Lipid exchange in crystal-confined fatty acid binding proteins: X-ray evidence and molecular dynamics explanation.

Fatty acid binding proteins (FABPs) are responsible for the long-chain fatty acids (FAs) transport inside the cell. However, despite the years, since their structure is known and the many studies published, there is no definitive answer about the stages of the lipid entry-exit mechanism. Their structure forms a ß -barrel of 10 anti-parallel strands with a cap in a helix-turn-helix motif, and there is some consensus on the role of the so-called portal region, involving the second α -helix from the cap ( α 2), ß C- ß D, and ß E- ß F turns in FAs exchange. To test the idea of a lid that opens, we performed a soaking experiment on an h-FABP crystal in which the cap is part of the packing contacts, and its movement is strongly restricted. Even in these conditions, we observed the replacement of palmitic acid by 2-Bromohexadecanoic acid (Br-palmitic acid). Our MD simulations reveal a two-step lipid entry process: (i) The travel of the lipid head through the cavity in the order of tens of nanoseconds, and (ii) The accommodation of its hydrophobic tail in hundreds to thousands of nanoseconds. We observed this even in the cases in which the FAs enter the cavity by their tail. During this process, the FAs do not follow a single trajectory, but multiple ones through which they get into the protein cavity. Thanks to the complementary views between experiment and simulation, we can give an approach to a mechanistic view of the exchange process.

Arginine-based surfactants alter the rheological and in-plane structural properties of stratum corneum model membranes.

HYPOTHESIS: Amino acid-based surfactants have been proposed as skin permeation enhancers. In this work, we investigated the potentiality of two arginine-based amphiphiles as permeation enhancers by studying their interaction with stratum corneum (SC) model lipid membranes. EXPERIMENTS: Nα-benzoyl arginine decyl- and dodecylamide were tested in comparison with the classical enhancer, oleic acid, and the non-enhancer, stearic acid. Two complementary approaches were used: lipid monolayers, taken as models of the unit film layer of SC, and atomistic molecular dynamics simulations. FINDINGS: The arginine-based amphiphiles studied were able to be incorporated into the SCM membrane and alter its rheological and structural properties by disordering the lipid chains, enhancing membrane elasticity, and thinning the overall membrane. They also affected the lateral structure of heterogeneous SC membranes at the nanoscale by relaxing and rounding the domain borders. Our work shows that the alteration observed of the overall rheological and structural properties of the SC membranes appears to be a shared ability for several amphiphilic permeation enhancers. Our results encourage future exploration of those amphiphiles as skin permeation enhancers.

What role do endogenous retroviruses play in domestic cats infected with feline leukaemia virus?

Feline leukaemia virus (FeLV) is a retrovirus that infects domestic and wild cats around the world. FeLV infection is associated with the development of neoplasms, bone marrow disorders and immunosuppression. Viral subgroups arise from mutations in the FeLV genome or from recombination of FeLV with ancestral endogenous retroviruses in the cat genome. The retroviral endogenisation process has allowed generation of a diversity of endogenous viruses, both functional and defective. These elements may be part of the normal functioning of the feline genome and may also interact with FeLV to form recombinant FeLV subgroups, enhance pathogenicity of viral subgroups, or inhibit and/or regulate other retroviral infections. Recombination of the env gene occurs most frequently and appears to be the most significant in terms of both the quantity and diversification of pathogenic effects in the viral population, as well as affecting cell tropism and types of disease that occur in infected cats. This review focuses on available information regarding genetic diversity, pathogenesis and diagnosis of FeLV as a result of the interaction between endogenous and exogenous viruses.

Genetic diversity of Chlamydia pecorum detected in sheep flocks from Mexico.

Chlamydia pecorum, an obligate intracellular bacterium, is associated with reproductive and systemic diseases in sheep, goats, pigs, cattle, and koalas. The main conditions include polyarthritis, conjunctivitis, enteritis, pneumonia, encephalomyelitis, orchitis, placentitis, and abortion. Even though there are several studies showing that C. pecorum infections are widely spread in the world, in Mexico there are no reports. During 2016, as part of a sheep restocking program in Mexico, sheep were imported from New Zealand. Briefly after their arrival in the herds in the State of Mexico, these sheep presented abortions during the last third of gestation. A total of 62 sheep vaginal swabs that had presented abortion from different municipalities of the State of Mexico were collected. Bacterial isolation was performed using L929 mouse fibroblasts, and molecular identification was achieved by 23S rRNA (Chlamydiaceae family) and ompA gene (species-specific) real-time polymerase chain reaction (PCR). In addition, the 16S rRNA subunit and ompA gene were amplified and sequenced. Seven of 62 samples were positive for C. pecorum by bacterial isolation, 23S rRNA, and ompA gene real-time PCR. The 16S rRNA subunit and ompA gene amplicons were purified and the nucleotide sequence was determined in both directions. The consensus sequences homology search was performed using BLASTn analysis and showed a 100% of homology with the C. pecorum 16S rRNA subunit and 99% with the C. pecorum ompA gene. The population structure analyses using ompA gene demonstrated 15 genetic populations or clusters of 198 sequences from GenBank and our sequences were in a particular genetic structure corresponding to genotype "O." Herein, we describe the presence of C. pecorum in sheep imported from New Zealand into Mexico. Genetic analysis of the ompA gene showed that the isolates belong to genotype O and are related to strains isolated from sheep, cattle, and koalas.

3D conformal bandpass millimeter-wave frequency selective surface with improved fields of view.

Conventional planar frequency selective surfaces (FSSs) are characterized in the far-field region and they are sensitive to the incidence angle of impinging waves. In this paper, a spherical dome FSS is presented, aiming to provide improved angular stable bandpass filtering performance as compared to its planar counterpart when the FSS is placed in the near-field region of an antenna source. A comparison between the conformal FSS and a finite planar FSS is presented through simulations at the frequency range between 26 to 40 GHz in order to demonstrate the advantages of utilizing the conformal FSS in the near-field. The conformal FSS is 3D printed and copper electroplated, which leads to a low-cost and lightweight bandpass filter array. Placing it in the near-field region of a primary antenna can be used as radomes to realize compact high-performance mm-wave systems. The comparison between simulated and measured conformal FSS results is in good agreement. The challenges that arise when designing, manufacturing, and measuring this type of structure are reported and guidelines to overcome these are presented.

Molecular dynamics simulation of the heart type fatty acid binding protein in a crystal environment.

Crystallographic data comes from a space-time average over all the unit cells within the crystal, so dynamic phenomena do not contribute significantly to the diffraction data. Many efforts have been made to reconstitute the movement of the macromolecules and explore the microstates that the confined proteins can adopt in the crystalline network. We explored different strategies to simulate a heart fatty acid binding protein (H-FABP) crystal by means of Molecular Dynamics (MD) simulations. We evaluate the effect of introducing restraints according to experimental isotropic B-factors and we analyzed the H-FABP motions in the crystal using Principal Component Analysis (PCA), isotropic and anisotropic B-factors. We compared the behavior of the protein simulated in the crystal confinement versus in solution, and we observed the effect of that confinement in the mobility of the protein residues. Restraining one-third of Cα atoms based on experimental B-factors produce lower B-factors than simulations without restraints, showing that the position restraint of the atoms with the lowest experimental B-factor is a good strategy to maintain the geometry of the crystal with an obvious decrease in the degrees of motion of the protein. PCA shows that, as position restraint reduces the conformational space explored by the system, the motion of the crystal is better recovered, for an essential subspace of the same size, in the simulations without restraints. Restraining only one Cα seems to be a good balance between giving flexibility to the system and preserving its structure. Communicated by Ramaswamy H. Sarma.

Study of duplicated galU genes in Rhodococcus jostii and a putative new metabolic node for glucosamine-1P in rhodococci.

BACKGOUND: Studying enzymes that determine glucose-1P fate in carbohydrate metabolism is important to better understand microorganisms as biotechnological tools. One example ripe for discovery is the UDP-glucose pyrophosphorylase enzyme from Rhodococcus spp. In the R. jostii genome, this gene is duplicated, whereas R. fascians contains only one copy. METHODS: We report the molecular cloning of galU genes from R. jostii and R. fascians to produce recombinant proteins RjoGalU1, RjoGalU2, and RfaGalU. Substrate saturation curves were conducted, kinetic parameters were obtained and the catalytic efficiency (kcat/Km) was used to analyze enzyme promiscuity. We also investigated the response of R. jostii GlmU pyrophosphorylase activity with different sugar-1Ps, which may compete for substrates with RjoGalU2. RESULTS: All enzymes were active as pyrophosphorylases and exhibited substrate promiscuity toward sugar-1Ps. Remarkably, RjoGalU2 exhibited one order of magnitude higher activity with glucosamine-1P than glucose-1P, the canonical substrate. Glucosamine-1P activity was also significant in RfaGalU. The efficient use of the phospho-amino-sugar suggests the feasibility of the reaction to occur in vivo. Also, RjoGalU2 and RfaGalU represent enzymatic tools for the production of (amino)glucosyl precursors for the putative synthesis of novel molecules. CONCLUSIONS: Results support the hypothesis that partitioning of glucosamine-1P includes an uncharacterized metabolic node in Rhodococcus spp., which could be important for producing diverse alternatives for carbohydrate metabolism in biotechnological applications. GENERAL SIGNIFICANCE: Results presented here provide a model to study evolutionary enzyme promiscuity, which could be used as a tool to expand an organism's metabolic repertoire by incorporating non-canonical substrates into novel metabolic pathways.

Antifungal activity of Euphorbia species against moulds responsible of cereal ear rots.

AIMS: This work aimed to identify secondary metabolites from aerial parts of Euphorbia species functional for control of toxigenic Fusarium species responsible of cereal grain rots. METHODS AND RESULTS: Aerial parts of Euphorbia serpens, Euphorbia schickendantzii and Euphorbia collina were sequentially extracted with hexane, ethyl acetate and methanol. The extracts were tested against strains of Fusarium verticillioides and Fusarium graminearum by microdilution tests. The hexane extract of E. collina provided the lowest IC50 s on both fungal species. Further fractionation showed that cycloartenol (CA) and 24-methylenecycloartanol are associated to the moderate inhibitory effect of the hexane extract on fungal growth.Sublethal concentrations of CA and 24MCA blocked deoxynivalenol (DON) and fumonisins production.CA and 24MCA co-applied with potassium sorbate, a food preservative used for Fusarium control, synergized the growth inhibition of fungi. The mixtures reduced mycotoxins accumulation when applied at sublethal concentrations. CONCLUSIONS: CA and 24MCA inhibited both fungal growth and mycotoxins production. This fact is an advantage respect to potassium sorbate which increased the mycotoxins accumulation at sublethal concentrations. SIGNIFICANCE AND IMPACT OF THE STUDY: CA and 24MCA synergized potassium sorbate and their mixtures offer a lower mycotoxigenic risk than potassium sorbate for control of the Fusarium species.

[Determinants of satisfaction with food-related life in older Chileans adults]. / Determinantes de la satisfacción con la alimentación en adultos mayores chilenos.

INTRODUCTION: The present study seeks to determine which demographic and behavioral factors affect satisfaction with food-related life in older Chilean adults. A questionnaire was applied to 785 older adults belonging to the adult centers of 30 communes in the Maule region, Chile. The questionnaires Satisfaction with Food-related Life, Satisfaction with Life Scale, Subjective Happiness Scale and independence in Activities of the Daily Life were applied. Sociodemographic characterization questions were included, in addition to questions about the consumption of eleven groups of foods and drinks at home, besides the expenses in restaurants. A descriptive analysis and logistic regression were performed, using statistical adjustment measures and collinearity diagnosis of the variables. In conclusion, the main factors positively related to a high satisfaction related to food are the female gender, being married or in a couple, greater perception of satisfaction with life and consumption of fish and wine. Good levels of commensality were determined in the three meals studied; consequently, reuniting the family and sharing daily can contribute positively to well-being. However, satisfaction with food was higher in rural areas than in urban areas and the group with the highest age (> 80 years) reported lower satisfaction with food when it was analyzed in a bivariable manner.

INTRODUCCIÓN: El presente trabajo busca determinar qué factores demográficos y conductuales inciden sobre la satisfacción con la vida relacionada con la alimentación de los adultos mayores (AM) de la región del Maule, Chile. Se aplicó un cuestionario a 785 AM pertenecientes a los Centros del Adulto Mayor de 30 comunas de la región del Maule, Chile. Se aplicaron los cuestionarios Satisfaction with Food-related Life, Satisfaction with Life Scale, Subjective Happiness Scale y cuestionario de independencia en Actividades de la Vida Diaria. Se incluyeron preguntas de caracterización sociodemográficas sobre el consumo de once grupos de alimentos y bebidas en el hogar, además de los gastos en restaurantes. Se realizó análisis descriptivo y regresión logística, utilizando medidas de ajuste estadístico y diagnóstico de colinealidad de las variables. En conclusión, los principales factores relacionados positivamente con una alta satisfacción relacionada con los alimentos son el sexo femenino, estar casado o en pareja, mayor percepción de satisfacción con la vida y el consumo de pescado y vino. Se determinaron buenos niveles de comensalidad en las tres comidas estudiadas. En consecuencia, reunir a la familia y compartir a diario puede contribuir positivamente al bienestar. Sin embargo, la satisfacción con la alimentación fue mayor en las áreas rurales que en las urbanas y el grupo con mayor edad (> 80 años) reportó menor satisfacción con la alimentación cuando fue analizado de forma bivariable.

Dispersion of Echinococcus granulosus eggs from infected dogs under natural conditions in Patagonia, Argentina.

Cystic echinococcosis caused by Echinococcus granulosus is a major zoonosis of public health significance in the Patagonian region of Argentina. This investigation sought to test the hypothesis that the persistence and dispersion of the parasite eggs can be explained by physical and meteorological parameters along with final host infection and behaviour. This observational study was carried out over a five-year period within an enclosure where two dogs harbouring a worm burden ranging from 100 to 1000 mature adult E. granulosus, as well as two uninfected dogs, had previously been kept for six months. Environmental canine faeces, topsoil, pond water, and sediment samples were examined to control for the presence of eggs and coproantigens of the parasite using microscope-based techniques and copro-ELISA plus copro-Western Blot tests. The parasite eggs were detected up to 41 months later in faeces from infected dogs, soil and sediment, and coproantigen tests remained positive for up to 70 months in faeces. Overall, parasite eggs were found within a maximum distance of 115 m from the contaminated dog faeces deposition site. Our findings indicate that under Patagonian environmental conditions, egg persistence and dispersion seem to be related to the worm burden and habits of the infected dog, to prevailing wind direction and to the existence of low bushes as well as natural bodies of water. The present study is the first to provide direct evidence of interaction between bioclimatic conditions and E. granulosus egg dispersion under Patagonian field conditions.

Progesterone in vitro increases growth, motility and progesterone receptor expression in third stage larvae of Toxocara canis.

The in vitro effect of progesterone in T. canis larvae on their enlargement and motility were evaluated, together to the possible presence of progesterone receptors (PRs). T. canis larvae were cultured in RPMI-1640 with different concentrations of progesterone (0, 20, 40, 80, 400 and 800 ng/mL). Enlargement and increases in motility were dependent on the concentration only from 0 to 80 ng/mL (p < 0.05). The mean percentage of PR + cells in newly obtained larvae as measured by flow cytometry was 8.16 ± 0.4. The number of PR + cells increased depending on concentration from 0 to 80 ng/mL (p < 0.001). Cells obtained from larvae stimulated at any of the studied hormone concentrations showed greater mean fluorescence intensity when compared to non-stimulated cells. Additionally, the expression and location of PR + cells were determined in the larvae. The sequence of an amplicon (420-bp) obtained by PCR from T. canis larvae showed 100% homology with a gene fragment that codes for the PR of the dog. PR + cells were immunolocated using confocal microscopy in the intestinal region of the larvae that had been recently obtained. The results of this study show that T. canis larvae can recognize and respond to the presence of progesterone through a molecule possibly able to bind it. Since we previously observed a similar response to prolactin, we suggest that both hormones could participate sequentially in the reactivation of T. canis larvae in pregnant bitches.

Concentrations of Mercury and Other Inorganic Ions in Wet Precipitation Collected from a Mountain Mining Zone and an Urban Area in Central Mexico.

We measured and compared mercury (Hg) and other ions in rainwater collected in San Joaquin (mining zone) and Juriquilla (urban area), central Mexico, from 2009 to 2012. A total of 274 rainwater samples were collected and analyzed for pH, electrical conductivity, [Formula: see text] Cl-, [Formula: see text] Na+, K+, Ca2+, Mg2+ and Hg. Mercury concentrations in rainwater varied from 24.21 to 248.89 (x-bar = 86.97 ± 10.77) µg L- 1 in San Joaquin (mining zone) and 11.26 to 176.91 (x-bar = 81.51 ± 10.24) µg L- 1 in Juriquilla (urban area). Rainwater sample were collected over periods 1-3 days, depending upon precipitation frequency. Significant correlations (p < 0.05) were found between [Formula: see text] Cl-, [Formula: see text] Na+, K+, Ca2+, Mg2+ and Hg at the San Joaquin site. Significant correlations were obtained between [Formula: see text] Na+, K+, Ca2+, Mg2+ and Hg at the Juriquilla site. In order to determine if there were significant differences among each measured parameter in rainwater collected in San Joaquin and Juriquilla, Kruskal-Wallis test was applied to data. We emphasized that the distribution and concentrations of Hg and the studied ions in rainwater samples were affected by atmospheric dust and local meteorological conditions of wind-speed and direction.

CARACTERIZACIÓN FISICOQUÍMICA DE OLEOGELES DE ACEITE DE AGUACATE (Persea americana) Y SACHA INCHI (Plukenetia volubilis) / PHYSICOCHEMICAL CHARACTERIZATION OF OLEOGELS OF AVOCADO OIL (Persea americana) AND SACHA INCHI (Plukenetia volubilis)

RESUMEN Debido a las consecuencias que presenta en la salud una dieta poco saludable y con gran contenido de grasas trans, se han desarrollado alternativas alimentarias para el cuidado de la salud, entre ellos, los alimentos naturales con el mínimo aporte de carbohidratos y de grasas saturadas. Por lo anterior, se propuso la formulación de oleogeles libre de grasas trans, a partir de emulsiones (w/o), usando aceite de aguacate y sacha inchi, estructurados con diferentes emulsificantes. Se consideró un diseño factorial 3x3, donde se varió el tipo de emulsificante: lecitina, monoesterato de glicerilo y la relación entre el aceite de aguacate y el aceite de sacha inchi para la fase oleosa del sistema oleoestructurado. Se obtuvo un producto con tintes verdosos y amarillos, cuya cromaticidad b* en sistema Cielab es afectado por el tipo de emulsificante, tomando tonalidades más amarillas, cuando se usa la mezcla lecitina-Monoesterato de glicerilo. Las formulaciones, con una relación de aceites 70/30 usando Lecitina, como emulsificante y la formulación con una relación de aceites 80/20 y usando Monoesterato de glicerilo, mostraron los mejores resultados en términos de fuerza firmeza, en contraste con las margarinas comerciales, cumpliendo con los requisitos fisicoquímicos, establecido en las normas vigentes para aceites y margarinas, como son: índice de peróxido (<10m-eq O2/kg de grasa), acidez (<0,8% de ácido oleico) y contenido de humedad (≥16% b.h).

SUMMARY Due to the health consequences of an unhealthy diet with a high content of trans fats, food alternatives for health care have been developed, including natural foods with the minimum amount of carbohydrates and saturated fats. Therefore, the formulation of oleogeles free of trans fats was proposed from (w/o) emulsion using avocado and sacha inchi oil and different emulsifiers. A 3x3 factorial design was used in which the type of emulsifier: lecithin, glyceryl monostearate and the ratio of avocado and sacha inchi oil was varied. A product was obtained with greenish and yellow dyes, whose chromaticity b* is affected by the type of emulsifier, taking more yellow tones when the lecithin-glyceryl monostearate mixture is used. Formulations with a 70/30 ratio of oils using Lecithin as an emulsifier agent and formulation with an 80/20 oil ratio and using glyceryl monostearate showed the best results in terms of firmness in contrast to commercial margarines, meeting the physico-chemical requirements established in the current standards for oils and margarines such as: peroxide value (<10m-eq O2/kg fat), acidity (<0.8% oleic acid) and moisture content (≥ 16% w.b).

Structural Basis of Outstanding Multivalent Effects in Jack Bean α-Mannosidase Inhibition.

Multivalent design of glycosidase inhibitors is a promising strategy for the treatment of diseases involving enzymatic hydrolysis of glycosidic bonds in carbohydrates. An essential prerequisite for successful applications is the atomic-level understanding of how outstanding binding enhancement occurs with multivalent inhibitors. Herein we report the first high-resolution crystal structures of the Jack bean α-mannosidase (JBα-man) in apo and inhibited states. The three-dimensional structure of JBα-man in complex with the multimeric cyclopeptoid-based inhibitor displaying the largest binding enhancements reported so far provides decisive insight into the molecular mechanisms underlying multivalent effects in glycosidase inhibition.

Pharmacist Adscription To Intensive Care: Generating Synergies. / Adscripción del farmacéutico a cuidados intensivos: generando sinergias.

OBJECTIVE: To evaluate incorporation of the hospital pharmacist to the routine activity of an Intensive Care Unit (ICU). DESIGN: A prospective observational study was carried out to evaluate the impact of pharmacist interventions, made by a pharmacist temporarily assigned to the ICU, upon medical prescriptions. SETTING: A medical and surgical ICU with 21 beds. PATIENTS: Patients with at least one ICU stay were included, while patients with admission and discharge in periods when the pharmacist was not present were excluded. INTERVENTIONS: The interventions were made after daily review of the prescriptions, and were communicated verbally or in writing to the supervising physician. MAIN VARIABLES: Number of interventions, therapeutic group of the drugs involved, type of intervention and degree of acceptance. RESULTS: A total of 194 interventions were made in 62 patients. The majority were related to safety aspects (33%) and the optimization of therapy (32%). The most frequent interventions were the administration of drugs via the nasogastric tube (19%) and pharmacokinetic monitoring (14.4%). The most frequently involved groups of drugs were anti-infectious agents (33%) and digestive system medications (27%). A total of 56.2% of the interventions were made verbally, and 80% were accepted. CONCLUSIONS: Pharmacist adscription to an ICU and the implementation of interventions on prescriptions have allowed improvement of safety and the optimization of pharmacotherapy in more than 50% of the patients. The high rate of acceptance of these interventions would support the implementation of such programs in critical care units.

Renal Transplantation in Second-Level Private Hospitals in the State of Mexico.

BACKGROUND: Kidney transplantation (KT) is the replacement therapy of choice in patients with end-stage renal disease (ESRD). Here we show a cohort of kidney transplant recipients from the period of May 1994 to May 2016 in 2 2nd-level private hospitals from the city of Toluca in the state of Mexico. METHODS: We checked the clinical files of all the patients that received KT in the period of study. RESULTS: We report 25 KT: 23 performed in Sanatorio Toluca and 2 in Sanatorio Florencia; 16 (64%) male and 9 (26%) female; mean age 36.03 ± 15.9 years (range, 10-66); 19 (76%) hemodialysis and 9 (24%) continuous ambulatory peritoneal dialysis before KT; ESRD etiology unknown in 16 (64%), diabetes in 5 (20%), IgA nephropathy in 2 (8%), and other in 2 (8%); living donors in 13 (52%) and deceased donors in 12 (48%); blood group 0+ in 18 (72%), A+ in 5 (20%), and B+ in 2 (8%); 21 (84%) with 0 and 4 (16%) with 1 HLA mismatch; and delayed graft function in 8 (32%), of which 7 were from deceased donors and 1 from a living donor. All 25 (100%) had a functional kidney at 1 year of follow-up. Immunosuppression regime consisted of multitarget maintenance therapy in all 25 (100%): cyclosporine in 18 (72%) and tacrolimus in 7 (28%). We used only methylprednisolone (MTP) as induction therapy. There were only 2 cases (8%) of acute rejection during the 1st 6 months of follow-up, and both responded to treatment with MTP. CONCLUSIONS: KT is the treatment of choice for patients with ESRD. The obtained results using only an MTP induction regime are satisfactory, with graft and patient survivals of 100% in the 1st year of follow-up.

Insights into the mechanisms of desiccation resistance of the Patagonian PAH-degrading strain Sphingobium sp. 22B.

AIM: To analyse the physiological response of Sphingobium sp. 22B to water stress. METHODS AND RESULTS: The strain was grown under excess of carbon source and then subjected to low (60RH) and high (18RH) water stress conditions for 96 h. Quantification of trehalose, glycogen, polyhydroxybutyrate (PHB) and transmission electron microscopy (TEM) was studied. Genes linked with desiccation were searched in Sphingobium sp. 22B and Sphingomonas 'sensu latu' genomes and their transcripts were quantified by real-time PCR. Results showed that, in the absence of water stress, strain 22B accumulated 4·76 ± 1·41% of glycogen, 0·84 ± 1·62% of trehalose and 44·9 ± 6·4% of PHB per cellular dry weight. Glycogen and trehalose were mobilized under water stressed conditions, this mobilization was significantly higher in 60RH in comparison to 18RH. Gene treY was upregulated sixfold in 60RH relative to control condition. TEM and quantification of PHB revealed that PHB was mobilized under 60RH condition accompanied by the downregulation of the phbB gene. TEM images showed an extracellular amorphous matrix in 18RH and 60RH. Major differences were found in the presence of aqpZ and trehalose genes between strain 22B and Sphingomonas genomes. CONCLUSION: Strain 22B showed a carbon conservative metabolism capable of accumulation of three types of endogenous carbon sources. The strain responds to water stress by changing the expression pattern of genes related to desiccation, formation of an extracellular amorphous matrix and mobilization of the carbon sources according to the degree of water stress. Trehalose, glycogen and PHB may have multiple functions in different degrees of desiccation. The robust endowment of molecular responses to desiccation shown in Sphingobium sp. 22B could explain its survival in semi-arid soil. SIGNIFICANCE AND IMPACT OF THE STUDY: Understanding the physiology implicated in the toleration of the PAH-degrading strain Sphingobium sp 22B to environmental desiccation may improve the bioaugmentation technologies in semi-arid hydrocarbon-contaminated soils.

A New Mexican Species of Orizabus Fairmaire (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini), with a Key to the Species of the Genus.

A new Orizabus species is described from Chilapa de Álvarez in the state of Guerrero (Mexico). The new species is similar to Orizabus rawlinsi Dechambre Bull Soc Entomol Fr 98:342, 1993, which is known from the state of Oaxaca but differs in the pygidial punctation, and the shape of the marginal pronotal bead and the parameres. A revised identification key to Orizabus species is provided.

Surfaceome profiling enables isolation of cancer-specific exosomal cargo in liquid biopsies from pancreatic cancer patients.

Background: Detection of circulating tumor DNA can be limited due to their relative scarcity in circulation, particularly while patients are actively undergoing therapy. Exosomes provide a vehicle through which cancer-specific material can be enriched from the compendium of circulating non-neoplastic tissue-derived nucleic acids. We carried out a comprehensive profiling of the pancreatic ductal adenocarcinoma (PDAC) exosomal 'surfaceome' in order to identify surface proteins that will render liquid biopsies amenable to cancer-derived exosome enrichment for downstream molecular profiling. Patients and methods: Surface exosomal proteins were profiled in 13 human PDAC and 2 non-neoplastic cell lines by liquid chromatography-mass spectrometry. A total of 173 prospectively collected blood samples from 103 PDAC patients underwent exosome isolation. Droplet digital PCR was used on 74 patients (136 total exosome samples) to determine baseline KRAS mutation call rates while patients were on therapy. PDAC-specific exosome capture was then carried out on additional 29 patients (37 samples) using an antibody cocktail directed against selected proteins, followed by droplet digital PCR analysis. Exosomal DNA in a PDAC patient resistant to therapy were profiled using a molecular barcoded, targeted sequencing panel to determine the utility of enriched nucleic acid material for comprehensive molecular analysis. Results: Proteomic analysis of the exosome 'surfaceome' revealed multiple PDAC-specific biomarker candidates: CLDN4, EPCAM, CD151, LGALS3BP, HIST2H2BE, and HIST2H2BF. KRAS mutations in total exosomes were detected in 44.1% of patients undergoing active therapy compared with 73.0% following exosome capture using the selected biomarkers. Enrichment of exosomal cargo was amenable to molecular profiling, elucidating a putative mechanism of resistance to PARP inhibitor therapy in a patient harboring a BRCA2 mutation. Conclusion: Exosomes provide unique opportunities in the context of liquid biopsies for enrichment of tumor-specific material in circulation. We present a comprehensive surfaceome characterization of PDAC exosomes which allows for capture and molecular profiling of tumor-derived DNA.

Progesterone inhibits the in vitro L3/L4 molting process in Haemonchus contortus.

We evaluated the direct effects of progesterone on the morphology, maturation and behavior of Haemonchus contortus larvae in vitro. The presence and location of possible progesterone receptors in these larvae were also determined. The addition of 8ng/mL of progesterone to larval cultures over 10days reduced larval enlargement, while the addition of 160ng/mL of the hormone increased the enlargement. Up to 62% and 65% of the H. contortus larvae molted from third-stage larvae (L3) to fourth-stage larvae (L4) when cultured in RPMI-1640 media without hormone for 5 and 10days, respectively. The addition of different progesterone concentrations (1, 8, 16, 80 and 160ng/mL) to the larval cultures significantly inhibited the molting process within the same periods. The addition of 8ng/mL or higher progesterone concentrations to the cultures significantly increased larval motility (p<0.05) compared with unstimulated larvae. Flow cytometry showed the expression of progesterone receptors (P4-R) in 15% of the cells from newly isolated H. contortus larvae. When the larvae were cultured for 5days in the presence of the hormone, the percentage of P4-R+ cells remained the same. In contrast, unstimulated larvae showed a significant reduction in the number of P4-R+ cells. Using confocal microscopy, a greater concentration of P4-Rs was immunolocated in the anterior portion of the alimentary tract of the larvae, suggesting that the cells in this region are targeted by the hormone. The results of the present study show that H. contortus larvae have possible P4-Rs and respond to this hormone by inhibiting their molting process, thereby suggesting the participation of progesterone in the larval arrest phenomenon.