Cardiac lipid levels show diurnal changes and long-term variations in healthy human subjects

(1) H-MRS is regularly applied to determine lipid content in ectopic tissue - mostly skeletal muscle and liver - to investigate physiological and/or pathologic conditions, e.g. insulin resistance. Technical developments also allow non-invasive in vivo assessment of cardiac lipids; however, basic data about methodological reliability (repeatability) and physiological variations are scarce. The aim of the presented work was to determine potential diurnal changes of cardiac lipid stores in humans, and to put the results in relation to methodological repeatability and normal physiological day-to-day variations. Optimized cardiac- and respiratory-gated (1) H-MRS was used for non-invasive quantification of intracardiomyocellular lipids (ICCL), creatine, trimethyl-ammonium compounds (TMA), and taurine in nine healthy young men at three time points per day on two days separated by one week. This design allowed determination of (a) diurnal changes, (b) physiological variation over one week and (c) methodological repeatability of the ICCL levels. Comparison of fasted morning to post-absorptive evening measurements revealed a significant 37 ± 19% decrease of ICCL during the day (p = 0.0001). There was a significant linear correlation between ICCL levels in the morning and their decrease during the day (p = 0.015). Methodological repeatability for the ICCL/creatine ratio was excellent, with a coefficient of variance of ~5%, whereas physiological variation was found to be considerably higher (22%) in spite of a standardized physiological preparation protocol. In contrast, TMA levels remained stable over this time period. The proposed (1) H-MRS technique provides a robust way to investigate relevant physiological changes in cardiac metabolites, in particular ICCL. The present results suggest that ICCL reveal a diurnal course, with higher levels in the morning as compared to evening. In addition, a considerable long-term variation of ICCL levels, in both the morning and evening, was documented. Given the high methodological repeatability, these effects should be taken into account in studies investigating the metabolic role of ICCL.

Precious Corals (Coralliidae) from North-Western Atlantic Seamounts

Two new species belonging to the precious coral genus Corallium were collected during a series of exploratory cruises to the New England and Corner Rise Seamounts in 2003-2005. One red species, Corallium bathyrubrum sp. nov., and one white species, C. bayeri sp. nov., are described. Corallium bathyrubrum is the first red Corallium to be reported from the western Atlantic. An additional species, C. niobe Bayer, 1964 originally described from the Straits of Florida, was also collected and its description augmented.

Host risk factors for rifamycin-resistant clostridium difficile infection: A case control study

Objective. To evaluate the host risk factors associated with rifamycin-resistant Clostridium difficile (C. diff) infection in hospitalized patients compared to rifamycin-susceptible C.diff infection.^ Background. C. diff is the most common definable cause of nosocomial diarrhea affecting elderly hospitalized patients taking antibiotics for prolonged durations. The epidemiology of Clostridium difficile associated disease is now changing with the reports of a new hypervirulent strain causing hospital outbreaks. This new strain is associated with increased disease severity and mortality. The conventional therapy for C. diff includes metronidazole and vancomycin but high recurrence rates and treatment failures are now becoming a major concern. Rifamycin antibiotics are being developed as a new therapeutic option to treat C. diff infection after their efficacy was established in a few in vivo and in vitro studies. There are some recent studies that report an association between the hypervirulent strain and emerging rifamycin resistance. These findings assess the need for clinical studies to better understand the efficacy of rifamycin drugs against C. diff.^ Methods. This is a hospital-based, matched case-control study using de-identified data drawn from two prospective cohort studies involving C. diff patients at St Luke's Hospital. The C. diff isolates from these patients are screened for rifamycin resistance using agar dilution methods for minimum inhibitory concentrations (MIC) as part of Dr Zhi-Dong Jiang's study. Twenty-four rifamycin-rifamycin resistant C. diff cases were identified and matched with one rifamycin susceptible C. diff control on the basis of ± 10 years of age and hospitalization 30 days before or after the case. De-identified data for the 48 subjects was obtained from Dr Kevin Garey's clinical study at St Luke's Hospital enrolling C. diff patients. It was reviewed to gather information about host risk factors, outcome variables and relevant clinical characteristic.^ Results. Medical diagnosis at the time of admission (p = 0.0281) and history of chemotherapy (p = 0.022) were identified as a significant risk factor while hospital stay ranging from 1 week to 1 month and artificial feeding were identified as an important outcome variable (p = 0.072 and p = 0.081 respectively). Horn's Index assessing the severity of underlying illness and duration of antibiotics for cases and controls showed no significant difference.^ Conclusion. The study was a small project designed to identify host risk factors and understand the clinical implications of rifamycin-resistance. The study was underpowered and a larger sample size is needed to validate the results.^

IDENTIFICATION AND ANALYSIS OF A NOVEL ROLE FOR THE TOUSLED-LIKE KINASE IN REGULATING MITOTIC SPINDLE DYNAMICS

Deregulation of kinase activity is one example of how cells become cancerous by evading evolutionary constraints. The Tousled kinase (Tsl) was initially identified in Arabidopsis thaliana as a developmentally important kinase. There are two mammalian orthologues of Tsl and one orthologue in C. elegans, TLK-1, which is essential for embryonic viability and germ cell development. Depletion of TLK-1 leads to embryonic arrest large, distended nuclei, and ultimately embryonic lethality. Prior to terminal arrest, TLK-1-depleted embryos undergo aberrant mitoses characterized by poor metaphase chromosome alignment, delayed mitotic progression, lagging chromosomes, and supernumerary centrosomes. I discovered an unanticipated requirement for TLK-1 in mitotic spindle assembly and positioning. Normally, in the newly-fertilized zygote (P0) the maternal pronucleus migrates toward the paternal pronucleus at the posterior end of the embryo. After pronuclear meeting, the pronuclear-centrosome complex rotates 90° during centration to align on the anteroposterior axis followed by nuclear envelope breakdown (NEBD). However, in TLK-1-depleted P0 embryos, the centrosome-pronuclear complex rotation is significantly delayed with respect to NEBD and chromosome congression, Additionally, centrosome positions over time in tlk-1(RNAi) early embryos revealed a defect in posterior centrosome positioning during spindle-pronuclear centration, and 4D analysis of centrosome positions and movement in newly fertilized embryos showed aberrant centrosome dynamics in TLK-1-depleted embryos. Several mechanisms contribute to spindle rotation, one of which is the anchoring of astral microtubules to the cell cortex. Attachment of these microtubules to the cortices is thought to confer the necessary stability and forces in order to rotate the centrosome-pronuclear complex in a timely fashion. Analysis of a microtubule end-binding protein revealed that TLK-1-depleted embryos exhibit a more stochastic distribution of microtubule growth toward the cell cortices, and the types of microtubule attachments appear to differ from wild-type embryos. Additionally, fewer astral microtubules are in the vicinity of the cell cortex, thus suggesting that the delayed spindle rotation could be in part due to a lack of appropriate microtubule attachments to the cell cortex. Together with recently published biochemical data revealing the Tousled-like kinases associate with components of the dynein microtubule motor complex in humans, these data suggest that Tousled-like kinases play an important role in mitotic spindle assembly and positioning.

Plankton abundance and feeding characteristics of Thysanoessa raschii from Godthabsfjord, Greenland

Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the Godthabsfjord (64°N, 51°W) SW Greenland, through a combination of fieldwork and laboratory experiments. Krill biomass was highest in the middle fjord and inner fjord, whereas no krill was found offshore. The dominating species Thysanoessa raschii revealed a type III functional response when fed with the diatom Thalassiosira weissflogii. At food saturation, T. raschii exhibited a daily ration of 1% body C/d. Furthermore, T. raschii was capable of exploiting plankton cells from 5 to 400 µm, covering several trophic levels of the pelagic food web. The calculated grazing impact by T. raschii on the fjord plankton community was negligible. However, the schooling and migratory behaviour of krill will concentrate and elevate the grazing in specific areas of the euphotic zone.

Feeding parameters of copepods from upwelling areas

Feeding patterns of mass herbivorous copepods in upwelling areas are investigated. Daily rations and aspects of their formation are examined in Calanoides carinatus (Benguela upwelling), Calanus pacificus (off the California coast), and Calanus australis (Peru upwelling). Rations were calculated based on gut plant pigment contents obtained at daily stations using laser spectrofluorometry, experimental data on the rate of gut evacuation and data on the carbon/chlorophyll ratio in phytoplankton and particulate matter at the respective stations. When phytoplankton was abundant, diel feeding rhythms were not pronounced and gut pigment level was high during the entire 24-h period. When phytoplankton biomass was low, distinct feeding rhythms were pronounced with a nocturnal maximum. During active upwelling intensive feeding on phytoplankton supports energy (respiration) and plastic (growth, development, reproduction, accumulation of reserves) metabolism of copepods. When upwelling was inactive, the surface part of the population feeds less actively and is able only partially to cover its energy expenditures. The actively growing and reproducing populations of C. pacificus and C. carinatus may consume close to 20% of primary production, whereas the inactive population of C. australis consumed only 0.2% of primary production when upwelling weakened.

Description of manganese nodules collected in a metamorphic limestone Cambrian formation near Philipsburg, Montana

In the Philipsburg district, in western Montana a low arch of a Paleozoic limestones has been cut and deformed on the east and a south sides by a small batholith of Tertiary granodiorite. The manganese deposits are confined to an area of about 2 square miles underlain by sedimentary rocks and adjacent to the granodiorite body. The ore, chiefly pyrolusite, was apparently derived from rhodochrosite that was abundant in the veins and had replaced the adjacent limestones. The oxide ore is found chiefly within 600 feet of the surface, though one small body was mined at a depth of 700 feet. Commonly these bodies are aggregates of nodules or spheroids that range in size from that of an egg to that of a coconut or larger. In some places they show an irregular texture somewhat like that of a sponge, and in others the material composing them is loose and friable and apparently structureless. Psilomelane is the principal constituent of many of the nodules, in which it forms layers that alternate with softer oxides.

Análisis de imágenes del rostro humano

El objetivo general de este trabajo es el correcto funcionamiento de un sistema de reconocimiento facial compuesto de varios módulos, implementados en distintos lenguajes. Uno de dichos módulos está escrito en Python y se encargarí de determinar el género del rostro o rostros que aparecen en una imagen o en un fotograma de una secuencia de vídeo. El otro módulo, escrito en C++, llevará a cabo el reconocimiento de cada una de las partes de la cara (ojos, nariz, boca) y la orientación hacia la que está posicionada (derecha, izquierda). La primera parte de esta memoria corresponde a la reimplementación de todas las partes de un analizador facial, que constituyen el primer módulo antes mencionado. Estas partes son un analizador, compuesto a su vez por un reconocedor (Tracker) y un procesador (Processor), y una clase visor para poder visualizar los resultados. Por un lado, el reconocedor o "Tracker.es el encargado de encontrar la cara y sus partes, que serán pasadas al procesador o Processor, que analizará la cara obtenida por el reconocedor y determinará su género. Este módulo estaba dise~nado completamente en C y OpenCV 1.0, y ha sido reescrito en Python y OpenCV 2.4. Y en la segunda parte, se explica cómo realizar la comunicación entre el primer módulo escrito en Python y el segundo escrito en C++. Además, se analizarán diferentes herramientas para poder ejecutar código C++ desde programas Python. Dichas herramientas son PyBindGen, Cython y Boost. Dependiendo de las necesidades del programador se contará cuál de ellas es más conveniente utilizar en cada caso. Por último, en el apartado de resultados se puede observar el funcionamiento del sistema con la integración de los dos módulos, y cómo se muestran por pantalla los puntos de interés, el género y la orientación del rostro utilizando imágenes tomadas con una cámara web.---ABSTRACT---The main objective of this document is the proper functioning of a facial recognition system composed of two modules, implemented in diferent languages. One of these modules is written in Python, and his purpose is determining the gender of the face or faces in an image or a frame of a video sequence. The other module is written in C ++ and it will perform the recognition of each of the parts of the face (eyes, nose , mouth), and the head pose (right, left).The first part of this document corresponds to the reimplementacion of all components of a facial analyzer , which constitute the first module that I mentioned before. These parts are an analyzer , composed by a tracke) and a processor, and a viewer to display the results. The tracker function is to find and its parts, which will be passed to the processor, which will analyze the face obtained by the tracker. The processor will determine the face's gender. This module was completely written in C and OpenCV 1.0, and it has been rewritten in Python and OpenCV 2.4. And in the second part, it explains how to comunicate two modules, one of them written in Python and the other one written in C++. Furthermore, it talks about some tools to execute C++ code from Python scripts. The tools are PyBindGen, Cython and Boost. It will tell which one of those tools is better to use depend on the situation. Finally, in the results section it is possible to see how the system works with the integration of the two modules, and how the points of interest, the gender an the head pose are displayed on the screen using images taken from a webcam.

The small GTP-binding protein Rho links G protein-coupled receptors and Gα12 to the serum response element and to cellular transformation

Receptors coupled to heterotrimeric G proteins can effectively stimulate growth promoting pathways in a large variety of cell types, and if persistently activated, these receptors can also behave as dominant-acting oncoproteins. Consistently, activating mutations for G proteins of the Gαs and Gαi2 families were found in human tumors; and members of the Gαq and Gα12 families are fully transforming when expressed in murine fibroblasts. In an effort aimed to elucidate the molecular events involved in proliferative signaling through heterotrimeric G proteins we have focused recently on gene expression regulation. Using NIH 3T3 fibroblasts expressing m1 muscarinic acetylcholine receptors as a model system, we have observed that activation of this transforming G protein-coupled receptors induces the rapid expression of a variety of early responsive genes, including the c-fos protooncogene. One of the c-fos promoter elements, the serum response element (SRE), plays a central regulatory role, and activation of SRE-dependent transcription has been found to be regulated by several proteins, including the serum response factor and the ternary complex factor. With the aid of reporter plasmids for gene expression, we observed here that stimulation of m1 muscarinic acetylcholine receptors potently induced SRE-driven reporter gene activity in NIH 3T3 cells. In these cells, only the Gα12 family of heterotrimeric G protein α subunits strongly induced the SRE, while Gβ1γ2 dimers activated SRE to a more limited extent. Furthermore, our study provides strong evidence that m1, Gα12 and the small GTP-binding protein RhoA are components of a novel signal transduction pathway that leads to the ternary complex factor-independent transcriptional activation of the SRE and to cellular transformation.

Mutagenesis of the human apolipoprotein B gene in a yeast artificial chromosome reveals the site of attachment for apolipoprotein(a).

Lipoprotein(a) [Lp(a)] is a lipoprotein formed by the disulfide linkage of apolipoprotein (apo) B100 of a low density lipoprotein particle to apolipoprotein(a). Prior studies have suggested that one of the C-terminal Cys residues of apo-B100 is involved in the disulfide linkage of apo-B100 to apo(a). To identify the apo-B100 Cys residue involved in the formation of Lp(a), we constructed a yeast artificial chromosome (YAC) spanning the human apo-B gene and used gene-targeting techniques to change Cys-4326 to Gly. The mutated YAC DNA was used to generate transgenic mice expressing the mutant human apo-B100 (Cys4326Gly). Unlike the wild-type human apo-B100, the mutant human apo-B100 completely lacked the ability to bind to apo(a) and form Lp(a). This study demonstrates that apo-B100 Cys-4326 is required for the assembly of Lp(a) and shows that gene targeting in YACs, followed by the generation of transgenic mice, is a useful approach for analyzing the structure of large proteins coded for by large genes.

A molecular sensor system based on genetically engineered alkaline phosphatase.

Binding and signaling proteins based on Escherichia coli alkaline phosphatase (AP; EC 3.1.3.1) were designed for the detection of antibodies. Hybrid proteins were constructed by using wild-type AP and point mutants of AP [Asp-101 --> Ser (D101S) and Asp-153 --> Gly (D153G)]. The binding function of the hybrid proteins is provided by a peptide epitope inserted between amino acids 407 and 408 in AP. Binding of anti-epitope antibodies to the hybrid proteins modulates the enzyme activity of the hybrids; upon antibody binding, enzyme activity can increase to as much as 300% of the level of activity in the absence of antibody or can decrease as much as 40%, depending on the presence or absence of the point mutations in AP. The fact that modulation is altered from inhibition to activation by single amino acid changes in the active site of AP suggests that the mechanism for modulation is due to structural alterations upon antibody binding. Modulation is a general phenomenon. The properties of the system are demonstrated by using two epitopes, one from the V3 loop of human immunodeficiency virus type 1 gp120 protein and one from hepatitis C virus core protein, and corresponding monoclonal antibodies. The trend of modulation is consistent for all hybrids; those in wild-type AP are inhibited by antibody, while those in the AP mutants are activated by antibody. This demonstrates that modulation of enzyme activity of the AP-epitope hybrid proteins is not specific to either a particular epitope sequence or a particular antibody-epitope combination.

Contribuições do direito norte-americano ao sistema de proteção do investidor no mercado de capitais brasileiro

O atual arcabouço normativo de proteção do investidor no mercado de capitais brasileiro teve suas linhas mestras cravadas pela reforma bancária introduzida pelas Leis 4.595, de 31 de dezembro de 1964, e 4.728, de 14 de julho de 1965, pela criação de um regulador especializado em mercado de capitais pela Lei 6.385, de 07 de dezembro de 1976, e pela reforma da legislação das sociedades anônimas introduzida pela Lei 6.404, de 15 de dezembro de 1976. Desde 1976, o arcabouço normativo de proteção do investidor no mercado de capitais brasileiro vem sendo desenvolvido a partir dessas linhas mestras iniciais, incorporando as lições aprendidas com as turbulências e euforias vividas pela economia nacional. Esse arcabouço normativo que aí está desde 1976 foi inspirado por contribuições do direito federal norte-americano, as quais foram conscientemente captadas no Brasil pelo legislador e pela comunidade jurídica nacional. Difundiram-se internacionalmente dos EUA para o Brasil os preceitos da proteção do investidor no mercado de capitais calcados na existência de um órgão regulador do mercado de capitais, na divulgação de informações relevantes para decisões de investimento (disclosure), na regulação funcional dos agentes do mercado de capitais e na vedação de fraudes com valores mobiliários.

Data compilation of marine pelagic organism biomasses, swimming velocities, clearance and respiration rates

Jellyfishes have functionally replaced several overexploited commercial stocks of planktivorous fishes. This is paradoxical, because they use a primitive prey capture mechanism requiring direct contact with the prey, whereas fishes use more efficient visual detection. We have compiled published data to show that, in spite of their primitive life-style, jellyfishes exhibit similar instantaneous prey clearance and respiration rates as their fish competitors and similar potential for growth and reproduction. To achieve this production, they have evolved large, water-laden bodies that increase prey contact rates. Although larger bodies are less efficient for swimming, optimization analysis reveals that large collectors are advantageous if they move through the water sufficiently slowly.

Identification of the nuclear localization signals within the Epstein-Barr virus EBNA-6 protein

Epstein-Barr virus nuclear antigen (EBNA)-6 is essential for EBV-induced immortalization of primary human B-lymphocytes in vitro. Previous studies have shown that EBNA-6 acts as a transcriptional regulator of viral and cellular genes; however at present, few functional domains of the 140 kDa EBNA-6 protein have been completely characterized. There are five computer-predicted nuclear localization signals (NLS), four monopartite and one bipartite, present in the EBNA-6 amino acid sequence. To identify which of these NLS are functional, fusion proteins between green fluorescent protein and deletion constructs of EBNA-6 were expressed in HeLa cells, Each of the constructs containing at least one of the NLS was targeted to the nucleus of cells whereas a construct lacking all of the NLS was cytoplasmic. Site-directed mutation of these NLS demonstrated that only three of the NLS were functional, one at the N-terminal end (aa 72-80), one in the middle (aa 412-418) and one at the C-terminal end (aa 939-945) of the EBNA-6 protein.

Increased expression of the MBP mRNA binding protein HnRNP A2 during oligodendrocyte differentiation

Heterogeneous nuclear ribonucleoprotein (hnRNP) A2, a trans-acting factor that mediates intracellular trafficking of myelin basic protein (MBP) mRNA to the myelin compartment in oligodendrocytes, is most abundant in the nucleus, but shuttles between the nucleus and cytoplasm. In the cytoplasm, it is associated with granules that transport mRNA from the cell body to the processes of oligodendrocytes. We found that the overall level of hnRNP A2 increased in oligodendrocytes as they differentiated into MBIP-positive cells, and that this augmentation was reflected primarily in the cytoplasmic pool of hnRNP A2 present in the form of granules. The extranuclear distribution of hnRNP A2 was also observed in brain during the period of myelination in vivo. Methylation and phosphorylation have been implicated previously in the nuclear to cytoplasmic distribution of hnRNPs, so we used drugs that block methylation and phosphorylation of hnRNPs to assess their effect on hnRNP A2 distribution and mRNA trafficking. Cultures treated with adenosine dialdehyde (AdOx), an inhibitor of S-adenosyl-L-homocysteine hydrolase, or with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), a drug that inhibits casein kinase 2 (CK2), maintained the preferential nuclear distribution of hnRNP A2. Treatment with either drug affected the transport of RNA trafficking granules that remained confined to the cell body. (C) 2004 Wiley-Liss, Inc.