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Adenylyl cyclase (AC) signal transduction has been shown to be affected in Alzheimer's disease (AD). Deficits have been described in different components of the system, from the receptor to the effector level. [3H]forskolin is a diterpene that binds with high affinity to AC. In the present report, we used autoradiography to study [3H]forskolin binding to sections of entorhinal cortex and hippocampus from 23 cases staged for AD pathology according to Braak and Braak [Acta Neuropathol. 82 (1991) 239-259]. This protocol defines six stages according to neurofibrillary changes, which start in the entorhinal region (stages I-II), spread to the hippocampus (stages III-IV) and finally to the isocortical areas (stages V-VI). The amyloid classification includes three stages in which the basal isocortex is first affected (stage A), followed by other isocortical association areas (stage B) and finally the primary isocortical areas (stage C). We also studied the effects of the GTP-analogue Gpp[NH]p on binding, in order to detect changes in G-protein-AC coupling. We used two different concentrations of Gpp[NH]p, that were previously reported to inhibit and stimulate [3H]forskolin binding via Gi and Gs, respectively. Results showed that [3H]forskolin binding declined significantly with staging for neurofibrillary changes only in the entorhinal region (P0.05, ANOVA). In addition, the decrease in [3H]forskolin binding observed in the presence of 1 microM Gpp[NH]p diminished significantly with staging in the entorhinal region (P0.05, ANOVA). No significant changes were seen with amyloid staging, with the exception of the CA1 subfield of the hippocampus, where [3H]forskolin binding in the absence of Gpp[NH]p was significantly decreased at stage B compared with all other stages (P0.05, ANOVA). In conclusion, our results showed a very limited decrease in [3H]forskolin binding with the progression of AD pathology, suggesting that the AC levels may be largely preserved in the disease. The specific change in the effect of a low concentration of Gpp[NH]p on the binding could indicate the loss of Ca2+/calmodulin-sensitive AC isoforms in AD.

The effect of the GTP analogue guanylyl-5'-imidodiphosphate (Gpp[NH]p) on [3H]forskolin binding was studied in rat brain using autoradiography. In the striatum the presence of 100 microM Gpp[NH]p produced a 40% increase in binding, whereas a decrease of about 30% was observed with low Gpp[NH]p concentrations (0.1 microM). In the molecular layer of the cerebellum all concentrations of Gpp[NH]p decreased [3H]forskolin binding. The decrease in binding disappeared in both striatum and the molecular layer of cerebellum in sections pretreated with 100 microM N-ethylmaleimide (NEM) for 10 min. NEM pretreatment did not significantly affect the stimulation of [3H]forskolin binding by micromolar concentrations of Gpp[NH]p in the striatum, but reversed the decrease observed in the molecular layer of the cerebellum, to an increase. Based on these data we suggest that the effects of Gpp[NH]p on [3H]forskolin binding may involve both Gs and Gi, where stimulation produces an increase and decrease in binding, respectively. The regional effects of Gpp[NH]p may reflect differences in the responsiveness of adenylate cyclase to Gs- and Gi-mediated effects.

The molecular recognition of specific transfer RNAs by the appropriate aminoacyl-tRNA synthetase is an important step in determining the accuracy of translation of the genetic message from nucleic acids into proteins. Recent studies using variant tRNAs with specific sequence modifications have indicated particular regions that determine their identity. Here we consider whether the base modifications commonly found in tRNAs contribute to their identity. Although unmodified tRNA(Asp) is charged with aspartate as efficiently as the modified native tRNA, it is mischarged with arginine with considerably increased efficiency. Our results indicate that post-transcriptional modification of tRNAs introduces structural 'anti-determinants', restricting the efficiency with which the tRNAs are charged with inappropriate amino acids.

The effect of the GTP-analogue guanylyl 5'-imidodiphosphate (Gpp[NH]p) on [3H]forskolin binding was studied in rat brain using autoradiography. In the striatum, 100 microM Gpp[NH]p produced a 40% increase in binding, whereas a decrease of about 30% was observed with low Gpp[NH]p concentrations (0.1-1 microM). In the molecular layer of the cerebellum all concentrations of Gpp[NH]p decreased [3H]forskolin binding. The decrease in binding disappeared in both striatum and the molecular layer of cerebellum in sections pretreated with 100 microM N-ethylmaleimide (NEM) for 10 min. NEM pretreatment did not significantly affect the stimulation of [3H]forskolin binding by micromolar concentrations of Gpp[NH]p in the striatum, but reversed the decrease observed in the molecular layer of the cerebellum, to an increase. Based on these data we suggest that the effects of the GTP-analogue Gpp[NH]p on [3H]forskolin binding may involve both Gs and Gi, where a stimulation produces an increase and decrease in binding respectively. The regional effects of Gpp[NH]p may reflect differences in the responsiveness of adenylyl cyclase to Gs and Gi-mediated effects.

RESUMEN Se realizó un estudio retrospectivo de los resultados de 712 exámenes coproparasitológicos a los que se les había efectuado por el método de Burrows en el Hospital "San Juan de Dios", Illapel IV° Región, Chile, durante 1995. Los resultados fueron separados por edad, sexo, estación del año, ruralidad y especie. Al analizar los resultados se encontró que el 39,4% de los exámenes estaban infectados ya sea por enteroparásitos patógenos o comensales. No hubo diferencias den los resultados obtenidos en cuanto al sexo y las estaciones del año. Se encontró mayor porcentaje de infección en pacientes provenientes de zonas rurales 54% versus 36,9%. Se observó que el 12,8% de los de los individuos tenían infecciones con dos o más especies. Las tres especies más frecuentes fueron Blastocystis hominis (18,4%), Endolimax nana (10,5%) y Entamoeba coli (9,7%) y Enterobius vermicularis (15,4%). ENTEROPARASITES AT THE SAN JUAN DE DIOS HOSPITAL, ILLAPEL, CHILE, 1995 A retrospective study was performed in stool samples examined by Burrows method and Graham technique applid to 212 persons from Illapel,Chile ,during 1995. Infection by parasites and /or commensals was demostrated in 280(39.4%)stool samples. More positive stool sample was found in rural patient(54%) versus 36,9%. Two third part of stool was infected by one specie. The most frequent agent was Blastocystis hominis (184%), followed by Enterobius vermicularis (15.4%) Endolimax nana (10.5%) and finally Entamoeba coli (28.4%).

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TJ-II 1 is a medium size stellarator under construction in Madrid, Spain. Its major plasma radius is 1.5 m and its minor plasma dimensions are 0.2m by 0.4m. The toroidal magnetic field on the axis is IT. The bean shaped helical plasma is contained in a stainless steel vacuum vessel 2 with a total of 96 ports, including 8 manholes to have access to its interior. The vacuum vessel will be baked at 150 °C. Its complicated geometry along with the high tolerance requirements make this component a difficult manufacturing challenge.

Nox1 is a member of the NADPH Oxidase family which has not been well characterized in the melanocytic cell lineage. Here we demonstrated that Nox1 and Nox4 were detected in melanocytic lineage, with only Nox1 detected in normal human melanocytes and Nox4 in a subset of metastatic melanoma cell lines. The protein level and enzymatic activity of Nox1 was elevated in all melanoma cells as compared to normal melanocytes. Over-expression of GFP-Nox1 protein in Wm3211 primary melanoma cells increased invasion rate by 4-6 fold as measured by Matrigel invasion assay, while knocking down or inhibiting Nox1 decreased invasion by approximately 40 to 60%. MMP-2 was increased by Nox1 over-expression at the mRNA, protein and activity levels, and decreased by Nox1 knockdown. MMP-2 promoter activity was also regulated by Nox1 knockdown. In addition, stable clones over-expressing Nox1 exhibited an epithelial-mesenchymal transition (EMT) as examined by cell morphology and EMT markers; knockdown or inhibiting Nox1 led to a reversal of EMT. Supplementing MMP-2 to culture media did not induce EMT, suggesting that EMT induction by Nox1 was not through MMP-2 up-regulation. In summary, Nox1 was over-expressed in all melanoma cell lines examined, and enhanced cell invasion by MMP-2 up-regulation and EMT induction. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2418. doi:1538-7445.AM2012-2418

Chemical carcinogens such as the aromatic amide 2-acetylaminofluorene (AAF) are known to induce -1 frameshift mutation hotspots at repetitive sequences. This mutagenesis pathway was suggested to involve slipped intermediates formed during replication. To investigate the stability and structure of such intermediates we have constructed DNA duplexes containing single AAF adducts within a run of three guanine residues. The strand complementary to that bearing the AAF adducts contained either the wild-type sequence (homoduplexes) or lacked one cytosine directly opposite the run of guanines containing the AAF adduct and thus modeled the putative slipped mutagenic intermediates (SMIs). The melting temperature of AAF-modified homoduplexes or the unmodified SMI was reduced by approximately 10 degrees C relative to the unmodified homoduplex. Surprisingly, AAF adducts stabilized the SMIs as evidenced by an increase in melting temperature to a level approaching that of the unmodified homoduplex. The chemical probes hydroxylamine and bromoacetaldehyde were strongly reactive toward cytosine residues opposite the adduct in AAF-modified homoduplexes, indicating adduct-induced denaturation. In contrast, no cytosine reactivities were observed in the AAF-modified SMIs, suggesting that the two cytosines were paired with unmodified guanines. Use of diethyl pyrocarbonate to probe the guanine residues showed that all three guanines in the unmodified SMI adopted a transient single-stranded state which was delocalized along the repetitive sequence. However, when an AAF adduct was present, reduced diethyl pyrocarbonate reactivity at guanines adjacent to the adduct in AAF-modified SMIs reflected localization of the bulge to the adducted base. Our results suggest that AAF exerts a local denaturing and destabilizing effect within the homoduplex which is alleviated by the formation of a bulge. The stabilization by the AAF adduct of the SMIs may contribute to the dramatic increase in -1 frameshift mutation frequency induced by AAF adducts in repetitive sequences.

TJ-II is a medium-size stellarator of the heliac-type being under construction in Madrid, Spain. The project was granted EURATOM preferential support phase II in November 89 and is expected to start operation in 95. This device allows the exploration of a wide range of magnetic configurations. The rotational transform can be varied from 0.9 to 2.5. Shear variation is possible up to 10%. Theory predicts maximum beta values as high as 6%. The average major plasma radius is 1.5 m. The minor dimensions of the bean-shaped plasma are approximately 0.4 m by 0.2 m. Toroidal field: 1T. Pulse length: 0.2 s to 1 s. Pulse break: 5 min. Auxiliary heating: 400 kW ECRH at 53.2 GHz in stage I; 2 MW NBI will be added in stage II. In stage III 4 MW NBI heating is planned to be applied. The paper gives an overview on the technical features of the experiment, describes the main aspects of the recent engineering work and presents the status of the device.

explored the correlation of faculty members’ publication productivity to student-faculty ratios in colleges of pharmacy. These investigators also evaluated the influence of other factors, such as research funding, public vs. private university status, and supportive faculty members on scholarship. While these areas are important topics of investigation where additional insight would be welcomed, I would like to point out 2 potentially serious methodological errors in the study. These authors attempted to compile publication rates of colleges of pharmacy by searching PubMed. While there is insufficient detail in the article about how these searches were performed, it appears that the authors utilized the affiliation field of the MEDLINE database to search for individual schools and colleges. Unfortunately

Chemical footprinting experiments on brewer's yeast tRNA(Asp) complexed to its cognate aspartyl-tRNA synthetase are reported: they demonstrate that bases of the anticodon loop, including the anticodon itself, are in close proximity with the synthetase. Contacts were determined using dimethylsulfate as the probe for testing reactivity of guanine and cytosine residues in free and complexed tRNA. Results correlate with the decrease in aspartylation activity of yeast tRNA(Asp) molecules mutated at these contact positions and will be compared with other structural data arising from solution and crystallographic studies on the aspartic acid complex.