Microbiome analysis and bacterial isolation from Lejía Lake soil in Atacama Desert

Extremophiles - As a consequence of the severe climatic change affecting our entire world, many lakes in the Andes Cordillera are likely to disappear within a few decades. One of these lakes is...     

Cloning and sequencing of a 16S/23S ribosomal spacer from Haemophilus parainfluenzae reveals an invariant, mosaic-like organisation of sequence blocks

A 16S/23S ribosomal spacer from a Haemophilus parainfluenzae rrn locus was cloned and sequenced. Analysis of PCR-amplified genomic fragments showed that this region is strongly conserved among unrelated isolates; computer analysis of database homologies showed that the spacer consists of sequence blocks, arranged in a mosaic-like structure, with strong homologies with analogous blocks present in the spacer regions of Haemophilus influenzae, Haemophilus ducreyi and Actinobacillus spp. It also contains a tRNA^Glu gene, which is highly homologous to tRNA^Glu genes found in spacers of other species. These data strongly support the hypothesis that recombination events are involved in the organisation of the sequence of the spacer, as a result of horizontal gene transfer.     

Paradoxical relationship between speed and accuracy in olfactory figure-background segregation

In natural settings, many stimuli impinge on our sensory organs simultaneously. Parsing these sensory stimuli into perceptual objects is a fundamental task faced by all sensory systems. Similar to other sensory modalities, increased odor backgrounds decrease the detectability of target odors by the olfactory system. The mechanisms by which background odors interfere with the detection and identification of target odors are unknown. Here we utilized the framework of the Drift Diffusion Model (DDM) to consider possible interference mechanisms in an odor detection task. We first considered pure effects of background odors on either signal or noise in the decision-making dynamics and showed that these produce different predictions about decision accuracy and speed. To test these predictions, we trained mice to detect target odors that are embedded in random background mixtures in a two-alternative choice task. In this task, the inter-trial interval was independent of behavioral reaction times to avoid motivating rapid responses. We found that increased backgrounds reduce mouse performance but paradoxically also decrease reaction times, suggesting that noise in the decision making process is increased by backgrounds. We further assessed the contributions of background effects on both noise and signal by fitting the DDM to the behavioral data. The models showed that background odors affect both the signal and the noise, but that the paradoxical relationship between trial difficulty and reaction time is caused by the added noise.     

The genus Mantisalca (Asteraceae) in southwest Europe

The diversity of the genus Mantisalca in southwest Europe is the subject of much controversy. The present taxonomic revision of the genus on the Iberian Peninsula allows four species to be recognized, whose morphological variability is described and various synonyms are typified. A new species is described, M. cabezudoi Ruiz de Clavijo and Devesa, endemic to southeast Spain. The name Microlonchus spinulosus Rouy is reinstated for a species endemic to the central and east Iberian Peninsula, for which a new combination is made: Mantisalca spinulosa (Rouy) Ruiz de Clavijo and Devesa. A diagnostic key to the taxa is given.     

Preclinical Demonstration of Synergistic Active Nutrients/Drug (AND) Combination as a Potential Treatment for Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a poor prognosis disease lacking adequate therapy. We have previously shown that ascorbic acid administration is toxic to MPM cells. Here we evaluated a new combined therapy consisting of ascorbate/epigallocatechin-3-gallate/gemcitabine mixture (called AND, for Active Nutrients/Drug). In vitro effects of AND therapy on various MPM cell lines revealed a synergistic cytotoxic mechanism. In vivo experiments on a xenograft mouse model for MPM, obtained by REN cells injection in immunocompromised mice, showed that AND strongly reduced the size of primary tumor as well as the number and size of metastases, and prevented abdominal hemorrhage. Kaplan Meier curves and the log-rank test indicated a marked increase in the survival of AND-treated animals. Histochemical analysis of dissected tumors showed that AND induced a shift from cell proliferation to apoptosis in cancer cells. Lysates of tumors from AND-treated mice, analyzed with an antibody array, revealed decreased TIMP-1 and -2 expressions and no effects on angiogenesis regulating factors. Multiplex analysis for signaling protein phosphorylation exhibited inactivation of cell proliferation pathways. The complex of data showed that the AND treatment is synergistic in vitro on MPM cells, and blocks in vivo tumor progression and metastasization in REN-based xenografts. Hence, the AND combination is proposed as a new treatment for MPM.     

Erectile Dysfunction and Essential Hypertension: The Same Aging-related Disorder?

An erection is a mechanical event dependent primarily on corporeal vascular dynamics wherein arterial inflow and storage of blood within the corpora is greater than the egress of blood from the corpora. The most common cause of erectile dysfunction (ED) is the inability of the corporal tissue to store the blood within the corporal sinusoids once inflow into the corpora begins. This failure to store is primarily due to a corporal smooth muscle dysfunction and, in most men, is most likely an aging-related occurrence. Because the corporal smooth muscle is embryologically and physiologically indistinguishable from the smooth muscle within our arterial system, the authors hypothesize that the aging-related dysfunction that occurs within the penis also occurs within the arterial system, and that this smooth muscle dysfunction within the arterial media is most likely the cause of what is called essential hypertension. This panvascular smooth muscle myopathy could explain why hypertension is the most common comorbidity associated with ED and appears to indicate that both ED and essential hypertension are the same disorder, albeit in two different organ systems.Key words: Erection, Endothelium, Smooth muscle, HypertensionAlmost all men recognize at some time in their lives that their erectile function begins to change. For most men, the ability to attain and maintain an erection during the teenage years is second nature. However, by the time men hit the fourth and fifth decade of life, many have recognized that their erectile function has changed, and the ability to maintain an erection during sex has diminished; the refractory period, the time in between erectile events, begins to increase. Although men in their teenage years and young adult lives are able to have multiple erectile events at will, this ability begins to fade as aging sets in. Because the ability to maintain an erection is directly related to the function of the corporal smooth muscle, this increase in the refractory period is a clinical sign that the smooth muscle of the corpora is likely becoming dysfunctional. This review highlights what we know about the corporal smooth muscle cell and demonstrates that what occurs to the corporal smooth muscle cell also occurs to its embryologic sibling, the smooth muscle cell within the media of the peripheral vascular system. As a result of this relationship, changes in the function of the penis can reflect changes in the vascular system.     

Co-localization of susceptibility loci for psoriasis (PSORS4) and atopic dermatitis (ATOD2) on human chromosome 1q21

Psoriasis (PS) is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation and altered differentiation. Atopic dermatitis (ATOD) is a chronic inflammatory, pruritic and eczematous disease frequently associated with respiratory atopy. These diseases are associated with distinct immunologic abnormalities and represent typical examples of complex diseases triggered by both genetic and environmental factors, as demonstrated by independent twin studies. Genome wide linkage studies have mapped susceptibility loci on several chromosomes (PSORS1-9; ATOD1-5). Four of them overlap on chromosomes 1q21, 3q21, 17q25 and 20p although ATOD is quite distinct from PS and these two diseases rarely occur together in the same patient. An association fine-mapping study has been performed to refine PSORS4 and ATOD2 susceptibility loci on chromosome 1q21 analyzing two independently collected cohorts of 128 PS and 120 ATOD trios. Genotype and haplotype analysis of PSORS4 and ATOD2 led us to detect significant p value for haplotypes defined by MIDDLE and ENDAL16 markers in both PS (p = 0.0000036) and ATOD (p = 0.0276), suggesting a strict co-localization within an interval of 42 kb. This genomic interval contains a single gene, LOR, encoding for loricrin. Polymorphic markers mapping in regulatory and coding regions did not show evidence of association in neither of the two diseases. However, expression profiles of LOR in skin biopsies have shown reduced levels in PS and increased levels in ATOD, suggesting the existence of a specific misregulation in LOR mRNA production.     

Fluorescence in situ hybridization mapping of six loci containing genes involved in the dioxin metabolism of domestic bovids

Six loci containing genes involved in the dioxin metabolism (ARNT, AHR, CYP1A1, CYP1A2, CYP1B1 and AHRR) were assigned, for the first time, to cattle (Bos taurus, 2n = 60, BTA), river buffalo (Bubalus bubalis, 2n = 50, BBU), sheep (Ovis aries, 2n = 54, OAR) and goat (Capra hircus, 2n = 60, CHI) chromosomes by comparative FISH-mapping and R-banding using bovine BAC-clones. The following chromosome locations were found: ARNT to BTA3q21, BBU6q21, OAR1p21 and CHI3q21, AHR to BTA4q15, BBU8q15, OAR4q15 and CHI4q15; CYP1A1 and CYP1A2 to BTA21q17, BBU20q17, OAR18q17 and CHI21q17; CYP1B1 to BTA11q16, BBU12q22, OAR3p16 and CHI11q16, AHRR to BTA20q24, BBU19q24, OAR16q24 and CHI20q24. All loci were mapped at the same homoeologous chromosomes and chromosome bands of the four bovid species. Comparisons with corresponding human locations were also reported.     

Regulation of autophagosome biogenesis by OFD1‐mediated selective autophagy

Autophagy is a lysosome‐dependent degradation pathway essential to maintain cellular homeostasis. Therefore, either defective or excessive autophagy may be detrimental for cells and tissues. The past decade was characterized by significant advances in molecular dissection of stimulatory autophagy inputs; however, our understanding of the mechanisms that restrain autophagy is far from complete. Here, we describe a negative feedback mechanism that limits autophagosome biogenesis based on the selective autophagy‐mediated degradation of ATG13, a component of the ULK1 autophagy initiation complex. We demonstrate that the centrosomal protein OFD1 acts as bona fide autophagy receptor for ATG13 via direct interaction with the Atg8/LC3/GABARAP family of proteins. We also show that patients with Oral‐Facial‐Digital type I syndrome, caused by mutations in the OFD1 gene, display excessive autophagy and that genetic inhibition of autophagy in a mouse model of the disease, significantly ameliorates polycystic kidney, a clinical manifestation of the disorder. Collectively, our data report the discovery of an autophagy self‐regulated mechanism and implicate dysregulated autophagy in the pathogenesis of renal cystic disease in mammals.