Ecological and phenotypic divergence in Iberian shrews (Soricidae)

There are examples of coexisting species with similar morphology and ecology, in apparent contradiction to competition theory. Shrews (Soricidae) are a paradigmatic example of this because members of this group exhibit a conserved body form, relatively low variability in lifestyle, and, in many cases, a sympatric distribution. Here, we combined geometric morphometrics and ecological niche modeling to test whether diversification of soricid species inhabiting the Iberian Peninsula has been driven by niche divergence or, conversely, whether niche conservatism has played a paramount role in this process. We also examined whether pairwise morphological distances increase as the degree of niche overlap between species becomes greater, as would be expected if interspecific competition promotes morphological differentiation. Our results showed that water shrews (Neomys), white‐toothed shrews (Crocidurinae), and red‐toothed shrews (Soricinae) are clearly differentiated in terms of both skull shape and mandible shape. However, we found a lack of phylogenetic signal in most morphological traits, indicating that closely related species are not more similar than expected by random chance. Notably, water shrews show a more “triangular” or sharp skull than white‐toothed and red‐toothed shrews, probably as an adaptation to their semiaquatic lifestyle. In agreement with the phenotypic data, climatic traits (mean annual temperature and annual precipitation) were highly labile and sister taxa showed extensive differentiation in their realized niche space. Finally, we found that phenotypic distances between species tend to increase as the degree of niche overlap increases, suggesting that interspecific competition is an important factor in determining the level of morphological resemblance among relatives. Overall, our results indicate that the existence of limited morphological disparity in a given group does not necessarily imply the existence of a niche conservatism signature.     

Characterization of heterotrophic growth and sesquiterpene production by Rhodobacter sphaeroides on a defined medium

Rhodobacter sphaeroides is a metabolically versatile bacterium capable of producing terpenes natively. Surprisingly, terpene biosynthesis in this species has always been investigated in complex media, with unknown compounds possibly acting as carbon and nitrogen sources. Here, a defined medium was adapted for R. sphaeroides dark heterotrophic growth, and was used to investigate the conversion of different organic substrates into the reporter terpene amorphadiene. The amorphadiene synthase was cloned in R. sphaeroides, allowing its biosynthesis via the native 2-methyl-d-erythritol-4-phosphate (MEP) pathway and, additionally, via a heterologous mevalonate one. The latter condition increased titers up to eightfold. Consequently, better yields and productivities to previously reported complex media cultivations were achieved. Productivity was further investigated under different cultivation conditions, including nitrogen and oxygen availability. This novel cultivation setup provided useful insight into the understanding of terpene biosynthesis in R. sphaeroides, allowing to better comprehend its dynamics and regulation during chemoheterotrophic cultivation.

     

SH3‐class Ras guanine nucleotide exchange factors are essential for Aspergillus fumigatus invasive growth

Proper hyphal morphogenesis is essential for the establishment and progression of invasive disease caused by filamentous fungi. In the human pathogen Aspergillus fumigatus, signalling cascades driven by Ras and Ras‐like proteins orchestrate a wide variety of cellular processes required for hyphal growth. For activation, these proteins require interactions with Ras‐subfamily‐specific guanine nucleotide exchange factors (RasGEFs). Although Ras‐protein networks are essential for virulence in all pathogenic fungi, the importance of RasGEF proteins is largely unexplored. A. fumigatus encodes four putative RasGEFs that represent three separate classes of RasGEF proteins (SH3‐, Ras guanyl nucleotide‐releasing protein [RasGRP]–, and LTE‐class), each with fungus‐specific attributes. Here, we show that the SH3‐class and RasGRP‐class RasGEFs are required for properly timed polarity establishment during early growth and branch emergence as well as for cell wall stability. Further, we show that SH3‐class RasGEF activity is essential for polarity establishment and maintenance, a phenotype that is, at least, partially independent of the major A. fumigatus Ras proteins, RasA and RasB. Finally, loss of both SH3‐class RasGEFs resulted in avirulence in multiple models of invasive aspergillosis. Together, our findings suggest that RasGEF activity is essential for the integration of multiple signalling networks to drive invasive growth in A. fumigatus.     

Cross-linked enzyme aggregates of recombinant Candida antarctica lipase B for the efficient synthesis of olvanil,a nonpungent capsaicin analogue

Despite the proven therapeutic role of capsaicin in human health, its usage is still hampered by its high pungency. In this sense, nonpungent capsaicin analogues as olvanil are a feasible alternative to the unpleasant sensations produced by capsaicin while maintaining a similar pharmacological profile. Olvanil can be obtained by a lipase-catalyzed chemoenzymatic process. In the present work, recombinant Candida antarctica lipase B (CALB) was expressed in Pichia pastoris and subsequently immobilized by cross-linked enzyme aggregate (CLEA) methodology for the synthesis of olvanil. The CALB-CLEAs were obtained directly from the fermentation broth of P. pastoris without any purification step in order to assess the role of the contaminant proteins of the crude extract as co-feeders. The CALB-CLEAs were also bioimprinted to enhance the catalytic performance in olvanil synthesis. When CALB was precipitated with isopropanol, the obtained CALB-CLEAs exhibited the highest activity in the synthesis of olvanil, regardless of the glutaraldehyde concentration. The maximum product synthesis was found at 72 hr obtaining 6.8 g L⁻¹ of olvanil with a reaction yield of 16%. When CALB was bioimprinted with olvanil, the synthesis was enhanced 1.3 times, reaching 10.7 g L⁻¹ of olvanil at 72 hr of reaction with a reaction yield of 25%. Scanning electron microscopy images indicated different morphologies of the CLEAs depending on the precipitating agent and the template used for bioimprinting. Recombinant CALB-CLEAs obtained directly from the fermentation broth are a suitable alternative to commercial enzymatic preparations for the synthesis of olvanil in organic medium.     

Generation of intra- and interspecific Saccharomyces hybrids with improved oenological and aromatic properties

Non-wine yeasts could enhance the aroma and organoleptic profile of wines. However, compared to wine strains, they have specific intolerances to winemaking conditions. To solve this problem, we generated intra- and interspecific hybrids using a non-GMO technique (rare-mating) in which non-wine strains of S. uvarum, S. kudriavzevii and S. cerevisiae species were crossed with a wine S. cerevisiae yeast. The hybrid that inherited the wine yeast mitochondrial showed better fermentation capacities, whereas hybrids carrying the non-wine strain mitotype reduced ethanol levels and increased glycerol, 2,3-butanediol and organic acid production. Moreover, all the hybrids produced several fruity and floral aromas compared to the wine yeast: β-phenylethyl acetate, isobutyl acetate, γ-octalactone, ethyl cinnamate in both varietal wines. Sc × Sk crosses produced three- to sixfold higher polyfunctional mercaptans, 4-mercapto-4-methylpentan-2-one (4MMP) and 3-mercaptohexanol (3MH). We proposed that the exceptional 3MH release observed in an S. cerevisiae × S. kudriavzevii hybrid was due to the cleavage of the non-volatile glutathione precursor (Glt-3MH) to detoxify the cell from the presence of methylglyoxal, a compound related to the high glycerol yield reached by this hybrid. In conclusion, hybrid generation allows us to obtain aromatically improved yeasts concerning their wine parent. In addition, they reduced ethanol and increased organic acids yields, which counteracts climate change effect on grapes.     

Hepatocytes--the choice to investigate drug metabolism and toxicity in man: in vitro variability as a reflection of in vivo

The pharmaceutical industry is committed to marketing safer drugs with fewer side effects, predictable pharmacokinetic properties and quantifiable drug-drug interactions. Drug metabolism is a major determinant of drug clearance and interindividual pharmacokinetic differences, and an indirect determinant of the clinical efficacy and toxicity of drugs. Progressive advances in the knowledge of metabolic routes and enzymes responsible for drug biotransformation have contributed to understanding the great metabolic variations existing in human beings. Phenotypic as well genotypic differences in the expression of the enzymes involved in drug metabolism are the main causes of this variability. However, only a minor part of phenotypic variability in man is attributable to gene polymorphisms, thus making the definition of a normal liver complex. At present, the use of human in vitro hepatic models at early preclinical stages means that the process of selecting drug candidates is becoming much more rational. Cultured human hepatocytes are considered to be the closest model to human liver. However, the fact that hepatocytes are located in a microenvironment that differs from that of the cell in the liver raises the question: to what extent does drug metabolism variability observed in vitro actually reflect that of the liver in vivo? By comparing the metabolism of a model compound both in vitro and in vivo in the same individual, a good correlation between the in vitro and in vivo relative abundance of oxidized metabolites and the hydrolysis of the compound was observed. Thus, it is reasonable to consider that the variability observed in human hepatocytes reflects the existing phenotypic heterogeneity of the P450 expression in human liver.     

National mass drug administration costs for lymphatic filariasis elimination

Background

Because lymphatic filariasis (LF) elimination efforts are hampered by a dearth of economic information about the cost of mass drug administration (MDA) programs (using either albendazole with diethylcarbamazine [DEC] or albendazole with ivermectin), a multicenter study was undertaken to determine the costs of MDA programs to interrupt transmission of infection with LF. Such results are particularly important because LF programs have the necessary diagnostic and treatment tools to eliminate the disease as a public health problem globally, and already by 2006, the Global Programme to Eliminate LF had initiated treatment programs covering over 400 million of the 1.3 billion people at risk.

Methodology/Principal Findings

To obtain annual costs to carry out the MDA strategy, researchers from seven countries developed and followed a common cost analysis protocol designed to estimate 1) the total annual cost of the LF program, 2) the average cost per person treated, and 3) the relative contributions of the endemic countries and the external partners. Costs per person treated ranged from $0.06 to $2.23. Principal reasons for the variation were 1) the age (newness) of the MDA program, 2) the use of volunteers, and 3) the size of the population treated. Substantial contributions by governments were documented – generally 60%–90% of program operation costs, excluding costs of donated medications.

Conclusions/Significance

MDA for LF elimination is comparatively inexpensive in relation to most other public health programs. Governments and communities make the predominant financial contributions to actual MDA implementation, not counting the cost of the drugs themselves. The results highlight the impact of the use of volunteers on program costs and provide specific cost data for 7 different countries that can be used as a basis both for modifying current programs and for developing new ones.     

Psychophysiological and Psychosocial Profile of Patients Attending Drug Addiction Centers

Drug treatment centres provide the highest level of rehab services for patients diagnosed with drug addictions. Most inpatient drug rehab programs focus on medical detox and mental health interventions. However, how to optimize the later remains a challenge. The aim of this study was to examine the psychophysiological and psychosocial profile of patients attending drug addiction centres in comparation with the general population. A total of 105 inpatient drug rehab patients and 50 participants from the general population were compared based on standardized psychophysiological and psychosocial measures. Results of this study suggest that patients attending drug addiction centers differ from general population in several different psychophysiological and psychosocial factors. Patients reported significantly lower levels of physical activity and increased sympathetic responsiveness, and significantly higher levels in loneliness, psychologically inflexibility and neuroticism. The results of this study highlight the importance of address healthy lifestyle behaviors such as sport practice and psychological variables such as loneliness, psychological (in)flexibility and neuroticism to improve current programs aim to prevent or reduce problematic drug consumptions.