Significance of structural chromosome aberrations in human sperm: analysis of induced aberrations

Summary A significant increase in the incidence of structural chromosome anomalies has been observed in the sperm of patients treated with radio and/or chemotherapy for different types of cancer when analyzed by the interspecific fertilization of hamster eggs. The analysis of these aberrations shows that while in controls only 9.4% of structural abnormalities are of the stable type, in treated patients this figure increases to 39.3%, thus indicating that the anomalies have not been produced during the fertilization of the hamster egg. However, it is possible that part, or even most, of the breaks appear as a result of a reduced repair capacity of sperm chromosomes in the cytoplasm of the hamster egg.     

Alkaloid synthesis is coupled to shoot morphogenesis in Argemone mexicana L. (Papaveraceae) in vitro cultures

During the induction process of an in vitro callus culture of Argemone mexicana L. (Papaveraceae), the levels of two benzylisoquinoline alkaloids known as berberine and sanguinarine displayed opposing trends. While the berberine levels steadily decreased from the initial explant stage up to the early proliferation of unorganized parenchymatous cell masses, the sanguinarine content increased. Once the callus culture was established, sanguinarine was the primary alkaloid present and berberine could no longer be detected. However, upon shoot regeneration, the berberine accumulation recovered, but sanguinarine was found in the newly formed leafy tissue. After root formation, sanguinarine was relocated to this organ, whereas berberine was evenly distributed between both tissues. Explants from stem internodes did not form callus, and berberine—plus sanguinarine—containing axillary shoots emerged from lateral buds in the induction medium. In contrast to callus-derived shoots, no root formation was observed. Therefore, alkaloid synthesis in A. mexicana in vitro cultures is related to the level of tissue organization in different ways, and while berberine accumulation seems to require the presence of differentiated organs, this is not the case for sanguinarine. Moreover, leafy parts of rootless shoots acquired the capacity to accumulate sanguinarine, which is usually absent in aerial tissues of mature plants. However, when these shoots were rooted, sanguinarine was mainly located in the newly formed roots, while berberine was detected in the shoots at similar levels found in the roots.

     

New species of Philocorydoras Suriano, 1986 (Monogenoidea: Dactylogyridae): Philocorydoras maltai n. sp., Philocorydoras beleniensis n. sp. and Philocorydoras alcantarai n. sp. from the gills of callichthyids (Siluriformes: Callichthyidae) from the Peruvian Amazonia

Systematic Parasitology - During a research on gills ectoparasites of callichthyids fishes from the Peruvian Amazonia, the following new monogenoideans species were recovered: Philocorydoras maltai...     

Metabolic Abnormalities Are Common among South American Hispanics Subjects with Normal Weight or Excess Body Weight: The CRONICAS Cohort Study

Objective

We aimed to characterize metabolic status by body mass index (BMI) status.

Methods

The CRONICAS longitudinal study was performed in an age-and-sex stratified random sample of participants aged 35 years or older in four Peruvian settings: Lima (Peru’s capital, costal urban, highly urbanized), urban and rural Puno (both high-altitude), and Tumbes (costal semirural). Data from the baseline study, conducted in 2010, was used. Individuals were classified by BMI as normal weight (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obese (≥30 kg/m²), and as metabolically healthy (0–1 metabolic abnormality) or metabolically unhealthy (≥2 abnormalities). Abnormalities included individual components of the metabolic syndrome, high-sensitivity C-reactive protein, and insulin resistance.

Results

A total of 3088 (age 55.6±12.6 years, 51.3% females) had all measurements. Of these, 890 (28.8%), 1361 (44.1%) and 837 (27.1%) were normal weight, overweight and obese, respectively. Overall, 19.0% of normal weight in contrast to 54.9% of overweight and 77.7% of obese individuals had ≥3 risk factors (p<0.001). Among normal weight individuals, 43.1% were metabolically unhealthy, and age ≥65 years, female, and highest socioeconomic groups were more likely to have this pattern. In contrast, only 16.4% of overweight and 3.9% of obese individuals were metabolically healthy and, compared to Lima, the rural and urban sites in Puno were more likely to have a metabolically healthier profile.

Conclusions

Most Peruvians with overweight and obesity have additional risk factors for cardiovascular disease, as well as a majority of those with a healthy weight. Prevention programs aimed at individuals with a normal BMI, and those who are overweight and obese, are urgently needed, such as screening for elevated fasting cholesterol and glucose.     

The Cell Division Protein FtsZ from Streptococcus pneumoniae Exhibits a GTPase Activity Delay

The cell division protein FtsZ assembles in vitro by a mechanism of cooperative association dependent on GTP, monovalent cations, and Mg²⁺. We have analyzed the GTPase activity and assembly dynamics of Streptococcus pneumoniae FtsZ (SpnFtsZ). SpnFtsZ assembled in an apparently cooperative process, with a higher critical concentration than values reported for other FtsZ proteins. It sedimented in the presence of GTP as a high molecular mass polymer with a well defined size and tended to form double-stranded filaments in electron microscope preparations. GTPase activity depended on K⁺ and Mg²⁺ and was inhibited by Na⁺. GTP hydrolysis exhibited a delay that included a lag phase followed by a GTP hydrolysis activation step, until reaction reached the GTPase rate. The lag phase was not found in polymer assembly, suggesting a transition from an initial non-GTP-hydrolyzing polymer that switches to a GTP-hydrolyzing polymer, supporting models that explain FtsZ polymer cooperativity.     

Evaluating the influence of off-shore cage aquaculture on the benthic ecosystem in Alghero Bay (Sardinia,Italy) using AMBI and M-AMBI

The impact of an off-shore fish farm in Alghero Bay (northwest Sardinia, Italy) on the benthic ecosystem was investigated in 2007 and 2008. In addition to studying the chemical and physical characteristics of the area (i.e., currents and sediment analyses), some biological analyses were also performed. The AZTI's Marine Biotic Index (AMBI) and the multivariate AMBI (M-AMBI) were calculated, which are being used in assessing the ecological status of benthic communities within the European Water Framework Directive (WFD). Clear impact gradients were detected according to both methods; they are related to farm production, prevailing currents, and characteristics of the area (i.e., water depth and distance to the cages). The site affected most was detected within 84 m from the cages; the area that no longer showed effects was over 907 m from the cages. The gradient is shown by decreasing AMBI values and percentage of opportunistic species and increasing richness, diversity, and the presence of sensitive species. This study highlights the importance of setting reference conditions for different areas when calculating M-AMBI. These reference conditions correspond to those in undisturbed sites in the opposite direction of the prevailing currents within the area.     

Biochemical characterization of ClpB3, a chloroplastic disaggregase from Arabidopsis thaliana

Plant Molecular Biology - The first biochemical characterization of a chloroplastic disaggregase is reported (Arabidopsis thaliana ClpB3). ClpB3 oligomerizes into active hexamers that resolubilize...     

Design,synthesis, and docking of highly hypolipidemic agents: Schizosaccharomyces pombe as a new model for evaluating α-asarone-based HMG-CoA reductase inhibitors

A series of α-asarone-based analogues was designed by conducting docking experiments with published crystal structures of human HMG-CoA reductase. Indeed, synthesis and evaluation of this series showed a highly hypocholesterolemic in vivo activity in a murine model, as predicted by previous docking studies. In agreement with this model, the polar groups attached to the benzene ring could play a key role in the enzyme binding and probably also in its biological activity, mimicking the HMG-moiety of the natural substrate. The hypolipidemic action mechanism of these compounds was investigated by developing a simple, efficient, and novel model for determining HMG-CoA reductase inhibition. The partial purification of the enzyme from Schizosaccharomyces pombe allowed for testing of α-asarone- and fibrate-based analogues, resulting in positive and significant inhibitory activity.