Oral Contraceptives,Depression, and Libido

Depression, headaches, and libido were rated in 272 women before starting a contraceptive method and at intervals during the first year of use—54 were fitted with an intrauterine device (I.U.D.) and 218 used one of three oral contraceptives. Side effects caused 25% of the oral contraceptive group and 13% of the I.U.D. group to stop the method. Depression, headaches, and loss of libido were the most common reasons for stopping oral contraceptives and breakthrough bleeding was the most common reason for stopping the I.U.D.The group of women who stopped or changed their oral contraceptives during the survey were compared with the group who remained on the same oral contraceptive throughout. The former had higher mean depression and neuroticism scores at the first clinic visit and contained more women with a history of premenstrual weepiness, depression during pregnancy, outpatient psychiatric treatment, and treatment with antidepressants. Changes in the depression, headache, and libido ratings throughout the survey are presented.     

Uterine stretch regulates temporal and spatial expression of fibronectin protein and its alpha 5 integrin receptor in myometrium of unilaterally pregnant rats

The adaptive growth of the uterus during pregnancy is a critical event that involves increased synthesis of extracellular matrix (ECM) proteins and dynamic remodeling of smooth muscle cell (SMC)-ECM interactions. We have previously found a dramatic increase in the expression of the mRNAs that encode fibronectin (FN) and its alpha5-integrin receptor (ITGA5) in pregnant rat myometrium near to term. Since the myometrium at term is exposed to considerable mechanical stretching of the uterine wall by the growing fetus(es), the objective of the present study was to examine its role in the regulation of FN and ITGA5 expression at late gestation and during labor. Using myometrial tissues from unilaterally pregnant rats, we investigated the temporal changes in Itga5 gene expression in gravid and empty uterine horns by Northern blotting and real-time PCR, in combination with immunoblotting and immunofluorescence analyses of the temporal/spatial distributions of the FN and ITGA5 proteins. In addition, we studied the effects of early progesterone (P4) withdrawal on Itga5 mRNA levels and ITGA5 protein detection. At all time-points examined, the Itga5 mRNA levels were increased in the gravid uterine horn, compared to the empty horn (P < 0.05). Immunoblot analysis confirmed higher ITGA5 and FN protein levels in the myometrium, associated with gravidity (P < 0.05). Immunodetection of ITGA5 was consistently high in the longitudinal muscle layer, increased with gestational age in the circular muscle layer of the gravid horn, and remained low in the empty horn. ITGA5 and FN immunostaining in the gravid horn exhibited a continuous layer of variable thickness associated directly with the surfaces of individual SMCs. In contrast to the effects of stretch, P4 does not appear to regulate ITGA5 expression. We speculate that the reinforcement of the FN-ITGA5 interaction: 1) contributes to myometrial hypertrophy and remodeling during late pregnancy; and 2) facilitates force transduction during the contractions of labor by anchoring hypertrophied SMCs to the uterine ECM.     

A complete conformational map for RNA.

A simple stereochemical framework for understanding RNA structure has remained elusive to date. We present a comprehensive conformational map for two nucleoside-5',3'-diphosphates and for a truncated dinucleotide derived from a grid search of all potential conformers using hard sphere steric exclusion criteria to define allowed conformers. The eight-dimensional conformational space is presented as a series of two-dimensional projections. These projections reveal several well-defined allowed and disallowed regions which correlate well with data obtained from X-ray crystallography of both large and small RNA molecules. Furthermore, the two-dimensional projections show that consecutive and ribose ring-proximal torsion angles are interdependent, while more distant torsion angles are not. Remarkably, using steric criteria alone, it is possible to generate a predictive conformational map for RNA.     

Brachypodium distachyon: making hay with a wild grass

Brachypodium distachyon is a wild grass with a short life cycle. Although it is related to small grain cereals such as wheat, its genome is only a fraction of the size. A draft genome sequence is currently available, and molecular and genetic tools have been developed for transformation, mutagenesis and gene mapping. Accessions collected from across its ancestral range show a surprising degree of phenotypic variation in many traits, including those implicated in domestication of the cereals. Thus, given its rapid cycling time and ease of cultivation, Brachypodium will be a useful model for investigating problems in grass biology.     

Fluctuation of microbial activities after influent load variations in a full-scale SBR: recovery of the biomass after starvation

Due to variations in the production levels, a full-scale sequencing batch reactor (SBR) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. In order to study how these changes affected the N-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. The recover capacity of the biomass was also studied in a lab-scale reactor operated with intermittent aeration without feeding for 36 days. The results showed that changes in the feeding negatively affected the nitrifying community, but the nitrogen removal efficiencies could be restored after the concentration stress. Species substitution was observed within the nitrifying bacteria, Nitrosomonas europaea and Nitrobacter predominated initially, and after an ammonia overload period, Nitrosomonas nitrosa and Nitrospira became dominant. Some denitrifiers, with nirS related to Alicycliphilus, Azospirillum, and Marinobacter nirS, persisted during long-term reactor operation, but the community fluctuated both in composition and in abundance. This fluctuating community may better resist the continuous changes in the feeding regime. Our results showed that a nitrifying–denitrifying SBR could be operated with low loads or even without feeding during production shut down periods.     

An InCytes from MBC Selection: The Mating-specific Gα Interacts with a Kinesin-14 and Regulates Pheromone-induced Nuclear Migration in Budding Yeast

As a budding yeast cell elongates toward its mating partner, cytoplasmic microtubules connect the nucleus to the cell cortex at the growth tip. The Kar3 kinesin-like motor protein is then thought to stimulate plus-end depolymerization of these microtubules, thus drawing the nucleus closer to the site where cell fusion and karyogamy will occur. Here, we show that pheromone stimulates a microtubule-independent interaction between Kar3 and the mating-specific Gα protein Gpa1 and that Gpa1 affects both microtubule orientation and cortical contact. The membrane localization of Gpa1 was found to polarize early in the mating response, at about the same time that the microtubules begin to attach to the incipient growth site. In the absence of Gpa1, microtubules lose contact with the cortex upon shrinking and Kar3 is improperly localized, suggesting that Gpa1 is a cortical anchor for Kar3. We infer that Gpa1 serves as a positional determinant for Kar3-bound microtubule plus ends during mating.     

QMEANclust: estimation of protein model quality by combining a composite scoring function with structural density information

Background  

The selection of the most accurate protein model from a set of alternatives is a crucial step in protein structure prediction both in template-based and ab initio approaches. Scoring functions have been developed which can either return a quality estimate for a single model or derive a score from the information contained in the ensemble of models for a given sequence. Local structural features occurring more frequently in the ensemble have a greater probability of being correct. Within the context of the CASP experiment, these so called consensus methods have been shown to perform considerably better in selecting good candidate models, but tend to fail if the best models are far from the dominant structural cluster. In this paper we show that model selection can be improved if both approaches are combined by pre-filtering the models used during the calculation of the structural consensus.     

Measurement of dietary exposure: a challenging problem which may be overcome thanks to metabolomics?

The diet is an important environmental exposure, and its measurement is an essential component of much health-related research. However, conventional tools for measuring dietary exposure have significant limitations being subject to an unknown degree of misreporting and dependent upon food composition tables to allow estimation of intakes of energy, nutrients and non-nutrient food constituents. In addition, such tools may be inappropriate for use with certain groups of people. As an alternative approach, the recent techniques of metabolite profiling or fingerprinting, which allows simultaneous monitoring of multiple and dynamic components of biological fluids, may provide metabolic signals indicative of food intake. Samples can be analysed through numerous analytical platforms, followed by multivariate data analysis. In humans, metabolomics has been applied successfully in pharmacology, toxicology and medical screening, but nutritional metabolomics is still in its infancy. Biomarkers of a small number of specific foods and nutrients have been developed successfully but less targeted and more high-throughput methods, that do not need prior knowledge of which signals might be discriminatory, and which may allow a more global characterisation of dietary intake, remain to be tested. A proof a principle project (the MEDE Study) is currently underway in our laboratories to test the hypothesis that high-throughput, non-targeted metabolite fingerprinting using flow injection electrospray mass spectrometry can be applied to human biofluids (blood and urine) to characterise dietary exposure in humans.