Reduced impact of ocean acidification on growth and swimming performance of newly hatched tropical sharks (Chiloscyllium plagiosum)

ABSTRACT

Sharks have been facing unprecedented pressure over the last decades, and ocean acidification may represent an additional threat, particularly during their most susceptible life stages. Hence, the present study aimed to investigate the effects of ocean acidification (control pCO₂ ~ 400 μatm; high pCO₂ ~ 900 μatm) on the growth, swimming performance and cholinergic system of juvenile white-spotted bamboo sharks (Chiloscyllium plagiosum). After 45 days of exposure, we observed that high CO₂ did not affect most of the end-points studied. However, somatic growth rate and the percentage of time that sharks spent swimming was significantly reduced under high CO₂ conditions. Moreover, AChE activity decreased in two of the seven brain macroareas analyzed, the telencephalon and optic lobes. As this near-threatened shark species showed small sub-lethal effects to high CO₂ levels, we argue that within a longer time-frame they can potentially reduce individual performance with cascading consequences to shark population dynamics.     

Prognostic impact of coronary microcirculation abnormalities in systemic sclerosis: a prospective study to evaluate the role of non-invasive tests

Introduction

Microcirculation dysfunction is a typical feature of systemic sclerosis (SSc) and represents the earliest abnormality of primary myocardial involvement. We assessed coronary microcirculation status by combining two functional tests in SSc patients and estimating its impact on disease outcome.

Methods

Forty-one SSc patients, asymptomatic for coronary artery disease, were tested for coronary flow velocity reserve (CFR) by transthoracic-echo-Doppler with adenosine infusion (A-TTE) and for left ventricular wall motion abnormalities (WMA) by dobutamine stress echocardiography (DSE). Myocardial multi-detector computed tomography (MDCT) enabled the presence of epicardial stenosis, which could interfere with the accuracy of the tests, to be excluded. Patient survival rate was assessed over a 6.7- ± 3.5-year follow-up.

Results

Nineteen out of 41 (46%) SSc patients had a reduced CFR (≤2.5) and in 16/41 (39%) a WMA was observed during DSE. Furthermore, 13/41 (32%) patients showed pathological CFR and WMA. An inverse correlation between wall motion score index (WMSI) during DSE and CFR value (r = -0.57, P <0.0001) was observed; in addition, CFR was significantly reduced (2.21 ± 0.38) in patients with WMA as compared to those without (2.94 ± 0.60) (P <0.0001). In 12 patients with abnormal DSE, MDCT was used to exclude macrovasculopathy. During a 6.7- ± 3.5-year follow-up seven patients with abnormal coronary functional tests died of disease-related causes, compared to only one patient with normal tests.

Conclusions

A-TTE and DSE tests are useful tools to detect non-invasively pre-clinical microcirculation abnormalities in SSc patients; moreover, abnormal CFR and WMA might be related to a worse disease outcome suggesting a prognostic value of these tests, similar to other myocardial diseases.     

The Genus Gluconobacter Oxydans: Comprehensive Overview of Biochemistry and Biotechnological Applications

ABSTRACT

The genus Gluconobacter comprises some of the most frequently used microorganisms when it comes to biotechnological applications. Not only has it been involved in “historical” production processes, such as vinegar production, but in the last decades many bioconversion routes for special and rare sugars involving Gluconobacter have been developed. Among the most recent are the biotransformations involved in the production of L-ribose and miglitol, both very promising pharmaceutical lead molecules. Most of these processes make use of Gluconobacter's membrane-bound polyol dehydrogenases. However, recently other enzymes have also caught the eye of industrial biotechnology. Among them are dextran dextrinase, capable of transglucosylating substrate molecules, and intracellular NAD-dependent polyol dehydrogenases, of interest for co-enzyme regeneration. As such, Gluconobacter is an important industrial microbial strain, but it also finds use in other fields of biotechnology, such as biosensor-technology. This review aims to give an overview of the myriad of applications for Gluconobacter, with a special focus on some recent developments.     

Induction of P‐glycoprotein and Bcrp at the rat blood–brain barrier following a subchronic morphine treatment is mediated through NMDA/COX‐2 activation

Subchronic morphine treatment induces P‐glycoprotein (P‐gp) up‐regulation at the blood–brain barrier. This study investigates the rate and extent to which P‐gp and breast cancer‐resistance protein (Bcrp) increase at the rat blood–brain barrier following subchronic morphine treatment. Rats were given increasing doses of morphine (10–40 mg/kg) or saline i.p. twice daily for 5 days. The brain cortex large vessels and microvessels were then mechanical isolated 6, 9, 12, 24, and 36 h after the last injection. The gene and protein expression of P‐gp and Bcrp in morphine‐treated and control rats were compared by qRT‐PCR and western blotting. The levels of Mdr1a and Bcrp mRNAs were not significantly modified 6 h post morphine, but the Mdr1a mRNA increased 1.4‐fold and Bcrp mRNA 2.4‐fold at 24 h. P‐gp and Bcrp protein expression in brain microvessels was unchanged 6 h post morphine and increased 1.5‐fold at 24 h. This effect was more pronounced in large vessels than in microvessels. However, extracellular morphine concentrations of 0.01–10 μM did not modify the expressions of the MDR1 and BCRP genes in hCMEC/D3 human endothelial brain cells in vitro. MK‐801 (NMDA antagonist) and meloxicam (cyclo‐oxygenase‐2 inhibitor) given after morphine treatment completely blocked P‐gp and Bcrp up‐regulation. Interestingly, misoprostol and iloprost, two well‐known agonists of prostaglandin E2 receptors induced both MDR1 and BCRP mRNA levels in hCMEC/D3. Thus, morphine does not directly stimulate P‐gp and Bcrp expression by the brain endothelium, but glutamate released during morphine withdrawal may do so by activating the NMDA/cyclo‐oxygenase‐2 cascade.     

Comparison of methane, nitrous oxide fluxes and CO2 respiration rates from a Mediterranean cork oak ecosystem and improved pasture

Background and aims

During the recent decades, cork oak (Q. suber) mortality has been increasing in Mediterranean oak woodland endangering the economical and environmental sustainability of the “montado” ecosystem. This fact in combination with climate change and conversion of forestland to pasture may significantly affect the soil-atmosphere greenhouse gases (GHGs) exchange. Our study evaluates the impact of oak trees as compared to pasture on net ecosystem GHG (CH_4, N₂O, and CO₂) exchange as well as the main environmental factors influencing this exchange.

Methods

We used field chamber measurements for the collection of GHGs under three different conditions: 1) open area (OA), 2) under tree canopy area (UC) and 3) improved pasture (IP). Experiments were done under typical Mediterranean climate at central Portugal in 2010 and 2011.

Results

The UC had higher nitrification potential, soil C/N ratio, electrical conductivity, litter input and soil organic matter (SOM) than OA and IP. SOM positively correlated with soil CH₄ and N₂O fluxes but not with soil CO₂ respiration rates. Soil water content (SWC) drives both CH₄ and N₂O fluxes. Under certain conditions, when SWC reached a threshold (7 % for CH₄ and 3 % for N₂O) the result was net uptake and that net uptake increased with SWC. This was the case for the UC and OA. Conversely, for the IP soil water content above 4 % promoted net CH₄ release.

Conclusions

Our results show that cork oak influences soil properties and consequently GHGs fluxes. In the UC the input of litter for SOM together with soil moisture, favoured microbiological activity and related GHGs fluxes. Soil temperature is a secondary factor in the studied conditions. Our results also emphasized the potential impact posed by decreased cork oak tree density in the functioning of the “montado” ecosystem.     

Cytochemical localization of 5′-nucleotidase in the enteric ganglia and in smooth muscle cells of the guinea-pig

Brain Cell Biology - Cytochemical techniques were used to study the localization of 5′-nucleotidase in the enteric ganglia and in smooth muscle cells of the guinea-pig ileum, iris and vas...     

Establishing the occurrence of major and minor glucosinolates in Brassicaceae by LC-ESI-hybrid linear ion-trap and Fourier-transform ion cyclotron resonance mass spectrometry

Glucosinolates (GLSs) are sulfur-rich plant secondary metabolites which occur in a variety of cruciferous vegetables and among various classes of them, genus Brassica exhibits a rich family of these phytochemicals at high, medium and low abundances. Liquid chromatography (LC) with electrospray ionization in negative ion mode (ESI-) coupled to a hybrid quadrupole linear ion trap (LTQ) and Fourier transform ion cyclotron resonance mass spectrometer (FTICRMS) was employed for the selective and sensitive determination of intact GLSs in crude sample extracts of broccoli (Brassica oleracea L. Var. italica), cauliflower (B. oleracea L. Var. Botrytis) and rocket salad (Eruca sativa L.) with a wide range of contents. When LTQ and FTICR mass analyzers are compared, the magnitude of the limit of detection was ca. 5/6-fold lower with the FTICR MS. In addition, the separation and detection by LC-ESI-FTICR MS provides a highly selective assay platform for unambiguous identification of GLSs, which can be extended to lower abundance (minor) GLSs without significant interferences of other compounds in the sample extracts. The analysis of Brassicaceae species emphasized the presence of eight minor GLSs, viz. 1-methylpropyl-GLS, 2-methylpropyl-GLS, 2-methylbutyl-GLS, 3-methylbutyl-GLS, n-pentyl-GLS, 3-methylpentyl-GLS, 4-methylpentyl-GLS and n-hexyl-GLS. The occurrence of these GLSs belonging to the saturated aliphatic side chain families C(4), C(5) and C(6), presumably formed by chain elongation of leucine, homoleucine and dihomoleucine as primary amino acid precursors, is described. Based on their retention behavior and tandem MS spectra, all these minor compounds occurring in plant extracts of B. oleracea L. Var. italica, B. oleracea L. Var. Botrytis and E. sativa L. were tentatively identified.     

ABO blood group polymorphisms and risk for ischemic stroke and peripheral arterial disease

Recent studies have demonstrated association between ABO blood system and thrombosis, indicating that individuals belonging to non-O blood groups (A, B or AB) present an increased risk of venous thrombosis, heart disease, and ischemic stroke (IS) as compared to O blood group carriers. In this study, we investigated the frequency of ABO blood group polymorphisms and its association with IS and peripheral arterial disease. Significant differences were observed for O1 (OR 0.57, 95 % CI 0.35–0.95, p < 0.05) and O2 (OR 3.47, 95 % CI 1.15–10.28, p < 0.05) alleles among IS patients while significant differences were observed for B phenotype (26.3 vs 9.5 %, OR 3.42, 95 % CI 1.32–8.76, p = 0.01, patients vs controls, respectively) and alleles A1 (OR 0.31, 95 % CI 0.11–0.84, p < 0.05), O2 (OR 4.61, 95 % CI 1.59–13.23, p < 0.01) and B (OR 3.42, 95 % CI 1.62–7.13, p < 0.001) alleles for PAD patients. O1 allele was an independent variable (OR 0.27, 95 % CI 0.12–0.57, p < 0.001) for IS patients. These data suggest the relationship of non-O blood groups in pathogenesis of thrombosis events and a possible protective effect of O blood group.     

Mass spectrometry and animal science: protein identification strategies and particularities of farm animal species

Proteomic approaches are gaining increasing importance in the context of all fields of animal and veterinary sciences, including physiology, productive characterization, and disease/parasite tolerance, among others. Proteomic studies mainly aim the proteome characterization of a certain organ, tissue, cell type or organism, either in a specific condition or comparing protein differential expression within two or more selected situations. Due to the high complexity of samples, usually total protein extracts, proteomics relies heavily on separation procedures, being 2D-electrophoresis and HPLC the most common, as well as on protein identification using mass spectrometry (MS) based methodologies. Despite the increasing importance of MS in the context of animal and veterinary science studies, the usefulness of such tools is still poorly perceived by the animal science community. This is primarily due to the limited knowledge on mass spectrometry by animal scientists. Additionally, confidence and success in protein identification is hindered by the lack of information in public databases for most of farm animal species and their pathogens, with the exception of cattle (Bos taurus), pig (Sus scrofa) and chicken (Gallus gallus). In this article, we will briefly summarize the main methodologies available for protein identification using mass spectrometry providing a case study of specific applications in the field of animal science. We will also address the difficulties inherent to protein identification using MS, with particular reference to experiments using animal species poorly described in public databases. Additionally, we will suggest strategies to increase the rate of successful identifications when working with farm animal species.     

Investigation of trypanothione reductase inhibitory activity by 1,3,4-thiadiazolium-2-aminide derivatives and molecular docking studies

The biological activities of a series of mesoionic 1,3,4-thiadiazolium-2-aminide derivatives have been studied. The most active compounds (MI-HH; MI-3-OCH(3); MI-4-OCH(3) and MI-4-NO(2)) were evaluated to determine their effect on trypanothione reductase (TryR) activity in Leishmania sp. and Trypanosoma cruzi. Among the assayed compounds, only MI-4-NO(2) showed enzyme inhibition effect on extracts from different cultures of parasites, which was confirmed using the recombinant enzyme from T. cruzi (TcTryR) and Leishmania infantum (LiTryR). The enzyme kinetics determined with LiTryR demonstrated a non-competitive inhibition profile of MI-4-NO(2). A molecular docking study showed that the mesoionic compounds could effectively dock into the substrate binding site together with the substrate molecule. The mesoionic compounds were also effective ligands of the NADPH and FAD binding sites and the NADPH binding site was predicted as the best of all three binding sites. Based on the theoretical results, an explanation at the molecular level is proposed for the MI-4-NO(2) enzyme inhibition effect. Given TryR as a molecular target, it is important to continue the study of mesoionic compounds as part of a drug discovery campaign against Leishmaniasis or Chagas' disease.