Subgingival biofilm microbiome in individuals with asthma and periodontitis: Metagenomic analysis.

OBJECTIVE: This observational study aimed to explore the metagenomics of subgingival biofilms in individuals with varying degrees of asthma, from severe to none, to elucidate the association between the subgingival microbiome and asthma. MATERIALS AND METHODS: Subgingival biofilm samples were collected from thirty participants at the Asthma Control Program Outpatient Clinic in Bahia (ProAR). These samples were categorized into six groups based on the severity of asthma and the presence or absence of periodontitis. We employed next-generation sequencing (Illumina MiSeq), targeting the 16S rRNA gene, to characterize the microbial communities present. Our analysis included descriptive statistics and sequencing data, evaluated using multivariate statistical methods such as the Shannon index, principal coordinate analysis, and the Bray-Curtis dissimilarity. RESULTS: Our findings indicate a higher prevalence of periodontally detrimental bacterial genera in individuals with severe asthma and periodontitis. Additionally, individuals with asthma, but without periodontitis, exhibited a tendency toward dysbiosis, particularly in cases of severe asthma. CONCLUSION: This research provides new insights into the composition of the subgingival microbiome in individuals with varying severities of asthma and periodontitis. The genera identified in this study underscore the need for further investigations to build upon these findings.

Induced drought strongly affects richness and composition of ground-dwelling ants in the eastern Amazon.

Species loss in tropical regions is forecast to occur under environmental change scenarios of low precipitation. One of the main questions is how drought will affect invertebrates, a key group for ecosystem functioning. We use 1 year of data from a long-term rainwater exclusion experiment in primary Amazonian rainforest to test whether induced water stress and covarying changes in soil moisture, soil respiration, and tree species richness, diversity, size, and total biomass affected species richness and composition (relative abundance) of ground-dwelling ants. Data on ant abundance and environmental variables were collected at two sites (control and experimental) in the Eastern Amazon. Since 2002, drought has been induced in the experimental plot by excluding 50% of normal rainfall. Ant species richness in the experiment plot was reduced and some generalist species responded positively. Ant species richness also increased in the experimental plot with increasing diversity of the plant species of the leaf litter. The relative abundance of ants differed between plots. The experimental plot was characterized by a higher frequency of generalist and other species that appeared to be favored by the reduction in rainfall. Between-plot comparisons suggested loss and changes in ant species composition in tropical forests were affected by increasing dryness. These changes could ultimately lead to cascading effects on ecosystem processes and the services they mediate.

The role of morphological traits in predicting the functional ecology of arboreal and ground ants in the Cerrado-Amazon transition.

There is often a vertical stratification of the vegetation in tropical forests, where each forest stratum has a unique set of environmental conditions, including marked differences in habitat heterogeneity, physical complexity, and microclimate. Additionally, many tropical forests are highly seasonal, and we need to consider the temporal variation in environmental conditions when assessing the functional aspects of their organisms. Here, we tested the hypothesis that vertical stratification and seasonality shape tropical ants' functional ecology and that there are differences in the functional trait diversity and composition between arboreal and ground-dwelling ant communities. We collected ants in the arboreal and ground strata in the rainy and dry seasons in six different areas, measuring seven morphological traits to characterize their functional ecology and diversity. Irrespective of the season, we found a distinct functional composition between arboreal and ground-dwelling ants and a higher functional richness on the ground. However, ground ants were more functionally redundant than arboreal ants. The differences in functional richness and redundancy between ant inhabiting strata and season could also be observed in the community-weighted mean traits: arboreal and ground ant traits can be distinguished in Weber's length, mandible length, eye length, and eye position on the head capsule. The differences in these functional traits are mainly related to the ants' feeding habits and the complexity of their foraging substrates. Overall, by providing the first systematic comparison of continuous traits between arboreal and ground-dwelling ants, our study opens new investigation paths, indicating important axes of functional diversification of tropical ants.

SELECTED OPHTHALMIC TESTS AND OCULAR DIMENSIONS IN RELATION TO ACTIVITY PATTERN IN THREE NEOTROPICAL NONHUMAN PRIMATES: BLACK-TUFTED MARMOSET (CALLITHRIX PENICILLATA), GUIANAN SQUIRREL MONKEY (SAIMIRI SCIUREUS), AND AZARA'S NIGHT MONKEY (AOTUS AZARAE INFULATUS).

The goals of this study were to compare ocular morphology, determine the reference intervals of selected ophthalmic tests, ocular measurements, intraocular pressure, and tear production, and to establish possible relationships in the visual ecology of three different Neotropical nonhuman primates (NHP). Nineteen black-tufted marmosets (Callithrix penicillate), 24 Guianan squirrel monkeys (Saimiri sciureus), and 24 night monkeys (Aotus azarae infulatus) were included in the study. Schirmer tear test, ocular dimensions, ocular ultrasonography, intraocular pressure, central corneal thickness, and corneal touch threshold were determined. The ratio of the average corneal diameters and axial diameters (CD/AGL) were established. No significant difference was noted between males and females, nor left and right eyes, for all three species for all measurements (P > 0.05). CD/AGL ratio was significantly higher (P < 0.0001) in night monkeys (a nocturnal species) as compared to black-tufted marmoset and Guianan squirrel monkeys (two diurnal species). The reference intervals will aid veterinary ophthalmologists to more accurately diagnose pathological changes in the eyes of these species. In addition, ocular dimension comparison will allow other NHP species to be evaluated and examined in relationship to behavioral traits (nocturnal versus diurnal).

Novel Anaplasmataceae agents Candidatus Ehrlichia hydrochoerus and Anaplasma spp. Infecting Capybaras, Brazil.

We amplified Ehrlichia and Anaplasma DNA from Amblyomma dubitatum tick-infested capybaras (Hydrochoerus hydrochaeris) in southern Brazil. Sequencing of 16S rRNA, sodB, and groEL indicated a novel Ehrlichia species, and sequencing of 16S rRNA from 2 capybaras indicated a novel Anaplasma species. The tick vectors remain unknown.

Feruloyl Esterases Protein Engineering to Enhance Their Performance as Biocatalysts: A Review.

Feruloyl esterases (FAEs) are versatile enzymes able to release hydroxycinnamic acids or synthesize their ester derivatives, both molecules with interesting biological activities such as: antioxidants, antifungals, antivirals, antifibrotic, anti-inflammatory, among others. The importance of these molecules in medicine, food or cosmetic industries provides FAEs with several biotechnological applications as key industrial biocatalysts. However, FAEs have some operational limitations that must be overcome, which can be addressed through different protein engineering approaches to enhance their thermal stability, catalytic efficiencies, and selectivity. This review aims to present a brief historical tour through the mutagenesis strategies employed to improve enzymes performance and analyze the current protein engineering strategies applied to FAEs as interesting biocatalysts. Finally, an outlook of the future of FAEs protein engineering approaches to achieve successful industrial biocatalysts is given.

Crystal structure of a C-type lysozyme from Litopenaeus vanamei exhibiting a high binding constant to its chitotriose inhibitor.

Although information about invertebrate lysozymes is scarce, these enzymes have been described as components of the innate immune system, functioning as antibacterial proteins. Here we describe the first thermodynamic and structural study of a new C-type lysozyme from a Pacific white shrimp Litopenaeus vannamei (LvL), which has shown high activity against both Gram (+) and Gram (-) bacteria including Vibrio sp. that is one of the most severe pathogens in penaeid shrimp aquaculture. Compared with hen egg-white lysozyme, its sequence harbors a seven-residue insertion from amino acid 97 to 103, and a nine-residue extension at the C-terminus only found in penaeid crustaceans, making this enzyme one of the longest lysozyme reported to date. LvL was crystallized in the presence and absence of chitotriose. The former crystallized as a monomer in space group P61 and the latter in P212121 with two monomers in the asymmetric unit. Since the enzyme crystallized at a pH where lysozyme activity is deficient, the ligand could not be observed in the P61 structure; therefore, we performed a docking simulation with chitotriose to compare with the hen egg lysozyme crystallized in the presence of the ligand. Remarkably, additional amino acids in LvL caused an increase in the length of α-helix H4 (residues 97-103) that is directly related to ligand recognition. The Ka for chitotriose (4.1 × 105 M-1), as determined by Isothermal Titration Calorimetry, was one order of magnitude higher than those for lysozymes from hen and duck eggs. Our results revealed new interactions of chitiotriose with residues in helix H4.

Reference values for selected ophthalmic diagnostic tests in two species of microchiroptera bats (Artibeus lituratus and Anoura caudifer).

OBJECTIVE: To establish reference values for ophthalmic tests in two bat species. BATS: Fourteen bats including seven great fruit-eating bats (Artibeus lituratus) and seven tailed tailless bats (Anoura caudifer). PROCEDURES: Normal values for following ophthalmic tests were investigated as follows: (a) aqueous tear production using the standardized endodontic paper point tear test (EPPTT), (b) rebound tonometry, and (c) horizontal palpebral fissure length. RESULTS: Aqueous tear production was 2.53 ± 1.65 mm/min for A lituratus and 1.89 ± 0.62 for A caudifer. Intraocular pressure measured in the upright position was 11.0 ± 3.28 mm Hg for A lituratus and 7.28 ± 2.70 for A caudifer. Horizontal palpebral fissure length was 5.04 ± 0.45 mm for A lituratus and 3.92 ± 0.51 for A caudifer. CONCLUSIONS: The data obtained in the present study may serve as a reference for ophthalmic parameters and help practitioners in the diagnosis and management of eye diseases in bats, as well for future investigations about microchiroptera bats.

Infrared thermography reveals surface body temperature changes during proestrus and estrus reproductive phases in Gyr heifers (Bos taurus indicus).

Our aim was to evaluate the application of infrared thermography (IRT) to detect body surface temperature variation of body regions during the proestrus and estrus phases of the reproductive cycle of Gyr heifers and investigate environmental factors that could affect these measurements. Fifty-seven heifers were submitted to an ovulation synchronization protocol. This was followed by monitoring the heifers every 12 h over 60 h. Heifers were monitored for rectal and vaginal temperature using a digital thermometer. The surface temperature of the eye, vulva, and muzzle regions were monitored by IRT. Meteorological data was recorded for temperature and humidity. Observation of sexual behavior was performed to monitor estrus onset. Transrectal ultrasonography was used to identify the dominant follicle and confirm ovulation of all heifers. We observed a decrease in temperature of the rectum and vagina, as well as in the eye and vulva regions within the first 12 h after the completion of the synchronization. This period coincides with the expected proestrus phase of the estrous cycle. A progressive increase in all temperatures was noticed in the following 36 h, which coincides with the estrus phase of the reproductive cycle. The regions evaluated around the vulva and eye exhibited the highest temperature and experienced less environmental distortion than the muzzle area thermographs. Environmental factors, such as rainfall and temperature-humidity index, influenced the IRT readings altering the radiation patterns detected. In conclusion, IRT is an effective method to detect temperature variation during the proestrus and estrus phases in Gyr heifers. Furthermore, biological and environmental effects should be considered when collecting and interpreting IRT data in livestock.

Comparison of blind intubation and a smartphone-based endoscope-assisted intubation in rabbits.

OBJECTIVE: To compare between blind and smartphone-based endoscope-assisted techniques for endotracheal intubation in rabbits. STUDY DESIGN: Prospective clinical study. ANIMALS: A total of 34 rabbits. METHODS: Rabbits were assigned to four groups: intubation by a veterinary anesthesiologist (VA) or an exotic pet medicine specialist (EPS) using blind or endoscope-assisted techniques. Propofol dose, number of attempts until successful intubation, total time for intubation, duration of the successful attempt and occurrence of lingual cyanosis/laryngeal lesions were recorded. Data were analyzed by t test, Wilcoxon-Mann-Whitney U test or chi-square test. Pearson correlation for body weight was performed. RESULTS: The success rate of blind intubation was 88.9% and 77.8% for VA and EPS, respectively. Propofol dose, total and median number of attempts, total time for intubation and duration of the successful attempt were 3.1 (0-6.2) mg kg-1, 19, 2 (1-5), 79 ± 65 and 30 ± 20 seconds for VA and 1.5 (0-4.5) mg kg-1, 24, 3 (1-5), 136 ± 92 and 38 ± 16 seconds for EPS. The success rate of endoscope-assisted intubation was 87.5% for both operators. Propofol dose, total and median number of attempts, total time for intubation and duration of the successful attempt were 2.5 (1.3-7.4) mg kg-1, 22, 3 (1-5), 170 (65-368) and 46 (22-150) seconds for VA and 3.2 (0-6) mg kg-1, 11, 1 (1-4), 56 (27-432) and 55 (26-79) seconds for EPS. VA performed blind intubation more quickly, propofol dose was lower and cyanosis was less frequent than in the endoscope-assisted group. CONCLUSIONS AND CLINICAL RELEVANCE: Both techniques were reliable for rabbit endotracheal intubation. Best results were achieved when the operator was experienced in the technique. The smartphone-based endoscope is a useful aid for rabbit intubation.

Syntheses, Characterization, and Antioxidant Evaluation of Cu2+, Mn2+, and Fe3+ Complexes with a 14 Membered EDTA-Derived Macrocycle.

The Cu2+, Mn2+, and Fe3+ complexes of a 14 membered macrocycle were synthesized and their antioxidant capacities were evaluated against ABTS and DPPH radicals, with the objective of collecting insights into the biomimetic role of the central metal ions. The macrocycle, abbreviated as H2L14, is a derivative of EDTA cyclized with 1,4-diamine, and the moderately flexible macrocyclic frame permits the formation of [ML14·H2O] chelates with octahedral coordination geometries common among the metal ions. The metal complexes were characterized by electrospray-ionization mass spectrometry, Fourier transform infrared spectroscopy, and Raman and X-ray photoelectron spectroscopic methods, as well as thermogravimetric analysis; the octahedral coordination geometries with water coordination were optimized by DFT calculations. The antioxidant assays showed that [FeL14·H2O]+ was able to scavenge synthetic radicals with moderate capacity, whereas the other metal chelates did not show significant activity. The Raman spectrum of DPPH in solution suggests that interaction was operative between the Fe3+ chelate and the radical so as to cause scavenging capability. The nature of the central metal ions is a controlling factor for antioxidant capacity, as every metal chelate carries the same coordination geometry.

Can Religious Coping and Depressive Symptoms Predict Clinical Outcome and Quality of Life in Panic Disorder? A Brazilian Longitudinal Study.

Few studies have investigated the relationship between spiritual/religious coping (S/R coping) and panic disorder (PD). This Brazilian longitudinal study evaluated if S/R coping and depressive symptoms can predict PD remission and improved quality of life (QoL). There were 101 outpatients with PD who were followed up for 12 to 16 weeks. The prevalence ratio (PR) between positive S/R coping and negative S/R coping and PD remission was assessed, as well as the association between positive S/R coping and negative S/R coping and QoL. After adjusting for confounding factors, positive S/R coping presented an inverse PR with PD remission, which was not statistically significant (0.88; p = 0.075). There was no association between S/R coping and QoL. Depressive symptoms were negatively associated with PD remission (PR = 0.97; p < 0.01) and were not predictive of a better QoL.

Structural insights from a novel invertebrate triosephosphate isomerase from Litopenaeus vannamei.

Triosephosphate isomerase (TIM; EC 5.3.1.1) is a key enzyme involved in glycolysis and gluconeogenesis. Glycolysis is one of the most regulated metabolic pathways, however little is known about the structural mechanisms for its regulation in non-model organisms, like crustaceans. To understand the structure and function of this enzyme in invertebrates, we obtained the crystal structure of triosephosphate isomerase from the marine Pacific whiteleg shrimp (Litopenaeus vannamei, LvTIM) in complex with its inhibitor 2-phosphogyceric acid (2-PG) at 1.7Å resolution. LvTIM assembles as a homodimer with residues 166-176 covering the active site and residue Glu166 interacting with the inhibitor. We found that LvTIM is the least stable TIM characterized to date, with the lowest range of melting temperatures, and with the lowest activation enthalpy associated with the thermal unfolding process reported. In TIMs dimer stabilization is maintained by an interaction of loop 3 by a set of hydrophobic contacts between subunits. Within these contacts, the side chain of a hydrophobic residue of one subunit fits into a cavity created by a set of hydrophobic residues in the neighboring subunit, via a "ball and socket" interaction. LvTIM presents a Cys47 at the "ball" inter-subunit contact indicating that the character of this residue is responsible for the decrease in dimer stability. Mutational studies show that this residue plays a role in dimer stability but is not a solely determinant for dimer formation.

Crystal structure of a class-mu glutathione S-transferase from whiteleg shrimp Litopenaeus vannamei: structural changes in the xenobiotic binding H-site may alter the spectra of molecules bound.

Glutathione S-transferases (GSTs) are dimeric proteins that play a key role in phase II cellular detoxification. Here, the first crystal structure of a GST class-mu from marine crustacean shrimp Litopenaeus vannamei is reported at a resolution of 2.0 Å. The coordinates reported here have the lowest sequence identity with previously reported GSTs class-mu deposited at the Protein Data Bank (PDB), although they have subtle conformational differences. One key feature of GST class-mu from L. vannamei is the active site crevice markedly reduced when it is compared with other GSTs class-mu. This finding together with the chemical change of residues into the cavity (F112 and Y210) points to a particular specialization in which smallest xenobiotics with nonstandard chemical characteristics can be bound to the H-site. This suggests that marine organisms have evolved structural strategies to provide efficient selectivity toward xenobiotics to be disposed of by the phase II detoxification process.

Quality-of-life and spirituality.

Spirituality has been identified as an important dimension of quality-of-life. The objective of this study was to review the literature on quality-of-life and spirituality, their association, and assessment tools. A search was conducted of the keyterms 'quality-of-life' and 'spirituality' in abstract or title in the databases PsycINFO and PubMed/Medline between 1979-2005, complemented by a new search at PUBMED from 2006-2016. Quality-of-life is a new concept, which encompasses and transcends the concept of health, being composed of multiple domains: physical, psychological, environmental, among others. The missing measure in health has been defined as the individual's perception of their position in life in the context of culture and value system in which they live and in relation to their goals, expectations, standards, and concerns. There is consistent evidence of an association between quality-of-life and religiosity/spirituality (R/S), through studies with reasonable methodological rigour, using several variables to assess R/S (e.g. religious affiliation, religious coping, and prayer/spirituality). There are also several valid and reliable instruments to evaluate quality-of-life and spirituality. Further studies are needed, however, especially in Brazil. Such studies will provide empirical data to be used in planning health interventions based on spirituality, seeking a better quality-of-life. In the last 10 years, research is consistently growing about quality-of-life and spirituality in many countries, and also in many areas of health research.

THE EYE OF THE AZARA'S AGOUTI ( DASYPROCTA AZARAE): MORPHOLOGICAL OBSERVATIONS AND SELECTED OPHTHALMIC DIAGNOSTIC TESTS.

The purpose of this study was to carry out a descriptive investigation of the Azara's agouti ( Dasyprocta azarae) eye and to establish reference values of select ophthalmic diagnostic tests and physiologic parameters. A total of 19 healthy agoutis were used. Select ophthalmic diagnostic tests were performed, including Schirmer tear test type I (STTI), analysis of the conjunctival bacterial microflora, corneal esthesiometry, and tonometry. B-mode ultrasonic biometry, fundus photography, optical coherence tomography, and gross and histologic analysis of two eyes were also performed. Reference range parameters found for the ocular diagnostic tests were esthesiometry, 4.50 ± 0.36 cm (0.7 ± 0.01 g/mm2); tonometry, 11.61 ± 0.44 mm Hg; palpebral fissure length, 1.70 ± 0.25 mm; STTI, 9.73 ± 0.47 mm/min; corneal thickness, 0.8 ± 0.003 mm; anterior chamber depth, 1.71 ± 0.07 mm; lens thickness, 5.03 ± 0.05 mm; vitreous chamber depth, 5.12 ± 0.01 mm; and globe axial length, 14.02 ± 0.01 mm. A paurangiotic, retinal, vascular pattern with a conspicuous pigment-laden optic disc was observed. The most frequent bacteria isolated were nonhemolytic Streptococcus sp. (36.84%), followed by Enterobacter harfinia (31.58%) and Escherichia coli (28.95%). No significant differences between genders or between left and right eyes were found for any of the results. Gross and histologic evaluation of two eyes confirmed the presence of melanocytic pigment granules between optic nerve fibers. The diagnostic values and the morphologic observations described here provide a reference to veterinarians to aid in the diagnosis of ocular disease.

Arginine kinase shows nucleoside diphosphate kinase-like activity toward deoxythymidine diphosphate.

Arginine kinase (AK) (ATP: L-arginine phosphotransferase, E.C. 2.7.3.3) catalyzes the reversible transfer of ATP γ-phosphate group to L-arginine to synthetize phospho-arginine as a high-energy storage. Previous studies suggest additional roles for AK in cellular processes. Since AK is found only in invertebrates and it is homologous to creatine kinase from vertebrates, the objective of this work was to demonstrate nucleoside diphosphate kinase-like activity for shrimp AK. For this, AK from marine shrimp Litopenaeus vannamei (LvAK) was purified and its activity was assayed for phosphorylation of TDP using ATP as phosphate donor. Moreover, by using high-pressure liquid chromatography (HPLC) the phosphate transfer reaction was followed. Also, LvAK tryptophan fluorescence emission changes were detected by dTDP titration, suggesting that the hydrophobic environment of Trp 221, which is located in the top of the active site, is perturbed upon dTDP binding. The kinetic constants for both substrates Arg and dTDP were calculated by isothermal titration calorimetry (ITC). Besides, docking calculations suggested that dTDP could bind LvAK in the same cavity where ATP bind, and LvAK basic residues (Arg124, 126 and 309) stabilize the dTDP phosphate groups and the pyrimidine base interact with His284 and Ser122. These results suggest that LvAK bind and phosphorylate dTDP being ATP the phosphate donor, thus describing a novel alternate nucleoside diphosphate kinase-like activity for this enzyme.

Synthesis, Characterization, and Cu(2+) Coordination Studies of a 3-Hydroxy-4-pyridinone Aza Scorpiand Derivative.

The synthesis, acid-base behavior, and Cu(2+) coordination chemistry of a new ligand (L1) consisting of an azamacrocyclic core appended with a lateral chain containing a 3-hydroxy-2-methyl-4(1H)-pyridinone group have been studied by potentiometry, cyclic voltammetry, and NMR and UV-vis spectroscopy. UV-vis and NMR studies showed that phenolate group was protonated at the highest pH values [log K = 9.72(1)]. Potentiometric studies point out the formation of Cu(2+) complexes of 1:2, 2:2, 4:3, 1:1, and 2:1 Cu(2+)/L1 stoichiometries. UV-vis analysis and electrochemical studies evidence the implication of the pyridinone moieties in the metal coordination of the 1:2 Cu(2+)/L1 complexes. L1 shows a stronger chelating ability than the reference chelating ligand deferiprone. While L1 shows no cytotoxicity in HeLa and ARPE-19 human cell lines (3.1-25.0 µg/mL), it has significant antioxidant activity, as denoted by TEAC assays at physiological pH. The addition of Cu(2+) diminishes the antioxidant activity because of its coordination to the pyridinone moiety phenolic group.

Kinetic and temporospatial gait parameters in a heterogeneous group of dogs.

BACKGROUND: A prime concern of the gait analysis in a heterogeneous group of dogs is the potential influence of factors such as individual body size, body mass, type of gait, and velocity. Thus, this study aimed to evaluate in a heterogeneous group of dogs a possible correlation of the stride frequency with kinetic and temporospatial variables, as well as the percentage of body weight distribution (%BWD), and compare symmetry index (SI) between trotting and walking dogs. Twenty-nine clinically healthy dogs moving in a controlled velocity were used. The dogs were organized into two groups based on duty factor. Group 1 comprised 15 walking dogs, aged from 9 months to 8 years and weighing about 22.3 kg. Group 2 had 14 trotting dogs, aged from 1 to 6 years and weighing about 6.5 kg. The kinetic data and temporospatial parameters were obtained using a pressure-sensing walkway. The velocity was 0.9-1.1 m/s. The peak vertical force (PVF), vertical impulse (VI), gait cycle time, stance time, swing time, stride length, and percentages of body weight distribution among the four limbs were determined. For each variable, the SIs were calculated. Pearson's coefficient was used to evaluate correlation between stride frequency and other variables, initially in each group and after including all animals. RESULTS: Except for the %BWD (approximately 60% for the forelimbs and 40% for the hind limbs), all other parameters differed between groups. Considering each Group individually a strong correlation was observed for most of the temporospatial parameters, but no significant correlation occurred between stride frequency and PVF, and stride frequency and %BWD. However, including all dogs a strong correlation was observed in all temporospatial parameters, and moderate correlation between stride frequency and VI, and weak correlation between stride frequency and PVF. There was no correlation between stride frequency and %BWD. Groups 1 and 2 did not differ statistically in SIs. CONCLUSIONS: In a heterogeneous group of dogs conducted at a controlled velocity, the %BWD and most of SIs presented low variability. However, %BWD seems to be the most accurate, since factors such as the magnitude of the variables may influence the SIs inducing wrong interpretation. Based on results obtained from correlations, the standardization of stride frequency could be an alternative to minimize the variability of temporospatial parameters.

The nuclear encoded subunits gamma, delta and epsilon from the shrimp mitochondrial F1-ATP synthase, and their transcriptional response during hypoxia.

The mitochondrial FOF1 ATP synthase produces ATP in a reaction coupled to an electrochemical proton gradient generated by the electron transfer chain. The enzyme also hydrolyzes ATP according to the energy requirements of the organism. Shrimp need to overcome low oxygen concentrations in water and other energetic stressors, which in turn lead to mitochondrial responses. The aim of this study was to characterize the full-length cDNA sequences of three subunits that form the central stalk of the F1 catalytic domain of the ATP synthase of the white shrimp Litopenaeus vannamei and their deduced proteins. The effect of hypoxia on shrimp was also evaluated by measuring changes in the mRNA amounts of these subunits. The cDNA sequences of the nucleus-encoded ATPγ, ATPδ and ATPε subunits are 1382, 477 and 277 bp long, respectively. The three deduced amino acid sequences exhibited highly conserved regions when compared to homologous sequences, and specific substitutions found in shrimp subunits are discussed through an homology structural model of F1 ATP-synthase that included the five deduced proteins, which confirm their functional structures and specific characteristics from the cognate complex of ATP synthases. Genes expression was evaluated during hypoxia-reoxygenation, and resulted in a generalized down-regulation of the F1 subunits and no coordinated changes were detected among these five subunits. The reduced mRNA levels suggest a mitochondrial response to an oxidative stress event, similar to that observed at ischemia-reperfusion in mammals. This model analysis and responses to hypoxia-reoxygenation may help to better understand additional mitochondrial adaptive mechanisms.