Survival, growth and biochemical parameters of silver catfish, Rhamdia quelen (Quoy & Gaimard, 1824), juveniles exposed to different dissolved oxygen levels

Silver catfish, Rhamdia quelen (Quoy & Gaimard, 1824), is an endemic species from Latin America that is raised in cultivation ponds, and consequently may be exposed to low oxygen levels. Therefore, the objective of this study was to verify the lethal concentration (CL_{50?96 h}) of dissolved oxygen levels for silver catfish juveniles. In addition, the effects of different dissolved oxygen levels (1.96±0.08, 3.10±0.10, 4.14±0.09, 5.20±0.07 and 6.16±0.03 mg L^?1) on growth and metabolic parameters (glycogen, glucose, protein, lactate levels and catalase activity) were also investigated. CL_{50?96 h} was 0.52 mg L^?1 (CI 0.42–0.61 mg L^?1) or 6.7% oxygen saturation. After exposure of silver catfish to hypoxia for 30 days, there were no changes in biochemical parameters indicating the use of an anaerobic pathway by the fish. However, the dissolved oxygen levels influenced silver catfish juvenile behaviour, survival and growth, and under the experimental conditions 5.2 mg L^?1 (or 65.6% oxygen saturation) is the minimum oxygen level recommended for the growth of this species.     

Chlamydophila psittaci in free-living Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil

Chlamydophila psittaci (C. psittaci) infection was evaluated in 77 free-living nestlings of Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil. Tracheal and cloacal swab samples from 32 wild parrot and 45 macaw nestlings were submitted to semi-nested PCR, while serum samples were submitted to complement fixation test (CFT). Although all 32 Amazon parrot serum samples were negative by CFT, cloacal swabs from two birds were positive for Chlamydophila DNA by semi-nested PCR (6.3%); these positive birds were 32 and 45 days old. In macaws, tracheal and cloacal swabs were positive in 8.9% and 26.7% of the samples, respectively. Complement-fixing antibodies were detected in 4.8% of the macaw nestlings; macaw nestlings with positive findings were between 33 and 88 days old. These results indicate widespread dissemination of this pathogen in the two evaluated psittacine populations. No birds had clinical signs suggestive of chlamydiosis. To the best of our knowledge, this is the first report on C. psittaci in free-living Blue-fronted Amazon parrots and Hyacinth macaws in Brazil.     

Influence of Steroidal Anti-Inflammatory Drugs on Viability and Fertility of Equine Semen

Considering the efficiency of steroidal anti-inflammatory drugs (SAIDs) in the immunomodulation of breeding-induced endometritis and the possibility of using these drugs by intrauterine route instead of the parenteral application, the present study aimed at evaluating the effect of SAIDs added to the semen extender on equine sperm viability and fertility. In experiment 1, 15 SAIDs were individually added to a skim milk-based extender and, based on the results of sperm motility, dexamethasone was the drug of choice for the subsequent trials. The effect of dexamethasone on the viability of fresh and 24-hour cooled semen was investigated in experiment 2. In experiment 3, fertility rate was measured in both post-breeding endometritis-resistant and susceptible mares. Although dexamethasone supplementation caused a premature decrease in sperm total and progressive motility and in sperm velocities (P < .05), no difference was observed for sperm membrane integrities and fertility (P > .05). Based on these results, we can conclude that dexamethasone can be added to equine semen at the time of insemination or before cooling, although its use was not able to increase fertility.     

Polyoxygenated Steroids from the Octocoral Leptogorgia punicea and in Vitro Evaluation of Their Cytotoxic Activity

Five new polyoxygenated marine steroids—punicinols A–E (1–5)—were isolated from the gorgonian Leptogorgia punicea and characterized by spectroscopic methods (IR, MS, ¹H, ¹³C and 2-D NMR). The five compounds induced in vitro cytotoxic effects against lung cancer A549 cells, while punicinols A and B were the most active, with IC₅₀ values of 9.7 μM and 9.6 μM, respectively. The synergistic effects of these compounds with paclitaxel, as well as their effects on cell cycle distribution and their performance in the clonogenic assay, were also evaluated. Both compounds demonstrated significant synergistic effects with paclitaxel.     

Acaricidal activity of Palicourea marcgravii, a species from the Amazon forest, on cattle tick Rhipicephalus (Boophilus) microplus

Leaves of Palicourea marcgravii were extracted successively with hexane, ethyl acetate and ethanol in order to evaluate their acaricidal activity on larvae and adult stages of the cattle tick Rhipicephalus (Boophilus) microplus. The ethyl acetate extract showed the highest bioactivity of the tested extracts, which contained 0.12% monofluoroacetic acid. On engorged female, the ethyl acetate extract showed a lethal concentration 50% - LC(50)=30.08 mg ml(-1), inhibitory concentration 50% - IC(50)=5.79 mg ml(-1) and lethal time 50% - LT(50)=4.72 days; 100% reproduction was controlled at concentrations of 50 mg ml(-1) and on larvae the ethyl acetate extract showed a LC(50)=2.46 mg ml(-1). No alkaloids were detected in any of the extracts. This is the first report on the acaricidal activity of P. marcgravii extracts against R. microplus as well as the acaricidal properties of a plant species containing monofluoroacetic acid.     

Fusariosis in rubber tree: pathogenic,morphological, and molecular characterization of the causal agent

Fusariosis, one of the phytosanitary problems found in rubber producing areas in the northwest of the state of São Paulo, is a disease that affects the bark of the adult plants, affecting the exploitation of latex. The typical symptoms appear as cracks in the bark that expand from the rootstock towards the tapping panel, causing a drying of the latex flux in the injured region, impeding latex tapping. Due to the recent incidence of this disease in rubber plantations, the goal of this study was to characterize the Fusarium associated with symptomatic rubber tissue in three different locations in the state of São Paulo. In order to identify Fusarium species, pathogenicity, morphological, cultural and molecular studies were carried out. A total of 51 isolates were obtained and separated into three groups based on macroconidium morphology, presence or absence of sporodochia, types of chlamydospores, formation of phialides and conidiogenesis of microconidia and mesoconidia, mycelial growth rate and coloring of the colonies. These groups were corroborated using DNA sequence information for five different genetic loci, and were subsequently recognized as Fusarium oxysporum, F. incarnatum and F. decemcellulare. Our results further showed that all 51 of the Fusarium isolates recovered were pathogenic to rubber tree seedlings of RRIM 600 standard clone. This study also reports for the presence of F. oxysporum and F. incarnatum in rubber plantations in the state of São Paulo and in Brazil.

     

Antimicrobial activity of extracts and some compounds from Calea platylepis

The antimicrobial activity of dichloromethane extracts (leaves, flowers and underground parts) and some compounds isolated from Calea platylepis were evaluated by the well diffusion method.     

Inheritance of type IV glandular trichome density and its association with whitefly resistance from <Emphasis Type="Italic">Solanum galapagense</Emphasis> accession LA1401

Tomato is affected by a large number of arthropod pests, among which the whitefly (Bemisia tabaci) is considered to be one of the most destructive. Several accessions of the wild species of Solanum galapagense, including accession LA1401, are considered resistant to whitefly (B. tabaci). This resistance has been associated with the presence of type IV glandular trichomes on the leaf surface. Our research aimed to study the inheritance of type IV glandular trichome density and its association with resistance to whitefly (B. tabaci biotype B) in populations derived from the interspecific cross Solanum lycopersicum × S. galapagense ‘LA1401.’ High estimates for both broad-sense and narrow-sense heritabilities of type IV glandular trichome densities suggest that inheritance of this trait is not complex. Whitefly resistance was associated with high density of type IV glandular trichomes. F₂ (S. galapagense × S. lycopersicum) population plants selected for the highest densities of type IV glandular trichomes showed similar levels of resistance to those found in the donor of resistance LA1401.     

Reproductive Development of Santa Inês Rams During the First Year of Life: Body and Testis Growth,Testosterone Concentrations,Sperm Parameters,Age at Puberty and Seminal Plasma Proteins

We have investigated the reproductive development of the tropically adapted Santa Inês ram, the most common hair sheep in Brazil. From 8 to 48 weeks of age, 16 animals were evaluated for body and testis growth, semen parameters, testosterone concentrations and seminal plasma proteins, using two‐dimensional SDS‐PAGE. Animals were weaned at 30 days and kept in feedlots thereafter, receiving hay, concentrate (18% of crude protein) and mineral supplement. Body weight increased from 12.3 ± 0.7 to 54.3 ± 1.6 kg between 8 and 48 weeks (p < 0.05), but changes in thoracic perimeter and scrotal circumference were non‐significant after 36 weeks (p > 0.05). The percentage of motile sperm increased slowly until 23 weeks and more rapidly after that age, but significant changes in progressive motility occurred after 25 weeks. Presence of abnormal sperm related inversely to age. Most significant changes in sperm concentration occurred between 38 and 44 weeks (0.38 ± 0.05 to 1.14 ± 0.24 × 10⁹ cells/ml, p < 0.05) and testosterone reached its highest concentrations at 42 weeks, decreasing afterwards. Rams reached puberty at 28.2 ± 0.8 weeks. The number of protein spots on seminal plasma gels was similar from 15 to 18 weeks (45 and 47 spots; p > 0.05), increased until 24 weeks (141 spots) and 28 weeks (170 spots; p < 0.05) and remained without significant (p > 0.05) changes from 28 to 48 weeks (186 ± 10 spots). Furthermore, the intensity of selected spots on 2D maps increased (p < 0.05) between 15 and 28 weeks, which preceded or coincided with the main developmental changes in sperm motility and percentage of defective sperm in the ejaculates. These results will support future studies designed to characterize specific seminal plasma proteins whose expression relate to the development of testis, epididymis and accessory sex glands.