus) immunised with porcine zonae pellucidae or recombinant brushtail possum ZP3 protein.  

PubMed

To evaluate the potential contraceptive effect of immunisation with zona pellucida antigens, 50 free-ranging koalas were immunised with either porcine zonae pellucidae (PZP), recombinant brushtail possum ZP3 (recBP-ZP3) or buffer, in complete Freund's adjuvant. A single booster immunisation in incomplete Freund's adjuvant was administered 3-5 months later. Where possible animals were recaptured, reproductive status was assessed and blood was collected at 1-3-month intervals for the next 33 months. Forty-three koalas were recaptured at least three times allowing reliable assessments of their fertility. Fourteen animals were observed never to have a pouch young. Of the remaining 29 animals the reproductive productivity of PZP treated females was reduced compared with control and recBP-ZP3 treated females, in terms of both total number of young produced, and failure to produce further young in females of proven fertility. One month after the initial immunisation, serum antigen-specific antibody titres were higher in animals immunised with PZP or recBP-ZP3 compared to controls, and reached a plateau by 4 months. Antibody against the relevant immunising antigen was also detected in ovarian follicular fluid, uterine fluid and vaginal secretions. Epitope analysis suggested that immune responses other than antibodies directed against the ZP3 amino acid sequence were responsible for mediating infertility. The results demonstrate that the fertility of female koalas can be compromised by immunisation against zona pellucida antigens. However, unlike in the eastern grey kangaroo and the brushtail possum, immunisation with bacterial recombinant brushtail possum ZP3 did not compromise fertility in the koala. PMID:19709753

Kitchener, Anne L; Kay, David J; Walters, Bryan; Menkhorst, Peter; McCartney, Carmen A; Buist, Janine A; Mate, Karen E; Rodger, John C

2009-10-01

213

Âge Paléozoïque inférieur (U—Pb sur zircon) de métagranophyres de la nappe du Grand-Saint-Bernard ( zona interna, vallée d'Aoste, Italie)  

NASA Astrophysics Data System (ADS)

Early Paleozoic U—Pb age of zircons from metagranophyres of the Grand-Saint-Bernard Nappe ( zona interna, Aosta Valley, Italy). The U—Pb age of a metagranophyre from the Val de Rhèmes (Briançonnais basement of the Aosta valley) of 511 ± 9 Ma suggests that the micaschists which dominate the pre-alpine basement of the Grand-Saint-Bernard Nappe are, in part, of Early Paleozoic age. The Briançonnais domain is characterized by a Cambrian to Ordovician alkaline to subalkaline (monzonitic) magmatism, similar in age to orthogneisses known in other parts of the Variscan belt and generally interpreted as related to an extensional event.

Bertrand, Jean-Michel; Guillot, François; Leterrier, Jacques

2000-04-01

214

Documenting Endangered Languages (DEL)  

NSF Publications Database

Full Proposal Preparation Instructions: This solicitation contains information that supplements the standard Grant Proposal Guide (GPG) proposal preparation guidelines. All DEL proposals for project grants and fellowships will receive specialist (ad hoc) and panel review within the NSF review process. More comprehensive information on NSF Award Conditions is contained in the NSF Grant Policy Manual (GPM) Chapter II, available electronically on the NSF Website at http://www.nsf.gov/...

215

Nevado del Huila, Columbia  

NASA Technical Reports Server (NTRS)

Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

2007-01-01

216

Observación y registro fotográfico del cometa HYAKUTAKE C/1996 B2  

NASA Astrophysics Data System (ADS)

Desde el momento en que nos llega la información del descubrimiento, comenzamos la observación de forma detallada a fin de apreciar y seguir su creciente actividad. La primera observación se realizó el 17 de febrero de 1996 a las 4h20m UT con nuestro telescopio de 300mm newtoniano de f/6.5, con una muy buena transparencia atmosférica, estimando una magnitud de 8.5. Realizábamos observaciones casi todas las noches, mientras nos lo permitían las condiciones climáticas. Ya el 26 de febrero el cometa presentaba un aspecto muy particular, ligeramente distinto a las primeras observaciones, ya que comenzamos a notar su gran actividad. En primer lugar se destacaba la cola de iones mucho mas extensa que la cola de polvo. Magnitud estimada 7.5. El 19 de marzo ya era visible a simple vista y en especial su cola muy abierta y extensa (3 grados) y no quedaba duda alguna que la última noche de observación del cometa en el horizonte de la Ciudad de Funes, que fue el 24 de marzo de 1996, un día antes del acercamiento a la Tierra, tendríamos una apreciación del cometa en su máximo esplendor. El 24 de marzo de 1996 a las 4hs UT, asomó el cometa por el horizonte NE, con su cola espectacular, llegando a medir 23 grados de longitud, muy recta y brillante, y su cabellera muy estelar. A este marco de observación se sumaron mas de 600 personas que participaron usando instrumentos, siendo la mayoría de los concurrentes de la vecina Ciudad de Rosario, ya que su observación era a muy baja atura sobre el horizonte norte. Instrumentos utilizados : Telescopio Newtoniano 300mm f/6.5, Telescopio Schmidt-Cassegrain 200mm , Binoculares 10 x 50, 7 x 50, Lente normal 50mm a f/1.8, Película 100 - 400 ASA Lugar de Observación : Ciudad de Funes, zona rural, ``Estancia La Polola" Latitud: - 32o 55' Longitud: 60o 40' Oeste

Arquiola, A. P.; Arquiola, F. E.

217

Boletín del Instituto Nacional del Cáncer - 02-02-2010  

Cancer.gov

En un estudio clínico en fase inicial que probó una vacuna terapéutica en pacientes con leucemia mieloide crónica (LMC) que tomaban el fármaco imatinib (Gleevec), no se pudieron detectar células cancerosas en 7 de los 19 participantes por un tiempo promedio de 22 meses. Los resultados del estudio fueron publicados en el número del 1º de enero de la revista Clinical Cancer Research.

218

Vacunas contra los virus del papiloma humano  

Cancer.gov

Hoja informativa acerca de las vacunas contra los virus del papiloma humano (VPH) para prevenir infecciones con ciertos tipos de VPH, los cuales son la causa principal del cáncer de cuello del útero o cérvix.

219

Seroprevalence and risk factors of toxoplasmosis in cattle from extensive and semi-intensive rearing systems at Zona da Mata, Minas Gerais state, Southern Brazil  

PubMed Central

Background Concerning the infection of humans by T. gondii, limited efforts have been directed to the elucidation of the role of horizontal transmission between hosts. One of the main routes of transmission from animals to humans occurs through the ingestion of raw or insufficiently cooked meat. However, even though the detection of T. gondii in meat constitutes an important short-term measure, control strategies can only be accomplished by a deeper understanding of the epidemiology of toxoplasmosis. The present study aimed to investigate the seroprevalence of toxoplasmosis in cattle from Zona da Mata, Minas Gerais, Brazil, and to identify associated risk factors, through an epidemiological investigation. Methods The animals studied (Bos indicus, breed Nelore or Gir) were reared in the Zona da Mata micro-region and killed at a commercial slaughterhouse at Juiz de Fora, Minas Gerais state. The animals came from 53 cattle farms with extensive (predominantly pasture feeding management) or semi-intensive (food management based on grazing, salt mineral and feed supplementation) rearing systems. Blood samples were collected from 1200 animals, and assigned to Indirect Fluorescent Antibody Test. Results When analyzing IgG anti-T.gondii we found an overall seroprevalence of 2.68%. In Brazil prevalences vary from 1.03% to 60%. Although in the present study, the seroprevalence per animal is considered low compared to those observed in other studies, we found out that of the 53 farms analyzed, 17 (34.69%) had one or more positive cattle. It is a considerable percentage, suggesting that the infection is well distributed through the Zona da Mata region. The results of the epidemiological investigation showed that the main risk factors of Toxoplasma gondii infection are related to animal management and to the definive host. There was a relationship between the number of seropositive cattle and the presence and number of resident cats, presence and number of stray cats, presence of cats walking freely, rat control by using cats and feed storage. Conclusion These results may contribute to the development of preventive strategies in Brazil and other developing countries were extensive and semi-intensive cattle rearing systems are very widespread and the efforts to control this important zoonotic disease have attained little success.

2013-01-01

220

Evaluation of sperm functional attributes in relation to in vitro sperm-zona pellucida binding ability and cleavage rate in assessing frozen thawed buffalo (Bubalus bubalis) semen quality.  

PubMed

The objective of this study was to evaluate sperm functional attributes in relation to in vitro sperm-zona binding ability and cleavage rate in assessing frozen thawed buffalo (Bubalus bubalis) semen quality. Frozen-thawed forty-eight ejaculates from eight Surti buffalo bulls (six ejaculates/bull) obtained by artificial vagina were used. Frozen semen from each bull was thawed, pooled, and subjected for sperm functional (six replicates) and in vitro fertilization (four replicates) tests. The progressive forward motility, plasmalemma functional integrity assessed by fluorogenic [6-carboxyfluorescein diacetate (CFDA), and propidium iodide (PI)], hypoosmotic swelling (HOS), and hypoosmotic swelling-Giemsa (HOS-G) test, mitochondrial membrane potential, sperm nuclear morphology, the number of sperm bound to zona and cleavage rate differed significantly (P<0.05) between bulls. When the animals were grouped based on cleavage rate (group I, >40% cleavage rate, n=5, and group II, <40% cleavage rate, n=3), in vitro fertility parameters and all the sperm functional attributes except sperm nuclear morphology differed significantly (P<0.05). The proportions of sperm with functional plasmalemma in the tail and intact acrosome assessed by HOS-G test (25.33, range: 17.48-40.27) were significantly (P<0.001) lower than the functional plasmalemma in the tail assessed by HOS test (39.80, range: 27.85-54.67). The number of sperm bound to zona had significant correlations with the mitochondrial membrane potential (r=0.90, P<0.01) and plasmalemma integrity (fluorogenic, r=0.74 and HOS, r=0.79, P<0.05) and HOS-G, r=0.87, P<0.01). The cleavage rate had significant (P<0.05) correlations with the mitochondrial membrane potential (r=0.70) and plasmalemma integrity measured by HOS-G test (r=0.68). The present study indicates that these attributes could represent important determinants of buffalo sperm quality influencing cleavage rate. PMID:17576042

Selvaraju, S; Ravindra, J P; Ghosh, J; Gupta, P S P; Suresh, K P

2008-07-01

221

Intranasal co-delivery with the mouse zona pellucida 3 and GM-CSF expressing constructs enhances humoral immune responses and contraception in mice.  

PubMed

Granulocyte-monocyte colony-stimulating factor (GM-CSF) regulates the function of antigen-presenting cells (APCs) and has been broadly used as the adjuvant. Here, we tested whether intranasal delivery of GM-CSF can improve the contraception of mouse zona pellucida 3 (mZP3) DNA vaccine. Our results showed that co-administration of GM-CSF and mZP3 DNA vaccine increased the levels of secretory IgA (sIgA) and IgG antibodies in vaginal washes and serum, respectively. Co-administration enhanced Th2 responses through improving the maturation of dendritic cells. Importantly, GM-CSF significantly reduced the fertility rate and mean litter size induced by mZP3 DNA vaccine alone without interfering the normal follicular development. These data suggest that GM-CSF could be used as adjuvant to develop immunocontraceptive vaccine. PMID:22924630

Ma, X; Li, J; Zhang, F

2012-12-01

222

Siga adelante: la vida después del tratamiento del cáncer  

Cancer.gov

Consejos para supervivientes de cáncer con información sobre temas relacionados con la vida después del tratamiento, entre ellos, la atención médica de seguimiento, los cambios físicos y emocionales y los cambios en el estilo de vida.

223

Siga adelante: la vida después del tratamiento del cáncer  

Cancer.gov

E-book con consejos para supervivientes de cáncer e información sobre temas relacionados con la vida después del tratamiento, entre ellos, la atención médica de seguimiento, los cambios físicos y emocionales y los cambios en el estilo de vida.

224

Boletín del Instituto Nacional del Cáncer - 05-25-2010  

Cancer.gov

Aproximadamente 41.000 participantes en un estudio en el Reino Unido se sometieron una sola vez a una examen de detección en la parte inferior del colon mediante el uso de un sigmoidoscopio, un instrumento delgado en forma de tubo que se inserta a través del recto para buscar lesiones precancerosas o cancerosas. Este dispositivo también tiene una herramienta para extraer pólipos potencialmente precancerosos.

225

Se da a conocer el plan del Instituto Nacional del Cáncer para acelerar la investigación del cáncer  

Cancer.gov

En la 100va Reunión Anual de la Asociación Estadounidense de Investigación del Cáncer realizada en Denver, el director del Instituto Nacional del Cáncer, doctor John E. Niederhuber, dio a conocer detalles importantes, tales como financiamiento de más subvenciones, creación de una plataforma para atención personalizada del cáncer y un programa acelerado de genética del cáncer que hará avanzar la investigación oncológica en este nuevo ambiente económico.

226

MODELADO Y SIMULACION DEL SISTEMA CARDIOVASCULAR FETAL  

Microsoft Academic Search

Resumen: En el modelado fisiológico, el propósito es comprender las funciones del cuerpo humano. Con este propósito, se abordan problemas del embarazo y el parto para minimizar las cesáreas innecesarias en mujeres propensas a cursar con Sufrimiento Fetal Agudo (SFA). En el presente estudio se realizó: el Modelado Matemático del Sistema Cardiovascular Fetal (SCVF), la Simulación y Validación del SCVF.

Rubén Moreno

227

Antioxidantes y prevención del cáncer  

Cancer.gov

Hoja informativa acerca de los antioxidantes, sustancias que pueden proteger las células del daño causado por moléculas inestables conocidas como radicales libres. El daño de los radicales libres puede resultar en cáncer.

228

Case Study: del Amo Bioventing  

EPA Science Inventory

The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study....

229

Alberto del Pozo  

NSDL National Science Digital Library

The Cuban Heritage Collection of the University of Miami Libraries was a recipient of 17 original illustrations by Alberto del Pozo in 1998 from the Campilli family. "The Oricha Collection" is their gift, and it contains illustrations in pen, crayon, and ink and the collection "pays homage to the primary gods and goddesses that comprise the Afro-Cuban religion of Santer'a." The "Introduction" near the top of the page, is a good place for visitors to start learning about Pozo, who was a Parson's School of Design-trained, Cuban artist who died at the age of 47. The "Biographical Sketch" is worth looking at as well. Examples of his colorful, heavily patterned and symbolism-intensive drawings of Santeria gods and goddesses can be found in the link "Gallery". The description of each drawing is given in English and Spanish. Finally, visitors interested in more information on the Santeria, can look at the "Further Readings" link for authoritative books on the subject.

230

Boletín del Instituto Nacional del Cáncer - 28 de febrero de 2012  

Cancer.gov

Los artículos originales en inglés están disponibles en las páginas del NCI Cancer Bulletin. El Boletín es una publicación del Instituto Nacional del Cáncer (NCI), una entidad gubernamental de los Estados Unidos creada en 1937.

231

Proteomic characterization and evolutionary analyses of zona pellucida domain-containing proteins in the egg coat of the cephalochordate, Branchiostoma belcheri  

PubMed Central

Background Zona pellucida domain-containing proteins (ZP proteins) have been identified as the principle constituents of the egg coat (EC) of diverse metazoan taxa, including jawed vertebrates, urochordates and molluscs that span hundreds of millions of years of evolutionary divergence. Although ZP proteins generally contain the zona pellucida (ZP) structural modules to fulfill sperm recognition and EC polymerization functions during fertilization, the primary sequences of the ZP proteins from the above-mentioned animal classes are drastically different, which makes it difficult to assess the evolutionary relationships of ZP proteins. To understand the origin of vertebrate ZP proteins, we characterized the egg coat components of Branchiostoma belcheri, an invertebrate species that belongs to the chordate subphylum Cephalochordata. Results Five ZP proteins (BbZP1-5) were identified by mass spectrometry analyses using the egg coat extracts from both unfertilized and fertilized eggs. In addition to the C-terminal ZP module in each of the BbZPs, the majority contain a low-density lipoprotein receptor domain and a von Willebrand factor type A (vWFA) domain, but none possess an EGF-like domain that is frequently observed in the ZP proteins of urochordates. Fluorescence in situ hybridization and immuno-histochemical analyses of B. belcheri ovaries showed that the five BbZPs are synthesized predominantly in developing eggs and deposited around the extracellular space of the egg, which indicates that they are bona fide egg coat ZP proteins. BbZP1, BbZP3 and BbZP4 are significantly more abundant than BbZP2 and BbZP5 in terms of gene expression levels and the amount of mature proteins present on the egg coats. The major ZP proteins showed high polymorphism because multiple variants are present with different molecular weights. Sequence comparison and phylogenetic analysis between the ZP proteins from cephalochordates, urochordates and vertebrates showed that BbZP1-5 form a monophyletic group and share no significant sequence similarities with the ZP proteins of urochordates and the ZP3 subtype of jawed vertebrates. By contrast, small regions of homology were identifiable between the BbZP and ZP proteins of the non-jawed vertebrate, the sea lamprey Petromyzon marinus. The lamprey ZP proteins were highly similar to the ZP1 and ZP2 subtypes of the jawed vertebrates, which suggests that the ZP proteins of basal chordates most likely shared a recent common ancestor with vertebrate ZP1/2 subtypes and lamprey ZP proteins. Conclusions The results document the spectra of zona pellucida domain-containing proteins of the egg coat of basal chordates. Particularly, the study provides solid evidence for an invertebrate origin of vertebrate ZP proteins and indicates that there are diverse domain architectures in ZP proteins of various metazoan groups.

2012-01-01

232

Immunocontraception of captive exotic species: V. Prolonged antibody titers in Dall sheep (Ovis dalli dalli) and domestic goats (Capra hircus) immunized with porcine zona pellucida.  

PubMed

Native porcine zona pellucida (PZP) immunocontraception has been used to inhibit fertility in more than 80 species of ungulates, although the duration of contraception efficacy varies among species in both Perissodactyla and Artiodactyla. This study examined anti-PZP antibody titers in Dall sheep and domestic goats at the Milwaukee County Zoo, and also Himalayan tahr and Armenian Mouflon sheep at the San Diego Zoo Safari Park, and, for comparison, Altai wapiti, lowland wisent, Javan banteng, and southern pudu at the San Diego Zoo Safari Park, all were given a primer dose and booster dose of PZP. Of the San Diego Zoo Safari Park animals, the 4 comparison species demonstrated the typical 1-yr pattern of anti-PZP antibodies, whereas the Armenian sheep and Himalayan tahr showed prolonged (2-3 yr) antibody responses after a single primer and booster dose. The Dall sheep and domestic goats had significantly longer durations of antibody titers (3 yr) from a single year's treatment (primer plus booster). Analysis of the data indicates that Armenian sheep, Himalayan tahr, Dall sheep, and domestic goats have prolonged responses, and are more sensitive to PZP in that they produce a protracted antibody response. PMID:24437081

Lyda, Robin O; Frank, Kimberly M; Wallace, Roberta; Lamberski, Nadine; Kirkpatrick, Jay F

2013-12-01

233

Production of tag-free recombinant fusion protein encompassing promiscuous T cell epitope of tetanus toxoid and dog zona pellucida glycoprotein-3 for contraceptive vaccine development.  

PubMed

Affinity tags can interfere in various physicochemical properties and immunogenicity of the recombinant proteins. In the present study, tag-free recombinant fusion protein encompassing promiscuous T cell epitope of tetanus toxoid [TT; amino acid (aa) residues 830-844] followed by dilysine linker and dog zona pellucida glycoprotein-3 (ZP3; aa residues 23-348) (TT-KK-ZP3) was expressed in Escherichia coli. The recombinant protein, expressed as inclusion bodies (IBs), was purified by isolation of IBs, processed to remove host cell proteins, followed by solubilization and refolding. A specific 39 kDa protein including ZP3 was identified by SDS-PAGE. CD spectra showed the presence of ?-helices and ?-sheets, and fluorescent spectroscopy revealed emission maxima of 265 A.U. at 339 nm for refolded protein and showed red shift in the presence of 6 M guanidine hydrochloride. Immunization of inbred FvB/J female mice with purified recombinant TT-KK-ZP3 (25 ?g/animal) led to generation of high antibody titers against the recombinant protein. The antibodies reacted specifically with ZP matrix surrounding mouse oocytes. Immunized mice showed significant reduction in fertility as compared to the control group. The studies described herein provide a simple method to produce and purify tag-free recombinant protein for the development of a contraceptive vaccine. PMID:23242635

Gupta, Neha; Shrestha, Abhinav; Panda, Amulya Kumar; Gupta, Satish Kumar

2013-07-01

234

Boletín del Instituto Nacional del Cáncer - 01-05-2010  

Cancer.gov

Al caminar por los pasillos del nuevo centro oncológico integral en la sede de Ciencias Médicas de la Universidad de Puerto Rico (UPR) en San Juan, uno debe mantener los ojos abiertos. La mujer que pasa caminando vigorosamente podría ser la doctora Marcia Roxana Cruz-Correa, y no debe uno perderse la oportunidad de conocerla.

235

Boletín del Instituto Nacional del Cáncer - 04-27-2010  

Cancer.gov

Cada vez es más evidente que los esfuerzos mundiales de salud de mayor éxito dependen no solo del aporte de las mentes más brillantes, sino de la colaboración entre ellas para marcar la diferencia en el escenario global. Este enfoque es el motor impulsor detrás de una asociación excepcional con el NCI, financiada en parte por Susan G.

236

Expression of a P-selectin Ligand in Zona Pellucida of Porcine Oocytes and P-selectin on Acrosomal Membrane of Porcine Sperm Cells. Potential Implications for Their Involvement in Sperm-Egg Interactions  

PubMed Central

The selectin family of cell adhesion molecules mediates initial leukocyte adhesion to vascular endothelial cells at sites of inflammation. O-glycan structural similarities between oligosaccharides from human leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) and from zona pellucida glycoproteins of porcine oocytes indicate the possible existence of a P-selectin ligand in the zona pellucida. Here, using biochemical as well as morphological approaches, we demonstrate that a P-selectin ligand is expressed in the porcine zona pellucida. In addition, a search for a specific receptor for this ligand leads to the identification of P-selectin on the acrosomal membrane of porcine sperm cells. In vitro binding of porcine acrosome-reacted sperm cells to oocytes was found to be Ca2+ dependent and inhibitable with either P-selectin, P-selectin receptor–globulin, or leukocyte adhesion blocking antibodies against P-selectin and PSGL-1. Moreover, porcine sperm cells were found to be capable of binding to human promyeloid cell line HL-60. Taken together, our findings implicate a potential role for the oocyte P-selectin ligand and the sperm P-selectin in porcine sperm– egg interactions.

Geng, Jian-Guo; Raub, Thomas J.; Baker, Carolyn A.; Sawada, Geri A.; Ma, Li; Elhammer, ?ke P.

1997-01-01

237

La Investigación del Cáncer en América Latina  

Cancer.gov

Este programa busca fomentar los esfuerzos locales y mundiales de prevención, diagnóstico y tratamiento del cáncer facilitando la creación de una infraestructura integral para la investigación del cáncer en América Latina.

238

Instantánea del cáncer de cuello uterino  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de cuello uterino; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

239

Instantánea del cáncer de seno (mama)  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de seno (mama); así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

240

Geología y registros magnéticos entre arroyo La Tapera y Santa Clara del Mar, Mar del Plata  

Microsoft Academic Search

Geology and magnetic records between Arroyo La Tapera and Santa Clara del Mar, Mar del Plata. Paleomagnetic studies were carried out in Pleistocene-Holocene sedimentary sequences exposed between Arroyo La Tapera and Santa Clara del Mar in Mar del Plata. The sediments exposed in the lower part of the La Tapera and Camet sections, which apparently belong to the Ensenada Formation,

Juan Carlos BIDEGAIN; Margarita L. OSTERRIETH; Adrianus J. VAN VELZEN; Yamile RICO

241

Variabilità interannuale del fi toplancton del Lago di Tovel (Trentino, Italia)  

Microsoft Academic Search

RIASSUNTO - Variabilità interannuale del fi toplancton del Lago di Tovel (Trentino, Italia) - Lo studio del fi toplancton del Lago di Tovel nel periodo 2002-2004 ha avuto come principali obiettivi l'analisi della variabilità interannuale delle dinamiche stagionali nel Bacino Principale e nella Baia Rossa, il confronto tra le associazioni fi toplanctoniche attuali e passate (prima e dopo la scomparsa

Monica TOLOTTI; Dámaso CALLIARI; Flavio CORRADINI

242

Características del desplazamiento forzado en Colombia  

Microsoft Academic Search

RESUMEN El presente estudio es una contribución a la explicación y comprensión de la problemática del desplazamiento forzado interno en Colombia, fenómeno considerado como violación masiva y múltiple de los derechos humanos, circunstancia de lesa humanidad además de ser infracción grave del Derecho Internacional Humanitario. Se identificaron los antecedentes históricos, la dinámica regional del fenómeno, la existencia de factores estructurales

Henry Fernández Pinto; JIMMY SÁNCHEZ REYEZ

2011-01-01

243

Del Mar College GIS Program  

NSDL National Science Digital Library

Del Mar College offers a comprehensive geospatial program with certificates and Associates degrees in GIS. This site includes description of the program and courses, along with further contact information. By clicking on the link for "Geographic Information Systems" you may download a PDF with information about the program.

2010-10-28

244

Los cuatro entornos del procomún  

Microsoft Academic Search

Bastan unos minutos para entender la inmensa complejidad que tiene la noción de procomún. Disponemos de muchas definiciones aceptables, aunque las más frecuentes bordean de una u otra manera el problema de la propiedad y la teoría del valor. Cuando decimos que pertenece al procomún todo cuanto es de todos y de nadie a mismo tiempo estamos pensando en un

Antonio Lafuente

245

ESTUDIO DE LAS POBLACIONES MICROBIANAS DE LA RIZÓSFERA DEL CULTIVO DE PAPA (Solanum tuberosum) EN ZONAS ALTOANDINAS A STUDY OF POTATO (Solanum tuberosum) CROP RHIZOSPHERE MICROBIAL POPULATION IN HIGHLAND ZONES  

Microsoft Academic Search

A study was conducted to investigate the microbial populations of the most representative genera in the potato rhizosphere in Highland regions. Total bacteria population in the two sampling regions was always higher than the fungi population. The more alkaline soil pH in Puno region can explain this fact. We observed that Actinomycetes and Azotobacter spp. populations were influenced by pH

Pamela Calvo Vélez; Luis Reymundo Meneses; Doris Zúñiga Dávila

2008-01-01

246

Oviduct-specific glycoprotein and heparin modulate sperm-zona pellucida interaction during fertilization and contribute to the control of polyspermy  

PubMed Central

Polyspermy is an important anomaly of fertilization in placental mammals, causing premature death of the embryo. It is especially frequent under in vitro conditions, complicating the successful generation of viable embryos. A block to polyspermy develops as a result of changes after sperm entry (i.e., cortical granule exocytosis). However, additional factors may play an important role in regulating polyspermy by acting on gametes before sperm–oocyte interaction. Most studies have used rodents as models, but ungulates may differ in mechanisms preventing polyspermy. We hypothesize that zona pellucida (ZP) changes during transit of the oocyte along the oviductal ampulla modulate the interaction with spermatozoa, contributing to the regulation of polyspermy. We report here that periovulatory oviductal fluid (OF) from sows and heifers increases (both, con- and heterospecifically) ZP resistance to digestion with pronase (a parameter commonly used to measure the block to polyspermy), changing from digestion times of ?1 min (pig) or 2 min (cattle) to 45 min (pig) or several hours (cattle). Exposure of oocytes to OF increases monospermy after in vitro fertilization in both species, and in pigs, sperm–ZP binding decreases. The resistance of OF-exposed oocytes to pronase was abolished by exposure to heparin-depleted medium; in a medium with heparin it was not altered. Proteomic analysis of the content released in the heparin-depleted medium after removal of OF-exposed oocytes allowed the isolation and identification of oviduct-specific glycoprotein. Thus, an oviduct-specific glycoprotein–heparin protein complex seems to be responsible for ZP changes in the oviduct before fertilization, affecting sperm binding and contributing to the regulation of polyspermy.

Coy, Pilar; Canovas, Sebastian; Mondejar, Irene; Saavedra, Maria Dolores; Romar, Raquel; Grullon, Luis; Matas, Carmen; Aviles, Manuel

2008-01-01

247

Romance without responsibilities: the use of the immunocontraceptive porcine zona pellucida to manage free-ranging bison (Bison bison) on Catalina Island, California, USA.  

PubMed

Prior to 2010, the introduced population of American bison (Bison bison) on Santa Catalina Island, California, was managed through the shipment of surplus bison to private ranches, Native American reservations, and livestock auctions on the mainland. In response to escalating costs, transport-induced stress to the animals, and ecologic impacts associated with high bison numbers on-island between shipments, the use of the immunocontraceptive vaccine porcine zona pellucida (PZP) as a fertility control option for managing the population was investigated. Between 2009 and 2012, a total of 64 bison cows (> or =1 yr old) received primer inoculations of 100 microg PZP emulsified with 0.5 ml Freund's modified adjuvant (FMA) delivered through a combination of intramuscular injections by hand (50 bison cows) during roundups and via field darting (14 bison cows). Pre-rut booster inoculations of 100 microg PZP emulsified with 0.5 ml Freund's incomplete adjuvant (FIA) were administered exclusively via field darting in 2010, 2011, and 2012 to 45, 48, and 61 bison cows (> or =1 yr old), respectively. During the present study, 38 adult cows (marked and unmarked) received one or more PZP inoculations during their first, second, or third trimesters of pregnancy, and of these individuals, 35 successfully produced calves. Low pregnancy values detected in the remaining three cows have been attributed to residual progesterone associated with unsuccessful fertilization. The 2010 pretreatment calving rate (calves born per cow) determined via direct observation was 67.4% (29 calves from 43 cows). Through the use of PZP, the calving rate was reduced to 10.4% by 2011 and to 3.3% by 2012. Considering the annual mortality rate of 2-5% documented during this study, the results demonstrate the potential of PZP use as an effective nonlethal tool for controlling population growth in free-ranging bison. PMID:24437092

Duncan, Calvin L; King, Julie L; Kirkpatrick, Jay F

2013-12-01

248

Molecular adjuvant interleukin-33 enhances the antifertility effect of Lagurus lagurus zona pellucida 3 DNA vaccine administered by the mucosal route  

PubMed Central

It has been shown that cytokines can act as molecular adjuvant to enhance the immune response induced by DNA vaccines, but it is unknown whether interleukin 33 (IL-33) can enhance the immunocontraceptive effect induced by DNA vaccines. In the present study, we explored the effects of murine IL-33 on infertility induced by Lagurus lagurus zona pellucida 3 (Lzp3) contraceptive DNA vaccine administered by the mucosal route. Plasmid pcD-Lzp3 and plasmid pcD-mIL-33 were encapsulated with chitosan to generate the nanoparticle chi-(pcD-Lzp3+pcD-mIL-33) as the DNA vaccine. Sixty female ICR mice, divided into 5 groups (n=12/group), were intranasally immunized on days 0, 14, 28, and 42. After intranasal immunization, the anti-LZP3-specific IgG in serum and IgA in vaginal secretions and feces were determined by ELISA. The results showed that chi-(pcD-Lzp3+pcD-mIL-33) co-immunization induced the highest levels of serum IgG, secreted mucosal IgA, and T cell proliferation. Importantly, mice co-immunized with chi-(pcD-Lzp3+pcD-mIL-33) had the lowest birth rate and mean litter size, which correlated with high levels of antibodies. Ovaries from infertile female mice co-immunized with chi-(pcD-Lzp3+pcD-mIL-33) showed abnormal development of ovarian follicles, indicated by atretic follicles and loss of oocytes. Our results demonstrated that intranasal delivery of the molecular adjuvant mIL-33 with chi-pcD-Lzp3 significantly increased infertility by enhancing both systemic and mucosal immune responses. Therefore, chi-(pcD-Lzp3+pcD-mIL-33) co-immunization could be a strategy for controlling the population of wild animal pests.

Tu, Y.X.; Li, X.P.; Kadir, Z.; Zhang, F.C.

2013-01-01

249

Pre-fertilization zona pellucida hardening by different cross-linkers affects IVF in pigs and cattle and improves embryo production in pigs.  

PubMed

Zona pellucida (ZP) hardening (resistance to proteolysis) has been classically identified as a post-fertilization event that contributes to the block to polyspermy. Di-(N-succinimidyl)-3,3'-dithiodipropionate (DSP), a permeable amine-reactive cross-linker, was recently shown to induce pre-fertilization ZP hardening and to improve porcine IVF productivity. The objectives of this study were to investigate i) how DSP affects pre-fertilization ZP hardening and IVF in cattle, ii) if a non-permeable amine-reactive cross-linker such as bis(sulfosuccinimidyl) suberate (BS3) affects ZP hardening and IVF in cattle and pigs, and iii) whether DSP or BS3, if improvement in IVF productivity was demonstrated in either species, affects in vitro embryo development. Bovine and porcine in vitro matured oocytes were incubated with the cross-linkers (0.06, 0.3, and 0.6 mg/ml) for 30 min. Then they were subjected to ZP digestion or IVF. In cattle, both DSP and BS3 induced ZP hardening and decreased the penetration rate, although monospermy, penetration, or male pronuclear formation was not affected. In pigs, BS3 treatment induced ZP hardening, decreased penetration and male pronuclear formation, and increased monospermy. IVF productivity only improved when porcine oocytes were exposed to DSP. When porcine zygotes derived from this treatment were further cultured in vitro, the cleavage and blastocyst formation rates increased. These results support the idea that mechanisms involved in the prevention of polyspermic fertilization in cattle and pigs have different efficiencies, and ZP hardening induced by DSP cross-linker may be useful for improving porcine embryo production. PMID:19261833

Canovas, Sebastian; Romar, Raquel; Grullon, Luis Alberto; Aviles, Manuel; Coy, Pilar

2009-05-01

250

Association of mutations in the zona pellucida binding protein 1 (ZPBP1) gene with abnormal sperm head morphology in infertile men  

PubMed Central

Nearly 7% of men are afflicted by male infertility worldwide, and genetic factors are suspected to play a significant role in the majority of these patients. Although sperm morphology is an important parameter measured in the semen analysis, only a few genetic causes of teratozoospermia are currently known. The objective of this study was to define the association between alterations in the genes encoding the Golgi-associated PDZ- and coiled-coil motif containing protein (GOPC), the protein interacting with C kinase 1 (PICK1) and the acrosomal protein zona pellucida binding protein 1 (ZPBP1/sp38) with abnormal sperm head morphology in infertile men. Previous reports demonstrated that mice lacking Gopc, Pick1 and Zpbp1 are infertile due to abnormal head morphology. Herein, using our validated RNA-based method, we studied spermatozoal cDNA encoding the human GOPC, PICK1 and ZPBP1 genes in 381 teratozoospermic and 240 controls patients via direct sequencing. Among these genes, we identified missense and splicing mutations in the sperm cDNA encoding ZPBP1 in 3.9% (15/381) of men with abnormal sperm head morphology. These mutations were not observed in 240 matched controls and the dbSNP database (?2 = 9.3, P = 0.002). In contrast, statistically significant and functionally relevant mutations were not discovered in the GOPC and PICK1 genes. In our study ZPBP1 mutations are associated with abnormal sperm head morphology, defined according to strict criteria, resembling the mouse Zpbp1 null phenotype. We hypothesize that missense mutations exert a dominant-negative effect due to altered ZPBP1 protein folding and protein:protein interactions in the acrosome.

Yatsenko, Alexander N.; O'Neil, Derek S.; Roy, Angshumoy; Arias-Mendoza, Paola A.; Chen, Ruihong; Murthy, Lata J.; Lamb, Dolores J.; Matzuk, Martin M.

2012-01-01

251

Trasformazioni e patologie del paesaggio  

Microsoft Academic Search

\\u000a Anche il paesaggio, come vedremo, si evolve. Ma parlare oggi di evoluzione è assai problematico e quindi non si può fare a\\u000a meno di un inquadramento più generale del fenomeno. Quando oggi si parla di evoluzione si presenta sovente un quadro che,\\u000a purtroppo, non ha sempre i caratteri della scienza e un dibattito che, di conseguenza, trascina polemiche anche fra

Vittorio Ingegnoli

252

Zona Land: Wave Interference 3  

NSDL National Science Digital Library

This applet demonstrates basic wave superposition. The user can draw two waveforms and view the resulting wave on a string as they move in opposite directions towards the middle of the string. The user can select to view each of the individual waves, the sum, or both. The simulation can be slowed down to help the user examine the phenomenon more closely.

Zobel, Edward

2008-08-10

253

Ca2+ and K+ channels of normal human adrenal zona fasciculata cells: Properties and modulation by ACTH and AngII  

PubMed Central

In whole cell patch clamp recordings, we found that normal human adrenal zona fasciculata (AZF) cells express voltage-gated, rapidly inactivating Ca2+ and K+ currents and a noninactivating, leak-type K+ current. Characterization of these currents with respect to voltage-dependent gating and kinetic properties, pharmacology, and modulation by the peptide hormones adrenocorticotropic hormone (ACTH) and AngII, in conjunction with Northern blot analysis, identified these channels as Cav3.2 (encoded by CACNA1H), Kv1.4 (KCNA4), and TREK-1 (KCNK2). In particular, the low voltage–activated, rapidly inactivating and slowly deactivating Ca2+ current (Cav3.2) was potently blocked by Ni2+ with an IC50 of 3 µM. The voltage-gated, rapidly inactivating K+ current (Kv1.4) was robustly expressed in nearly every cell, with a current density of 95.0 ± 7.2 pA/pF (n = 64). The noninactivating, outwardly rectifying K+ current (TREK-1) grew to a stable maximum over a period of minutes when recording at a holding potential of ?80 mV. This noninactivating K+ current was markedly activated by cinnamyl 1-3,4-dihydroxy-?-cyanocinnamate (CDC) and arachidonic acid (AA) and inhibited almost completely by forskolin, properties which are specific to TREK-1 among the K2P family of K+ channels. The activation of TREK-1 by AA and inhibition by forskolin were closely linked to membrane hyperpolarization and depolarization, respectively. ACTH and AngII selectively inhibited the noninactivating K+ current in human AZF cells at concentrations that stimulated cortisol secretion. Accordingly, mibefradil and CDC at concentrations that, respectively, blocked Cav3.2 and activated TREK-1, each inhibited both ACTH- and AngII-stimulated cortisol secretion. These results characterize the major Ca2+ and K+ channels expressed by normal human AZF cells and identify TREK-1 as the primary leak-type channel involved in establishing the membrane potential. These findings also suggest a model for cortisol secretion in human AZF cells wherein ACTH and AngII receptor activation is coupled to membrane depolarization and the activation of Cav3.2 channels through inhibition of hTREK-1.

Enyeart, Judith A.

2013-01-01

254

Effect of oviductal and cumulus cells on zona pellucida and cortical granules of porcine oocytes fertilized in vitro with epididymal spermatozoa.  

PubMed

The objective of this study was to evaluate the effects of porcine oviductal epithelial cell (POEC) monolayers and cumulus cells on the zona pellucida (ZP) and cortical granules (CG) of in vitro matured porcine oocytes. Denuded and cumulus-enclosed oocytes were exposed to POEC before or during in vitro fertilization (IVF). The functional effects of the co-culture system were the tested on the ZP resistance, measured by the time necessary to dissolve the ZP with 0.1% pronase, and the distribution and density of the cortical granules. CG density in the equator and cortex of each oocyte was evaluated by confocal microscopy after staining with fluorescein isothiocyanate-labelled peanut agglutinin (FITC-PNA). Both variables were assessed immediately after an in vitro maturation period (IVM group), 3 and 6h after culture with or without (Control) oviductal cells (Experiment 1) and 3h after insemination with frozen-thawed epididymal spermatozoa in the presence or absence (Control) of oviductal cells (Experiment 2). The time to dissolve the ZP of oocytes from IVM group was 440.4 +/- 61.7 s and no difference was observed among groups in Experiment 1. In contrast, the density of CG was affected; oocytes pre-incubated for 6h had a higher density than those pre-incubated for 3 h (P <0.001). Oocytes fertilized in vitro in the presence of POEC (Experiment 2) had a similar ZP digestion time as control oocytes 3 h after insemination. The presence of POEC during IVF as well as the presence of cumulus cells had no effect on the density and distribution of CG. However, a significant decrease in the density of CG was observed in the fertilized oocytes compared to in vitro matured oocytes (P <0.001). It is concluded that under the conditions employed the oviductal and cumulus cells in the perifertilization period had no effect on ZP hardening and CG density. However, an increase in CG density was observed when oocytes were maintained in culture. In addition, no hardening of ZP was observed after IVF, and denuded and cumulus-enclosed oocytes showed similar cortical reactions after insemination with epididymal spermatozoa regardless of the presence of POEC. PMID:15581512

Romar, R; Coy, P; Gadea, J; Rath, D

2005-02-01

255

Ayuda para usar el sitio web en español del Instituto Nacional del Cáncer  

Cancer.gov

Página de guía que le permite al lector entender la forma en que está organizado el sitio web del Instituto Nacional del Cáncer (NCI), las categorías de información disponibles y las políticas que rigen este sitio web.

256

Effect of the size of zona pellucida opening by laser assisted hatching on clinical outcome of frozen cleaved embryos that were cultured to blastocyst after thawing in women with multiple implantation failures of embryo transfer: a retrospective study  

Microsoft Academic Search

Purpose  To evaluate the effect of the size of zona pellucida opening by laser assisted hatching for frozen cleaved embryo that were\\u000a thawed after both fresh and frozen cleaved embryo transfer cycles failed and were cultured to blastocyst after thawing in\\u000a patients with multiple implantation failures.\\u000a \\u000a \\u000a \\u000a Materials and methods  Of 101 consecutive procedures (October 2003 to June 2006), 30 patients declined to

Kenichiro Hiraoka; Megumi Fuchiwaki; Kaori Hiraoka; Toshitaka Horiuchi; Tomoyo Murakami; Masayuki Kinutani; Kazuo Kinutani

2008-01-01

257

Aplicación del cálculo de las diferencias al problema del efecto de embalse  

Microsoft Academic Search

Resumen Presentamos una solución numérica del problema del efecto de embalse con ayuda de una ecuación lineal inhomogénea en diferencias finitas de primer orden, suponiendo una ley lineal del desagüe. Este método numérico es de maneje cómodo para un cálculo aproximado.

Hans Ertel

1962-01-01

258

Un GIS per la pianificazione degli interventi atti a mitigare il rischio idrogeologico del bacino endoreico del torrente Asso, a Sud di Lecce  

Microsoft Academic Search

Introduzione Il torrente Asso è un antico corso fluviale naturale che, nel passato, convogliava le sole acque della zona a Sud di Lecce tra i comuni Nardò, Galatone, Seclì, Noha, Aradeo per condurle a Nord, in contrada \\

Giaccari Emanuele; Vitale Andrea

259

Control del dolor: Apoyo para las personas con cáncer  

Cancer.gov

Libro sobre el control del dolor en pacientes con cáncer. Cubre los métodos y medicinas, así como los efectos físicos y emocionales del dolor. Es una adaptación cultural para el público de habla hispana del libro en inglés Pain Control.

260

Fractional Indices of Log del Pezzo Surfaces  

NASA Astrophysics Data System (ADS)

The fractional index of a (possibly singular) Q-Gorenstein del Pezzo surface X is the greatest rational number r such that -K_X\\equiv rH, where H is a primitive Cartier divisor. This paper describes the set of values taken by fractional indices of del Pezzo surfaces with log terminal singularities. Bibliography: 7 titles.

Alekseev, V. A.

1989-06-01

261

Fisiología del embarazo: Interacción materno-infantil  

Microsoft Academic Search

ResumenEn los últimos años los datos han demostrado de qué manera el bienestar vitalicio depende considerablemente del crecimiento y el desarrollo intrauterinos durante la vida dentro del útero. El crecimiento fetal puede alcanzar únicamente su potencial íntegro mediante una interacción adecuada y armonizada entre la madre, la placenta y el feto. Este delicado equilibrio puede ser alterado por varios factores

Irene Cetin; Manuela Cardellicchio

2010-01-01

262

La gestione perioperatoria del paziente diabetico  

Microsoft Academic Search

\\u000a Il continuo aumento dei pazienti diabetici che giungono all’osservazione degli anestesisti rende sempre più importante la\\u000a conoscenza delle patologie comunemente associate al diabete e delle strategie da attuare per mantenere un equilibrio glicemico\\u000a ottimale nel periodo perioperatorio.\\u000a \\u000a \\u000a Per questa ragione, dopo aver sinteticamente descritto il metabolismo del glucosio, verrà trattato in questo capitolo il problema\\u000a del corretto trattamento insulinico del

Biagio Allaria

263

Centro para la Salud Mundial del NCI  

Cancer.gov

El Centro para la Salud Mundial del NCI coordina actividades de investigación y trabaja con socios nacionales e internacionales para entender y enfrentar la carga que representa el cáncer a nivel mundial.

264

Exploración del Nuevo Laboratorio Científico de Marte  

NASA Video Gallery

Únase a Fernando Abilleira, un analista de trayectoria de la NASA para la Oficina de Exploración de Marte, y conozca las nuevas tecnologías que el nuevo robot Curiosity del Laboratorio Científico d...

265

Dust formation in Nova Del 2013  

NASA Astrophysics Data System (ADS)

We present the result of the IR photometry of Nova Del 2013 obtained at the Crimean Station (Nauchny, Ukraine) of the Sternberg Astronomical Institute. JHKLM photometry was carried out with 125-cm telescope using a InSb-photometer on:

Shenavrin, V. I.; Taranova, O. G.; Tatarnikov, A. M.

2013-09-01

266

ANÁLISIS DEL ÍNDICE DE DESARROLLO DEL GOBIERNO ELECTRÓNICO EN CUBA Y SU COMPARACIÓN CON DISTINTAS REGIONES Y PAÍSES  

Microsoft Academic Search

Se realiza un estudio comparado del grado de desarrollo del gobierno electrónico en distintas regiones y países del mundo, dedicándole una atención particular al caso Cuba. Para ello se utiliza el Índice de desarrollo de gobierno electrónico (IDGE) establecido por las Naciones Unidas. A partir de los componentes del IDGE que son, el índice de servicios en línea (ISL), el

Alejandro de Armas Suárez; Roberto de Armas Urquiza

2011-01-01

267

Manual del McVCO 1999  

USGS Publications Warehouse

El McVCO es un generador de frecuencias basado en un microcontrolador que reemplaza al oscilador controlado por voltaje (VCO) utilizado en telemetría analógica de datos sísmicas. Acepta señales de baja potencia desde un sismómetro y produce una señal subportadora modulada en frecuencia adecuada para enlaces telefónicos o vía radio a un lugar remoto de recolección de datos. La frecuencia de la subportadora y la ganancia pueden ser seleccionadas mediante un interruptor. Tiene la opción de poder operar con dos canales para la observación con ganancia alta y baja. El McVCO fue diseñado con el propósito de mejorar la telemetría analógica de las señales dentro de la Pacific Northwest Seismograph Network (PNSN) (Red Sismográfica del Noroeste del Pacífico). Su desarrollo recibió el respaldo del Programa de Geofísica de la Universidad de Washington y del "Volcano Hazards and Earthquake Hazards programs of the United States Geological Survey (USGS) (Programa de Investigaciones de Riesgos Volcánicos y Programa de Investigaciones de Riesgos Sísmicos de los EEUU). Cientos de instrumentos se han construido e instalado. Además de utilizarlo el PNSN, el McVCO es usado por el Observatorio Vulcanológico de Alaska para monitorear los volcanes aleutianos y por el USGS Volcano Disaster Assistance Program (Programa de Ayuda en las Catástrofes Volcánicas del USGS) para responder a crisis volcánicas en otros países. Este manual cubre el funcionamiento del McVCO, es una referencia técnica para aquellos que necesitan saber con más detalle cómo funciona el McVCO, y cubre una serie de temas que requieren un trato explícito o que derivan del despliegue del instrumento.

McChesney, P.J.

1999-01-01

268

La capacidad redistributiva y estabilizadora del presupuesto del gobierno central español  

Microsoft Academic Search

El objetivo de este trabajo es estimar los efectos redistributivo y estabilizador\\/asegurador del presupuesto de la Administración Pública Central española en el período 1991-1996 a nivel regional. Este análisis se lleva a cabo para el conjunto del presupuesto a través de los saldos fiscales regionales y, separadamente, para el conjunto de ingresos y gastos y sus principales categorías. La metodología

NURIA BOSCH; MARTA ESPASA; PILAR SORRIBAS

2002-01-01

269

Rapporto del Sottocomitato Ricerca del Workshop Internazionale dell'Occhio Secco (2007)  

Microsoft Academic Search

I membri del Sottocomitato Ricerca del DEWS hanno esaminato i dati in letteratura relativi meccanismi ba- se della malattia dell'occhio secco. Sono state valutate le evidenze scientifiche riguardanti il film lacrimale, la ghian- dola lacrimale primaria e le ghiandole lacrimali accessorie, gli epiteli della superficie oculare (incluse cornea e con- giuntiva), le ghiandole di Meibomio, il sistema dei dotti lacri-

Membri del Sottocomitato Ricerca; Ilene K. Gipson; Pablo Argüeso; Roger Beuerman; Stefano Bonini; Igor Butovich; Reza Dana; Darlene Dartt; Dan Gamache; Bryan Ham; Marcia Jumblatt; Donald Korb; Friederich Kruse; Yoko Ogawa; Friedrich Paulsen; Michael Stern; Deborah F. Sweeney; John Tiffany; John Ubels; Mark Willcox

270

Efectos del color en la aceptabilidad, artificialidad, dulzor e intensidad del sabor de bebidas lácteas  

Microsoft Academic Search

El objetivo del presente estudio es analizar el efecto de la concentración de colorantes en bebidas lác- teas (batidos de vainilla) y de los parámetros de color, pureza o c ro m a, cl a ridad y tono, sobre las ex- p e c t at ivas del grado de acep t abilidad global de dichas bebidas así como sobre

T. Coello García; C. Díaz Berciano; N. Gómez Pestaña

2000-01-01

271

Intertextual Sexual Politics: Illness and Desire in Enrique Gomez Carrillo's "Del amor", "del dolor y del vicio" and Aurora Caceres's "La rosa muerta"  

ERIC Educational Resources Information Center

This study explores the intertextuality between Aurora Caceres's "La rosa muerta" (1914) and the novel "Del amor, del dolor y del vicio" (1898) by her ex-husband, Enrique Gomez Carrillo. Caceres strategically mentions Gomez Carrillo's novel in "La rosa muerta" to invite a reading of her work in dialogue with his. Both narratives follow the sexual…

LaGreca, Nancy

2012-01-01

272

Extensión del Formalismo de Orbitales de Defecto Cuántico al tratamiento del efecto Stark (SQDO).  

NASA Astrophysics Data System (ADS)

El estudio experimental de las interacciones de átomos Rydberg altamente excitados con campos eléctricos ha experimentado un creciente interés durante las dos últimas décadas debido, en gran medida, al desarrollo de nuevas técnicas para crear y estudiar átomos Rydberg en el laboratorio. Acompañando a estas nuevas técnicas experimentales, es necesario el desarrollo de modelos teóricos que nos permitan contrastar sus medidas y conocer mejor los fundamentos de los mismos. Desde el punto de vista teórico el conocimiento del desdoblamiento de los niveles energéticos de un átomo en función de la magnitud del campo eléctrico aplicado (lo que se conoce como mapa Stark) es el mejor punto de partida para la descripción del sistema y un prerrequisito fundamental para el cálculo de distintas propiedades atómicas en presencia del campo eléctrico tales como intensidades de transición, umbrales de ionización de campo eléctrico, tiempos de vida, posición y anchura de cruces evitados, etc. En este trabajo presentamos la adaptación del método de orbitales de defecto cuántico [1,2,3] al tratamiento del efecto Stark (SQDO) [4] y su aplicación al cálculo de los desdoblamientos energéticos y fuerzas de oscilador de estados Rydberg en los átomos de Li, Na y K. El propósito de este estudio es, por un lado, desarrollar métodos fiables para la determinación de propiedades atómicas en presencia de campos eléctricos y, por otro, mostrar la fiabilidad de las funciones de onda QDO en la descripción del efecto Stark en sistemas atómicos.

Menéndez, J. M.; Martín, I.; Velasco, A. M.

273

El Servicio de Información sobre el Cáncer del Instituto Nacional del Cáncer  

Cancer.gov

El Servicio de Información del Cáncer (CIS) del Instituto Nacional del Cáncer facilita la información más actualizada y precisa sobre el cáncer a pacientes, a sus familias, al público en general y a profesionales médicos. El CIS brinda respuestas personalizadas a preguntas específicas sobre el cáncer y asistencia a los fumadores que quieren abandonar el hábito. Comuníquese con el CIS al 1-800-422-6237 (1-800-4-CANCER) o al 1-877-448-7848 (1-877-44U-QUIT).

274

La reconstrucción del seno después de una mastectomía  

Cancer.gov

Hoja informativa que describe la reconstrucción del seno (mama) después de una mastectomía. Contiene información sobre las opciones quirúrgicas, los cuidados de seguimiento y los exámenes de detección del cáncer de seno después de la reconstrucción.

275

Transformación de los programas de estudios clínicos del NCI  

Cancer.gov

Información sobre los programas e iniciativas del NCI que patrocinan, realizan, crean o apoyan estudios clínicos, entre los que se incluyen la Red Nacional de Estudios Clínicos (NCTN) y el Programa de Investigación Oncológica Comunitaria (NCORP) del NCI.

276

Exportaciones del Sector Maderas y Papeles No Tradicional  

Microsoft Academic Search

fueron México (23.0% % de participación), Estados Unidos (15.4%), China (15.1%), Venezuela (8.2%) y Ecuador (8.1%). En conjunto estos cinco países concentraron el 66.8.0% del total de exportaciones del sector. Las ventas hacia los mercados de México, China, Ecuador y Venezuela, fueron superiores a las registradas en el mismo periodo del 2007, creciendo durante los primeros seis meses del año

Millones FOB

277

33 CFR 80.1118 - Marina Del Rey, CA.  

Code of Federal Regulations, 2013 CFR

...1 2013-07-01 2013-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters...DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South...

2013-07-01

278

Boletín del Instituto Nacional del Cáncer - 8 de noviembre de 2011  

Cancer.gov

Le invitamos a que comparta esta publicación con sus amigos, familiares y colegas y nos ayude a continuar nuestra misión de difundir las investigaciones más recientes sobre la prevención, el tratamiento y la información del cáncer.

279

Impacto del conflicto colombiano en los periodistas  

Microsoft Academic Search

Introducción: Este artículo esboza las dificultades que presentan los periodistas colombianos en su trabajo y caracteriza el impacto del conflicto armado colombiano en su relación con este ejercicio profesional. Método: Los autores realizaron 70 entrevistas a algunos periodistas colombianos que cubren el conflicto. Para el análisis de las entrevistas se intentó entender la lógica de su conducta y cómo representan

Ismael Roldán; Diana Sofía Giraldo; Miguel Ángel Flórez

2008-01-01

280

Exámenes selectivos de detección del cáncer colorrectal  

Cancer.gov

Un ejemplo excelente del poder de la investigación de prevención es el progreso sustancial que hemos logrado en la reducción de la incidencia y muerte por cáncer colorrectal, con nuevos conocimientos que iluminan el camino a incluso mayores reducciones en un futuro cercano.

281

Vigilando la Calidad del Agua de los Grandes Rios de la Nacion: El Programa NASQAN del Rio Grande (Rio Bravo del Norte)  

USGS Publications Warehouse

La Oficina del Estudio Geologico de los Estados Unidos (U.S. Geological Survey, 0 USGS) ha monitoreado la calidad del agua de la cuenca del Rio Grande (Rio Bravo del Norte) desde 1995 como parte de la rediseiiada Red Nacional para Contabilizar la Calidad del Agua de los Rios (National Stream Quality Accounting Network, o NASOAN) (Hooper and others, 1997). EI programa NASOAN fue diseiiado para caracterizar las concentraciones y el transporte de sedimento y constituyentes quimicos seleccionados, encontrados en los grandes rios de los Estados Unidos - incluyendo el Misisipi, el Colorado y el Columbia, ademas del Rio Grande. En estas cuatro cuencas, el USGS opera actualmente (1998) una red de 40 puntos de muestreo pertenecientes a NASOAN, con un enfasis en cuantificar el flujo en masa (la cantidad de material que pasa por la estacion, expresado en toneladas por dial para cada constituyente. Aplicacando un enfoque consistente, basado en la cuantificacion de flujos en la cuenca del Rio Grande, el programa NASOAN esta generando la informacion necesaria para identificar fuentes regionales de diversos contaminantes, incluyendo sustancias qui micas agricolas y trazas elementos en la cuenca. EI efecto de las grandes reservas en el Rio Grande se puede observar segun los flujos de constituyentes discurren a 10 largo del rio. EI analisis de los flujos de constituyentes a escala de la cuenca proveera los medios para evaluar la influencia de la actividad humana sobre las condiciones de calidad del agua del Rio Grande.

Lurry, Dee L.; Reutter, David C.; Wells, Frank C.; translated by Rivera, M.C.; Munoz, A.

1998-01-01

282

Boletín del Instituto Nacional del Cáncer - 31 de enero de 2012  

Cancer.gov

Dr. Nils Daulaire Salud mundial a través de la colaboración y el liderazgo Para conmemorar el Día Mundial del Cáncer que tuvo lugar el 4 febrero, el doctor Nils Daulaire, director de la Oficina de Asuntos Internacionales del Departamento de Salud y Servicios Humanos de los Estados Unidos habla sobre las razones por las cuales los Estados Unidos deben participar en iniciativas para mejorar la salud mundial.

283

Comportamiento del Helio en estrellas químicamente peculiares  

NASA Astrophysics Data System (ADS)

Las estrellas químicamente peculiares (CP) se caracterizan por tener deficiencias y sobreabundancias de algunos elementos químicos de hasta 106 veces la abundancia solar. Además presentan variaciones en las líneas espectrales. Se piensa que ello se debe a que los campos magnéticos presentes en este tipo de estrellas son principalmente dipolares, con un eje de simetría diferente del eje de rotación. La distribución de los elementos sobreabundantes y deficientes no es homogénea sobre la superficie estelar y las variaciones observadas serían una consecuencia directa de la rotación estelar. Entre los elementos con abundancia anómala se encuentra el Helio, cuyas líneas tienen intensidades que no son consistentes con una abundancia normal, que no puede ser determinada del modo usual, o sea, considerando una atmósfera con composición solar. Con el fin de determinar la abundancia de este elemento, se inició un estudio de estrellas anómalas de Helio, Hew y He strong. Además se determinarán las abundancias de otros elementos anómalos como ser el Si, Cr, Mg, Mn y Fe. Las mismas se determinan del modo tradicional, o sea: a) medida de los anchos equivalentes de las líneas de los distintos elementos analizados; b) adopción de la temperatura efectiva, gravedad y abundancia del Helio; c) cálculo del modelo de atmósfera d) comparación con las observaciones y reinicio de un proceso iterativo hasta lograr un acuerdo entre todos los parámetros analizados. Las observaciones se llevaron a cabo en el Complejo Astronómico El Leoncito. Se observaron setenta y ocho estrellas anómalas de Helio. En este momento se está procediendo a calcular las abundancias correspondientes a los distintos elementos químicos. Para ello se hace uso de los modelos de Kurucz, ATLAS9. Los cálculos NLTE de las líneas de Helio se llevan a cabo con el programa MULTI y se compararán con los realizados con el programa WIDTH9 de Kurucz (LTE), con el objeto de resaltar la importancia de los efectos NLTE.

Malaroda, S. M.; López García, Z.; Leone, F.; Catalano, F.

284

A case report concerning male gametes rescued from a Siamese Eld's deer (Rucervus eldii siamensis): post-thawed testicular and epididymal sperm quality and heterologous zona pellucida binding ability.  

PubMed

In the present study, the quality of frozen-thawed epididymal and testicular sperm recovered from a Siamese Eld's deer was examined. The epididymal sperm quality was assessed in fresh, cold-stored at 4°C and frozen-thawed samples. Zona binding ability of the frozen-thawed epididymal samples with Burmese Eld's deer oocytes was also evaluated. Testicular sperm extracted from tissues frozen at -80 or -196°C for one month were examined for membrane and DNA integrity. Epididymal sperm retained their quality for up to 24 hr of cold storage at 4°C. The percentages of sperm motility, intact membrane, intact acrosome and intact DNA were 30, 46.5, 27 and 89.5% in the frozen and thawed epididymal sperm, and the average ability to bind with oocytes was 92.5 ± 64 sperm/oocytes. Around 70% of the sperm extracted from testicular tissues cryopreserved at -196 and -80°C for one month showed an intact membrane. In conclusion, epididymal and testicular sperm survived for more than 13 hr post-mortem. Furthermore, cold storage at 4°C and cryopreservation at -196 and -80°C maintain the quality of epididymal and testicular sperm. This study represents a model for male gamete rescue in endangered Eld's deer. PMID:22971799

Thuwanut, Paweena; Thongphakdee, Ampika; Sommanustweechai, Angkana; Siriaroonrat, Boripat; Chatdarong, Kaywalee

2013-01-31

285

Granulocyte-Macrophage Colony-Stimulating Factor Enhances the Humoral Immune Responses of Mouse Zona Pellucida 3 Vaccine Strategy Based on DNA and Protein Coadministration in BALB/c Mice  

PubMed Central

We recently demonstrated that co-administration of mouse zona pellucida 3 (mZP3) DNA and protein vaccine enhanced the contraception of mice by increasing humoral immune responses. In this study, we try to use granulocyte–macrophage colony-stimulating factor (GM-CSF) to further improve the humoral immune responses induced by mZP3 DNA and protein co-administration. BALB/c mice were intranasally pre-injected with GM-CSF 4 days before co-administration. Compared to DNA and protein coadministration without GM-CSF, the combination of GM-CSF and coadministration significantly enhances humoral immune responses, especially the level of secretory immunoglobulin A (sIgA) in vaginal washes. The enhanced antibody responses are correlated with the upregulated level of interleukin 4 (IL-4) and enhanced maturation of dendritic cells (DCs). Thus, GM-CSF is a potential candidate adjuvant to be used for the development of a safe and effective contraceptive vaccine.

Kadir, Zibirnisa; Ma, Xiaolin

2013-01-01

286

[Orientamento religioso e disturbi del comportamento alimentare].  

PubMed

riassunto. Introduzione. L'obiettivo principale del presente studio caso-controllo è stato quello di valutare le relazioni intercorrenti tra la psicopatologia dei disturbi del comportamento alimentare (DCA) con il differente orientamento religioso: intrinseco ed estrinseco. Metodi. Sono stati confrontati un gruppo di pazienti affetti da DCA (23 con anoressia nervosa, 10 con bulimia nervosa e 39 con disturbo d'alimentazione incontrollata) con un gruppo di controllo di soggetti sani, utilizzando la Religious Orientation Scale (ROS). Risultati. I pazienti affetti da DCA hanno mostrato punteggi più alti nella sottoscala della religiosità estrinseca e minori punteggi nella sottoscala riguardante la religiosità intrinseca rispetto ai controlli sani. Nessuna differenza significativa è stata osservata tra i gruppi di DCA in termini di punteggi ROS. Conclusioni. Punteggi più elevati riscontrati in pazienti con orientamento religioso estrinseco sembrano essere associati con la presenza di DCA, mentre un orientamento religioso di tipo intrinseco sembra rappresentare un fattore protettivo. PMID:25000890

Castellini, Giovanni; Zagaglioni, Alice; Godini, Lucia; Monami, Francesca; Dini, Carla; Faravelli, Carlo; Ricca, Valdo

2014-01-01

287

Del Norte means north to recycling  

SciTech Connect

Del Norte Regional Recycling and Transfer Station is owned by the city of Oxnard, California and operated by BLT Enterprises, Inc. The Del Norte facility--located in southwestern Ventura County about an hour northwest of Los Angeles--processes polyethylene terephthalate (PET) and high-density polyethylene (HDPE) plastic containers, aluminum, steel, glass, old corrugated containers (OCC), newspapers, computer printout paper, white and colored ledger paper, coated book, supermix paper, telephone books, and old magazines. According to the company, there has been virtually no community opposition to the site. The facility has few neighbors, and those are agricultural. To keep the community relationship strong, the facility`s design and location all but eliminated odor and noise complaints. The building was designed against the prevailing wind pattern, and BLT processes odorous material fast. A misting system installed for dust suppression also can be used with a solution for odor control should the need arise.

Aquino, J.T.

1998-06-01

288

Vascular endothelial tight junctions and barrier function are disrupted by 15(S)-hydroxyeicosatetraenoic acid partly via protein kinase C ?-mediated zona occludens-1 phosphorylation at threonine 770/772.  

PubMed

Disruption of tight junctions (TJs) perturbs endothelial barrier function and promotes inflammation. Previously, we have shown that 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE), the major 15-lipoxygenase 1 (15-LO1) metabolite of arachidonic acid, by stimulating zona occludens (ZO)-2 tyrosine phosphorylation and its dissociation from claudins 1/5, induces endothelial TJ disruption and its barrier dysfunction. Here, we have studied the role of serine/threonine phosphorylation of TJ proteins in 15(S)-HETE-induced endothelial TJ disruption and its barrier dysfunction. We found that 15(S)-HETE enhances ZO-1 phosphorylation at Thr-770/772 residues via PKC?-mediated MEK1-ERK1/2 activation, causing ZO-1 dissociation from occludin, disrupting endothelial TJs and its barrier function, and promoting monocyte transmigration; these effects were reversed by T770A/T772A mutations. In the arteries of WT mice ex vivo, 15(S)-HETE also induced ZO-1 phosphorylation and endothelial TJ disruption in a PKC? and MEK1-ERK1/2-dependent manner. In line with these observations, in WT mice high fat diet feeding induced 12/15-lipoxygenase (12/15-LO) expression in the endothelium and caused disruption of its TJs and barrier function. However, in 12/15-LO(-/-) mice, high fat diet feeding did not cause disruption of endothelial TJs and barrier function. These observations suggest that the 12/15-LO-12/15(S)-HETE axis, in addition to tyrosine phosphorylation of ZO-2, also stimulates threonine phosphorylation of ZO-1 in the mediation of endothelial TJ disruption and its barrier dysfunction. PMID:24338688

Chattopadhyay, Rima; Dyukova, Elena; Singh, Nikhlesh K; Ohba, Motoi; Mobley, James A; Rao, Gadiparthi N

2014-02-01

289

Enfoques de programación matemática fuzzy multiobjetivo para la planificación operativa del transporte en una cadena de suministro del sector del automóvil = Fuzzy Multiobjective Mathematical Programming Approaches for Operational Transport Planning in an Automobile Supply Chain  

Microsoft Academic Search

En este trabajo se presenta un modelo de programación matemática fuzzy multiobjetivo para la planificación del transporte a nivel operativo en una cadena de suministro. Los objetivos del modelo propuesto son la minimización del número de camiones utilizados y del inventario total, considerando como parámetro borroso las capacidades de los vehículos empleados. Se propone una metodología de resolución para transformar

Manuel Díaz-Madroñero; David Peidro; Josefa Mula; Francisco J. Ferriols

2010-01-01

290

SISTEMA PARA GESTIONAR LA ACTIVIDAD CIENTÍFICA DEL DEPARTAMENTO DE INFORMÁTICA DE LA UNIVERSIDAD DE GUANTÁNAMO  

Microsoft Academic Search

El sistema para gestionar la actividad científica del Departamento de Informática de la Universidad de Guantánamo surge debido a la necesidad de gestionar de manera más rápida, segura y eficaz los procesos que se desarrollan actualmente en dicho centro. Fue desarrollado utilizando los lenguajes PHP del lado del servidor con CodeIgniter como framework y JavaScript del lado del cliente. Se

Denis Boizan Romero

2012-01-01

291

Epidemiologia della malattia dell'Occhio Secco: Rapporto del Sottocomitato Epidemiologia del Workshop Internazionale dell'Occhio Secco (2007) Epidemiologia  

Microsoft Academic Search

Il rapporto del Sottocomitato Epidemiologia del Workshop dell'Occhio Secco del 2007 riassume le cono- scenze attuali dell'epidemiologia della malattia dell'occhio secco, fornendo i dati di prevalenza e incidenza derivanti da varie popolazioni. Mette in risalto la necessità di allargare gli studi epidemiologici a ulteriori aree geografiche, di incorpo- rare varie razze ed etnie negli studi futuri e di determinare un

Sottocomitato Epidemiologia; Janine A. Smith; Julie Albeitz; Carolyn Begley; Barbara Caffery; Kelly Nichols; Debra Schaumberg; Oliver Schein

292

Descripción del funcionamiento del mercado secundario de bonos soberanos locales en Chile  

Microsoft Academic Search

En este trabajo se describe el funcionamiento del mercado secundario de los bonos de largo plazo soberanos locales. Más específicamente, se describen en profundidad los agentes involucrados, los instrumentos transados y los tipos de plataformas existentes. A partir de este trabajo es posible obtener las siguientes conclusiones. Primero, existe un alto grado de segmentación en el mercado secundario de renta

Sergio D’Acuña; Sergio Godoy; Nicolás Malandre

2009-01-01

293

Eficiencia y determinantes del funcionamiento del mercado paralelo de divisas en Colombia  

Microsoft Academic Search

El presente trabajo analiza la relación entre el tipo de cambio negro y el oficial, al igual que la eficiencia del mercado paralelo de divisas en Colombia. Con base en datos mensuales para el período 1970-1989, se encontró que la tasa de cambio oficial y paralela estaban cointegradas, lo cual implica que el dólar oficial y el negro mantuvieron una

Santiago Herrera

1990-01-01

294

Ajuste estructural y mercado del trabajo: Nigeria después de la crisis del petróleo  

Microsoft Academic Search

En este artículo examinamos la experiencia de Nigeria durante la crisis petrolera de los años 1980 y el comienzo de la aplicación de un paquete de ajuste estructural. Nuestro análisis se concentra en el rol jugado por el mercado del trabajo, particularmente en relación a la situación de empleo y desempleo, como también a los flujos migratorios despertados por la

Paul Collier; Luis Riveros

295

Mujeres en ascenso: dinámica del sistema educativo y del mercado laboral en Colombia, 1900-2000  

Microsoft Academic Search

El objetivo principal de la presente investigación es describir y analizar los cambios en la transmisión de conocimiento en los establecimientos educativos femeninos de Bogotá y la participación de la mujer dentro del mercado laboral bogotano. Con base en los resultados que arrojó la Encuesta de empleo de 1963-1970 para Bogotá y la Encuesta Integrada de hogares 2006, se elaboró

María del Pilar López-Uribe; Diana Quintero Castellanos; Loly Aylú Gaitán Guerrero

2011-01-01

296

La quimera del mezzo termine. La contribución franco-británica a la caída del liberalismo peninsular  

Microsoft Academic Search

En 1823, en un contexto marcado por el temor a despertar del fantasma de la revolución en Europa, pasó a un primer plano la posibilidad de ensayar en la Península fórmulas moderadas de organización política, un mezzo termine que conjugara la renuncia a los principios más revolucionarios con el reconocimientos de ciertos derechos y garantías individuales. El debate creado en

Gonzalo Butrón Prida

2001-01-01

297

Boletín del Instituto Nacional del Cáncer - 11 de septiembre de 2012  

Cancer.gov

Con la ayuda de herramientas genéticas, investigadores han identificado subconjuntos de células que parecen impulsar el crecimiento de tumores en ratones. Estos resultados ofrecen factores adicionales que sustentan la hipótesis de la existencia de células madre del cáncer, es decir, la idea de que algunos tumores contienen células que se autorenuevan y dan origen a todo tipo de células tumorales.

298

Diseño del saneamiento de Urdaibai (País Vasco) bajo una perspectiva de preservación ambiental del litoral  

Microsoft Academic Search

Los sistemas de saneamiento unitarios, del mismo modo que cualquier obra de infraestructura dispuesta a soportar fenómenos naturales, pre- sentan, inevitablemente, una determinada probabilidad de fallo, igual, a la de que los efectos producidos por estos superen a los considerados en su diseño. Por tanto, el comportamiento general de los mismos sólo puede evaluarse en términos probabilísticos. Siendo la lluvia

ANDRÉS GARCÍA; KALIN N. KOEV; JOSÉ A. REVILLA; JOSÉ A. JUANES

299

Alcune osservazioni sulle cause di tenuta del settore del franchising nelle fasi recessive  

Microsoft Academic Search

La ricerca esamina le imprese che operano in franchising attraverso microdati raccolti da Assofranchising, la principale associazione italiana nel campo del franchising. Mediante tecniche esplorative e multivariate si dimostra che, ceteris paribus, un aumento della scala delle reti, basata sulla crescita delle risorse umane e materiali, ha un effetto positivo sull’efficienza aziendale attraverso il miglioramento di indicatori strategici di produttività.

Antonio Bernardi

2011-01-01

300

Tratamiento adyuvante del carcinoma de recto  

Microsoft Academic Search

Resumen\\u000a Objectivo  Neustro objetivo es analizar los resultados del tratamiento adyuvante en pacientes operados por un carcinoma rectal localmente\\u000a avanzado, tratados con radioquimioterapia concomitante o secuencial.\\u000a \\u000a \\u000a \\u000a Material y métodos  Entre enero de 1994 y septiembre de 1997, 122 pacientes fueron tratados postquirúrgicamente por un adenocarcinoma rectal en\\u000a estadio B2-C. Setenta y siete pacientes fueron tratados siguiendo un esquema alternante de quimiorradioterapia y

Javier Valencia Julve; Ricardo Escó Barón; Javier Sanz Lacalle; Miguel Burillo Cordero; Pedro Mateo de las Heras; Carmen Lainez Baquero

2003-01-01

301

UBVJHKLM photometry of Nova Del 2013  

NASA Astrophysics Data System (ADS)

We present the results of the optical and IR photometry of Nova Del 2013 obtained at the Crimean Station (Nauchny, Ukraine) of the Sternberg Astronomical Institute. UBV photometry was carried out with 60-cm Zeiss telescope using a photoelectric photometer on August 15.94 UT: U=4.54+/-0.02, B=5.07+/-0.01, V=5.05+/-0.01; on August 16.80 UT: U=4.54+/-0.01, B=4.85+/-0.02, V=4.68+/-0.01; on August 16.86 UT: U=4.66+/-0.01, B=4.92+/-0.01, V=4.73+/-0.01.

Burlak, A. M.; Shenavrin, I. V.; Tatarnikov, M. A.; Tatarnikova, A. A.

2013-08-01

302

TEMA V TENDENCIAS RECIENTES EN EL MERCADO DE TRABAJO (I): LA CONSTRUCCIÓN SOCIOHISTÓRICA DEL MERCADO DE TRABAJO CONTEMPORÁNEO: DEL FORDISMO AL POSFORDISMO  

Microsoft Academic Search

Este tema presenta un conjunto de cuestiones relacionadas con las transformaciones históricas más recientes del trabajo y del empleo. Intentaremos aquí seguir su trayectoria en la segunda mitad del siglo XX para poder analizar las tendencias más recientes del mercado de trabajo que se proyectan hacia el siglo XXI y que sirven de contexto y de marco de explicación al

Antonio Santos Ortega

303

MÚSICA Y AGRUPACIONES DE CARNAVAL A FINALES DEL SIGLO XX EN ANDALUCÍA OCCIDENTAL. LA REVITALIZACIÓN FESTIVA Y EL RENACIMIENTO DEL CARNAVAL  

Microsoft Academic Search

Con este trabajo pretendemos acercarnos al Carnaval de Andalucía occidental a partir de su recuperación durante la Transición y los gobiernos socialistas en la década de los años ochenta del pasado siglo XX. Este proceso tuvo lugar en un marco de participación ciudadana, modernización económica, estado del bienestar, constitución de las comunidades autónomas, sociedad del espectáculo y del entretenimiento, y

Francisco José García Gallardo

2005-01-01

304

Instantánea de los cánceres de cerebro y del sistema nervioso central  

Cancer.gov

Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre los cánceres de cerebro y del sistema nervioso central; así como ejemplos de actividades del NCI y adelantos en la investigación de estos tipos de cáncer.

305

Decoding F508del Misfolding in Cystic Fibrosis  

PubMed Central

The functional deficiency of the cystic fibrosis transmembrane conductance regulator (CFTR), a plasma membrane chloride channel, leads to the development of cystic fibrosis. The deletion of a phenylalanine at residue 508 (F508del) is the most common cause of CFTR misfolding leading to the disease. The F508del misfolding originates in the first nucleotide-binding domain (NBD1), which induces a global conformational change in CFTR through NBD1’s interactions with other domains. Such global misfolding produces a mutant chloride channel that is impaired in exocytic trafficking, peripheral stability, and channel gating. The nature and atomic details of F508del misfolding have been subject to extensive research during the past decade. Current data support a central role for NBD1 in F508del misfolding and rescue. Many cis-acting NBD1 second-site mutations rescue F508del misfolding in the context of full-length CFTR. While some of these mutations appear to specifically counteract the F508del-induced misfolding, others release certain inherent conformational constraints of the human wild-type CFTR. Several small-molecule correctors were recently found to act on key interdomain interfaces of F508del CFTR. Potential rational approaches have been proposed in an attempt to develop highly effective small molecule modulators that improve the cell surface functional expression of F508del CFTR.

Wang, Xiaodong Robert; Li, Chenglong

2014-01-01

306

Conceptos fundamentales del desarrollo de proveedores (Caso de negocios 13)  

Microsoft Academic Search

El desarrollo de proveedores es una actividad que enriquece la gestión de la cadena de suministro, dotándola de mayor valor a través del aporte mutuo entre empresas clientes y subcontratistas. Este aporte incluye nuevas tecnologías, know-how, herramientas de la calidad y organización del trabajo, además de negociaciones sobre la política de precios, entre otros temas. En este trabajo presentamos sus

Enrique Yacuzzi

2012-01-01

307

Fomento de la investigación del cáncer en América Latina  

Cancer.gov

La Oficina para el Desarrollo de Programas de Cáncer en América Latina (OLACPD), fruto de una alianza innovadora entre el Instituto Nacional del Cáncer (NCI) y el Centro Internacional Fogarty (FIC), fue creada en reconocimiento de la oportunidad de apoyar y mejorar la investigación y el tratamiento del cáncer en América Latina.

308

El presidente Obama anuncia nombramiento del doctor Harold Varmus  

Cancer.gov

En los últimos cinco años como director del NCI, y en otras funciones ejercidas durante muchos años, he disfrutado ampliamente cada oportunidad que he tenido de visitar los laboratorios y las oficinas, desde Bethesda hasta Frederick, para conocer en persona a los miembros del personal y compartir mis opiniones sobre temas importantes en torno a la ciencia y al manejo de este gran Instituto.

309

El sistema muscular es el impulsor del desarrollo esquelético  

Microsoft Academic Search

ExtractoEn esta revisión se abordan los conceptos metodológicos de evaluación de la función de la musculatura esquelética y adaptación ósea. Actualmente se considera que la propiedad crítica del hueso no es tanto su peso como su resistencia, y que el control de la resistencia ósea se ejerce principalmente a través del efecto de las cargas mecánicas que inciden sobre el

Eckhard Schoenau

2006-01-01

310

The hydrothermal system of Nevado del Ruiz volcano, Colombia  

Microsoft Academic Search

Hot springs and steam vents on the slopes of Nevado del Ruiz volcano provide evidence regarding the nature of hydrothermal activity within the summit and flanks of the volcano. At elevations below 3000 m, alkali-chloride water is discharged from two groups of boiling springs and several isolated warm springs on the western slope of Nevado del Ruiz. Chemical and isotopic

Neil C. Sturchio; Stanley N. Williams; Nestor P. Garcia; Adela C. Londono

1988-01-01

311

Gestión ambiental de la vitivinicultura: aplicación del cuadro de mando  

Microsoft Academic Search

Resumen La vitivinicultura es una de las principales industrias de San Juan, Argentina. En esta provincia existen más de 266 bodegas. Actualmente, existe mayor conciencia, por parte del consumidor, del proceso de elaboración de un producto, desde el punto de vista medioambiental, sobre todo en países como Estados Unidos y el Reino Unido, los cuales son los principales países importadores

Rosa Ana Rodríguez; Gustavo R. Traconis

2012-01-01

312

An Accretion Disc Model For Eclipsing Binary System: AV Del  

Microsoft Academic Search

We investigate the light and radial-veloci -ty curves of the eclipsing binary AV Del. Using the most new version of Wilson & Van Hamme (2003) code, the absolute elements, fundamental orbital and physical parameters of the system are determined. Then, using the new SHELLSPEC code, we study and present an accretion disc model for the system. We found AV Del

Sayyed Mohammad Reza Ghoreyshi; Jamshid Ghanbari; Fatemeh Salehi

313

Molecular basis of DEL phenotype in the Chinese population  

PubMed Central

Background Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles vary in different populations. We conducted the present study to examine the genotype of DEL individuals and to elucidate whether novel alleles exist in the Chinese population. Methods DEL phenotype was identified by a serologic adsorption-elution method. The nucleotide sequences of ten RHD exons and exon-intron boundary regions were evaluated by RHD gene-specific PCR-SSP and sequencing. Results Of 42306 samples from individual donors and patients, 165 samples were typed as D-negative. Among these D-negative samples, 41 DEL individuals were observed. Thirty-seven DELs were confirmed to have the RHD1227A allele. Two DELs seemed to have RHD-CE-D hybrid alleles, including one RHD-CE (4–7)-D and one RHD-CE (2–5)-D. Two novel RHD alleles were found among the rest of the DEL samples, including one RHD93T?>?A and one RHD838G?>?A. Conclusion In this study, about 24.85% (41/165) of the apparent D-negative Chinese individuals were DEL. RHD1227G?>?A is the most frequent allele in Chinese DEL phenotypes, accounting for 90.24% (37/41). The RHD-CE-D hybrid allele might be the second most frequent DEL allele in the Chinese population. Our study would contribute to the understanding of the molecular mechanism underlying D antigen expression of DEL individuals and provide useful information for designing suitable genotyping strategies in RhD-negative individuals in Asia.

2014-01-01

314

El Instituto Nacional del Cáncer de EE. UU. y la República del Perú firman una Declaración de Intención  

Cancer.gov

El Instituto Nacional del Cáncer y la República del Perú firmaron una declaración de intención para compartir el interés en fomentar la investigación biomédica de oncología, basándose en la colaboración mutua de ambas entidades, así como el objetivo común de educar y capacitar la futura generación de científicos y clínicos en investigación oncológica.

315

La dimensione del tumore è predittiva della sopravvivenza nel tumore del polmone non a piccole cellule in stadio IA  

Microsoft Academic Search

Oggetto dello studio: La premessa base dello screening mediante TC è che la dimensione sia una determinante importante della sopravvivenza per il cancro del polmone. Noi abbiamo cer- cato di esaminare questa ipotesi per il tumore del polmone non a piccole cellule (NSCLC) in stadio IA. Metodi: È stata condotta una analisi retrospettiva di tutti i pazienti con NSCLC istologicamente

Jeffrey L. Port; Michael S. Kent; Robert J. Korst; Daniel Libby; Mark Pasmantier; Nasser K. Altorki

2004-01-01

316

[Strengths and future of the Revista Médica del Instituto Mexicano del Seguro Social].  

PubMed

The journals of medicine arose as a communication tool more than 200 years ago. At the beginning, their nature was local; later, their aim was to spread medical information along the nation; and, finally, they sought to reach the world distribution. The Revista Médica del Instituto Mexicano del Seguro Social was published for the first time 52 years ago, and it has walked its way from local to international distribution. This journal has 23 000 subscribers, it is included in Medline and it reached a 0.112 SCImago Journal Rank in 2012. Its website receives around 200 000 visits monthly and 45 % are foreign visits. In the future, the peer review system is going to be strengthened, and the journal is going to offer audio, video, and applications to reinforce interactive participation between authors, readers in order to reach modernity and draw young new attention. PMID:24758842

Fajardo-Dolci, Germán

2014-01-01

317

El metabolismo social del País Vasco desde el análisis de flujos materiales  

Microsoft Academic Search

La desvinculación de la mejora del bienestar respecto del uso de los recursos y de la contaminación es esencial para lograr un desarrollo sostenible. Para avanzar en esta dirección es preciso partir del conocimiento del metabolismo de la sociedad. Es decir, debemos analizar en qué medida nuestras sociedades “ingieren” materias primas, que son “metabolizadas” para producir bienes y servicios, y

Iñaki Arto

2009-01-01

318

La teoría de juegos conductual, el dilema del viajero alternativo y la maximización de pagos  

Microsoft Academic Search

Dentro del área de teoría de juegos conductual nos enfocamos en un contexto específico, el del juego que denominamos Dilema del viajero alternativo. En este contexto hemos observado que los participantes tienden a elegir estrategias estrictamente dominadas. Para explicar tendencias similares en otros juegos, los investigadores del área han apelado a sesgos cognitivos o bien a factores motivacionales. Proponemos un

Rodrigo Moro; Esteban Freidin; Fernando Tohmé; Marcelo Auday

319

Doctor Harold Varmus, director del NCI: Bienvenidos a Cancer.gov en español  

Cancer.gov

El director del NCI, doctor Harold Varmus, da la bienvenida a los visitantes al sitio web del NCI y habla sobre la complejidad del cáncer, así como de los avances alcanzados gracias a las nuevas herramientas y tecnologías para la investigación del cáncer.

320

Antenatal Rh prophylaxis is unnecessary for “Asia type” DEL women  

Microsoft Academic Search

BackgroundGenerally Rh-negative patients need to be transfused with Rh-negative red blood cells. For pregnant women carrying Rh-positive fetus, the antenatal anti-D detection and Rh immunoglobulin prophylaxis are required worldwide. In East Asia, a RhD variant, termed “Asia type” DEL, was found in approximately 30% of apparent Rh-negative individuals. The antigenic and molecular properties of the DEL were previously defined. Few

Chao-Peng Shao; Hua Xu; Qun Xu; Guo-Dong Sun; Jian-Ping Li; Bo-Wei Zhang; Xiao-Hua Liang; Zhong Liu; Ying Zhou; Dan Li; Nai-Bao Zhuang

2010-01-01

321

Modelo semi-empírico de protuberancia solar a partir del diagnóstico de densidades  

NASA Astrophysics Data System (ADS)

A partir de la observación del espectro del quintuplete de C III alrededor de 1175 Å, se ha realizado el diagnóstico de la densidad y presión electrónica, basado en el cálculo del cociente de las intensidades observadas. Una vez establecida la densidad electrónica, y con el cálculo de las velocidades Doppler, hemos investigado el flujo de masa en la protuberancia en función de la temperatura. Estableciendo como hipótesis la conservación del número de partículas que ingresan y salen del cuerpo de la protuberancia, se investiga la variación del área de un tubo de flujo semi-empírico en función de la temperatura. A partir de dicho diagnóstico, se examina el comportamiento del radio del tubo magnético en función de la temperatura, los que dan cuenta de la abertura de las líneas de campo magnético que confinan el plasma y de la divergencia del campo magnético en diferentes alturas de la atmósfera solar.

Cirigliano, D.; Vial, J. C.; Rovira, M.

322

Peat soil flows in Bahía del Buen Suceso, Tierra del Fuego (Argentina)  

NASA Astrophysics Data System (ADS)

On the southeastern edge of Tierra del Fuego, a mountainous area with a cold humid oceanic climate, peat soils cover not only flat areas but also steep hillslopes under an evergreen Nothofagus betuloides forest. Peat flows in the form of chutes are very frequent on these hillslopes. Some data were gathered on the field for 11 of these movements and from aerial photographs for 21 of them. The results suggest that peat soils become unstable when thickness exceeds a critical value which depends on the slope. This critical slope depends on the altitude and aspect regardless of soil thickness. A temporal analysis carried out by tree-ring counting demonstrated that the occurrence of these movements is not random though there are some periods of higher hazard, the probable triggering mechanisms being heavy snowfalls or earthquakes.

Gallart, Francesc; Clotet-Perarnau, Núria; Bianciotto, Oscar; Puigdefàbregas, Joan

1994-05-01

323

Análisis del espectro infrarrojo del polvo interestelar asociado con cúmulos globulares y de su evolución temporal  

NASA Astrophysics Data System (ADS)

El trabajo que se presenta investiga la dinámica de las partículas de polvo interestelar eyectadas por estrellas gigantes rojas en un cúmulo globular utilizando simulaciones numéricas de su interacción con el campo gravitatorio y con la radiación electromagnética de las estrellas. Se pretende con ello determinar la distribución espacial de ese material como una función del tiempo en un sistema similar a NGC 104 (47 Tuc). A partir de la distribución espacial resultante se obtuvo el espectro infrarrojo integrado el cual sugiere que el máximo contraste con la radiación estelar ocurre en longitudes de onda cercanas a 300 ?m y que decrece rápidamente hacia longitudes de onda menores, en las que suelen realizarse las observaciones.

Pellizza, L. J.; Forte, J. C.; Carpintero, D.

324

El diseño final del espectrógrafo de banco (EBASIM) para CASLEO  

NASA Astrophysics Data System (ADS)

Utilizando el código de óptica ACCOS V se ha finalizado el diseño del espectrógrafo de banco para CASLEO. En una comunicación anterior habíamos indicado que utilizaríamos un colimador de 150 mm de diámetro con un radio de curvatura de 1540 mm. Para el espejo cámara, que tiene un diámetro de 200 mm, el radio de curvatura es de 1200 mm, ambos radios con una tolerancia no mayor a los 3 mm. En la presente, se informa sobre los detalles finales del cálculo del espectrógrafo que incluye el cómputo para 5 longitudes de onda diferentes y alrededor de 100 rayos. En todos los casos el 75 % de energía está dentro de un diámetro de 13 micrones. El diseño ha sido probado entre 3500 Å hasta 9000 Å con resultados satisfactorios.

Simmons, J.; Levato, H.

325

EFECTO GENOTÓxICO DEL DICROMATO DE POTASIO EN ERITROCITOS DE SANGRE PERIFéRICA DE Oreochromis niloticus (TILAPIA)  

Microsoft Academic Search

RESUMEN Existen múltiples reportes del efecto genotóxico y cancerígeno del cromo VI, los seres humanos tenemos una permanente exposición a este elemento. Objetivos. Evidencias la genotoxicidad del dicromato de potasio utilizando como sistema biológico a Oreochromis niloticus \\

Zulita Prieto; Julio León-Incio; Carlos Quijano-Jara; Radigud Fernández; Edgardo Polo-Benites; Roger Vallejo-Rodríguez; Luis Villegas-Sanchez

326

Field measurements of del13C in ecosystem respiration  

NASA Astrophysics Data System (ADS)

Stable carbon isotope del13C-measurements are extensively used to study ecological and biogeochemical processes in ecosystems. Above terrestrial ecosystems, atmospheric del13C can vary largely due to photosynthetic fractionation. Photosynthetic processes prefer the uptake of the lighter isotope 12C (in CO2), thereby enriching the atmosphere in 13C and depleting the ecosystem carbon. At night, when ecosystem respiratory fluxes are dominant, 13C-depleted CO2 is respired and thereby depletes the atmospheric del13C-content. Different ecosystems and different parts of one ecosystem (type of plant, leaves, and roots) fractionate and respire with a different del13C-ratio signature. By determining the del13C-signature of ecosystem respiration in temporal and spatial scale, an analysis can be made of the composition of respiratory sources of the ecosystem. A field study at a dry cropland after harvest (province of Viterbo, Lazio, Italy) was performed in the summer of 2013. A FTIR (Fourier Transform Infrared Spectrometer) was set up to continuously measure CO2-, CH4-, N2O-, CO- and del13C-concentrations. The FTIR was connected to 2 different flux measurements systems: a Flux Gradient system (sampling every half hour at 1.3m and 4.2m) and 2 flux chambers (measured every hour), providing a continuous data set of the biosphere-atmosphere gas fluxes and of the gas concentrations at different heights. Keeling plot intercept values of respiratory CO2, measured by the Flux Gradient system at night, were determined to be between -25‰ and -20‰. Keeling plot intercept values of respiratory CO2, measured by the flux chamber system, varied between -24‰ and -29‰, and showed a clear diurnal pattern, suggesting different (dominant) respiratory processes between day and night.

van Asperen, Hella; Sabbatini, Simone; Nicolini, Giacomo; Warneke, Thorsten; Papale, Dario; Notholt, Justus

2014-05-01

327

El doctor Varmus dirigirá una institución "inigualable", afirma el director del NCI, doctor John Niederhuber  

Cancer.gov

En un mensaje dirigido al personal del Instituto Nacional del Cáncer (NCI) y a quienes se interesan por la oncología, el doctor John Niederhuber, director del NCI, aplaude el nombramiento de Harold Varmus y afirma que esta designación le "dará al NCI un liderazgo fuerte no solo en la institución sino mas allá de ella, así como una voz muy respetada en el Congreso, que abogue por los recursos que son tan necesarios para sostener la misión del Instituto.

328

Net'aa chonaarãweda nepiripata p’edaa = Tradición oral del pueblo épera  

Microsoft Academic Search

La presencia épera en el Ecuador se remonta a principios de los años sesenta del siglo pasado, cuando pequeñas olas migratorias de indígenas colombianos del Saija llegaron a Ecuador y se asentaron en la región noroccidental de la provincia de Esmeraldas en la costa del Pacífico. Algunas razones para la migración fueron el comercio y la similitud entre su medio

J. Gómez Rendón; W. Poirama; L. Quiroz; B. Chiripua; Y. Capena

2008-01-01

329

Política monetaria y cambios de régimen en los tipos de interés del mercado interbancario español  

Microsoft Academic Search

En este trabajo analizamos el comportamiento dinámico del tipo de interés a un mes del mercado interbancario español entre 1987 y 2001. Se utiliza un proceso de difusión tipo raíz cuadrada que permite que el tipo cambie dependiendo del estado de la economía. El cambio entre regímenes es dirigido por un proceso de Markov de primer orden con probabilidades de

José Luis Fernández-Serrano; M. Dolores Robles Fernández

2004-01-01

330

Política Monetaria y Cambios de Régimen en los tipos de Interés del Mercado Interbancario  

Microsoft Academic Search

En este trabajo analizamos el comportamiento dinámico del tipo de interés a un mes del mercado interbancario español entre 1987 y 2001. Se utiliza un proceso de difusión tipo raíz cuadrada que permite que el tipo cambie dependiendo del estado en el que se encuentre la economía. El cambio entre regímenes es dirigido por un proceso de Markov de primer

José Luis Fernández Serrano; Dolores Robles Fernández

2002-01-01

331

Estudio Hidrológico del río Arlanzón a su paso por el Término Municipal de Burgos  

Microsoft Academic Search

Para la ordenación del territorio en el Término Municipal de Burgos se necesita conocer el riesgo de inundación por las aguas de los ríos Arlanzón, Vena, Cardeñadijo y Ubierna. Por ello, se ha realizado un estudio hidrológico de la cuenca del Arlanzón partiendo de los datos de precipitaciones, cartografía referente a usos del suelo, edafología, geología y topografía, fotografías aéreas

Iñigo OLEAGORDIA MONTAÑA; Rebeca RODRÍGUEZ GARCÍA; Joaquín NAVARRO HEVIA; CASTILLO NOVO

332

ESTUDIO MESOMECÁNICO DE LA FRACTURA DEL HORMIGÓN PARA DIFERENTES VELOCIDADES DE CARGA  

Microsoft Academic Search

Resumen. En este artículo se analiza el comportamiento del hormigón a un nivel mesomecánico de observación bajo cargas de tracción uniaxial dependientes del tiempo. Como punto de partida se ha empleado un modelo mesoestructural en 2D para materiales heterogéneos basado en elementos junta de espesor nulo, desarrollado dentro del grupo de investigación de la ETSECCPB-UPC. En este modelo, la estructura

Ricardo Lorefice; Guillermo Etse; Carlos M. López; Ignacio Carol

333

Interdisciplinary Unit: La Isla del Encanto (The Enchanted Island).  

ERIC Educational Resources Information Center

This document presents a series of 14 lesson plans in an interdisciplinary Spanish unit on "La isla del encanto/The Enchanted Island." The materials were prepared for students in grades 5 or 6 who have had basic Spanish instruction in previous grades. The students should also be familiar with basic concepts in English such as math computation, map…

Ford-Guerrera, Rebecca

334

Regulaciones del mercado laboral: un estudio comparativo entre países  

Microsoft Academic Search

En este trabajo se analizan tres tipos de instituciones prevalecientes en los mercados laborales de muchos países, normas sobre salario mínimo, introducción de costos no salariales (prestaciones complementarias) y las políticas de salario y empleo del gobierno. Se sostiene que estos tres son los aspectos estratégicos a analizar en el caso de los países en desarrollo con respecto a las

Peter R. Fallon; Luis Riveros

335

Estimación endógena del repudio en mercados soberanos de crédito  

Microsoft Academic Search

En vista de la falta de fundamentos teóricos en la bibliografía relacionada con el repudio en los mercados soberanos de crédito, se construye un modelo que considera todas las peculiaridades de los mercados internacionales de crédito. En particular, se incluye la idea de sanciones en el caso de repudio. Del modelo se extraen diversas conclusiones que contrastan con lo existente.

Fausto Hernández Trillo

1994-01-01

336

Del Mod: A State-Wide System for School Improvement.  

ERIC Educational Resources Information Center

This is a retrospective account of the Del Mod System, a statewide project to improve science and mathematics education in the elementary and secondary schools of Delaware. The project functioned from 1970-76 under the auspices of a committee including the presidents of institutions of higher education, the state superintendent of public…

Neale, Daniel C.

337

Advances in optical technologies at Pontificia Universidad Católica del Perú  

NASA Astrophysics Data System (ADS)

In this work, it is shown a panoramically view of advances and works on fundamental optical technology developed and Physics Section at Pontificia Universidad Católica del Perú PUCP in Lima Peru. This includes works in, precision optics manufacturing, optical testing, and optical design and simulation and also in optical thin film evaporation and its design techniques

Baldwin, Guillermo; Asmad, Miguel; Romero, Sandra; Gonzales, Franco; Gálvez, Gonzalo; Sánchez, Rubén; Córdova, Darwin

2011-05-01

338

Tratamiento del paludismo pediátrico: Papel de las intervenciones nutricionales  

Microsoft Academic Search

ResumenEl paludismo es una causa primordial de morbilidad y mortalidad en niños, particularmente en África subsahariana. Aunque se ha logrado un progreso considerable en el tratamiento del paludismo pediátrico con el tratamiento de combinación basado en la artemisinina, siguen existiendo numerosos obstáculos que se oponen a la puesta en práctica efectiva de estas nuevas opciones terapéuticas sumamente eficaces. Análogamente, si

Akoto Kwame Osei; Davidson H. Hamer

2008-01-01

339

Medical Ethnobotany of the Teribes of Bocas del Toro, Panama  

Microsoft Academic Search

Ethnomedical uses of 108 medicinal plant species, belonging to 52 families, 89 genera, used by the Teribe Amerindians of Bocas del Toro Province in Panama, along with their socio-cultural practices are reported here. The methods of administration of the herbal remedies, the plant parts used, their families and local names are also documented. The recorded medicinal plants were used mainly

M. P. Gupta; P. N. Solís; A. I. Calderón; F. Guinneau-Sinclair; M. Correa; C. Galdames; C. Guerra; A. Espinosa; G. I. Alvenda; G. Robles; R. Ocampo

2005-01-01

340

Aspetti evolutivi del sistema agro-alimentare in Algeria  

Microsoft Academic Search

Aspetti evolutivi del sistema agro-alimentare in Algeria (di Antonio Guariglia) - ABSTRACT: Even if it’s estimated that Algeria has potentially around 39 millions hectares of cultivable grounds, at present, the SAU is estimated equal to only 8 millions hectares (3% of territorial surface) situated in the almost totality along the fruitful and narrow coastal plan, while around 31 thousand hectares

Antonio Guariglia

2000-01-01

341

Regional geoid determination in Tierra del Fuego including GPS levelling  

Microsoft Academic Search

A regional geoid model for the Argentine part of the Isla Grande de Tierra del Fuego, established in previous works on the basis of GPS levelling, suffers a lack of observation data in the remote south-western investigation area. In order to improve the data distribution in this region, the mean lake level of Lago Fagnano has been regarded as a

Daniel del Cogliano; Reinhard Dietrich; Andreas Richter; Raúl Perdomo; José Luis Hormaechea; Gunter Liebsch; Mathias Fritsche

2007-01-01

342

Geological and Geophysical Investigations at Sierra del Medio Massif - Argentine.  

National Technical Information Service (NTIS)

Geological investigations were performed at Sierra del Medio (Chubut Province), a mountainous massif of about 25 km by 8 km of migmatic origin, which emerges from a depressed tectonic trench or graben called Pampa de Gastre. The most ancient rocks belong ...

J. C. Perucca E. Llambias H. H. Puigdomenech E. Cebrelli C. E. Castro

1987-01-01

343

The mercury clock of the Libros del Saber  

Microsoft Academic Search

The Libros del Saber de Astronomia is a compilation of various Arabic astronomical works translated into Castilian in the second half of the thirteenth century, under the direction of King Alfonso X of Spain. A section describing a mercury clock has been suggested to be of particular significance in view of the likely invention of the mechanical clock around this

A. A. Mills

1988-01-01

344

Políticas Española e Italiana según la Directiva Marco del Agua  

Microsoft Academic Search

RESUMEN Se ha elaborado un análisis de la evolución de la política internacional y europea, en relación a la gestión de los recursos hídricos, para identificar y comparar principios, objetivos y métodos de actuación en dos países mediterráneos miembros de la Unión Europea: Italia y España. La comparativa obtenida se hace tomando como referencia esencial la Directiva Marco del Agua,

Luis Miguel Valenzuela Montes; Anna Rigossi

2009-01-01

345

MATEMÁTICAS Y ORDENADORES EN EL CONOCIMIENTO DEL MUNDO  

Microsoft Academic Search

espacios abstractos, llamados hoy espacios de Hilbert, sería la base ,matemática de la ,Mecánica Cuántica. Esta situación contrasta con la del siglo XVII, en que Newton se vió obligado a desarrollar por sí mismo el cálculo diferencial para hacer convincentes las conclu- siones de los Principia, en tanto que a Hilbert le parecía que esfuerzos de este ,tipo ya no

M ANUEL L ÓPEZ; P ELLICER

346

L' IMPOLLINAZIONE DEL MIRTILLO GIGANTE AMERICANO (VACCINIUM CORYMBOSUM L.)  

Microsoft Academic Search

Nella fascia montana della nostra Regione la coltivazione delle specie frutticole minori è stata introdotta negli anni '80 come atti- vità agricola alternativa per diversificare le produzioni e come possibile integrazione al reddito per le aree marginali. Tra le diverse specie coltivate si annovera anche il mirtillo gigante (Vaccinium corymbosum L.). I fiori del mirtillo, di forma urceola- ta, sono

D. Prodorutti; F. Frilli; P. A. Belletti

347

Faculty Activity Analysis in the Universidad Tecnica Del Estado Campuses.  

ERIC Educational Resources Information Center

An analysis of academic activities of college faculty at the eight campuses of Chile's Universidad Tecnica del Estado was conducted. Activities were grouped into seven categories: direct teaching, indirect teaching, research, community services, faculty development, academic administration, and other activities. Following the narrative…

Karadima, Oscar

348

Se lanza Red Nacional de Estudios Clínicos del NCI  

Cancer.gov

El Instituto Nacional del Cáncer (NCI) puso en marcha una nueva red de investigación de estudios clínicos con el objetivo de mejorar el tratamiento de más de 1,6 millones de estadounidenses que reciben un diagnóstico de cáncer cada año.

349

Cosmogenic Radionuclides in the Campo Del Cielo Iron Meteorite  

NASA Technical Reports Server (NTRS)

Cosmogenic Be-10, Al-26, Cl-36, Ca-41, and Ni-59 were measured in the Campo del Cielo iron meteorite. Our results led us to conclude that the pre-atmospheric radius might have been approximately 2 m. Comparisons with other big bodies are also presented. Additional information is contained in the original extended abstract.

Liberman, R. G.; FernandezNiello, J. O.; Reedy, R. C.; Fifield, L. K.; diTada, M. L.

2001-01-01

350

Efecto del Programa de Entrenamiento "Manejo del Dolor" en la Documentaci?n de Enfermer?a en el Expediente Electr?nico  

PubMed Central

Resumen En el presente trabajo se muestra la importancia de entrenar al personal de enfermería para mejorar la documentación en el expediente electrónico. Se eligió el manejo del dolor por ser un área prioritaria; una alta proporción de pacientes en período post operatorio cursa con dolor, por lo tanto, la documentación debe ser útil para la toma de decisiones clínicas. Se implementó un programa de entrenamiento denominado “Manejo del Dolor” dirigido al personal de enfermería. Se utilizó la tecnología de la información como herramienta para fortalecer el conocimiento con base en la revisión sistemática de la literatura; el personal de enfermería participante seleccionó la mejor evidencia; posteriormente se trabajó en la transferencia de este conocimiento a la práctica a través del diseño de un protocolo para el manejo del dolor. Se concluye que el conocimiento del manejo del dolor es fundamental para que enfermería documente con mayor precisión sus intervenciones.

Monsivais, Maria Guadalupe Moreno; Guzman, Ma. Guadalupe Interial; Flores, Paz Francisco Sauceda; Arreola, Leticia Vazquez

2012-01-01

351

Molecular and cytogenetic characterization of del(9p) syndrome  

SciTech Connect

The del(9p) syndrome is characterized by mental retardation, trigonocephaly, midface hypoplasia, upward slanting palpebral fissures, a long philtrum, and is typically associated with a breakpoint at 9p22. Seventeen unrelated patients with del(9p) and their parents were analyzed by high resolution chromosome studies, molecular analysis using a series of highly polymorphic dinucleotide repeat markers for 9p, and fluorescence in situ hybridization (FISH) to characterize precisely the extent of chromosome loss. Eleven patients were found to have an interstitial deletion with breakpoints assigned to 9p22.1 and 9p24.3 in most cases. Two patients had familial unbalanced translocations of maternal origin and four had de novo complex rearrangements identified by high resolution analysis and FISH utilizing chromosome libraries. PCR analysis of eleven families with eight minisatellite markers determined paternal origin of the deletion in six cases and maternal origin in five. This suggests that the molecular event resulting in the deletion is equally prevalent in both male and female gametogenesis and that genomic imprinting does not play a role in the pathogenesis of del(9p) syndrome. Increased precision in mapping these minisatellite markers was also possible through this work. This study demonstrates the existence of molecular heterogeneity as six patients with a cytological breakpoint at 9p22.1 revealed three different molecular breakpoints. These findings suggest that genotype-phenotype correlations in deletion syndromes such as this should be based on high-resolution molecular analysis of the deleted chromosome segment. Work is in progress to map a series of cosmid probes by FISH relative to chromosomal breakpoints in these patients. These combined studies should provide a better understanding of the mechanisms involved in the pathogenesis of del(9p) syndrome and may identify loci where genes responsible for one or more aspects of the del(9p) phenotype may reside.

Micale, M.A.; Haren, J.M.; Schwartz, S. [Case Western Reserve Univ. School of Medicine, Cleveland, OH (United States)] [and others

1994-09-01

352

LA CONSOLIDACIÓN DEL HAMBRE Y DEL DERECHO A LA ALIMENTACIÓN EN LAS AGENDAS POLÍTICAS DE AMÉRICA LATINA  

Microsoft Academic Search

América Latina y el Caribe es la única región en desarrollo que puede acabar con el hambre en nuestra generación. Tiene 52,4 millones de personas subnutridas (10% de población) y 9 millones de niños con desnutrición crónica, pero también es la principal productora mundial de alimentos y tiene recursos financieros, naturales, humanos e institucionales para hacer del hambre un recuerdo

Jose Luis Viveros; Niemeyer Almeida Filho

2008-01-01

353

La democracia constitucional en América Latina y las evoluciones recientes del presidencialismo. Memorias Encuentro del Instituto Iberoamericano de Derecho Constitucional  

Microsoft Academic Search

Siempre será oportuno reflexionar sobre la democracia, su contenido, sus desafíos, su presente y su futuro, las transformaciones y percepciones que de ella se tienen. No son pocas las preocupaciones o inquietudes que la democracia suscita en esta parte del mundo, y muestra de ello son los más variados estudios e informes sobre el estado actual de la democracia y

Pedro Pablo Vanegas

354

Prognostic Impact of del(17p) and del(22q) as Assessed by Interphase FISH in Sporadic Colorectal Carcinomas  

PubMed Central

Background Most sporadic colorectal cancer (sCRC) deaths are caused by metastatic dissemination of the primary tumor. New advances in genetic profiling of sCRC suggest that the primary tumor may contain a cell population with metastatic potential. Here we compare the cytogenetic profile of primary tumors from liver metastatic versus non-metastatic sCRC. Methodology/Principal Findings We prospectively analyzed the frequency of numerical/structural abnormalities of chromosomes 1, 7, 8, 13, 14, 17, 18, 20, and 22 by iFISH in 58 sCRC patients: thirty-one non-metastatic (54%) vs. 27 metastatic (46%) disease. From a total of 18 probes, significant differences emerged only for the 17p11.2 and 22q11.2 chromosomal regions. Patients with liver metastatic sCRC showed an increased frequency of del(17p11.2) (10% vs. 67%;p<.001) and del(22q11.2) (0% vs. 22%;p?=?.02) versusnon-metastatic cases. Multivariate analysis of prognostic factors for overall survival (OS) showed that the only clinical and cytogenetic parameters that had an independent adverse impact on patient outcome were the presence of del(17p) with a 17p11.2 breakpoint and del(22q11.2). Based on these two cytogenetic variables, patients were classified into three groups: low- (no adverse features), intermediate- (one adverse feature) and high-risk (two adverse features)- with significantly different OS rates at 5-years (p<.001): 92%, 53% and 0%, respectively. Conclusions/Significance Our results unravel the potential implication of del(17p11.2) in sCRC patients with liver metastasis as this cytogenetic alteration appears to be intrinsically related to an increased metastatic potential and a poor outcome, providing additional prognostic information to that associated with other cytogenetic alterations such as del(22q11.2). Additional prospective studies in larger series of patients would be required to confirm the clinical utility of the new prognostic markers identified.

Gonzalez-Gonzalez, Maria; Munoz-Bellvis, Luis; Mackintosh, Carlos; Fontanillo, Celia; Gutierrez, M. Laura; Abad, M. Mar; Bengoechea, Oscar; Teodosio, Cristina; Fonseca, Emilio; Fuentes, Manuel; De Las Rivas, Javier

2012-01-01

355

76 FR 58562 - Additional Designations, Foreign Narcotics Kingpin Designation Act  

Federal Register 2010, 2011, 2012, 2013

...Manuel Clouthier 486, Colonia Prados Vallarta, Guadalajara, Jalisco, Mexico; Plaza Del Sol Local 28, Zona R, Guadalajara, Jalisco, Mexico; Paseo Del Heliotropo 3426, Monraz, Guadalajara, Jalisco, Mexico; DOB 09 Aug 1955; POB...

2011-09-21

356

Fair trade, premio di prezzo e fallimenti del mercato  

Microsoft Academic Search

Il premio di prezzo è solo una componente, non marginale, sicuramente la più caratteristica e facilmente comunicabile, ma certamente non decisiva nel modello Fair Trade. L’avere incentrato l’attenzione su questo specifico aspetto del meccanismo complessivo ha nascosto altri aspetti più rilevanti dello schema operativo. Nel presente lavoro si cerca di mostrare come l’impatto maggiore delle strategie di Fair Trade riguarda

A. Arrighetti

2007-01-01

357

The Borexino detector at the Laboratori Nazionali del Gran Sasso  

Microsoft Academic Search

Borexino, a large volume detector for low energy neutrino spectroscopy, is currently running underground at the Laboratori Nazionali del Gran Sasso, Italy. The main goal of the experiment is the real-time measurement of sub-MeV solar neutrinos, and particularly of the monoenergetic (862keV) 7Be electron capture neutrinos, via neutrino–electron scattering in an ultra-pure liquid scintillator. This paper is mostly devoted to

G. Alimonti; C. Arpesella; H. Back; M. Balata; D. Bartolomei; A. de Bellefon; G. Bellini; J. Benziger; A. Bevilacqua; D. Bondi; S. Bonetti; A. Brigatti; B. Caccianiga; L. Cadonati; F. Calaprice; C. Carraro; G. Cecchet; R. Cereseto; A. Chavarria; M. Chen; A. Chepurnov; W. Czech; D. D’Angelo; F. Dalnoki-Veress; A. De Bari; E. De Haas; A. Derbin; M. Deutsch; A. Di Credico; A. Di Ludovico; G. Di Pietro; R. Eisenstein; F. Elisei; A. Etenko; F. von Feilitzsch; R. Fernholz; K. Fomenko; R. Ford; D. Franco; B. Freudiger; N. Gaertner; C. Galbiati; F. Gatti; S. Gazzana; V. Gehman; M. Giammarchi; D. Giugni; M. Goeger-Neff; T. Goldbrunner; A. Golubchikov; C. Grieb; C. Hagner; T. Hagner; W. Hampel; E. Harding; S. Hardy; F. X. Hartmann; R. von Hentig; T. Hertrich; G. Heusser; M. Hult; A. Ianni; An. Ianni; L. Ioannucci; K. Jaenner; M. Joyce; H. de Kerret; S. Kidner; J. Kiko; T. Kirsten; V. Kobychev; G. Korga; G. Korschinek; Yu. Kozlov; D. Kryn; P. La Marche; V. Lagomarsino; M. Laubenstein; C. Lendvai; M. Leung; T. Lewke; E. Litvinovich; B. Loer; F. Loeser; P. Lombardi; L. Ludhova; I. Machulin; S. Malvezzi; A. Manco; J. Maneira; W. Maneschg; I. Manno; D. Manuzio; G. Manuzio; M. Marchelli; A. Martemianov; F. Masetti; U. Mazzucato; K. McCarty; D. McKinsey; Q. Meindl; E. Meroni; L. Miramonti; M. Misiaszek; D. Montanari; M. E. Monzani; V. Muratova; P. Musico; H. Neder; A. Nelson; L. Niedermeier; S. Nisi; L. Oberauer; M. Obolensky; M. Obolensky; F. Ortica; M. Pallavicini; L. Papp; R. Parcells; S. Parmeggiano; M. Parodi; N. Pelliccia; L. Perasso; A. Pocar; R. Raghavan; G. Ranucci; W. Rau; A. Razeto; E. Resconi; P. Risso; A. Romani; D. Rountree; A. Sabelnikov; P. Saggese; R. Saldhana; C. Salvo; R. Scardaoni; D. Schimizzi; S. Schönert; K. H. Schubeck; T. Shutt; F. Siccardi; H. Simgen; M. Skorokhvatov; O. Smirnov; A. Sonnenschein; F. Soricelli; A. Sotnikov; S. Sukhotin; C. Sule; Y. Suvorov; V. Tarasenkov; R. Tartaglia; G. Testera; D. Vignaud; S. Vitale; R. B. Vogelaar; V. Vyrodov; B. Williams; M. Wojcik; R. Wordel; M. Wurm; O. Zaimidoroga; S. Zavatarelli; G. Zuzel

2009-01-01

358

Paradigmas de verbos en el zapoteco del istmo  

Microsoft Academic Search

Varios an?lisis se han hecho o pueden hacerse de las conjugaciones de los verbos en el zapoteco, una familia de lenguas de Oaxaca, M?xico. Marlett y Pickett 1987, siguiendo el an?lisis de Speck 1984, proponen uno para el zapoteco del istmo que hace referencia a un an?lisis de la estructura sil?bica de la lengua. Pickett 1967 presenta otro. Un desaf?o

Isthmus Zapotec; Verb Paradigms

359

3. 1939 DROP STRUCTURE IN DEL MAR PARK SURMOUNTED BY ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. 1939 DROP STRUCTURE IN DEL MAR PARK SURMOUNTED BY RECENT PEDESTRIAN BRIDGE. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

360

2. COURSE OF THE LATERAL THROUGH DEL NORTHWEST MAR PARK. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. COURSE OF THE LATERAL THROUGH DEL NORTHWEST MAR PARK. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

361

Solar adaptive optics at the Observatorio del Teide, Tenerife  

NASA Astrophysics Data System (ADS)

Observing the Sun with high angular resolution is difficult because the turbulence in the atmosphere is strongest during day time. In this paper we describe the principles of solar adaptive optics exemplified by the two German solar telescopes VTT and GREGOR at the Observatorio del Teide. With theses systems we obtain near diffraction limited images of the Sun. Ways to overcome the limits of conventional AO by applying multiconjugate adaptive optics (MCAO) are shown.

Soltau, Dirk; Berkefeld, Thomas; Schmidt, Dirk; von der Lühe, Oskar

2013-10-01

362

Nuevo sitio web en español del Instituto Nacional del Cáncer, (NCI, por sus siglas en inglés) Cancer.gov en español - Silvia Inéz Salazar - transcript  

Cancer.gov

Transmisiones de radio para promover Cancer.gov en espa%XF1ol | Nuevo sitio web en espa%XF1ol del Instituto Nacional del C%XE1ncer, (NCI, por sus siglas en ingl%XE9s) Cancer.gov en espa%XF1ol | Transcripci%XF3n Transmisiones de radio para promover

363

Un gobierno alternativo en una región olvidada de Colombia: entrevista al taita Floro Alberto Tunubalái Paja, gobernador del departamento del Cauca  

Microsoft Academic Search

El Departamento del Cauca está situado al Sur de Colombia. En los últimos años ha ocupado el penúltimo lugar en su aporte económico al país. Lós índices de pobreza son grandes, la oferta de trabajo es baja y la desatención y disminución del Estado se acentúa, haciendo cada vez más dificil la solución de las desigualdades sociales que vive la

Diego Jaramillo Salgado

2001-01-01

364

Correction: First high resolution ultraviolet (HST/STIS) and supporting optical spectroscopy of V339 Del = Nova Del 2013  

NASA Astrophysics Data System (ADS)

Due to an error in transcription, the distance is given incorrectly in the text of ATel#5409. Along with the typo "Space Telescope Imaging Spectrograph", the text should read: Comparing these STIS UV spectra with high resolution IUE spectra of the CO nova OS And 1986 obtained between 12 days (LWP) and 22 days (SWP) after optical discovery (1986 Dec. 17, 27 respectively) shows a very close agreement such that when independently dereddened, the ratio of V339 Del to OS And between 1200 and 1900A is ~1.5 in flux (similar in the 2000-3000A range but more uncertain because of the earlier date of the long wavelength IUE observation), indicating that the distance to V339 Del is about 4.2 kpc (distance to OS And ~ 5.1 kpc with E(B-V)=0.25+/-0.05, see Schwarz et al.

Shore, S. N.

2013-09-01

365

The 2012 Reactivation of Nevado del Ruiz Volcano, Colombia  

NASA Astrophysics Data System (ADS)

Nevado Del Ruiz volcano is most known for its tragic November 13, 1985 explosive event, when a small eruption produced an enormous lahar that buried and destroyed the town of Armero in Tolima, causing an estimated 25,000 deaths. Similar but less deadly incidents occurred in 1595 and 1845, again where a small explosive eruption was followed by a large lahar. Other minor explosive events occurred in 1805, 1828-9, and 1989. The Armero tragedy was a major factor in the establishment of a volcano monitoring program in Colombia. The network monitoring Nevado del Ruiz volcano has dramatically improved since the 1985 eruption and now includes geodetic, geophysical, geochemical and visual monitoring. The activity of Nevado Del Ruiz between 1985 and 1991 saw significant increases in seismicity and significant gas emissions with the main eruptive events of November 13, 1985 and September 1st, 1989. The volcano became seismically active again in 1995 and 2002, whit an increase in seismicity, without any gas emission or eruption. In October 2010 the volcano entered in a new phase of unrest with increased seismicity (HB events), deformation and gas emissions, likely associated with a new magma intrusion. In February, 2012 the volcano had a new and significant increase in seismicity (VT-LP), followed in May and June 2012 by small phreatic and phreato-magmatic eruption. This eruptive activity is still ongoing. Deformation measurements at Nevado Del Ruiz volcano have been carried out since just after the tragic eruption of the 13th of November 1985. In 2007 seven new electronic tilt meters were set up to monitor the deformation. Significant uplift was measured from August 2007 to October 2010, for a total cumulative value of more than 500 microradians. From the end of 2011 to July 2012, moderate changes of uplift were detected for a total of 70 microradians. The analysis of these deformation data shows a pattern of surface displacement associated with an intrusion of new magma coming from a reservoir located approximately at a depth of approximately 8 km and accumulating in shallow reservoir less than 2 km beneath the main crater. We fit the data with both a spherical and a vertical spheroid source. The spherical source indicates the existence of an intrusion at a depth of 1823±1056 m with a volume change of (7±17)×106 m3 . The vertical spheroidal source suggests a source 1855 m deep with a volume change of 6×106 m3 . These results imply that while we have strong bounds on the depth of the intrusion, the actual volume of the source is less certain. Gas emission from Nevado del Ruiz volcano in April 7, 2012.

Ordoñez, M.; Lopez, C.; Cortes, G. P.; Londoño, J.; Battaglia, M.

2012-12-01

366

Mutations in TP53 are exclusively associated with del(17p) in multiple myeloma  

PubMed Central

Deletion of the 17p13 chromosomal region [del(17p)] is associated with a poor outcome in multiple myeloma. Most of the studies have targeted the TP53 gene for deletion analyses, although no study showed that this gene is the deletion target. In order to address this issue, we sequenced the TP53 gene in 92 patients with multiple myeloma at diagnosis, 54 with a del(17p) and 38 lacking del(17p). At least one mutation was found in 20 patients, all of them presenting a del(17p). The analysis of the mutation location showed that virtually all of them occurred in highly conserved domains involved in the DNA-protein interactions. In conclusion, we showed that 37% of the myeloma patients with del(17p) present a TP53 mutation versus 0% in patients lacking the del(17p). The prognostic significance of these mutations remains to be evaluated.

Lode, Laurence; Eveillard, Marion; Trichet, Valerie; Soussi, Thierry; Wuilleme, Soraya; Richebourg, Steven; Magrangeas, Florence; Ifrah, Norbert; Campion, Loic; Traulle, Catherine; Guilhot, Francois; Caillot, Denis; Marit, Gerald; Mathiot, Claire; Facon, Thierry; Attal, Michel; Harousseau, Jean-Luc; Moreau, Philippe; Minvielle, Stephane; Avet-Loiseau, Herve

2010-01-01

367

VEGF: A modifier of the del22q11 (DiGeorge) syndrome?  

Microsoft Academic Search

Hemizygous deletion of chromosome 22q11 (del22q11) causes thymic, parathyroid, craniofacial and life-threatening cardiovascular birth defects in 1 in 4,000 infants. The del22q11 syndrome is likely caused by haploinsufficiency of TBX1, but its variable expressivity indicates the involvement of additional modifiers. Here, we report that absence of the Vegf164 isoform caused birth defects in mice, reminiscent of those found in del22q11

Ingeborg Stalmans; Diether Lambrechts; Frederik De smet; Sandra Jansen; Jian Wang; Sunit Maity; Paige Kneer; Maren von der Ohe; Ann Swillen; Christa Maes; Marc Gewillig; Daniel G. M. Molin; Peter Hellings; Thurid Boetel; Maartin Haardt; Veerle Compernolle; Mieke Dewerchin; Stephane Plaisance; Robert Vlietinck; Beverly Emanuel; Adriana C. Gittenberger-de Groot; Peter Scambler; Bernice Morrow; Deborah A. Driscol; Lieve Moons; Camila V. Esguerra; Geert Carmeliet; Annett Behn-Krappa; Koen Devriendt; Désiré Collen; Simon J. Conway; Peter Carmeliet

2003-01-01

368

Efectos derivados de la puesta en pr ctica del marketing de relaciones en los servicios profesionales  

Microsoft Academic Search

El objetivo del presente trabajo es identificar la influencia sobre el consumidor y sobre el resultado empresarial de dos dimensiones b sicas de los servicios profesionales: la dimensi¢n formal o calidad del servicio prestado y la dimensi¢n informal o interacci¢n personal con el cliente. Sobre la base te¢rica del marketing de relaciones, se analiza c¢mo influyen los aspectos formales e

Paolo Freire de Carvalho Filho; Carmen Camarero Izquierdo

2003-01-01

369

Use of Real Time PCR for Rapid Detection of Del Phenotype in Taiwan  

Microsoft Academic Search

During routine serologic procedures, Rh Del blood is often not identified and subsequently labeled as RhD-negative. Recently, several reports have shown the ability of Del blood to induce anti-D in RhD-negative recipients. Among Korean, Japanese, and Chinese, almost all individuals with Del blood have a nucleotide change in the RHD gene of 1227G>A (RHDK407K). Thus, nucleotide 1227A at RHD exon

Chien-Feng Sun; Jui-Ping Liu; Ding-Ping Chen; Wei-Ting Wang; Tyng-Tyng Yang

370

Els Fragments del Sacramentari de Sant Boi de Lluçanès (Vic. Bib. Espisc., Frag I\\/6)  

Microsoft Academic Search

Els disset folis del manuscrit Vic, Bib. Episc., frag. I\\/6 són les restes d'un sacramentari de tipus gregorià mixt, procedents de la parròquia de Sant Boi de Lluçanès. Foren escrites en l'últim quart del segle X, però, al segon quart del segle XII s'hi feren esmenes adaptant el seu cànon als models d'aquest segle. En això rau la seva singularitat.

Miquel dels Sants Gros i Pujol

2005-01-01

371

Distribución del continuo ultravioleta e infrarrojo en estrellas Be  

NASA Astrophysics Data System (ADS)

Estamos interesados en interpretar los excesos de flujo infrarrojo y/o ultravioleta observados en estrellas Be con respecto al de estrellas B normales, así como su posible correlación. Una envoltura rodeando la estrella distingue una estrella Be de una B normal; para explicar las observaciones es necesario entonces tener en cuenta todos los posibles procesos físicos que en ella tienen lugar. Adoptando un modelo atmosférico específico, hemos estudiado el proceso de recombinación dielectrónica de metales como MgII y FeII, teniendo en cuenta la posible influencia de la opacidad del medio en el flujo emitido.

Cruzado, A.; Ringuelet, A.; di Rocco, H.

372

Variabilidad del metabolismo oxidativo de fármacos en la población uruguaya Polimorfismo genético del citocromo P-450 2D6  

Microsoft Academic Search

Resumen El estudio ele losj¿7ctores gméticos que determirmr7 la respuesta a los 7~2edictr7i2erzfo.s se demmirm ,fi77.7rlacogerrética. EH la década del 70 se describió el polirnorfïsmo perr&ico dc Iri Llchri.coqLrina-hidroxiiasa. u77 hallazgo de gran r-elevatrcia dado que rnlrclîo.r.f¿í~\\/llcrc,o.c utili:ados cu terapéutica se oxidar? por la misma \\\\jía metahólic~a. Esto e.xpliccr ,grrrrr parte LIP iir var-iahilitiud iudividual que se obset-va en las

Francisco E. Estévez; Marcos Giusti; Susana Parrillo; Miguel Pr-ando

1997-01-01

373

Aparición del cometa Hale - BOPP C / 1995-01  

NASA Astrophysics Data System (ADS)

El Cometa Hale - Bopp fue observado a partir de la 10ma. magnitud con el telescopio de 300mm de abertura a f/6.5. En esas primeras observaciones desde luego no hubo mucho detalle. A su vez las posiciones del cometa para nuestro hemisferio no fueron favorables, solamente asomó por el horizonte N.O. para nuestra latitud cuando se alejaba de la Tierra. Se registró la observación visualmente con binoculares 10 x 50, y fotográficamente con un Telezoom de 210mm a f/4,5 con película 400 ASA color. Todas las imágenes fueron procesadas y digitalizadas a fin de obtener las diferentes escalas de brillo. El aspecto que presentó para nuestra posición geográfica fue discreta ya que tuvo su máximo brillo cuando era visible desde el hemisferio norte. Presentó la clásica cola de polvo curva, y con su aspecto casi estelar, destacándose entre la luminosidad del crepúsculo. Instrumentos Utilizados: Telezoom de 210mm a f/4.5, Telescopio refractor de 80mm a f/15, Binocular 10 x 50

Arquiola, A.

374

Deadly Lahars from Nevado del Ruiz, Colombia: November 13, 1985  

NSDL National Science Digital Library

This web site describes a series of Lahars that occurred from the Nevado del Ruiz volcano in the Andes mountains, the northernmost and highest volcano in Colombia. Beginning in November 1984, the volcano began showing clear signs of unrest. An explosive eruption from Ruiz's summit crater on November 13, 1985, at 9:08 p.m. generated an eruption column and sent a series of pyroclastic flows and surges across the volcano's summit. Within minutes, pumice and ash began to fall to the northeast along with heavy rain that had started earlier in the day. Within four hours, lahars had traveled 100 km and left behind a wake of destruction: more than 23,000 people killed, about 5,000 injured, and more than 5,000 homes destroyed along the Chinchina, Guali, and Lagunillas rivers and destroying the town of Armero, Columbia. This deadly eruption of Nevado del Ruiz offers lessons on the generation of lahars for scientists, emergency-response professionals, and communities located downstream of such ice- and snow-covered volcanoes. The narrative is illustrated with 9 photographs.

Banks, N.; Marso, J.; Pierson, T.; Janda, R.

375

Descubrimiento del primer yacimiento cuaternario (Riss-Wiirm) de vertebrados con restos humanos en la provincia de Madrid (Pinilla del Valle)  

Microsoft Academic Search

We give notice of a new fossiliferous loeality with vertebrate rests of Pleistocene age, placed in Pinilla del Valle (Madrid). It is made up by quaternary sediments filling a ca)careous fallen shelter.

E. ALFÉREZ; G. MOLERO; E. MALDONADO; P. BREA; A. IV

376

Targeting F508del-CFTR to develop rational new therapies for cystic fibrosis  

Microsoft Academic Search

The mutation F508del is the commonest cause of the genetic disease cystic fibrosis (CF). CF disrupts the function of many organs in the body, most notably the lungs, by perturbing salt and water transport across epithelial surfaces. F508del causes harm in two principal ways. First, the mutation prevents delivery of the cystic fibrosis transmembrane conductance regulator (CFTR) to its correct

Zhi-wei Cai; Jia Liu; Hong-yu Li; David N Sheppard

2011-01-01

377

Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas  

Microsoft Academic Search

Se estudian las violaciones al Principio de Equivalencia en Teorías con Dilatón de Cuerdas. En estos modelos, algunas de las constantes fundamentales dependen del espacio y del tiempo. Se muestra que los experimentos de caída libre no tienen aún precisión como para poner límites a los parámetros de la teoría.

S. J. Landau; P. D. Sisterna; H. Vucetich

2003-01-01

378

Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas  

NASA Astrophysics Data System (ADS)

Se estudian las violaciones al Principio de Equivalencia en Teorías con Dilatón de Cuerdas. En estos modelos, algunas de las constantes fundamentales dependen del espacio y del tiempo. Se muestra que los experimentos de caída libre no tienen aún precisión como para poner límites a los parámetros de la teoría.

Landau, S. J.; Sisterna, P. D.; Vucetich, H.

379

El Instituto Nacional del Cáncer publica nuevo atlas de mortalidad por cáncer  

Cancer.gov

El Instituto Nacional del Cáncer (NCI, por sus siglas en inglés) ha publicado un nuevo atlas, el Atlas de Mortalidad por Cáncer en los Estados Unidos, 1950-94, que muestra los patrones geográficos de las tasas de mortalidad por cáncer durante más de cuatro décadas, en más de 3.000 condados a lo largo del país.

380

Vertebrates of the El Pelillal locality (Campanian, Cerro Del Pueblo Formation), southeastern Coahuila, Mexico  

Microsoft Academic Search

A new locality named El Pelillal (Cerro del Pueblo Formation, Late Cretaceous, Campanian) in the southeastern area of the State of Coahuila, México yields an assemblage of vertebrates that is important for correlation due to its frequent occurrence in other localities along the Cerro del Pueblo Formation outcrops. It is located in the Municipio de Ramos Arizpe, Coahuila. Among the

Ruben A. Rodriguez-De La Rosa; Sergio R. S. Cevallos-Ferriz

1998-01-01

381

Screening of antibacterial activity of Amaicha del Valle (Tucumán, Argentina) propolis  

Microsoft Academic Search

Propolis is extensively used in Argentine folk medicine. Alcoholic extracts of propolis from four localities of Amaicha del Valle (El Paraiso, La Banda Este, La Banda Oeste and El Molino), Province of Tucumán and from Cerrillos, Province of Santiago del Estero, Argentina were prepared. All showed antibacterial activity against Gram positive bacteria, the propolis from La Banda Este being the

M. I. Nieva Moreno; M. I. Isla; N. G. Cudmani; M. A. Vattuone; A. R. Sampietro

1999-01-01

382

Determinantes del precio de la vivienda en Santiago: Una estimación hedónica  

Microsoft Academic Search

Siguiendo la tradición de una extensa literatura de la economía urbana, desarrollada a partir de la base teórica propuesta por Rosen (1974), aquí se utiliza un modelo de precios hedónicos para analizar la determinación del precio de la vivienda (casas) en el mercado de Santiago. La estimación empírica del modelo permite explicar sobre el 70 por ciento de la varianza

Eugenio Figueroa; George Lever

383

Caracterización del mercado de energía elétrica para usuarios no regulados en Colombia  

Microsoft Academic Search

En este artículo se presenta un análisis sobre las características del mercado de energía para usuarios no regulados en Colombia, el cual puede ser considerado como un sub-mercado dentro del mercado global de energía eléctrica en Colombia. En este análisis se incluye un indicador de concentración de mercado (Herfindahl-Hirschman), así como los porcentajes de participación en cubrimiento de demanda y

Ana Cecilia Escudero; Sergio Botero Botero

2006-01-01

384

Boletín No 11: Caracterización del Trabajo Independiente y su Afiliación a la Seguridad Social en Colombia  

Microsoft Academic Search

El tema central del presente Boletín es aparentemente un tema de coyuntura. En efecto, la afiliación del trabajador independiente al sistema de seguridad social integral está generando arduos debates, económicos y jurídicos, desde la implementación de la Planilla Integrada de Liquidación de Aportes –PILA- a mediados de este año. Sin embargo, el trabajo independiente en relación a la seguridad social

Stefano Farne; Jesus Perdomo; Carlos Andrés Vergara

2008-01-01

385

Eleven new cases of del(9p) and features from 80 cases  

Microsoft Academic Search

We report 11 cases of del(9p) and review 69 previously published ones. Of the 80 cases, 39 have a del(9p) as the sole anomaly. The symptoms are typical and diagnosis should be suspected at birth. The sex ratio does not appear to be unbalanced. A cardiac murmur is often present but surgery is rarely necessary. Mean IQ is 48. The

J L Huret; C Leonard; B Forestier; M O Rethoré; J Lejeune

1988-01-01

386

ERUPCIÓN DEL VOLCÁN HUDSON Y CRISIS GANADERA EN LA MESETA CENTRAL SANTACRUCEÑA, PATAGONIA ARGENTINA  

Microsoft Academic Search

El sector ovino-extensivo de la Meseta Central Santacruceña, extensa región ecológica del centro-Norte de la provincia de Santa Cruz (Patagonia Argentina), en las últimas décadas atraviesa una situación de crisis, evidenciada en el escaso porcentaje de parcelas que mantienen el uso del suelo tradicional. Las interpretaciones con respecto a las causas de la crisis no son muy numerosas, en la

Alberto Vazquez

2012-01-01

387

SENSIBILIDAD IN VITRO DE AISLADOS DEL HONGO PHYTOPHTHORA CAPSICI A FUNGUICID AS  

Microsoft Academic Search

RESUMEN En el cultivo de chile, la incidencia de la enfermedad marchitez del chile causada por el hongo oomyceto Phytophthora capsici Leo., constituye a nivel nacional, uno de los principales problemas que afectan la productividad del cultivo. El presente estudio tuvo como objetivo: conocer la respuesta de 14 aislados de Phytophthora capsici a diferentes fungicidas. Los fungicidas utilizados fueron azoxystrobin,

Luis Pérez-Moreno; Luisa Josefina Durán-Ortiz; Rafael Ramírez-Malagón; Jesús Ricardo Sánchez-Pale; Víctor Olalde-Portugal

388

Descubrimiento del conocimiento en base de datos utilizando herramienta de software libre, caso: DAIS  

Microsoft Academic Search

El desempeño académico es un indicador que muestra el nivel de desempeño escolar de los estudiantes, en el presente artículo se describe los resultados del proceso de descubrimiento del conocimiento en bases de datos (KDD) para identificar las asignaturas que inciden en el rendimiento académico de los estudiantes de la División Académica de Informática y Sistemas de la Universidad Juárez

José Luís Gómez Ramos; Homero Alpuín Jiménez; Candelario Vicente Osorio; Mirtha Angelica; Taracena Martinez

389

Efecto de la modificación del perfil en el rendimiento de altavoces dinámicos de radiación directa  

Microsoft Academic Search

Uno de los parámetros más significativos de los altavoces es, probablemente, su rendimiento. Este puede definirse como la relación entre la potencia radiada y la potencia eléctrica consumida. Normalmente se\\u000aexpresa en % y puede ser determinado aplicado expresiones en las que figuran los valores de los componentes del circuito equivalente del altavoz. Un primer elemento necesario es la impedancia

Jesús Alba Fernández; Jaime Ramis Soriano

1970-01-01

390

El desarrollo de la creatividad a través del proceso docente como problema social  

Microsoft Academic Search

El artículo tiene como propósito reflejar aspectos sobre el desarrollo de la creatividad en estudiantes de Educación Inicial del Programa Nacional de Formación de Educadores y Educadoras (PNFE). En tal sentido el Problema científico es ¿Cómo perfeccionar los modos de actuación en los estudiantes del PNFE? El Objetivo está dirigido a la Elaboración de una metodología para favorecer el desarrollo

Magaly Sarmiento Romero

2011-01-01

391

62. R.L.T., photographer November 1, 1934 DEL NORTE COUNTY, SECTION ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

62. R.L.T., photographer November 1, 1934 DEL NORTE COUNTY, SECTION D, HIGHWAY 1. REDWOOD CLEARING ON EXISTING LINE, 1-DN-71-A #26, R.L.T. 11-1-34. Stamped office copy. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

392

El cuento del cáncer de cérvix podría tener un final feliz  

Cancer.gov

El cuento del cáncer de cérvix podría tener un final feliz Por el Instituto Nacional del Cáncer El cáncer de cérvix fue en un tiempo la causa principal de muerte por cáncer entre mujeres estadounidenses. Pero, en los últimos 50 años, el número de

393

Aspectos generales de la Red Nacional de Estudios Clínicos del NCI  

Cancer.gov

Reseña general sobre la estructura organizativa de la Red Nacional de Estudios Clínicos del NCI, así como un resumen de los cambios que se están llevando a cabo y una sinopsis de cómo estos cambios se basan en el éxito del programa de Grupos Cooperativos.

394

63. G.F.H., photographer July 30, 1932 DEL NORTE COUNTY, SECTION ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

63. G.F.H., photographer July 30, 1932 DEL NORTE COUNTY, SECTION A, HIGHWAY 1. 1-DN A #124, STA. 164=00 SHOWING DRAINAGE CONDITIONS, G.F.H., 7-30-32. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

395

Estudio del Selenio y la Vitamina E para Prevenir el Cáncer (SELECT)  

Cancer.gov

SELECT sigue evaluando los efectos de los suplementos aunque los participantes ya no toman los suplementos del estudio. El Comité de Vigilancia de Datos y Seguridad del estudio, que opera con plena independencia, descubrió que el selenio y la vitamina E, tomados solos o juntos por un promedio de 5 años y medio, no impiden el cáncer de próstata.

396

Los grupos fricativa+nasal del polaco: realización sonora y fenómenos intermedios  

Microsoft Academic Search

El presente trabajo es un estudio de la sonoridad y de los fenómenos intermedios en la realización de los grupos consonanticos fricativa + nasal del polaco. El estudio acústico se ha realizado mediante el sistema CSL, en el que se pueden observar simultáneamente el oscilograma, el espectrograma, la onda glotal y los pulsos glotales. Los resultados del análisis han puesto

Dorota Szmidt; Joan Castellví Vives

2006-01-01

397

Crueldad, simulacion, absurdo y amenaza: Barbarie del drama moderno y tradicion hermetica en los esperpentos de Ramon del Valle-Inclan  

Microsoft Academic Search

The purpose of this dissertation is to demonstrate that the esperpentos by the Spanish playwright Ramón del Valle-Inclán (1866–1936), represent a culminating moment of theatrical precepts of modern European drama, while perpetuating the ancient esoteric traditions of the Iberian Peninsula. Focusing on four plays—Los cuernos de Don Friolera (1920), Luces de Bohemia (1921), Las galas del difunto (1926) y La

Barbara Safille

2004-01-01

398

Metodologie di diagnosi e monitoraggio della malattia dell'Occhio Secco: Rapporto del Sottocomitato Metodologia Diagnostica del Workshop Internazionale dell'Occhio Secco (2007) Metodologia Diagnostica  

Microsoft Academic Search

Il ruolo del Sottocomitato Metodologia Diagno- stica del Workshop dell'Occhio Secco è stato: 1) identificare i test utilizzati per lo screening, la diagnostica e il monito- raggio dell'occhio secco, 2) stabilire i criteri per l'esecuzione dei test e 3) valutare l'utilizzo dei test per i vari impieghi clini- ci. Il Comitato ha creato un database di test utilizzati per dia-

Membri del Sottocomitato; Metodologia Diagnostica; Antony J. Bron; Anthony J. Bron; Mark B. Abelson; George Ousler; E. Pearce; Alan Tomlinson; Norihiko Yokoi; Janine A. Smith; Carolyn Begley; Barbara Caffery; Kelly Nichols; Debra Schaumberg; Oliver Schein; Margarita Calonge; Christophe Baudouin; Eiki Goto; Franz Grus; Jerry Paugh

399

78 FR 6173 - Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and...  

Federal Register 2010, 2011, 2012, 2013

...Transportation Board [Docket No. FD 35652] Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund...petition filed on August 1, 2012, by Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew...

2013-01-29

400

Screening of antibacterial activity of Amaicha del Valle (Tucumán, Argentina) propolis.  

PubMed

Propolis is extensively used in Argentine folk medicine. Alcoholic extracts of propolis from four localities of Amaicha del Valle (El Paraiso, La Banda Este, La Banda Oeste and El Molino), Province of Tucumán and from Cerrillos, Province of Santiago del Estero, Argentina were prepared. All showed antibacterial activity against Gram positive bacteria, the propolis from La Banda Este being the most active (MIC = 7.8 microg/ml) against Streptococcus piogenes, an antibiotic resistant bacterium. Thin layer chromatographic (TLC) separation profiles of propolis from Amaicha del Valle region were similar but differ from the alcoholic extract of the propolis from Cerrillos, another phytogeographical region of Argentina (provincia chaqueña). Bioautographic assays of the TLC profiles showed that several separated compounds of the Amaicha del Valle propolis have antibacterial activity. The difference in composition between Amaicha del Valle and Cerrillos propolis coincides with a different phytogeographical formation. PMID:10624867

Nieva Moreno, M I; Isla, M I; Cudmani, N G; Vattuone, M A; Sampietro, A R

1999-12-15

401

ACTIVIDADES FORESTALES Y SU RELACIÓN CON EL SIG EN FORESTAL BOSQUES DEL PLATA S.A. FORESTRY ACTIVITIES AND THEY RELATIONSHIPS WITH THE GIS IN FORESTAL BOSQUES DEL PLATA S.A  

Microsoft Academic Search

Resumen El objetivo del presente trabajo es presentar las relaciones existentes entre algunas de las actividades forestales actualmente desarrolladas en Forestal Bosques del Plata S.A. y el sistema de información geográfica (SIG) vigente. Con el uso de nuevas tecnologías y capacitación del personal se han desarrollado proyectos de estudios de plantación establecida, instalación de parcelas permanentes, fichas de rodal y

R. Trujillo; R. Pezzutti; S. Schmidt; F. Rodríguez

402

Infraestructuras urbanas de la Segunda Revolución Tecnológica. La difusión del teléfono en las ciudades españolas, 1877-1930  

Microsoft Academic Search

El uso del teléfono es en el mundo globalizado de hoy algo tan indisolublemente ligado a nuestros hábitos cotidianos que resulta casi impensable concebir una época en que tal servicio estuviera ausente. Profundizar en el estudio del origen y desarrollo del teléfono supone, pues, enfrentarse con algunas de las claves de la civilización actual. \\u000a\\u000aLa difusión del teléfono en las

Àngel Calvo Calvo

2007-01-01

403

Disruption of cytokeratin-8 interaction with F508del-CFTR corrects its functional defect  

PubMed Central

We have previously reported an increased expression of cytokeratins 8/18 (K8/K18) in cells expressing the F508del mutation of cystic fibrosis transmembrane conductance regulator (CFTR). This is associated with increased colocalization of CFTR and K18 in the vicinity of the endoplasmic reticulum, although this is reversed by treating cells with curcumin, resulting in the rescue of F508del-CFTR. In the present work, we hypothesized that (i) the K8/K18 network may interact physically with CFTR, and that (ii) this interaction may modify CFTR function. CFTR was immunoprecipitated from HeLa cells transfected with either wild-type (WT) CFTR or F508del-CFTR. Precipitates were subjected to 2D-gel electrophoresis and differential spots identified by mass spectrometry. K8 and K18 were found significantly increased in F508del-CFTR precipitates. Using surface plasmon resonance, we demonstrate that K8, but not K18, binds directly and preferentially to the F508del over the WT human NBD1 (nucleotide-binding domain-1). In vivo K8 interaction with F508del-CFTR was confirmed by proximity ligation assay in HeLa cells and in primary cultures of human respiratory epithelial cells. Ablation of K8 expression by siRNA in F508del-expressing HeLa cells led to the recovery of CFTR-dependent iodide efflux. Moreover, F508del-expressing mice topically treated with K8-siRNA showed restored nasal potential difference, equivalent to that of WT mice. These results show that disruption of F508del-CFTR and K8 interaction leads to the correction of the F508del-CFTR processing defect, suggesting a novel potential therapeutic target in CF.

Colas, Julien; Faure, Grazyna; Saussereau, Emilie; Trudel, Stephanie; Rabeh, Wael M.; Bitam, Sara; Guerrera, Ida Chiara; Fritsch, Janine; Sermet-Gaudelus, Isabelle; Davezac, Noelie; Brouillard, Franck; Lukacs, Gergely L.; Herrmann, Harald; Ollero, Mario; Edelman, Aleksander

2012-01-01

404

Assessing Glacier Hazards At Ghiacciaio Del Belvedere, Macugnaga, Italian Alps  

NASA Astrophysics Data System (ADS)

The uppermost section of the Valle Anzasca behind and above the community of Macugnaga in the Italian Alps is one of the most spectacular high-mountain land- scapes in Europe, with gigantic rock walls and numerous steep hanging glaciers. Its main glacier, Ghiacciaio del Belvedere at the foot of the huge Monte Rosa east face, is a heavily debris-covered glacier flowing on a thick sediment bed. Problems with floods, avalanches and debris flows from this ice body have been known for extended time periods. Most recently, however, the evolution of this highly dynamic environ- ment has become more dramatic. An outburst of Lago delle Locce, an ice-dammed lake at the confluenec of the tributary Ghiacciaio delle Locce with Ghiacciaio del Belvedere, caused heavy damage in 1979 and necessitated site investigation and con- struction work to be done for flood protection. The intermittent glacier growth ten- dency in the 1970es induced strong bulging of the glacier surface and, in places, caused the glacier tongue to override historical morains and to destroy newly-grown forest stands. A surge-type flow acceleration started in the lower parts of the Monte- Rosa east face during summer 2000, leading to strong crevassing and deformation of Ghiacciaio del Belvedere and extreme bulging of its orographic right margin. High water pressure and accelerated movement lasted into winter 2001/2002: the ice now started overriding the LIA moraine near Rifugio Zamboni of the CAI. In addition but rather independently, a most active detachment zone for rock falls and debris flows developed for several years now in the east face of Monte Rosa, somewhat more to the south of the accelerated glacier movement and at an altitude where relatively warm permafrost must be expected. Besides the scientific interest in these phenomena, the growing hazard potential to the local infrastructure must be considered seriously. Es- pecially potentials for the destabilization of large rock and ice masses in the east face of Monte Rosa, for interruption of the access trail to the Rifugio Zamboni by overrid- ing and/or collapse of the lateral moraine, for impacts by ice invading various instal- lations (cable car, restaurant, ski runs, trails) near the moraine hill of Belvedere, and for sudden outbursts of pressurized subglacial water or the newly formed supraglacial lake must be envisaged.

Haeberli, W.; Chiarle, M.; Mortara, G.; Mazza, A.

405

Evaluación y perspectivas del Código Nacional de Recursos Naturales de Colombia en sus 30 años de vigencia  

Microsoft Academic Search

Los artículos presentados estudian la eficacia, vigencia y perspectivas del Código Nacional de Recursos Naturales, decreto 2811 de 1974, teniendo de presente el avanzado estado de la ciencia en Colombia establecido por la Constitución del 91, y la Ley 99 de 1993; de esta manera los doctrinantes retoman la historia y las funciones del Código, la biodiversidad, la diversidad de

Autores varios

406

Taphonomy of guanaco bones in Tierra del Fuego  

NASA Astrophysics Data System (ADS)

Guanaco carcasses are deposited in great quantities in Cabo San Pablo, Tierra del Fuego (Argentina), as a result of winter stress. Taphonomic studies indicate that the gnawing action of foxes on guanaco ( Lama guanicoe) carcasses produces only very tenuous marks on the bones. Lack of sustained interest in the carcasses by carnivores results in slow disarticulation. The articulated and disarticulated bones are exposed to heavy trampling by guanacos, a process that produces vertical migration of small/dense bones and fracturing of the most weathered bones. An understanding of this ongoing process is important for local archaeology, since modern bones are migrating into archaeological contexts. A regional approach to taphonomy is the most appropriate instrument to solve this and other related problems.

Borrero, Luis Alberto

1990-11-01

407

Clean cities: Award winning coalition -- Paso del Norte  

SciTech Connect

Designated the 41st Clean Cities coalition in November 1995, the Paso del Norte Clean Cities Coalition (PDNCCC) is the first in the country to gain international participation. Spanning the US-Mexico border; the coalition includes stakeholders from El Paso, Texas; Ciudad Juarez, Mexico; and Las Cruces, New Mexico. PDNCCC developed a comprehensive plan to jump-start its program place, alternative fuel vehicles (AFVs) on the road, and eliminate barriers inhibiting alternative fuel market growth. PDNCC raised more than $2.3 million for alternative fuel activities and clean air initiatives in less than 26 months. In 1998, the US Department of Energy (DOE) recognized that PDNCCC accomplishment with its Rainmaker Award for leveraging the most funds from outside sources. PDNCCC is proud of its efforts to drive the alternative fuels and AFV market in the El Paso/Juarez region.

O'Connor, K.

1999-10-25

408

High precision ages from the Torres del Paine Intrusion, Chile  

NASA Astrophysics Data System (ADS)

The upper crustal bimodal Torres del Paine Intrusion, southern Chile, consists of the lower Paine-Mafic- Complex and the upper Paine-Granite. Geochronologically this bimodal complex is not well studied except for a few existing data from Halpern (1973) and Sanchez (2006). The aim of this study is to supplement the existing data and to constrain the age relations between the major magmatic pulses by applying high precision U-Pb dating on accessory zircons and 40Ar/39Ar-laser-step-heating-ages on biotites from the Torres del Paine Intrusion. The magmatic rocks from mafic complex are fine to medium-grained and vary in composition from quartz- monzonites to granodiorites and gabbros. Coarse-grained olivine gabbros have intruded these rocks in the west. The granitic body is represented by a peraluminous, biotite-orthoclase-granite and a more evolved leucocratic granite in the outer parts towards the host-rock. Field observations suggest a feeder-zone for the granite in the west and that the granite postdates the mafic complex. Two granite samples of the outermost margins in the Northeast and South were analyzed. The zircons were dated by precise isotope-dilution U-Pb techniques of chemically abraded single grains. The data are concordant within the analytical error and define weighted mean 206/238U ages of 12.59 ± 0.03 Ma and 12.58 ± 0.01 Ma for the two samples respectively. A 40Ar/39Ar-age for the second sample yield a date of 12.37 ± 0.11 Ma. Three 40Ar/39Ar -ages of biotites were obtained for rocks belonging to the mafic complex. A hbl-bio- granodiorite from the central part, approximately 150 m below the subhorizontal contact with the granite, gives an age of 12.81 ± 0.11 Ma. A hbl-bio-granodiorite and an olivine-gabbro west of the feeder-zone date at 12.42 ± 0.14 Ma and 12.49 ± 0.11 Ma, respectively. The obtained older age of 12.81 Ma for the granodiorite in the central part is consistent with structural relationships of brittle fracturing of the mafic complex by the granite and we conclude that some parts of the mafic complex were emplaced before the granite. The well defined 206/238U-age for zircons and the slightly younger 40Ar/39Ar -ages for biotites of both rock suites show that emplacement and cooling of the Torres del Paine Intrusion took place in a relatively short time-frame. Halpern, 1973, Geological Society of America Bulletin, 84/7: 2407-2422. Sanchez et.al., 2006. V SSAGI, Punta del Este, April 2006.

Michel, J.; Baumgartner, L.; Cosca, M.; Ovtcharova, M.; Putlitz, B.; Schaltegger, U.

2006-12-01

409

[Scorpions(Arachnida) from Bocas del Toro archipelago, Panamá].  

PubMed

Four species of buthid scorpions (Ananteris platnicki Lourenço, 1993; Centruroides limbatus [Pocock, 1898]; Tityus pachyurus [Pocock, 1897]; and T. ocelote Francke and Stockwell, 1987) are recorded for the first time from some islands and cays of the Bocas del Toro Archipelago, Panama. Morphological variation and ecological data are given for all the species. This is the first Panamanian record for both C. limbatus and T. ocelote. The scorpion fauna of the Bocas de Toro Archipelago is related with the recent fauna of the Atlantic continental lowland region of Costa Rica and Panama and includes Amazonian-Guyanese (genera Ananteris and Tityus) as well as Mexican-North Central American (genus Centruroides) elements. PMID:12298241

Montoya, Michel; de Armas, Luis F

2002-03-01

410

Numerical Kähler-Einstein Metric on the Third del Pezzo  

NASA Astrophysics Data System (ADS)

The third del Pezzo surface admits a unique Kähler-Einstein metric, which is not known in closed form. The manifold’s toric structure reduces the Einstein equation to a single Monge-Ampère equation in two real dimensions. We numerically solve this nonlinear PDE using three different algorithms, and describe the resulting metric. The first two algorithms involve simulation of Ricci flow, in complex and symplectic coordinates respectively. The third algorithm involves turning the PDE into an optimization problem on a certain space of metrics, which are symplectic analogues of the “algebraic” metrics used in numerical work on Calabi-Yau manifolds. Our algorithms should be applicable to general toric manifolds. Using our metric, we compute various geometric quantities of interest, including Laplacian eigenvalues and a harmonic (1,1)-form. The metric and (1,1)-form can be used to construct a Klebanov-Tseytlin-like supergravity solution.

Doran, Charles; Headrick, Matthew; Herzog, Christopher P.; Kantor, Joshua; Wiseman, Toby

2008-09-01

411

Ozone studies in the Paso del Norte region  

NASA Astrophysics Data System (ADS)

The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment. The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are conducive to high ozone episodes. In addition, the planetary boundary height is studied to understand its impact on high ozone episodes. Several studies report that ground level ozone non-attainment regulations could be caused not only by local emissions, but also by atmospheric transport. In this work the atmospheric advection of pollutants into the region is analyzed using HYSPLIT backward trajectories. Furthermore, a novel backward trajectory clustering technique is implemented for the summer of 2006. The "ozone weekend effect" (OWE) is a phenomenon by which in some geographical regions ambient ozone concentrations tend to be higher on weekends than on weekdays, despite the lower emissions of ozone precursors during those days. The observed local OWE has never previously been studied in terms of the photolysis rates of four of the main ozone precursors. In this research a novel method that allows the calculation of actinic fluxes, photolysis frequencies and photolysis rates with a high degree of accuracy and reliability has been developed. This method utilizes a combination of the experimental data available for this region in conjunction with a radiative transfer model (TUV model). Three weekend-weekday cases during summers 2006, 2009 and 2010 are studied in this work. In this research, the photolysis impact on the local OWE is studied. The results obtained from this photolysis study demonstrate that the local ground level ozone formation is not only influenced by the strong solar radiation and changing aerosol makeup, but also by other heterogeneous factors and reactions. In addition, this research provided good evidence that the ground level ozone precursor regime in El Paso during the ozone episode of June 2006 was mostly VOC-limited. Much of this estimation was derived from measurements of local ambient VOC/NOx ratios. This finding shows that at least during June 2006, the non-linear surface ozone production increased during weekends compared to workdays in a habitually VOC-limited regime. The seasonal variations of columnar ozone as measured by a Multi-filter Rotating Shadowband instrument installed at the UTEP campus are analyzed for the first time for this region and results are presented. This investigation has addressed the problem of ground-level ozone formation in the Paso del Norte region. Urban ozone is a complex problem with many aspects that are not fully understood. In this investigation, a range of techniques has been used to address the study of local surface ozone episodes with the purpose of acquiring new insights and knowledge that will help understand and remediate the diverse atmospheric pollution events that affect this bi-national region recurrently. Innovative techniques were developed and used, ranging from the use of local ambient atmospheric pollution data to the utilization of complex modeling techniques to achieve the best possible computer results. Finally, the influence of ground level ozone concentrations in admissions to hospitals for this region due to respiratory diseases is analyzed. The comprehensive results obtained in this work will help to better understand ozone formation in the Paso del Norte Region for future policy regulation implementations.

Becerra-Davila, Fernando

412

Isotope hydrology of groundwaters in the Pampa del Tamarugal, Chile  

NASA Astrophysics Data System (ADS)

The water resources in northern Chile are extremely scarce and development is limited by this. This paper discusses the isotope hydrology of groundwaters in the Pampa del Tamarugal — an area of extreme aridity (rainfall < 1 mm/yr.) — whose groundwater resources are mined for the town of Iquique, as well as for industrial and agricultural purposes. The aim of the project was to obtain information on modern recharge and to delineate, if possible recharge environments. To obtain the necessary background information a precipitation survey in the high Andes, as well as spring- and surface-water studies were carried out. The results show that a well-defined meteoric water line exists where ? 2H = (7.8 ? 18O + 10.3)% , and altitude effects depend on air-mass movements and cannot be defined without a broader regional and detailed sampling programme. However, it is still possible to assign maximum altitudes of recharge to springs in the Andes and at the eastern border of the Pampa del Tamarugal. Comparison of these data with groundwater compositions show, that these groundwaters originate from infiltrating surface water rather than directly infiltrated precipitation. A dependence of individual groundwater systems on specific quebradas (river valleys) is recognized. However, low 14C activities indicate that most of the waters pumped today are fossil and at least several hundreds if not thousands of years old. Some minor subsurface recharge does occur at the foot of the Andes, especially at Pica where high-altitude waters discharge, but even there groundwater appears to be a diminishing resource.

Fritz, P.; Suzuki, O.; Silva, C.; Salati, E.

1981-09-01

413

Fertilization by Sperm Microinjection and Zona-Drilling: Methods,  

National Technical Information Service (NTIS)

Successful microinjection of sperm or sperm nuclei into oocytes depends upon many factors. For example, injection needles must be large enough to pick up a sperm (nucleus) yet not so large as to kill the oocyte. The suction/pressure system should be very ...

S. D. Perreault

1988-01-01

414

LP55 Stereological Parameters of Zona Glomerulosa after Octreotide Treatment  

Microsoft Academic Search

Introduction The neuropeptide somatostatin is widely expressed both in the periphery and in the central nervous system. It has multiple functions: regulates endocrine and exocrine secretion, possesses antiproliferative properties and it acts as neurotransmitter\\/ neuromodulator by five distinct subtypes of receptors (sst1-5). Because of its ability to inhibit many functions of various organs, expectation was that somatostatin would be of

S. Trifunovic; V. Ajdzanovic; B. Filipovic; M. Sekulic; V. Milosevic

415

Estimación de la vulnerabilidad sísmica de viviendas en zonas urbanas  

Microsoft Academic Search

A method to estimate the probable number of houses affected during earthquakes is proposed. The results obtained with this method are compared with data of damaged housing from recent earthquakes: Tehuacan 1999 and Colima 2003, relatively good correlation was found. Costs to reduce seismic vulnerability by means of strengthening techniques are estimated and compared with the cost of material losses

Horacio Ramírez de Alba; Brenda Pichardo Lewenstein; Sandra Paola; Arzate Cruz

2007-01-01

416

FERTILIZATION BY SPERM MICROINJECTION AND ZONA-DRILLING: METHODS  

EPA Science Inventory

Successful microinjection of sperm or sperm nuclei into oocytes depends upon many factors. For example, injection needles must be large enough to pick up a sperm (nucleus) yet not so large as to kill the oocyte. The suction/pressure system should be very precisely controlled so a...

417

El camino recorrido: el aporte del Grupo Banco Interamericano de Desarrollo (BID) a la microempresa en los últimos 30 años en El Salvador  

Microsoft Academic Search

La idea de este libro surge con motivo del décimo aniversario de la celebración del Foro Interamericano de la Microempresa, esta vez con sede en El Salvador. El objetivo del mismo es contribuir a documentar el impacto producido por iniciativas del banco durante estos treinta años de trabajo conjunto con la microempresa en El Salvador. El libro presenta un resumen

Mercedes del Carmen Góchez; Carmen Cristina Álvarez

2007-01-01

418

Modelli history-friendly dell'evoluzione delle industrie: il caso dell'industria del computer  

Microsoft Academic Search

Modelli history-friendly dell'evoluzione delle industrie: il caso dell'industria del computer (di Franco Malerba, Luigi Orsenigo) - ABSTRACT: In this paper, we review and discuss the main features of a new generation of evolutionary models: \\

Luigi Orsenigo; Franco Malerba

2001-01-01

419

Geostatistical investigations of rock masses. The Sierra del Medio Case (Argentina).  

National Technical Information Service (NTIS)

The geostatistical tehniques applied for the selection of a minimun fracturation volume in Sierra del Medio allow to quantify and qualify the variability of mechanic characteristics and density of fracture and also the level of reliability in estimations....

J. A. Matar M. A. Sarquis J. P. Girardi G. H. Tabbia

1987-01-01

420

[Progress in InDel as a new generation of genetic marker].  

PubMed

As forensic DNA typing experienced three generations of genetic marker researching stage, short tandem repeat (STR) has been widely used in forensic identification as a mature tool. Further exploration of the human genome led to the discovery of polymorphism markers of single nucleotide polymorphism (SNP) and Insertion/Deletion (InDel). InDel, which combines the desirable characteristics of previous genetic markers as a new type of genetic marker, has got extensive concern in fields like medical molecular biology and forensic biology. This paper generally reviews the history of research and the corresponding results of InDel along the line of time axis as well as the different aims of these research focusing on the progress in the multiple amplification system with several InDel as the genetic marker (autosomal or X chromosome) in forensic biology and anthropology. Finally, the direction of research in this field and the problems to be solved have been put forward. PMID:23930511

Sun, Kuan; Zhang, Su-Hua; Zhu, Ru-Xin; Zhao, Shu-Min; Li, Cheng-Tao

2013-04-01

421

The extracellular matrix protein Del1 induces apoptosis via its epidermal growth factor motif.  

PubMed

Mouse Del1 is an extracellular matrix protein mainly expressed in the developing embryo. Del1 has three EGF motifs and two discoidin domains. The second EGF motif reportedly contains an RGD sequence that binds to integrin receptors. Here, we provide evidence that Del1 protein induces cell death in vitro. Chromatin condensation and DNA laddering were observed, suggestive of apoptosis. The results of analysis using the TUNEL method and annexin V staining were also consistent with apoptosis. The apoptosis-inducing activity of Del1 could be mapped to the third EGF motif, which fitted the consensus sequence CX(D/N)XXXX(F/Y)XCXC, wherein the aspartic acid residue (D) could be beta-hydroxylated. As little as twenty-five picomolar of recombinant E3 could induce apoptosis. PMID:20171188

Kitano, Hisataka; Kokubun, Shinichiro; Hidai, Chiaki

2010-03-19

422

EFECTO DEL GATUÑO SOBRE LA FERTILIDAD DEL SUELO Y LA BIOMASA HERBÁCEA EN PASTIZALES DEL CENTRO DE MÉXICO Effect of Catclaw Mimosa on Soil Fertility and Forage Yield in Rangelands in Central Mexico  

Microsoft Academic Search

RESUMEN El trabajo se realizó durante los años 2002 y 2003, en los estados de Aguascalientes y Jalisco, con el objetivo de evaluar el efecto del gatuño (Mimosa monancistra) en el grado de asociación de algunas variables edáficas, como pH, materia orgánica (MO), fósforo, calcio y magnesio, así como la cantidad de biomasa herbácea en tres sitios con diferente grado

Ernesto Flores; Juan Frías; Pedro Jurado; Víctor Olalde; Juan de Dios Figueroa; Arturo Valdivia; Edmundo García

423

CÁLCULO DEL VOLUMEN ESPECÍFICO DE LÍQUIDOS PUROS CON ECUACIONES DE ESTADO CÚBICAS  

Microsoft Academic Search

RESUMEN. En este trabajo se presenta una revisión de los cambios que se han producido en los últimos años en las ecuaciones de estado cúbicas de más amplia aceptación y se hace un estudio comparativo del cálculo del volumen específico de once líquidos puros por medio de cinco ecuaciones cúbicas: Van der Waals, Redlich-Kwong, Soave-Redlich-Kwong, Peng-Robinson y Valderrama-Patel- Teja .

BIBIAN HOYOS

424

Calculo del valor de la cuota lactea en las explotaciones de leche gallegas  

Microsoft Academic Search

RESUMEN: El nivel de cuota l�ctea por explotaci�n y la transferencia de cuota entre las distintas explotaciones juegan un papel principal en la reestructuraci�n del sector productor de leche en Espa�a. En este trabajo se estiman el valor de una unidad de cuota, de su valor de capitalizaci�n en el horizonte del a�o 2006 y la concreci�n de algunos determinantes

Jose Carlos De Miguel Dominguez; Tomas Perez Vidal; Xose Anton Rodriguez Gonzalez

2003-01-01

425

Avaluació de plantes protegides, amenaçades o rares al Parc Natural del Cadí-Moixeró (Pirineus orientals)  

Microsoft Academic Search

Sintetitzem els resultats obtinguts des de 1995 amb l'estudi de les plantes rares o protegides del Parc Natural del Cadí-Moixeró (Pirineus orientals, Catalunya). Es presenta una llista de flora d'interès especial d'aquest espai protegit, que actualment consta de 63 tàxons, distribuïts en 4 grups de diferent prioritat de conservació. Es donen dades sobre alguns tàxons per als quals s'han realitzat

Pere Aymerich i Boixader

2006-01-01

426

El Teatre Principal de Figueres: una història del dinou (1814-1902)  

Microsoft Academic Search

Aquest article és una aproximació a la idea, el projecte i l’execució de l’equipament\\u000apúblic més rellevant que Figueres duu del segle XIX i part del XX, juntament amb la Rambla. El significat d’aquesta construcció, excessiva per a una ciutat petita, va molt més enllà de l’edifici neoclàssic, ja que suposa una nova manera d’entendre l’urbanisme públic de la mà

Alfons Martínez i Puig

2009-01-01

427

[Molecular mechanism of RhDel phenotype in blood donation population of Chinese Harbin area].  

PubMed

This study was aimed to explore the molecular mechanism of RhDel phenotype expression in blood donors of Chinese Harbin area. Three hundred and seventy-four RhD negative donors confirmed by indirect antiglobulin test were detected by using serological and molecular methods for red blood cell RhD blood group genotyping and RH gene variant detection. And the other special samples of undetermined RhD genotype were sequenced. The results showed that 62 cases of Del type were detected in 374 negative blood donors' samples, accounting for 16.6%, among them there were 61 cases of RHD1227A, and 1 case of rare RHD Del (cde) 1 allele was found. Sequencing analysis indicated that RHD711DelC allele existed in 11 cases. In addition, the new mutant alleles were found in 3 samples. It is concluded that RHD1227A allele is generally carried allele in Del phenotype population of Chinese Harbin area and is an important genetic marker in Del phenotype individual. PMID:23257457

Li, Ji-Hong; Zhang, Chun-Yan; Sun, Jian-Hua; Liu, Jie

2012-12-01

428

Heterotic horizons, Monge-Ampère equation and del Pezzo surfaces  

NASA Astrophysics Data System (ADS)

Heterotic horizons preserving 4 supersymmetries have sections which are T 2 fibrations over 6-dimensional conformally balanced Hermitian manifolds. We give new examples of horizons with sections S 3 × S 3 × T 2 and SU(3). We then examine the heterotic horizons which are T 4 fibrations over a Kähler 4-dimensional manifold. We prove that the solutions depend on 6 functions which are determined by a non-linear differential system of 6 equations that include the Monge-Ampére equation. We show that this system has an explicit solution for the Kähler manifold S 2 × S 2. We also demonstrate that there is an associated cohomological system which has solutions on del Pezzo surfaces. We raise the question of whether for every solution of the cohomological problem there is a solution of the differential system, and so a new heterotic horizon. The horizon sections have topologies which include (( k - 1) S 2 × S 4# k( S 3 × S 3) × T 2 indicating the existence of exotic black holes. We also find an example of a horizon section which gives rise to two different near horizon geometries.

Gutowski, J.; Papadopoulos, G.

2010-10-01

429

CASP8 -652 6N Del Polymorphism Contributes to Colorectal Cancer Susceptibility: Evidence from a Meta-Analysis  

PubMed Central

Objective Caspase-8 (CASP8) plays a central role in the apoptotic pathway and aberrant regulation of this pathway may cause cancers. Previous studies investigating the association between CASP8 -652 6N ins/del polymorphism and colorectal cancer (CRC) risk showed inconclusive results. We performed a meta-analysis of all available studies to investigate this association. Methods All studies published up to October 2013 on the association between CASP8 -652 6N ins/del polymorphism and CRC risk were identified by searching electronic databases PubMed, EMBASE, and Cochrane library. The association between CASP8 -652 6N ins/del polymorphism and CRC risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs). Results Six studies with 6,325 cases and 6,842 controls were included in the meta-analysis. We observed that the CASP8 -652 6N ins/del polymorphism was significantly correlated with CRC risk when all studies were pooled into the meta-analysis (ins/del vs. ins/ins: OR?=?0.890, 95%CI 0.821–0.964, P?=?0.004; del/del + ins/del vs. ins/ins: OR?=?0.899, 95%CI 0.833–0.970, P?=?0.006). In stratified analyses by ethnicity, source of control, and quality score, significant association was observed in Asians (ins/del vs. ins/ins: OR?=?0.862, 95%CI 0.761–0.977, P?=?0.020; del/del + ins/del vs. ins/ins: OR?=?0.845, 95%CI 0.749–0.953, P?=?0.006), population-based studies (ins/del vs. ins/ins: OR?=?0.890, 95%CI 0.813–0.975, P?=?0.012; del/del + ins/del vs. ins/ins: OR?=?0.901, 95%CI 0.827–0.982, P?=?0.018), and high quality studies. However, in subgroup analysis according to cancer location, no significant association was detected. Conclusions The present meta-analysis suggests that the CASP8 is a candidate gene for CRC susceptibility. The CASP8 -652 6N ins/del polymorphism may play a protective role in CRC development especially among Asians. Further large and well-designed studies are needed to confirm this association.

Chen, Zhiping; Li, Ruolin; Wang, Jian; Deng, Yan; Li, Taijie; Qin, Xue; Li, Shan

2014-01-01

430

Resolución de problemas basada en el análisis. Hacer del análisis y del razonamiento el foco de la enseñanza de la física  

Microsoft Academic Search

Resumen. Usando los resultados provenientes de la investigación educativa en áreas tales como concepciones alternativas, diferencias entre expertos y novatos, adquisición de esquemas, sobrecarga cognitiva y análisis jerárquico, hemos desarrollado un marco para pensar sobre la organización del conocimiento y su uso para la comunicación, y sobre el razonamiento y la resolución de problemas. Basados en este marco y en

J. Leonard William; William J. Gerace; Robert J. Dufresne

2002-01-01

431

La red exterior de Puertos del Estado: Información oceanográfica en tiempo real. Puertos del Estado deep water network: Oceanographic information in real time  

Microsoft Academic Search

SUMMARY In the last 20 years, Puertos del Estado has settled a complex marine monitoring system that allows the access to real time oceanographic and meteorological information. One of the networks in this system is the deep water network with buoys deployed at open sea. The access to this information is completely free through the web pages where users can

Marta Alfonso; José Damián López; Isabel Ruiz; Enrique Álvarez; Nuevas Tecnologías

432

ESTADO DEL ARTE DE LA IMPLEMENTACIÓN DEL MÉTODO DE CRÉDITOS ACADÉMICOS - APRENDIZAJE AUTÓNOMO EN LAS INSTITUCIONES DE EDUCACIÓN SUPERIOR EN COLOMBIA  

Microsoft Academic Search

This paper intends to assess the current situation of the application process of academic loans in higher education institutions and to visualize new decision-making scenarios to generate spaces, dynamics and methodologies needed for its appropriate implementation. The study was based on three national universities: Universidad Militar Nueva Granada in Bogotá, Corporación Universita- ria del Meta -Unimeta-, and Universidad de los

RODRIGO PALACIO GÓMEZ; CLAUDIA LILIANA; MANCERA GUZMÁN; LUIS EDGAR CRUZ; WILLIAM PARRA PIÑEROS

2006-01-01

433

Screening for F508del as a first step in the molecular diagnosis of cystic fibrosis*,**  

PubMed Central

OBJECTIVE: To determine the relevance of screening for the F508del mutation of the cystic fibrosis transmembrane conductance regulator gene as a first step in the genetic diagnosis of cystic fibrosis (CF) by associating the genotype with various clinical variables. METHODS: We evaluated 180 CF patients regarding the F508del mutation. The clinical data were obtained from the medical records of the patients and from interviews with their parents or legal guardians. RESULTS: Of the 180 patients studied, 65 (36.1%) did not carry the F508del mutation (group 0 [G0]), 67 (37.2%) were F508del heterozygous (G1), and 48 (26.7%) were F508del homozygous (G2). All three groups showed associations with the clinical variables. Homozygosis was associated with younger patients, younger age at CF diagnosis, and younger age at the first isolation of Pseudomonas aeruginosa (PA), as well as with higher prevalence of pancreatic insufficiency (PI) and non-mucoid PA (NMPA) colonization. In comparison with G1+G2 patients, G0 patients were older; first experienced clinical symptoms, digestive disease, and pulmonary disease at an older age; were older at CF diagnosis and at first PA isolation; and had a lower prevalence of PI and meconium ileus, as well as of colonization by NMPA, mucoid PA, and Burkholderia cepacia. In G1 patients, values were intermediate for age at CF diagnosis; age at first PA isolation, first pulmonary symptoms, and first clinical manifestations; MPA colonization; and OR for PI. CONCLUSIONS: The identification of F508del in 63.9% of the patients studied showed that this can be a useful tool as a first step in the genetic diagnosis of CF. The F508del genotype was associated with clinical severity of the disease, especially with the variables related to CF onset.

Marson, Fernando Augusto de Lima; Bertuzzo, Carmen Silvia; Ribeiro, Maria Angela Goncalves de Oliveira; Ribeiro, Antonio Fernando; Ribeiro, Jose Dirceu

2013-01-01

434

El comerç de pintura antiga i el col·leccionisme a Barcelona a la segona meitat del segle XIX  

Microsoft Academic Search

En aquesta presentació es fa un breu recorregut per les col·leccions pictòriques construïdes a Catalunya durant la primera meitat del segle XIX. Es citen, però, els dos precedents més destacats. El més antic és la col·lecció del músic moianès Josep Elies (1690-1779) que fou organista del convent de les Descalzas Reales de Madrid, ciutat en la qual aplegà pintura barroca

Bonaventura Bassegoda

2009-01-01

435

Using Del-1 to tip the angiogenic balance in endothelial cells in modular constructs.  

PubMed

Modular tissue engineering is a method of building vascularized tissue-engineered constructs. Submillimeter-sized collagen pieces (modules) coated with a layer of endothelial cells (EC; vascular component), and with embedded functional cells, are self-assembled into a larger, three-dimensional tissue. In this study, we examined the use of developmental endothelial locus-1 (Del-1), an extracellular matrix protein with proangiogenic properties, as a means of tipping the angiogenic balance in human umbilical vein endothelial cells incorporated in modular tissue-engineered constructs. The motivation was to enhance the vascularization of these constructs upon transplantation in vivo, in this case, without the use of exogenous mesenchymal stromal cells. EC were transduced using a lentiviral construct to overexpress Del-1. The Del-1 EC formed more sprouts in a fibrin gel sprouting assay in vitro compared with eGFP (control) transduced EC, as expected. Del-1 EC had a distinct profile of gene expression (upregulation of matrix metalloproteinase-9 [MMP-9], urokinase-type plasminogen activator [uPA/PLAU], vascular endothelial growth factor [VEGF-A], and intercellular adhesion molecule-1 [ICAM-1]; downregulation of angiopoietin-2 [Ang2]), also supporting the notion of "tipping the angiogenic balance". On the other hand, contrary to our expectations, when Del-1 EC-coated modules were implanted subcutaneously in a severe combined immunodeficient/beige animal model, the proangiogenic effect of Del-1 was less remarkable. There was only a small increase in the number of blood vessels formed in Del-1 implants compared with the eGFP implants, and only few blood vessels formed at the implant site in both cases. This was presumed due to limited EC survival after transplantation. We speculate that if we could improve EC survival in our study (for example, by adding other prosurvival factors or supporting cells), we would see a greater Del-1-induced angiogenic benefit in vivo as a consequence of increased Del-1 secretion by a higher number of surviving cells. PMID:24138448

Ciucurel, Ema C; Vlahos, Alexander E; Sefton, Michael V

2014-04-01

436

Magnetic fabric of the Torres del Paine, Patagonia  

NASA Astrophysics Data System (ADS)

The Miocene bimodal Torres del Paine Intrusive Complex (TIPC) consists of the lower Paine-Mafic-Complex (PMC) and the overlaying Paine Granite. Igneous structures (layering, xenolith orientations, and major contacts) are vertical in the westernmost part of the PMC, while they are sub-horizontal in the central and eastern parts. The TPIC is very homogeneous except in the PMC where complex interactions between mafic and felsic magmas were observed. No foliation or lineations are present in the field. Based on field-observations we distinguish at least three different sheet-like units in the Paine Granite, each one several tens to hundreds of meters thick. Younger sheets generally under-plate their precursor. We measured the anisotropy of magnetic susceptibility (AMS) on 145 samples from sites distributed horizontally over the entire surface of the TPIC and along 4 vertical profiles. The high intensity of the magnetic susceptibility for most of the Paine Granite and the PMC samples is due to the presence of magnetite. The magnetic lineations show a general WNW-ESE trend, parallel to the long axis of the intrusion. Lineations in the western part are strongly west-dipping to subvertical, parallel to the magmatic layering in the PMC. This supports the interpretation of a feeder-zone in that area. The lineations are sub-horizontal in the rest of the intrusion. Only minor variations in lineation orientation are observed in several hundred meter long vertical profiles in the central part of the Paine Granite. The magnetic foliations show the structural control exerted by the contact of the intrusion during its assembly: they are mostly horizontal in the central part, and are progressively steeper towards the contact. The low anisotropy is in agreement with the absence of texture observed in the field and thin sections. No sub-solidus deformation took place during the TPIC construction. The internal structures and magnetic fabrics support the interpretation of an intrusion assembled by horizontal transfer of magma in the form of sheet-like pulses stacking them vertically. Our results also show that the regional syn-magmatic deformation played no role in the emplacement of the TPIC.

Michel, J.; Baumgartner, L.; de Saint-Blanquat, M.; Putlitz, B.; Sanchez, A.; Darbellay, B.; Cavargna, M.

2007-12-01

437

The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection  

NASA Astrophysics Data System (ADS)

This paper seeks to analyze in an objective way the circumstances and events that contributed to the 1985 Nevado del Ruiz catastrophe, in order to provide useful guidelines for future emergencies. The paper is organized into two principal parts. In the first part, an Anatomy of the catastrophe is developed as a step-by-step chronicle of events and actions taken by individuals and organizations during the period November 1984 through November 1985. This chronicle provides the essential background for the crucial events of November 13. This year-long period is broken down further to emphasize essential chapters: the gradual awareness of the awakening of the volcano; a long period of institutional skepticism reflecting an absence of credibility; the closure of the credibility gap with the September 11 phreatic eruption, followed by an intensive effort to gird for the worst; and a detailed account of the day of reckoning. The second part of the paper, Retrospection, examines the numerous complicated factors that influenced the catastrophic outcome, and attempts to cull a few "lessons from Armero" in order to avoid similar occurrences in the future. In a nutshell, the government on the whole acted responsibly but was not willing to bear the economic or political costs of early evacuation or a false alarm. Science accurately foresaw the hazards but was insufficiently precise to render reliable warning of the crucial event at the last possible minute. Catastrophe was therefore a calculated risk, and this combination — the limitations of predication/detection, the refusal to bear a false alarm and the lack of will to act on the uncertain information available — provided its immediate and most obvious causes. But because the crucial event occurred just two days before the Armero emergency-management plan was to be critically examined and improved, the numerous circumstances which delayed progress of emergency management over the previous year also may be said to have contributed to the outcome. Thus the catastrophe was not caused by technological ineffectiveness or detectiveness, nor by an overwhelming eruption, or by an improbable run of bad luck, but rather by cumulative human error — by misjudgment, indecision and bureaucratic shortsightedness. Armero could have produces no victims, and therein dwells its immense tragedy.

Voight, Barry

1990-07-01

438

The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection  

NASA Astrophysics Data System (ADS)

This paper seeks to analyze in an objective way the circumstances and events that contributed to the 1985 Nevado del Ruiz catastrophe, in order to provide useful guidelines for future emergencies. The paper is organized into two principal parts. In the first part, an Anatomy of the catastrophe is developed as a step-by-step chronicle of events and actions taken by individuals and organizations during the period November 1984 through November 1985. This chronicle provides the essential background for the crucial events of November 13. This year-long period is broken down further to emphasize important chapters: the gradual awareness of the awakening of the volcano; a long period of institutional skepticism reflecting an absence of credibility; the closure of the credibility gap with the September 11 phreatic eruption, followed by an intensive effort to gird for the worst; and a detailed account of the day of reckoning. The second part of the paper, Retrospection, examines the numerous complicated factors that influenced the catastrophic outcome, and attempts to cull a few "lessons from Armero" in order to avoid similar occurrences in the future. In a nutshell, the government on the whole acted responsibly but was not willing to bear the economic or political costs of early evacuation or a false alarm. Science accurately foresaw the hazards but was insufficiently precise to render reliable warning of the crucial event at the last possible minute. Catastrophe was therefore a calculated risk, and this combination - the limitations of prediction/detection, the refusal to bear a false alarm and the lack of will to act on the uncertain information available - provided its immediate and most obvious causes. But because the crucial event occurred just two days before the Armero emergency management plan was to be critically examined and improved, the numerous circumstances which delayed progress of emergency management over the previous year also may be said to have contributed to the outcome. Thus the catastrophe was not caused by technological ineffectiveness or defectiveness, nor by an overwhelming eruption, or by an improbable run of bad luck, but rather by cumulative human error - by misjudgment, indecision and bureaucratic shortsightedness. Armero could have produced no victims, and therein dwells its immense tragedy.

Voight, Barry

1990-12-01

439

Correlated Occurrence and Bypass of Frame-Shifting Insertion-Deletions (InDels) to Give Functional Proteins  

PubMed Central

Short insertions and deletions (InDels) comprise an important part of the natural mutational repertoire. InDels are, however, highly deleterious, primarily because two-thirds result in frame-shifts. Bypass through slippage over homonucleotide repeats by transcriptional and/or translational infidelity is known to occur sporadically. However, the overall frequency of bypass and its relation to sequence composition remain unclear. Intriguingly, the occurrence of InDels and the bypass of frame-shifts are mechanistically related - occurring through slippage over repeats by DNA or RNA polymerases, or by the ribosome, respectively. Here, we show that the frequency of frame-shifting InDels, and the frequency by which they are bypassed to give full-length, functional proteins, are indeed highly correlated. Using a laboratory genetic drift, we have exhaustively mapped all InDels that occurred within a single gene. We thus compared the naive InDel repertoire that results from DNA polymerase slippage to the frame-shifting InDels tolerated following selection to maintain protein function. We found that InDels repeatedly occurred, and were bypassed, within homonucleotide repeats of 3–8 bases. The longer the repeat, the higher was the frequency of InDels formation, and the more frequent was their bypass. Besides an expected 8A repeat, other types of repeats, including short ones, and G and C repeats, were bypassed. Although obtained in vitro, our results indicate a direct link between the genetic occurrence of InDels and their phenotypic rescue, thus suggesting a potential role for frame-shifting InDels as bridging evolutionary intermediates.

Rockah-Shmuel, Liat; Toth-Petroczy, Agnes; Sela, Asaf; Wurtzel, Omri; Sorek, Rotem; Tawfik, Dan S.

2013-01-01

440

Correlated occurrence and bypass of frame-shifting insertion-deletions (InDels) to give functional proteins.  

PubMed

Short insertions and deletions (InDels) comprise an important part of the natural mutational repertoire. InDels are, however, highly deleterious, primarily because two-thirds result in frame-shifts. Bypass through slippage over homonucleotide repeats by transcriptional and/or translational infidelity is known to occur sporadically. However, the overall frequency of bypass and its relation to sequence composition remain unclear. Intriguingly, the occurrence of InDels and the bypass of frame-shifts are mechanistically related - occurring through slippage over repeats by DNA or RNA polymerases, or by the ribosome, respectively. Here, we show that the frequency of frame-shifting InDels, and the frequency by which they are bypassed to give full-length, functional proteins, are indeed highly correlated. Using a laboratory genetic drift, we have exhaustively mapped all InDels that occurred within a single gene. We thus compared the naive InDel repertoire that results from DNA polymerase slippage to the frame-shifting InDels tolerated following selection to maintain protein function. We found that InDels repeatedly occurred, and were bypassed, within homonucleotide repeats of 3-8 bases. The longer the repeat, the higher was the frequency of InDels formation, and the more frequent was their bypass. Besides an expected 8A repeat, other types of repeats, including short ones, and G and C repeats, were bypassed. Although obtained in vitro, our results indicate a direct link between the genetic occurrence of InDels and their phenotypic rescue, thus suggesting a potential role for frame-shifting InDels as bridging evolutionary intermediates. PMID:24204297

Rockah-Shmuel, Liat; Tóth-Petróczy, Ágnes; Sela, Asaf; Wurtzel, Omri; Sorek, Rotem; Tawfik, Dan S

2013-10-01

441

77 FR 36041 - Additional Designations, Foreign Narcotics Kingpin Designation Act  

Federal Register 2010, 2011, 2012, 2013

...Central 1191-35, Condominio Malaga, Colonia Parques de la Castellana, Zapopan, Jalisco, Mexico; Local 9 Zona E, Plaza Universidad, Zapopan, Jalisco, Mexico; Avenida Nayar 222, Colonia Ciudad del Sol, Zapopan, Jalisco, Mexico; Avenida...

2012-06-15

442

Observaciones del disco solar y de una protuberancia quiescente en radiación ultravioleta  

NASA Astrophysics Data System (ADS)

Observaciones del disco solar y de una protuberancia quiescente en el rango de longitudes de onda ultravioleta fueron obtenidas con el instrumento CDS (Coronal Diagnostic Spectrograph) y SUMER (Solar Ultraviolet Measurements of emitted radiation) a bordo de la sonda SOHO. El propósito es investigar las velocidades macroscópicas de varias especies metálicas que se observan tanto en el disco solar como en el plasma de las protuberancias. Para calcular las velocidades del disco solar aplicamos una técnica mixta para modelar la distribución de estructuras en UV en el Sol quieto. Las velocidades macroscópicas en las protuberancias se calcularon a partir de los corrimientos Doppler en cada línea espectral y luego se tomaron las del disco solar como referencia. Obtuvimos valores absolutos para las velocidades macroscópicas entre 5 y 40 km/seg. También detectamos comportamientos diferentes en las velocidades de las protuberancias en el centro con respecto a los bordes.

Cirigliano, D.; Vial, J.-C.; Rovira, M.

443

CASE REPORT: Phenotypic presentation of the Ser63Del MPZ mutation  

PubMed Central

Mutations in MPZ cause CMT1B, the second most frequent cause of CMT1. Elegant studies with Ser63del mice suggest that Ser63del MPZ is retained in the ER where it activates the unfolded protein response (UPR) that contributes to the neuropathy. Clinical information about patients with this mutation is limited. We present clinical and electrophysiological data on a large multigenerational family with CMT1B caused by Ser63del MPZ. The patients have a classical CMT1 phenotype that is much less severe than that of patients with Arg98Cys MPZ that also activates the UPR. These results suggest that clinical presentation along cannot predict which MPZ mutations will be retained in the ER and activate the UPR.

Miller, Lindsey J.; Patzko, Agnes; Lewis, Richard A.; Shy, Michael E.

2013-01-01

444

Biotic association and palaeoenvironmental reconstruction of the "Loma del Pterodaustro" fossil site (Early Cretaceous, Argentina)  

USGS Publications Warehouse

A sedimentological analysis of the basal section of the Early Cretaceous, lacustrine Lagarcito Formation at "Loma del Pterodaustro" (San Luis, Argentina) and a summary of its biological components are presented. Three sedimentological facies can be recognized in the basal sequence of the Lagarcito Formation. Fossil remains are particularly abundant in laminated claystones of a facies interpreted as deposits formed in offshore areas of the lake. The preservation of delicate structures allows recognition of these deposits as a Konservat Lagersta??tte. Up to now, rocks at "Loma del Pterodaustro" have yielded plants, conchostracans, semionotid and pleuropholid fishes, pterodactyloid pterosaurs, and a variety of invertebrate traces. The chronology of the Lagarcito Formation is discussed and it is concluded that this unit is of Albian age. The palaeoenvironment of deposition of the basal sequence of the Lagarcito Formation at "Loma del Pterodaustro" is interpreted as a perennial, shallow lake developed within an alluvial plain, under semiarid climatic conditions.

Chiappe, L.; Rivarola, D.; Cione, A.; Fregenal-Martinez, M.; Sozzi, H.; Buatois, L.; Gallego, O.; Laza, J.; Romero, E.; Lopez-Arbarello, A.; Buscalioni, A.; Marsicano, C.; Adamonis, S.; Ortega, F.; McGehee, S.; Di, Iorio, O.

1998-01-01

445

EVALUACIÓN DEL CRECIMIENTO Y PRODUCCIÓN DE Pleurotus ostreatus SOBRE DIFERENTES RESIDUOS AGROINDUSTRIALES DEL DEPARTAMENTO DE CUNDINAMARCA EVALUATION OF GROWTH AND PRODUCTION OF Pleurotus ostreatus ON DIFFERENT AGROINDUSTRIALS WASTES OF CUNDINAMARCA  

Microsoft Academic Search

Resumen Se llevó a cabo la evaluación del cultivo de Pleurotus ostreatus, para determinar el residuo sobre el cual este hongo genera mejor crecimiento y producción. Los sustratos evaluados fueron residuos agroindustriales del departamento de Cundinamarca (capacho de uchuva, cáscara de arveja y tusa de maíz); teniendo como sustrato control el aserrín de roble. Las mezclas a evaluar fueron empacadas

Claudia López-Rodríguez; Ricardo Hernández-Corredor; Christian Suárez-Franco; Marta Borrero; Facultad de Ciencias

2008-01-01

446

Origin and distribution of the BRCA2-8765delAG mutation in breast cancer  

PubMed Central

Background The BRCA2-8765delAG mutation was firstly described in breast cancer families from French-Canadian and Jewish-Yemenite populations; it was then reported as a founder mutation in Sardinian families. We evaluated both the prevalence of the BRCA2-8765delAG variant in Sardinia and the putative existence of a common ancestral origin through a haplotype analysis of breast cancer family members carrying such a mutation. Methods Eight polymorphic microsatellite markers (D13S1250, centromeric, to D13S267, telomeric) spanning the BRCA2 gene locus were used for the haplotype analysis. Screening for the 8765delAG mutation was performed by PCR-based amplification of BRCA2-exon 20, followed by automated sequencing. Results Among families with high recurrence of breast cancer (? 3 cases in first-degree relatives), those from North Sardinia shared the same haplotype whereas the families from French Canadian and Jewish-Yemenite populations presented distinct genetic assets at the BRCA2 locus. Screening for the BRCA2-8765delAG variant among unselected and consecutively-collected breast cancer patients originating from the entire Sardinia revealed that such a mutation is present in the northern part of the island only [9/648 (1.4%) among cases from North Sardinia versus 0/493 among cases from South Sardinia]. Conclusion The BRCA2-8765delAG has an independent origin in geographically and ethnically distinct populations, acting as a founder mutation in North but not in South Sardinia. Since BRCA2-8765delAG occurs within a triplet repeat sequence of AGAGAG, our study further confirmed the existence of a mutational hot-spot at this genomic position (additional genetic factors within each single population might be involved in generating such a mutation).

Palomba, Grazia; Cossu, Antonio; Friedman, Eitan; Budroni, Mario; Farris, Antonio; Contu, Antonio; Pisano, Marina; Baldinu, Paola; Sini, Maria C; Tanda, Francesco; Palmieri, Giuseppe

2007-01-01

447

[Il ruolo del cervelletto nella depressione unipolare e bipolare: una rassegna delle principali evidenze neurobiologiche].  

PubMed

riassunto. Evidenze derivanti da numerosi studi condotti sia su pazienti affetti da patologie cerebellari sia su soggetti sani suggeriscono che il cervelletto eserciti, oltre a un ruolo ormai ben definito nel controllo e nella regolazione delle funzioni motorie, una significativa attività di modulatore del tono dell'umore, del comportamento e delle funzioni cognitive. In questo lavoro di revisione abbiamo passato in rassegna tutti quegli studi di neuroimaging volti a indagare la presenza di alterazioni cerebellari sia morfologiche sia funzionali in pazienti affetti da disturbo bipolare (DB) e disturbo depressivo maggiore (DDM), ipotizzando l'esistenza di un meccanismo fisiopatologico alla base di questi disturbi, che coinvolga, almeno in parte, il cervelletto. Allo stesso scopo, sono stati esaminati anche quegli studi post mortem che indagavano la presenza di alterazioni cellulari e molecolari a partire da campioni di tessuto cerebellare, per esempio alterazioni delle proteine mitocondriali, della tirosin-chinasi B e del brain-derived neurotrophic factor (BDNF), del fattore di trascrizione SP4, della proteina fibrillare acida della glia (GFAP). In totale sono stati esaminati 28 studi, 12 inerenti le alterazioni morfologiche e funzionali del cervelletto nel DB, 13 inerenti le alterazioni morfologiche e funzionali del cervelletto nel DDM e 4 inerenti le alterazioni cerebellari post mortem in entrambi i disturbi. Dal nostro lavoro di revisione, in linea con quanto presente nella letteratura internazionale, emerge l'interessante ipotesi che il cervelletto funzioni come un "pacemaker emotivo" e che quindi una sua lesione potrebbe tradursi nell'incapacità dell'individuo di rimanere in equilibrio sulla sottile linea dell'eutimia, giustificando in questo modo la comparsa di profonde oscillazioni emotive sia sul versante depressivo sia su quello maniacale. PMID:25000888

Minichino, Amedeo; Bersani, Francesco Saverio; Trabucchi, Guido; Albano, Gabriella; Primavera, Martina; Delle Chiaie, Roberto; Biondi, Massimo

2014-01-01

448

Haplotype analysis of the 185delAG BRCA1 mutation in ethnically diverse populations  

PubMed Central

The 185delAG* BRCA1 mutation is encountered primarily in Jewish Ashkenazi and Iraqi individuals, and sporadically in non-Jews. Previous studies estimated that this is a founder mutation in Jewish mutation carriers that arose before the dispersion of Jews in the Diaspora ?2500 years ago. The aim of this study was to assess the haplotype in ethnically diverse 185delAG* BRCA1 mutation carriers, and to estimate the age at which the mutation arose. Ethnically diverse Jewish and non-Jewish 185delAG*BRCA1 mutation carriers and their relatives were genotyped using 15 microsatellite markers and three SNPs spanning 12.5?MB, encompassing the BRCA1 gene locus. Estimation of mutation age was based on a subset of 11 markers spanning a region of ?5?MB, using a previously developed algorithm applying the maximum likelihood method. Overall, 188 participants (154 carriers and 34 noncarriers) from 115 families were included: Ashkenazi, Iraq, Kuchin-Indians, Syria, Turkey, Iran, Tunisia, Bulgaria, non-Jewish English, non-Jewish Malaysian, and Hispanics. Haplotype analysis indicated that the 185delAG mutation arose 750–1500 years ago. In Ashkenazim, it is a founder mutation that arose 61 generations ago, and with a small group of founder mutations was introduced into the Hispanic population (conversos) ?650 years ago, and into the Iraqi–Jewish community ?450 years ago. The 185delAG mutation in the non-Jewish populations in Malaysia and the UK arose at least twice independently. We conclude that the 185delAG* BRCA1 mutation resides on a common haplotype among Ashkenazi Jews, and arose about 61 generations ago and arose independently at least twice in non-Jews.

Laitman, Yael; Feng, Bing-Jian; Zamir, Itay M; Weitzel, Jeffrey N; Duncan, Paul; Port, Danielle; Thirthagiri, Eswary; Teo, Soo-Hwang; Evans, Gareth; Latif, Ayse; Newman, William G; Gershoni-Baruch, Ruth; Zidan, Jamal; Shimon-Paluch, Shani; Goldgar, David; Friedman, Eitan

2013-01-01

449

A review on Balanites aegyptiaca Del (desert date): phytochemical constituents, traditional uses, and pharmacological activity.  

PubMed

Balanites aegyptiaca Del. (Zygophyllaceae), known as 'desert date,' is spiny shrub or tree up to l0 m tall, widely distributed in dry land areas of Africa and South Asia. It is traditionally used in treatment of various ailments i.e. jaundice, intestinal worm infection, wounds, malaria, syphilis, epilepsy, dysentery, constipation, diarrhea, hemorrhoid, stomach aches, asthma, and fever. It contains protein, lipid, carbohydrate, alkaloid, saponin, flavonoid, and organic acid. Present review summarizes the traditional claims, phytochemistry, and pharmacology of B. aegyptiaca Del reported in scientific literature. PMID:22096319

Chothani, Daya L; Vaghasiya, H U

2011-01-01

450

Parental origin of de novo chromosome 9 deletions in del(9p) syndrome  

SciTech Connect

Parental origin of de novo deletions in the short arm of chromosome 9 in patients with a clinical diagnosis of del(9p) syndrome was assessed in 13 patients using polymerase chain reaction (PCR) analysis of highly polymorphic dinucleotide repeat microsatellite markers located in the putative deleted region. The deletion was found to be of paternal origin in 9 cases and of maternal origin in the remaining 4 cases, suggesting that the molecular event resulting in the deletion occurs in both male and female gametogenesis and that genomic imprinting does not appear to play a role in the pathogenesis of del(9p) syndrome. 22 refs., 1 fig.

Micale, M.A.; Haren, J.M.; Conroy, J.M. [Case Western University School of Medicine, Clevelend, OH (United States)

1995-05-22

451

A review on Balanites aegyptiaca Del (desert date): phytochemical constituents, traditional uses, and pharmacological activity  

PubMed Central

Balanites aegyptiaca Del. (Zygophyllaceae), known as ‘desert date,’ is spiny shrub or tree up to l0 m tall, widely distributed in dry land areas of Africa and South Asia. It is traditionally used in treatment of various ailments i.e. jaundice, intestinal worm infection, wounds, malaria, syphilis, epilepsy, dysentery, constipation, diarrhea, hemorrhoid, stomach aches, asthma, and fever. It contains protein, lipid, carbohydrate, alkaloid, saponin, flavonoid, and organic acid. Present review summarizes the traditional claims, phytochemistry, and pharmacol