The use of Ocimum americanum essential oil against the pathogens Aeromonas hydrophila and Gyrodactylus sp. in silver catfish (Rhamdia quelen).

UNLABELLED: The bactericidal activity (minimum inhibitory concentration (MIC)-test) of Ocimum americanum (inflorescences) essential oil (OAEO) against Aeromonas hydrophila was determined in this study. Also investigated was the potential of OAEO and the main compound found in the oil (linalool) at subinhibitory concentrations to be inhibitors of haemolysis caused by Aer. hydrophila in fish erythrocytes. An in vivo experiment was conducted to evaluate the survival of fish (Rhamdia quelen) experimentally infected with Aer. hydrophila and exposed to OAEO. A second experiment was conducted to evaluate the in vitro and in vivo activity of OAEO (mix from inflorescences and leaves) against the parasite Gyrodactylus sp. The OAEO showed weak in vitro activity against Aer. hydrophila (6400 µg ml(-1) ). Subinhibitory concentrations of OAEO (100 µg ml(-1) ) inhibited haemolysis (90%) caused by Aer. hydrophila in fish erythrocytes, however, linalool did not inhibit haemolysis activity. At the low concentrations (10 and 20 mg l(-1) ) added to the water, OAEO promoted the survival of fish experimentally infected with Aer. hydrophila. Lastly, the OAEO mix (50 mg l(-1) ) was effective against Gyrodactylus sp., significantly reducing (60%) the number of parasites in the fish. SIGNIFICANCE AND IMPACT OF THE STUDY: Phytochemicals, such as essential oils (EOs) are a great source of new molecules and have shown potential to be used in aquaculture systems. However, additional studies focused on the in vivo efficacy, mode of action and identification of the active compounds are needed. This study determined the potential of Ocimum americanum EO for use against two important fish pathogens, Aeromonas hydrophila and Gyrodactylus sp., as well as providing preliminary information about the role of the main EO compound (linalool) against Aer. hydrophila virulence.

Reduction of Toxoplasma gondii Development Due to Inhibition of Parasite Antioxidant Enzymes by a Dinuclear Iron(III) Compound.

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan that can infect a wide range of vertebrate cells. Here, we describe the cytotoxic effects of the dinuclear iron compound [Fe(HPCINOL)(SO4)]2-µ-oxo, in which HPCINOL is the ligand 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, on T. gondii infecting LLC-MK2 host cells. This compound was not toxic to LLC-MK2 cells at concentrations of up to 200 µM but was very active against the parasite, with a 50% inhibitory concentration (IC50) of 3.6 µM after 48 h of treatment. Cyst formation was observed after treatment, as indicated by the appearance of a cyst wall, Dolichos biflorus lectin staining, and scanning and transmission electron microscopy characteristics. Ultrastructural changes were also seen in T. gondii, including membrane blebs and clefts in the cytoplasm, with inclusions similar to amylopectin granules, which are typically found in bradyzoites. An analysis of the cell death pathways in the parasite revealed that the compound caused a combination of apoptosis and autophagy. Fluorescence assays demonstrated that the redox environment in the LLC-MK2 cells becomes oxidant in the presence of the iron compound. Furthermore, a reduction in superoxide dismutase and catalase activities in the treated parasites and the presence of reactive oxygen species within the parasitophorous vacuoles were observed, indicating an impaired protozoan response against these radicals. These findings suggest that this compound disturbs the redox equilibrium of T. gondii, inducing cystogenesis and parasite death.

Karyotypic diversity in a population of Bryconamericus aff. iheringii (Characidae).

Bryconamericus comprises 56 species distributed into three groups, on the basis of the position and shape of the maxillary teeth: B. exodon, B. microcephalus and B. iheringii groups. Few cytogenetic data are available for this genus, but the diploid number of 52 chromosomes is quite common, although the karyotypic variability is extensive. This study aimed to characterize a population of B. aff. iheringii and thus contribute more cytogenetic information and better understanding of the structure and karyotypic evolution of this genus. We found 6 cytotypes with different NOR patterns: cytotype I showed a karyotype formula of 12m+10sm+16st+14a (FN = 90) and single NORs; cytotype II with 18m+14sm+10st+10a (FN = 94) and cytotype III with 20m+18sm+4st+10a (FN = 94), showing both single and multiple NORs; cytotype IV with 20m+14sm+12st+6a (NF = 98), cytotype V with 22m+18sm+8st+4a (FN = 100) and cytotype VI with 18m+24sm+6st+4a (FN = 100), all with multiple NORs. Cytotype I is the most different in relation to FN and NOR pattern, and can be regarded as belonging to another species of the genus Bryconamericus, living in sympatry in Três Bocas Stream. The remaining cytotypes may have been generated by crosses between them and by pericentric inversions. Meiotic cells were also analyzed and showed that despite the high karyotypic variability, chromosome pairing occurred normally. The great variability found in B. aff. iheringii may be related to a high degree of polymorphism; nevertheless, the possibility of occurrence of more than one species in this location is not ruled out, demonstrating the need for conservation of the Três Bocas Stream.

Larvicidal activity of Brazilian plant essential oils against Coenagrionidae larvae.

Odonate larvae can be serious pests that attack fish larvae, postlarvae, and fingerlings in fish culture tanks, causing significant loss in the supply and production of juveniles. This study reports a screen of the essential oils (EOs) of Nectandra megapotamica (Sprengel) Mez, Nectandra grandiflora Nees, Hesperozygis ringens (Bentham) Epling, Ocimum gratissimum L., Aloysia gratissima (Gillies & Hooker) Troncoso, and Lippia sidoides Chamisso against Coenagrionidae larvae. In addition, the most effective EO and its 50% lethal concentration (LC50) and chemical analysis are described. The larvae of Acanthagrion Selys, Homeoura Kennedy, Ischnura Charpentier, and Oxyagrion Selys were used to assess the EO effects. EO obtained from H. ringens, O. gratissimum, and L. sidoides showed the highest larvicidal effects at 19 h of treatment. The major constituents of the EO of H. ringens include pulegone and limonene, while eugenol and Z-beta-ocimene predominate in the EO of O. gratissimum, and carvacrol and rho-cymene were the major compounds of the EO of L. sidoides. Leaf EOs from H. ringens, O. gratissimum, and L. sidoides showed activity against Coenagrionidae larvae at similar concentrations with LC50s of 62.92, 75.05, and 51.65 microl liter(-1), respectively, and these were considered the most promising treatments.

Behavioral effects of a low molecular weight peptide fraction from Phaseolus vulgaris in rats.

Seminal studies stated that bean proteins are efficient neuronal tracers with affinity for brain tissue. A low molecular weight peptide fraction (<3kDa) from Phaseolus vulgaris (PV3) was previously reported to be antioxidant, non-cytotoxic, and capable of reducing reactive oxygen species and increasing nitric oxide in cells. We evaluated the effects of PV3 (5, 50, 100, 500, and 5000 µg/kg) on behavior and the molecular routes potentially involved. Acute and chronic PV3 treatments were performed before testing Wistar rats: i) in the elevated plus-maze (EPM) to assess the anxiolytic-like effect; ii) in the open field (OF) to evaluate locomotion and exploration; and iii) for depression-like behavior in forced swimming (FS). Catecholaminergic involvement was tested using the tyrosine hydroxylases (TH) enzyme inhibitor, α-methyl-DL-tyrosine (AMPT). Brain areas of chronically treated groups were dissected to assess: i) lipid peroxidation (LPO); ii) carbonylated proteins (CP); iii) superoxide dismutase (SOD) and catalase (CAT) enzymatic activities. Neuronal nitric oxide synthases (nNOS) and argininosuccinate synthase (ASS) protein expression was evaluated by western blotting. Acute treatment with PV3 increased the frequency and time spent in the EPM open arms, suggesting anxiolysis. PV3 increased crossing episodes in the OF. These PV3 effects on anxiety and locomotion were absent in the chronically treated group. Acute and chronic PV3 treatments reduced the immobility time in the FS test, suggesting an antidepressant effect. TH inhibition by AMPT reverted acute PV3 effects. PV3 decreased LPO and CP levels and SOD and CAT activities, whereas nNOS and ASS were reduced in few brain areas. In conclusion, PV3 displayed central antioxidant actions that are concomitant to catecholaminergic-dependent anxiolytic and antidepressant effects.

Braylin induces a potent vasorelaxation, involving distinct mechanisms in superior mesenteric and iliac arteries of rats.

Arterial hypertension is a risk factor for various cardiovascular and renal diseases, representing a major public health challenge. Although a wide range of treatment options are available for blood pressure control, many hypertensive individuals remain with uncontrolled hypertension. Thus, the search for new substances with antihypertensive potential becomes necessary. Coumarins, a group of polyphenolic compounds derived from plants, have attracted intense interest due to their diverse pharmacological properties, like potent antihypertensive activities. Braylin (6-methoxyseselin) is a coumarin identified in the Zanthoxylum tingoassuiba species, described as a phosphodiesterase-4 (PDE4) inhibitor. Although different coumarin compounds have been described as potent antihypertensive agents, the activity of braylin on the cardiovascular system has yet to be investigated. To investigate the vasorelaxation properties of braylin and its possible mechanisms of action, we performed in vitro studies using superior mesenteric arteries and the iliac arteries isolated from rats. In this study, we demonstrated, for the first time, that braylin induces potent vasorelaxation, involving distinct mechanisms from two different arteries, isolated from rats. A possible inhibition of phosphodiesterase, altering the cyclic adenosine monophosphate (cAMP)/cAMP-dependent protein kinase (PKA) pathway, may be correlated with the biological action of braylin in the mesenteric vessel, while in the iliac artery, the biological action of braylin may be correlated with increase of cyclic guanosine monophosphate (cGMP), followed by BKCa, Kir, and Kv channel activation. Together, these results provide evidence that braylin can represent a potential therapeutic use in preventing and treating cardiovascular diseases.

Antinociceptive effect of topiramate in models of acute pain and diabetic neuropathy in rodents.

This study assesses the antinociceptive effect induced by different dosages of topiramate (TP), an anticonvulsant drug that is orally administered in models of neuropathic pain and acute pain in rats and mice, respectively. Orally administered TP (80 mg/Kg) in mice causes antinociception in the first and second phases of a formalin test, while in doses of 20 and 40 mg/Kg it was only effective in the second phase. TP (80 mg/Kg, p.o) also exhibited antinociceptive action in the hot plate test, however, it did not have an effect in the capsaicin test in mice, nor in the model of neuropathic pain in diabetic rats. The antinociceptive effect caused by TP (80 mg/Kg, p.o) in the formalin test was reversed by prior treatment with naloxone (opioid antagonist), but not with glibenclamide (antagonist of the potassium channel), ondansetron (antagonist of the serotonin 5HT3 receptor) or cyproheptadine (antagonist of the serotonin 5HT2A receptor).The data show that TP has an important antinociceptive effect in the models of nociception induced by chemical (formalin) or thermal (hot plate) stimuli, and that the opioid system plays a part in the antinociceptive effect, as shown by formalin.

Reproducibility of quantitative sensory testing applied to musculoskeletal orofacial region: Site and sex differences.

BACKGROUND: This study estimated the inter-rater reliability and agreement of the somatosensory assessment performed at masseter and temporomandibular joint (TMJ) region in a group of healthy female and male participants. METHODS: Forty healthy participants (20 men and 20 women) were evaluated in two sessions by two different examiners. Cold detection threshold (CDT), warm detection threshold (WDT), thermal sensory limen (TSL), cold pain threshold (CPT), heat pain threshold (HPT), mechanical detection threshold (MDT), mechanical pain threshold (MPT), wind-up ratio (WUR) and pressure pain threshold (PPT) were assessed on the skin overlying TMJ and masseter body. Mixed ANOVA, intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were applied to the data (α = 5%). Nonoverlapping 95% confidence intervals (95% CI) of ICCs were considered significantly different. RESULTS: The ICCs of 77% of all quantitative sensory testing (QST) measurements were considered fair to excellent (ICCs: 0.47-0.97), and WUR presented the lowest values. The reliability of WDT, TSL and HPT of masseter was significantly higher than TMJ, whereas the MDT reliability of TMJ was higher than masseter. In addition, the following combination of test/sites presented significantly lower ICCs for women: HPT, MDT of TMJ and MPT of both TMJ and masseter. Finally, the highest SEM values were presented for CPT and MPT. CONCLUSION: The overall somatosensory assessment of the masticatory structures performed by two examiners can be considered sufficiently reliable to discriminate participants, except WUR. Possible site and sex influences on the reproducibility parameters should be taken into account for an appropriate interpretation and clinical application of QST. SIGNIFICANCE: The test site and participant's sex can significantly influence the relative reliability and agreement of quantitative sensory testing applied to musculoskeletal orofacial region, which affect the capacity to discriminate participants and to evaluate changes over time.

Behavioral effects of Bj-PRO-7a, a proline-rich oligopeptide from Bothrops jararaca venom.

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.

Phospholipases A2 isolated from Micrurus lemniscatus coral snake venom: behavioral, electroencephalographic, and neuropathological aspects.

The present study evaluated four phospholipase A2 (PLA2) (Mlx-8, Mlx-9, Mlx-11 and Mlx-12) isolated from Micrurus lemniscatus snake venom (Elapidae). The effects of intrahippocampal administration of these toxins have been determined on behavior, electroencephalography, and neuronal degeneration in rats. These four PLA2 toxins induced motor and EEG alterations in a dose-dependent manner. Behavioral convulsions were characterized by clonic movements and were often accompanied by EEG alterations. Mlx toxins were convulsive but weakly epileptogenic, since low rates of seizure discharges were observed in EEG records. Neuronal injury seemed to depend on the dose of the toxin used. The highest doses of toxins caused severe intoxication and death of some animals. The injury of hippocampal cells was characterized by massive neuronal loss and hippocampal gliosis. A high occurrence of compulsive scratching was observed. Moreover, the onset of seizures induced by Mlx toxins was markedly delayed. The similarities between the effects of Mlx PLA2s and those isolated from other Elapidae snakes venoms suggest that their toxicity are probably due to their specific binding to neuronal membranes and to the catalysis of phospholipid hydrolysis, producing lysophospholipids and fatty acids. These compounds likely disturb the membrane conformation, causing a marked increase in the release of neurotransmitters and concurrent inhibition of vesicle fission and recycling. These toxins can be a useful tool to investigate properties of endogenous secretory PLA2s and therefore may be important both to study mechanisms involved in neurotransmitter release at nerve terminals and to explain the convulsive properties of PLA2s toxins.

NO production and potassium channels activation induced by Crotalus durissus cascavella underlie mesenteric artery relaxation.

Animal toxins are natural resources for pharmacological studies. The venom of Crotalus durissus cascavella (C.d. cascavella) may be a source in the bio-prospecting of new anti-hypertensive agents. The aim of this study was to investigate vascular effects of the venom of C.d. cascavella in normotensive rats. Studies were performed using isolated mesenteric artery segments and aortic endothelial cells. The cumulative administration of the venom of C.d. cascavella (0.001-30 µg/mL) on phenylephrine (Phe; 10 µM) pre-contracted rings induced a concentration-dependent vasorelaxation in the presence of vascular endothelium (Emax = 47.9 ± 5.0% n = 8), and its effect was almost abolished in the absence of endothelium (Emax = 5.8± 2.4% n = 5 (∗∗∗p < 0.001)). Tissue viability was maintained as there was no difference in the contractile capacity of rings before and after the administration of venom. The vasorelaxant effect of the venom was also abolished when arteries were pre-contracted with potassium chloride (KCl; 80 mM) (Emax = 6.4± 0.9% n = 5, ∗∗∗p < 0.001). When assessing the participation of endothelium-derived relaxing factors, it was noted that non-selective COX inhibition with indomethacin (10 µM) caused a significant reduction in the vasorelaxant effect of C.d. cascavella (*p < 0.05). When investigating the participation of NO released by endothelium, there was a significant reduction of the vasorelaxant effect of venom in rings treated with L-NAME (100 µM; Emax = 17.5± 2.2% n = 6; **p < 0.01). Similar results were noted in the presence of ODQ (10 µM), an inhibitor of soluble guanylyl cyclase (Emax = 11.2± 3.5%, n = 6) and PTIO (100 µM), a stable radical scavenger for nitric oxide (Emax = 10.77± 3.6%, n = 6). Moreover, the venom induced the release of NO by isolated aortic endothelial cells through amperometric studies. When assessing the participation of K+ channels on the vasodilatory response of the venom, tyrode solution with 20 mM of KCl caused a significant reduction in the relaxation response (p < 0.001) (Emax = 21.3 ± 8%, n = 7), as did inhibitor of delayed rectifier K+ channels (4-amynopiridine 1 mM; Emax = 9.5 ± 1.3, %, n = 5, ***p < 0.001), and vasorelaxation was almost abolished in the presence of Iberiotoxin (IbTx 100 nM). Therefore, these results suggest that the venom of C.d. cascavella induces vasorelaxation in superior mesenteric artery rings of normotensive rats in an endothelium-dependent manner. Specifically, the venom stimulates the generation of endothelium-derived relaxing factors, especially NO, and activates vascular smooth muscle hyperpolarization through K+ channels. These data illustrate that C.d. cascavella is a source of bioactive molecules and therefore has therapeutic potential in the treatment of cardiovascular diseases such as hypertension.

Behavioral effects of a low molecular weight peptide fraction from Phaseolus vulgaris in rats

Seminal studies stated that bean proteins are efficient neuronal tracers with affinity for brain tissue. A low molecular weight peptide fraction (<3kDa) from Phaseolus vulgaris (PV3) was previously reported to be antioxidant, non-cytotoxic, and capable of reducing reactive oxygen species and increasing nitric oxide in cells. We evaluated the effects of PV3 (5, 50, 100, 500, and 5000 µg/kg) on behavior and the molecular routes potentially involved. Acute and chronic PV3 treatments were performed before testing Wistar rats: i) in the elevated plus-maze (EPM) to assess the anxiolytic-like effect; ii) in the open field (OF) to evaluate locomotion and exploration; and iii) for depression-like behavior in forced swimming (FS). Catecholaminergic involvement was tested using the tyrosine hydroxylases (TH) enzyme inhibitor, α-methyl-DL-tyrosine (AMPT). Brain areas of chronically treated groups were dissected to assess: i) lipid peroxidation (LPO); ii) carbonylated proteins (CP); iii) superoxide dismutase (SOD) and catalase (CAT) enzymatic activities. Neuronal nitric oxide synthases (nNOS) and argininosuccinate synthase (ASS) protein expression was evaluated by western blotting. Acute treatment with PV3 increased the frequency and time spent in the EPM open arms, suggesting anxiolysis. PV3 increased crossing episodes in the OF. These PV3 effects on anxiety and locomotion were absent in the chronically treated group. Acute and chronic PV3 treatments reduced the immobility time in the FS test, suggesting an antidepressant effect. TH inhibition by AMPT reverted acute PV3 effects. PV3 decreased LPO and CP levels and SOD and CAT activities, whereas nNOS and ASS were reduced in few brain areas. In conclusion, PV3 displayed central antioxidant actions that are concomitant to catecholaminergic-dependent anxiolytic and antidepressant effects.

Folha de amendoeira como aditivo em dietas para Betta splendens / Use of almond leaf as additive in diets for Betta splendens

O objetivo do presente estudo foi avaliar o desempenho zootécnico, os parâmetrosmorfométricos, o comportamento social, a viabilidade econômica e a análise microbiológica da água de cultivo e de tecidos corpóreos de Betta splendens alimentados com folha da amendoeira Terminalia catappa (FFDA) como aditivo. Foram utilizados 28 machos de Bettas, acondicionados individualmente em aquários de 1,5L, por 50 dias. O experimento foi realizado em delineamento experimental inteiramente ao acaso, com quatro tratamentos: 0,00%; 0,25%; 0,50% e 0,75% de inclusão da FFAD e sete repetições. Ao término do experimento, foram avaliados os parâmetros: desempenho zootécnico (ganho de peso diário, consumo de ração, conversão alimentar aparente, taxa de eficiência proteica, taxa de crescimento específico e fator de condição), morfométrico (comprimento total, padrão e da cabeça, altura, índice de perfil e índice de cabeça), comportamento social, viabilidade econômica da ração, análise microbiana do conteúdo intestinal, filé e escama e análise microbiológica da água. Pela ANOVA, pelo teste de Tukey e pela regressão (P>0,05), os parâmetros: peso final, ganho de peso, comprimento padrão, comprimento total e taxa de crescimento específico foram influenciados pelos tratamentos (P<0,05), apresentando um efeito quadrático. Assim, recomenda-se o nível de 0,50% de Terminalia catappa como aditivo em dietas de Betta splendens.(AU)

The objective of this study was to evaluate the performance, morphometric parameters, social behavior, economic viability, the presence of enterobacteria in the intestinal contents and a microbiological analysis of the water culture of Betta splendens fed with almond-tree-leaf flour (ATLF) as an additive. Twenty-eight male B. splendens were individually put in 1.5 L aquariums. The experiment was done in a completely randomized experimental design with four treatments: 0.00%; 0.25%; 0.50% and 0.75%, of the ATLF, dehydrated Terminalia catappa with seven repetitions each. At the end of the experimental period, the parameters were evaluated: performance (daily weight gain, feed intake, apparent feed conversion, protein efficiency rate, specific growth rate and condition factor), morphometric (total length, standard head, height, profile index and head index), social behavior, economic viability of the feed, microbial analysis of intestinal contents, fillet and scales, and microbiological analysis of the water. Though ANAVA, Tukey test and regression analysis (P> 0.05), the parameters: final weight, weight gain, standard length, total length and specific growth rate were influenced by the treatments (P< 0.05), presenting a quadratic effect. Therefore, the 0.50% level of Terminalia catappa is recommended as additive in Betta splendens diets.(AU)

Frequência cardíaca, lactacidemia e gasto energético de equinos da raça Crioula em provas credenciadoras ao Freio de Ouro / [Heart rate, lactate concentration and energy expenditure of Creole breed horses during qualifying tests at Freio de Ouro]

Avaliações com o intuito de mensurar marcadores de eficiência na performance esportiva do cavalo Crioulo são escassas e de fundamental importância no que tange às possíveis especificidades da raça. O objetivo do presente trabalho foi avaliar e determinar os padrões de frequência cardíaca, velocidade, concentração de lactato e gasto energético de equinos da raça Crioula durante provas credenciadoras ao Freio de Ouro. Tais variáveis foram avaliadas durante a realização das etapas funcionais da competição. Observaram-se flutuações superiores da variável frequência cardíaca (FC) durante a realização das etapas de Andadura, Figura, Volta sobre Patas e Esbarradas (And/fig/VSP) (203bpm) e menores valores na etapa Paleteada II (185bpm) (P<0,05). Em relação à velocidade, o maior valor atingido foi registrado na etapa de Paleteada II (39,7km/h). A concentração de lactato sanguíneo aferida se mostrou elevada em todas as fases da competição, sendo o maior valor observado na etapa de Paleteada II (14,5mmol/L) (P<0,05) e o menor durante a etapa de Mangueira I (9,3mmol/L). Superior gasto energético foi atribuído à etapa de And/Fig/VSP (853,28kcal/kgPV/min). Portanto, todas as etapas funcionais podem ser classificadas como anaeróbias, por apresentarem concentrações de lactato sanguíneo acima de 4mmol/L, e demandam alto gasto energético pelos competidores.(AU)

Evaluations of athletic performance markers of Crioulo breed horses are scarce yet fundamentally important regarding possible unique characteristics of this breed. This study aimed to evaluate and determine heart rate, speed, blood lactate and energy expenditure patterns of Crioulo breed horses during qualifying tests in the functional phases of the "Freio de Ouro" championship. Higher values of heart rate during the phases "andadura, figura, voltas sobre patas, esbarradas" (And/Fig/VSP) (203bpm) and lower values at "Paleteada II" (185bpm) (P<0.05) were noticed. Regarding speed variable, the maximum value was registered at "Paleteada II" (39.7km/h). During all the phases, blood lactate concentration was high, with the highest value found at "Paleteada II" (14.5mm/L) and the lowest during "Mangueira I" (9.3mm/L) (P<0.05). Superior energy expenditure was noticed in the "And/Fig/VSP" phase (853.28Kcal/kgPV/min). Thus, all functional phases can be classified as anaerobic, as blood lactate concentrations remained above 4mmol/L, with high energy demand of the horses.(AU)

Toxins isolated from the venom of the Brazilian coral snake (Micrurus frontalis frontalis) include hemorrhagic type phospholipases A2 and postsynaptic neurotoxins.

Toxins isolated from the venom of the Brazilian coral snake (Micrurus frontalis frontalis) include hemorrhagic type phospholipases A2 and postsynaptic neurotoxins. Toxicon 35, 1193-1203, 1997.-Two sets of proteins have been purified from the venom of the Brazilian coral snake, Micrurus frontalis frontalis. One set has mol. wts, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), in the 8000-13,000 range and includes some proteins which are toxic to mice and others which are not. These proteins appear to be isoforms of postsynaptic toxins. The other set shows phospholipase A2 (PLA2) activity and the toxic members of this set promote hemorrhage in mice in a manner closely resembling that produced by PLA2s isolated from the venom of the Australian tiger snake (Notechis scutatus scutatus). These PLA2s migrate on SDS-PAGE with apparent mol. wts in the 18,000-22,000 range which is characteristic of PLA2s that have an alpha-helix D similar to pancreatic PLA2s. Elapid venom PLA2s of the type which typically migrate on SDS-PAGE with mol. wts in the 13,000-16,000 range and do not have alpha-helix D have not been detected in M. f. frontalis venom.

The evolution of the AIDS illness and the polarisation of values.

This article is based on a study carried out in Sao Paolo, Brazil, from 1983 to 1986 among male homosexuals. It deals with the various practices and life-styles which constitute the homosexual world in Sao Paulo, and questions regarding AIDS. An analysis is made of the contrasting biographies of two patients suffering from the AIDS virus. The emphasis will be placed on the evolution of the illness and the changes in values that occur during this period. The ways in which the sexual life-style adopted prior to the illness influences the individual social course or mobility [i.e., trajectory] of the inflicted person will also be illustrated.

PIP: MC and KR are two young men who were living with AIDS in Sao Paulo, Brazil, during 1983-86. MC is a 25-year old son of Italian immigrants and KR is a 24-year old grandson of German immigrants. MC attained a relative degree of professional success by working as an airline steward, while KR was never really able to secure and maintain full-time, gainful employment. The author describes how being diagnosed and living with AIDS changed their lives and the way in which they perceive themselves. As a steward, MC traveled extensively to Europe and the US where he frequented the best gay clubs and saunas. He was open and proud of his homosexuality. Being diagnosed with AIDS and going through its sequelae of morbidity and lost income and productivity, however, changed this self-perception. MC began to deny his homosexuality, embraced religion, and avoided talking about his past. In so doing, he distanced himself from all that was responsible for his currently painful experiences. KR, however, had lived a very modest suburban life, having sexual relations with men in the city for money when the need and desire motivated him. KR enjoyed sex with men, but hated being homosexual. He had therefore denied his homosexuality and hid it from as many people as possible. As it did for MC, diagnosis and hospitalization with AIDS changed KR's life. KR's life, however, changed for the better. Once back at home out of the hospital, KR began telling everyone that he had AIDS. A well-known weekly doing a story on AIDS subsequently used a photo of KR for its cover and began paying KR a minimum salary. For the first time in his life, KR gained notoriety and began receiving affection from a broad segment of the community. KR had achieved some degree of success. KR explained that facing death gave him a newfound openness and the ability to stop considering all that is relative as absolute, such as sexuality, the family, sin, and friendship. Death became the only absolute. MC therefore fell from success to failure, while the opposite was true for KR. Both had been role models for their brothers. Once that role was compromised, the brothers rejected MC and KR. The author notes how individuals, once confronted with situations which fall outside the ordinary social world, are obliged to reconstruct and reinterpret their new situation, and suggests to what extent AIDS becomes a determining factor in recognizing and accepting homosexuality.

Oribatid mite (Acari: Oribatida) contribution to decomposition dynamic of leaf litter in primary forest, second growth, and polyculture in the Central Amazon.

We studied the contribution of oribatid mites in the dynamics of litter decomposition in an experiment using litterbags of three different mesh sizes (20 microns, 250 microns, and 1 cm). The experiment was carried out at a primary forest (FLO), a secondary forest (SEC), and at two polyculture systems (POA and POC). We compared the weight loss of the leaves of Vismia guianensis and the changes of the oribatid mite species community. We processed the samples after 26, 58, 111, 174, 278, and 350 days from the beginning of the experiment by using the Berlese-Tullgren to extract the animals. We hypothesized that: 1. the abundance and diversity of oribatid mites would exert an influence in the decomposition process; 2. there would be a successional changing of the species during decomposition; and 3. there would be differences in the colonization of species in relation to the mesh size of the litterbags. A total of 95 species of oribatid mites was found. The biomass data was the first registered for the Amazon region. The great dominance of oribatid mites did not exert an influence in the decomposition process. There was not a successional changing of the species during the course of the decomposition process, unlike those shown by results obtained in the temperate forest, because we found neither early colonizers nor species that prefer advanced decomposition stages. The oribatid mite community, which developed in the litterbags under tropical conditions, was atypical of the normal stages of leaf litter breakdown and decomposition. There were differences in the colonization of species in relation to the mesh size of the litterbags. These differences were very closely related to the specific habits and habitat of the dominant species.

Behavioral effects of Bj-PRO-7a, a proline-rich oligopeptide from Bothrops jararaca venom

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.