Evolutionary history of trypanosomes from South American caiman (Caiman yacare) and African crocodiles inferred by phylogenetic analyses using SSU rDNA and gGAPDH genes

In this study, using a combined data set of SSU rDNA and gGAPDH gene sequences, we provide phylogenetic evidence that supports clustering of crocodilian trypanosomes from the Brazilian Caiman yacare (Alligatoridae) and Trypanosoma grayi, a species that circulates between African crocodiles (Crocodilydae) and tsetse flies. In a survey of trypanosomes in Caiman yacare from the Brazilian Pantanal, the prevalence of trypanosome infection was 35% as determined by microhaematocrit and haemoculture, and 9 cultures were obtained. The morphology of trypomastigotes from caiman blood and tissue imprints was compared with those described for other crocodilian trypanosomes. Differences in morphology and growth behaviour of caiman trypanosomes were corroborated by molecular polymorphism that revealed 2 genotypes. Eight isolates were ascribed to genotype Cay01 and 1 to genotype Cay02. Phylogenetic inferences based on concatenated SSU rDNA and gGAPDH sequences showed that caiman isolates are closely related to T. grayi, constituting a well-supported monophyletic assemblage (clade T. grayi). Divergence time estimates based on clade composition, and biogeographical and geological events were used to discuss the relationships between the evolutionary histories of crocodilian trypanosomes and their hosts.     

Intravaginal progesterone device and/or temporary weaning on reproductive performance of anestrous crossbred Angus x Nelore cows

The objective of this experiment was to evaluate effects of treatments with intravaginal progesterone (P4) device and/or 48h temporary weaning (TW) on reproductive performance of postpartum anestrous crossbred AngusxNelore cows, throughout the breeding season (BS). Anestrous cows (n=286; 53+/-5 DPP, body condition score between 2.5 and 3.5, on a 1-5 scale) were assigned randomly to four treatments (2x2 factorial design): (1) Control Group (no treatment; n=73); (2) TW Group (48h TW beginning on day 0 of BS; n=70); (3) P4 Group (Intravaginal P4 device between days -7 and 0 of BS; n=73); and (4) P4+TW Group (Intravaginal P4 device between days -7 and 0 of BS followed by 48h TW; n=70). On day 0 of BS (when P4 devices were removed and TW was initiated), cows had their ovaries evaluated by ultrasonography aiming to evaluate size of the largest follicle. Signs of behavioral estrus were observed twice a day (morning and evening), between days 0 and 25 of BS, and cows observed in estrus were inseminated 12h later. Between days 26 and 80 of BS, cows were submitted to natural service. Pregnancy diagnosis was conducted by transrectal ultrasonography on days 32 and 53 (pregnancies by AI) and 114 (pregnancies by natural service). Rates of detection of estrus during the first 3 days and within 25 days of BS were greater in cows receiving TW (45.0% compared with 9.6% and 50.0% compared with 29.5%, respectively; P<0.01). Conception rate in cows inseminated in the first 3 days of BS was greater in cows treated with P4 (54.8% compared with 11.1%; P<0.01). Combining P4+TW increased pregnancy rate in the first 3 days (Control: 1.4%, TW: 4.3%, P4: 8.2% and P4+TW: 24.3%; P<0.01) and in 25 days of BS (Control: 10.9%, TW: 7.1%, P4: 13.7% and P4+TW: 28.6%; P<0.05). Pregnancy rate at the end of BS did not differ among treatment groups. In conclusion, TW alone increased estrous behavior whereas P4 alone benefited conception. Combining P4 with TW improved pregnancy rate with direct benefits to behavioral estrus and conception.     

Intracellular alpha-keto acid quantification by fluorescence-HPLC

Procedures for the analysis of free alpha-keto acids in human fluids (i.e. plasma, cerebrospinal fluid, urine, etc.) as well as for studying the dynamic free alpha-keto acid pools in differentiated tissues and organ cells have been the subject of growing clinical interest in the study of metabolic regulatory and pathophysiological phenomena. Due to the high instability and polarity of the alpha-keto acids being examined, the development of a quantitative and reproducible analysis of metabolically relevant intracellular alpha-keto acids still presents a substantial methodological challenge. The aim of small sample size, rapid, non-damaging and "metabolism-neutral" cell isolation, careful sample preparation and stability, as well as reproducible analytics technology is not often achieved. Only few of the methods described can satisfy the rigorous demands for an ultra-sensitive, comprehensive and rapid intracellular alpha-keto acid analysis.     

Cilostazol and pentoxifylline decrease angiogenesis,inflammation, and fibrosis in sponge-induced intraperitoneal adhesion in mice

AimsAdhesion formation following abdominal intervention is an abnormal peritoneal healing process. Our aim was to investigate the effects of controlling adhesion development by inhibiting its key components (angiogenesis, inflammation and fibrosis) using phosphodiesterase (PDE) inhibitors.Main methodsTwo PDE inhibitors including cilostazol a PDE3 inhibitor (40 and 400 mg/kg), and pentoxifylline (PTX), a PDE 1–5 inhibitor (50 and 500 mg/kg) were used for a period of 7 days to inhibit angiogenesis, inflammation, and fibrosis in a murine model of sponge-induced peritoneal adhesion. Angiogenesis was assessed by hemoglobin content, vascular endothelial growth factor (VEGF) levels, and morphometric analysis. Accumulation of neutrophils and macrophages was determined by measuring myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activities, respectively. Levels of TNF-α were also determined. Fibrosis was assessed by determining the amount of collagen in the implant; TGF-β1 levels in the implant were also measured.Key findingsOur results show that the treatments attenuated the main components of the adhesion tissue by reducing the amount of fibrovascular tissue that infiltrated the sponge matrix (wet weight). Hemoglobin content and VEGF levels were also decreased by approximately 40%. Neutrophil accumulation was unaffected by the compounds. However, NAG activity was reduced by pentoxifylline, but not by cilostazol. These compounds also decreased the levels of the pro-inflammatory and pro-fibrogenic cytokines TNF-α and TGF-β1, respectively, and collagen synthesis.SignificanceOur results suggest that cilostazol and PTX decreased the development of peritoneal adhesions in the model, which might be associated with cyclic nucleotide modulation. Therapies to intervene in these pathways may be beneficial for the prevention of these lesions.     

A Unique β-1,2-Mannosyltransferase of Thermotoga maritima That Uses Di-myo-Inositol Phosphate as the Mannosyl Acceptor

In addition to di-myo-inositol-1,3′-phosphate (DIP), a compatible solute widespread in hyperthermophiles, the organic solute pool of Thermotoga maritima comprises 2-(O-β-d-mannosyl)-di-myo-inositol-1,3′-phosphate (MDIP) and 2-(O-β-d-mannosyl-1,2-O-β-d-mannosyl)-di-myo-inositol-1,3′-phosphate (MMDIP), two newly identified β-1,2-mannosides. In cells grown under heat stress, MDIP was the major solute, accounting for 43% of the total pool; MMDIP and DIP accumulated to similar levels, each corresponding to 11.5% of the total pool. The synthesis of MDIP involved the transfer of the mannosyl group from GDP-mannose to DIP in a single-step reaction catalyzed by MDIP synthase. This enzyme used MDIP as an acceptor of a second mannose residue, yielding the di-mannosylated compound. Minor amounts of the tri-mannosylated form were also detected. With a genomic approach, putative genes for MDIP synthase were identified in the genome of T. maritima, and the assignment was confirmed by functional expression in Escherichia coli. Genes with significant sequence identity were found only in the genomes of Thermotoga spp., Aquifex aeolicus, and Archaeoglobus profundus. MDIP synthase of T. maritima had maximal activity at 95°C and apparent K_m values of 16 mM and 0.7 mM for DIP and GDP-mannose, respectively. The stereochemistry of MDIP was characterized by isotopic labeling and nuclear magnetic resonance (NMR): DIP selectively labeled with carbon 13 at position C1 of the l-inositol moiety was synthesized and used as a substrate for MDIP synthase. This β-1,2-mannosyltransferase is unrelated to known glycosyltransferases, and within the domain Bacteria, it is restricted to members of the two deepest lineages, i.e., the Thermotogales and the Aquificales. To our knowledge, this is the first β-1,2-mannosyltransferase characterized thus far.Thermotoga maritima was first isolated from hot marine sediments on Vulcano Island, Italy, being able to grow between 55°C and 90°C (14). This strictly anaerobic bacterium ferments a variety of simple and complex carbohydrates to acetate, hydrogen, and CO₂ (10). In line with these metabolic traits, a substantial percentage of the genes annotated in the genome of this hyperthermophile are allocated to the metabolism of mono- and polysaccharides (8, 23). Therefore, T. maritima has been pointed out as a source of glycoside hydrolases with potential industrial relevance, namely, in processes of conversion of biomass into biofuels (3, 34).Like many other hyperthermophiles isolated from marine environments, Thermotoga maritima is slightly halophilic (optimum NaCl concentration of 2.7%, wt/vol) and has developed biochemical strategies to counterbalance the external osmotic pressure. The accumulation of low-molecular-mass organic compounds in the cytoplasm is the most common osmoadaptation mechanism, which enables a rapid response to fluctuations in the salinity of the external medium. Interestingly, the organic solutes encountered in organisms adapted to thrive in hot environments are clearly different from those used by mesophiles, leading to the view that osmolytes of (hyper)thermophiles could play an additional role as protectors of macromolecules and other cellular components against heat damage. This notion is further fuelled by the finding that the total pool of organic solutes of (hyper)thermophiles increases notably not only at supraoptimal salinity but also in response to heat stress conditions (30).Over the last decade, our team has directed considerable effort to assess the role of osmolytes in the thermo-adaptation strategies of hyperthermophiles. Despite the scarcity of genetic tools for manipulation of marine hyperthermophiles, a number of novel organic solutes were identified and the corresponding biosynthetic pathways characterized at the genetic and biochemical levels (15, 17, 30), providing critical knowledge for engaging in elucidation of the molecular basis of the whole process, from the sensing of stress to the synthesis of specific osmolytes. In this context, we recently reported the characterization of the pathway for synthesis of di-myo-inositol-1,3′-phosphate, the most common solute within hyperthermophiles (5). Additionally, the genes and enzymes involved in the relevant reaction steps were disclosed. The synthesis proceeds via a phosphorylated form of DIP, and the respective synthase is a membrane-associated enzyme that catalyzes the condensation of CDP-inositol with inositol-1-phosphate (26, 27).The solute pool in members of the order Thermotogales was investigated a few years ago (19). Thermotoga neapolitana responded to heat stress with a strong accumulation of DIP and DIP derivatives. One of the solutes was assigned to a mannosylated form of DIP, at that time designated di-mannosyl-di-myo-inositol phosphate; moreover, the presence of a second DIP derivative was proposed, but its structure remained elusive. Therefore, we set out to fully characterize the solute pool of Thermotoga spp. and to identify the genes and the enzyme(s) involved in the synthesis of the DIP derivatives. Members of the genus Thermotoga accumulated DIP and two mannosylated forms of this compound, herein fully characterized using isotopic labeling, NMR, and mass spectrometry. Moreover, the pathway for the synthesis of these novel solutes was identified, leading to the discovery of a unique β-1,2-mannosyltransferase that catalyzes the transfer of the mannosyl group from GDP-mannose to DIP.     

Structure and Mode of Action of Microplusin, a Copper II-chelating Antimicrobial Peptide from the Cattle Tick Rhipicephalus (Boophilus) microplus

Microplusin, a Rhipicephalus (Boophilus) microplus antimicrobial peptide (AMP) is the first fully characterized member of a new family of cysteine-rich AMPs with histidine-rich regions at the N and C termini. In the tick, microplusin belongs to the arsenal of innate defense molecules active against bacteria and fungi. Here we describe the NMR solution structure of microplusin and demonstrate that the protein binds copper II and iron II. Structured as a single α-helical globular domain, microplusin consists of five α-helices: α1 (residues Gly-9 to Arg-21), α2 (residues Glu-27 to Asn-40), α3 (residues Arg-44 to Thr-54), α4 (residues Leu-57 to Tyr-64), and α5 (residues Asn-67 to Cys-80). The N and C termini are disordered. This structure is unlike any other AMP structures described to date. We also used NMR spectroscopy to map the copper binding region on microplusin. Finally, using the Gram-positive bacteria Micrococcus luteus as a model, we studied of mode of action of microplusin. Microplusin has a bacteriostatic effect and does not permeabilize the bacterial membrane. Because microplusin binds metals, we tested whether this was related to its antimicrobial activity. We found that the bacteriostatic effect of microplusin was fully reversed by supplementation of culture media with copper II but not iron II. We also demonstrated that microplusin affects M. luteus respiration, a copper-dependent process. Thus, we conclude that the antibacterial effect of microplusin is due to its ability to bind and sequester copper II.     

Synthesis,antiplatelet and in silico evaluations of novel N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazides

This paper describes the synthesis, antiplatelet and theoretical evaluations of 10 N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazides (2a–j). These compounds were synthesized, characterized and screened for their in vitro antiplatelet profile against human platelet aggregation using arachidonic acid, adrenaline and ADP as agonists. Among NAH derivatives 2a–j, the compounds 2a, 2c, 2e, 2g and 2h were the most promising molecules with significant antiplatelet activity.     

A multilocus phylogeny of Malagasy scincid lizards elucidates the relationships of the fossorial genera Androngo and Cryptoscincus

A phylogeny for 29 species of scincine lizards from Madagascar, based on 3693 bp of six mitochondrial and five nuclear genes, revealed multiple parallel evolution of adaptations for a burrowing life, and unexpected relationships of the monotypic genera Androngo and Cryptoscincus. Androngo trivittatus was sister to Pygomeles braconnieri, and Cryptoscincus minimus was deeply nested within the genus Paracontias, all of these being fossorial taxa of elongated bodies and partly or fully reduced limbs. To account for these results, we place Cryptoscincus as a junior synonym of Paracontias, and discuss possible taxonomic consequences that may affect the status of Androngo, once additional data become available.