Organization and chromosomal localization of the gene encoding the mouse acid labile subunit of the insulin-like growth factor binding complex.

After birth, most of insulin-like growth factor I and II (IGFs) circulate as a ternary complex formed by the association of IGF binding protein 3-IGF complexes with a serum protein called acid-labile subunit (ALS). ALS retains the IGF binding protein-3-IGF complexes in the vascular compartment and extends the t1/2 of IGFs in the circulation. Synthesis of ALS occurs mainly in liver after birth and is stimulated by growth hormone. To study the basis for this regulation, we cloned and characterized the mouse ALS gene. Comparison of genomic and cDNA sequences indicated that the gene is composed of two exons separated by a 1126-bp intron. Exon 1 encodes the first 5 amino acids of the signal peptide and contributes the first nucleotide of codon 6. Exon 2 contributes the last 2 nt of codon 6 and encodes the remaining 17 amino acids of the signal peptide as well as the 580 amino acids of the mature protein. The polyadenylylation signal, ATTAAA, is located 241 bp from the termination codon. The cDNA and genomic DNA diverge 16 bp downstream from this signal. Transcription initiation was mapped to 11 sites over a 140-bp TATA-less region. The DNA fragment extending from nt -805 to -11 (ATG, +1) directed basal and growth hormone-regulated expression of a luciferase reporter plasmid in the rat liver cell line H4-II-E. Finally, the ALS gene was mapped to mouse chromosome 17 by fluorescence in situ hybridization.

Pea formaldehyde-active class III alcohol dehydrogenase: common derivation of the plant and animal forms but not of the corresponding ethanol-active forms (classes I and P).

A plant class III alcohol dehydrogenase (or glutathione-dependent formaldehyde dehydrogenase) has been characterized. The enzyme is a typical class III member with enzymatic parameters and substrate specificity closely related to those of already established animal forms. Km values with the pea enzyme are 6.5 microM for NAD+, 2 microM for S-hydroxymethylglutathione, and 840 microM for octanol versus 9, 4, and 1200 microM, respectively, with the human enzyme. Structurally, the pea/human class III enzymes are closely related, exhibiting a residue identity of 69% and with only 3 of 23 residues differing among those often considered in substrate and coenzyme binding. In contrast, the corresponding ethanol-active enzymes, the long-known human liver and pea alcohol dehydrogenases, differ more (47% residue identities) and are also in functionally important active site segments, with 12 of the 23 positions exchanged, including no less than 7 at the usually much conserved coenzyme-binding segment. These differences affect functionally important residues that are often class-distinguishing, such as those at positions 48, 51, and 115, where the plant ethanol-active forms resemble class III (Thr, Tyr, and Arg, respectively) rather than the animal ethanol-active class I forms (typically Ser, His, and Asp, respectively). Calculations of phylogenetic trees support the conclusions from functional residues in subgrouping plant ethanol-active dehydrogenases and the animal ethanol-active enzymes (class I) as separate descendants from the class III line. It appears that the classical plant alcohol dehydrogenases (now called class P) have a duplicatory origin separate from that of the animal class I enzymes and therefore a paralogous relationship with functional convergence of their alcohol substrate specificity. Combined, the results establish the conserved nature of class III also in plants, and contribute to the molecular and functional understanding of alcohol dehydrogenases by defining two branches of plant enzymes into the system.

Escherichia coli exhibits negative chemotaxis in gradients of hydrogen peroxide, hypochlorite, and N-chlorotaurine: products of the respiratory burst of phagocytic cells.

Escherichia coli can respond to gradients of specific compounds, moving up gradients of attractants and down gradients of repellents. Stimulated phagocytic leukocytes produce H2O2, OCl-, and N-chlorotaurine in a response termed the respiratory burst. E. coli is actively repelled by these compounds. Catalase in the suspending medium eliminated the effect of H2O2. Repulsion by H2O2 could be demonstrated with 1 microM H2O2, which is far below the level that caused overt toxicity. Strains with defects in the biosynthesis of glutathione or lacking hydroperoxidases I and II retained this response to H2O2, and 2.0 mM CN- did not interfere with it. Mutants with defects in any one of the four known methyl-accepting chemotaxis proteins also retained the ability to respond to H2O2, but a "gutted" mutant that was deleted for all four methyl-accepting chemotaxis proteins, as well as for CheA, CheW, CheR, CheB, CheY, and CheZ, did not respond to H2O2. Hypochlorite and N-chlorotaurine were also strongly repellent. Chemotaxis down gradients of H2O2, OCl-, and N-chlorotaurine may contribute to the survival of commensal or pathogenic microorganisms.

Assignment of Rfp-Y to the chicken major histocompatibility complex/NOR microchromosome and evidence for high-frequency recombination associated with the nucleolar organizer region.

Rfp-Y is a second region in the genome of the chicken containing major histocompatibility complex (MHC) class I and II genes. Haplotypes of Rfp-Y assort independently from haplotypes of the B system, a region known to function as a MHC and to be located on chromosome 16 (a microchromosome) with the single nucleolar organizer region (NOR) in the chicken genome. Linkage mapping with reference populations failed to reveal the location of Rfp-Y, leaving Rfp-Y unlinked in a map containing >400 markers. A possible location of Rfp-Y became apparent in studies of chickens trisomic for chromosome 16 when it was noted that the intensity of restriction fragments associated with Rfp-Y increased with increasing copy number of chromosome 16. Further evidence that Rfp-Y might be located on chromosome 16 was obtained when individuals trisomic for chromosome 16 were found to transmit three Rfp-Y haplotypes. Finally, mapping of cosmid cluster III of the molecular map of chicken MHC genes (containing a MHC class II gene and two rRNA genes) to Rfp-Y validated the assignment of Rfp-Y to the MHC/NOR microchromosome. A genetic map can now be drawn for a portion of chicken chromosome 16 with Rfp-Y, encompassing two MHC class I and three MHC class II genes, separated from the B system by a region containing the NOR and exhibiting highly frequent recombination.

Identification of auxin-responsive elements of parB and their expression in apices of shoot and root.

Detailed analysis of transgenic tobaccos containing a series of chimeric parB promoter/beta-glucuronidase (GUS) gene constructs allowed us to define two auxin-responsive elements (AREs) of 48 bp and 95 bp (positions -210 to -163 and -374 to -280) in the parB promoter. The two AREs responded independently to physiological concentrations of auxin. Gel retardation assays revealed binding of nuclear protein(s) to the sequence conserved between ARE I and ARE II. The auxin responsiveness of the parB promoter did not mediate the pathway through the as-1 element and transcription factor ASF-1. AREs I and II were responsive to auxin at physiological concentrations, whereas as-1 responded only to higher concentrations of auxin which may be interpreted as stress, though as-1 had been reported to be a minimal ARE [Liu, X. & Lam, E. (1994) J. Biol. Chem. 269, 668-675]. Histochemical staining of transgenic tobacco that contained a parB promoter/GUS construct demonstrated the expression of GUS activity in the shoot apex as well as in the root tips, suggesting the involvement of parB expression in meristematic activity or differentiation. The drastic change in auxin responsiveness in the transgenic plants between the 6th and 10th day after imbibition of seeds implies the development or the activation of auxin signal transduction systems during plant development.

Proyecto RE-Sahara: taller cooperativo entre las asignaturas de Proyectos I, Estructuras II y Construcción III de la titulación de Arquitectura

Tras los sustanciales cambios en el plan de estudios actual debido a la futura implantación del nuevo Título de Grado de Arquitectura, es preciso dar cabida a metodologías docentes que potencien las habilidades y competencias específicas del arquitecto al tiempo que respondan a las prestaciones que demanda la sociedad de la Arquitectura. Por ello, se ha propuesto, en distintas asignaturas de la titulación, un taller multidisciplinar que engloba tres de las áreas de conocimiento fundamentales para el desarrollo del alumno de arquitectura como son Proyectos, Estructuras y Construcción. Con ejercicios de este tipo, se pretende contribuir a una mayor coordinación entre estas áreas con el fin de que los estudiantes no perciban la docencia fragmentada en disciplinas estancas. La metodología docente empleada ha consistido en la realización de un trabajo práctico común con un tema de carácter social, con el objetivo de involucrar a los futuros arquitectos en el desarrollo de propuestas reales. Trabajo supervisado mediante correcciones conjuntas con la participación del profesorado de las tres asignaturas de manera coordinada. En conclusión, el alumnado ha mostrado una preferencia mayoritaria por esta metodología docente ya que proporciona una visión conjunta entre asignaturas, englobadas en un único trabajo vinculado a la práctica profesional real.

Petri Artedi renovati pars I. et II. [III-V] : i.e. bibliotheca et philosophia ichthyologica / cura Iohannis Iulii Walbaumii.

v.1-2

Petri Artedi renovati pars I. et II. [III-V] : i.e. bibliotheca et philosophia ichthyologica / cura Iohannis Iulii Walbaumii.

v.3

Adolescent suicide attempts and adult adjustment

Background: Adolescent suicide attempts are disproportionally prevalent and frequently of low severity, raising questions regarding their long-term prognostic implications. In this study, we examined whether adolescent attempts were asso- ciated with impairments related to suicidality, psychopathology, and psychosocial functioning in adulthood (objective 1) and whether these impairments were better accounted for by concurrent adolescent confounders (objective 2). Method: Eight hundred and sixteen adolescents were assessed using interviews and question- naires at four time points from adolescence to adulthood. We examined whether lifetime suicide attempts in adolescence (by T2, mean age 17) predicted adult out- comes (by T4, mean age 30) using linear and logistic regressions in unadjusted models (objective 1) and adjusting for sociodemographic background, adolescent psychopathology, and family risk factors (objective 2). Results: In unadjusted analyses, adolescent suicide attempts predicted poorer adjustment on all outcomes, except those related to social role status. After adjustment, adolescent attempts remained predictive of axis I and II psychopathology (anxiety disorder, antisocial and borderline personality disorder symptoms), global and social adjustment, risky sex, and psychiatric treatment utilization. However, adolescent attempts no longer predicted most adult outcomes, notably suicide attempts and major depressive disorder. Secondary analyses indicated that associations did not differ by sex and attempt characteristics (intent, lethality, recurrence). Conclusions: Adolescent suicide attempters are at high risk of protracted and wide-ranging im- pairments, regardless of the characteristics of their attempt. Although attempts specifically predict (and possibly influence) several outcomes, results suggest that most impairments reflect the confounding contributions of other individual and family problems or vulnerabilites in adolescent attempters.

Dynamics of the Developing Chick Chorioallantoic Membrane Assessed by Stereology, Allometry, Immunohistochemistry and Molecular Analysis.

The chick chorioallantoic membrane (CAM) is a widely used model for the study of angiogenesis, tumour growth, as well as drug efficacy. In spite of this, little is known about the developmental alteration from its appearance to the time of hatching. In the current study the CAM has been studied by classical stereology and allometry. Expression levels of selected angiogenesis-related molecules were estimated by RT-PCR and cell dynamics assessed by proliferation and apoptosis assays. Absolute CAM volume increased from a low of 0.47 ± 0.11 cm3 at embryonic day 8 (E8) to a high of 2.05 ± 0.27 cm3 at E18, and then decreased to 1.6 ± 0.47 cm3 at E20. On allometric analysis, three growth phases were identifiable. Between E8-13 (phase I), the CAM grew fastest; moderately in phase II (E13-18) but was regressing in phase III (E18-20). The chorion, the mesenchyme and the allantoic layers grew fastest in phase I, but moderately in phase II. The mesenchyme grew slowly in phase III while the chorion and allantois were regressing. Chorionic cell volume increased fastest in phase I and was regressing in phase III. Chorionic capillaries grew steadily in phase I and II but regressed in phase III. Both the chorion and the allantois grew by intrinsic cell proliferation as well as recruitment of cells from the mesenchyme. Cell proliferation was prominent in the allantois and chorion early during development, declined after E17 and apoptosis started mainly in the chorion from E14. VEGFR2 expression peaked at E11 and declined steadily towards E20, VEGF peaked at E13 and E20 while HIF 1α had a peak at E11 and E20. Studies targeting CAM growth and angiogenesis need to take these growth phases into consideration.

Adolescent suicide attempts and adult adjustment

Background: Adolescent suicide attempts are disproportionally prevalent and frequently of low severity, raising questions regarding their long-term prognostic implications. In this study, we examined whether adolescent attempts were asso- ciated with impairments related to suicidality, psychopathology, and psychosocial functioning in adulthood (objective 1) and whether these impairments were better accounted for by concurrent adolescent confounders (objective 2). Method: Eight hundred and sixteen adolescents were assessed using interviews and question- naires at four time points from adolescence to adulthood. We examined whether lifetime suicide attempts in adolescence (by T2, mean age 17) predicted adult out- comes (by T4, mean age 30) using linear and logistic regressions in unadjusted models (objective 1) and adjusting for sociodemographic background, adolescent psychopathology, and family risk factors (objective 2). Results: In unadjusted analyses, adolescent suicide attempts predicted poorer adjustment on all outcomes, except those related to social role status. After adjustment, adolescent attempts remained predictive of axis I and II psychopathology (anxiety disorder, antisocial and borderline personality disorder symptoms), global and social adjustment, risky sex, and psychiatric treatment utilization. However, adolescent attempts no longer predicted most adult outcomes, notably suicide attempts and major depressive disorder. Secondary analyses indicated that associations did not differ by sex and attempt characteristics (intent, lethality, recurrence). Conclusions: Adolescent suicide attempters are at high risk of protracted and wide-ranging im- pairments, regardless of the characteristics of their attempt. Although attempts specifically predict (and possibly influence) several outcomes, results suggest that most impairments reflect the confounding contributions of other individual and family problems or vulnerabilites in adolescent attempters.

Sedimentological investigations and age model on sediment core PS2561-2

Benthic d13C values (F. wuellerstorfi), kaolinite/chlorite ratios and sortable silt median grain sizes in sediments of a core from the abyssal Agulhas Basin record the varying impact of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) during the last 200 ka. The data indicate that NADW influence decreased during glacials and increased during interglacials, in concert with the global climatic changes of the late Quaternary. In contrast, AABW displays a much more complex behaviour. Two independent modes of deep-water formation contributed to the AABW production in the Weddell Sea: 1) brine rejection during sea ice formation in polynyas and in the sea ice zone (Polynya Mode) and 2) super-cooling of Ice Shelf Water (ISW) beneath the Antarctic ice shelves (Ice Shelf Mode). Varying contributions of the two modes lead to a high millennial-scale variability of AABW production and export to the Agulhas Basin. Highest rates of AABW production occur during early glacials when increased sea ice formation and an active ISW production formed substantial amounts of deep water. Once full glacial conditions were reached and the Antarctic ice sheet grounded on the shelf, ISW production shut down and only brine rejection generated moderate amounts of deep water. AABW production rates dropped to an absolute minimum during Terminations I and II and the Marine Isotope Transition (MIS) 4/3 transition. Reduced sea ice formation concurrent with an enhanced fresh water influx from melting ice lowered the density of the surface water in the Weddell Sea, thus further reducing deep water formation via brine rejection, while the ISW formation was not yet operating again. During interglacials and the moderate interglacial MIS 3 both brine formation and ISW production were operating, contributing various amounts to AABW formation in the Weddell Sea.