Allelopathic effects of Araucaria angustifolia needle extracts in the growth of Lactuca sativa seeds

Araucaria forest, named due to the high abundance of Araucaria angustifolia, occurs mainly in the southern Brazilian highlands, and the abundance of A. angustifolia in the forest is a current forest issue. The present study aimed at evaluating a potential allelopathic effect of A. angustifolia needle extracts that could mediate plant successional dynamics in the Araucaria forests. Senescent araucaria needles from A. angustifolia were evaluated for their allelopathic potential on Lactuca sativa through an in vitro study. The effect was evaluated by determining the germination of seeds, length of seedling and germination rate. The allelopathic potential of the A. angustifolia was confirmed for the highest doses tested (187.5 and 250?mg of the extracts). The potential allelochemical compounds identified were ent-kaurene and phyllocladene. In conclusion, A. angustifolia showed a potential allelophatic effect that may play an important role in successional dynamics of Araucaria forests.     

Population variability based on the morphometry and chemical composition of the acorn in Holm oak (Quercus ilex subsp. ballota [Desf.] Samp.)

We have studied in this work the natural variability in Holm oak (Quercus ilex subsp. ballota) by analyzing acorn morphometry and chemical composition in 13 populations from the Andalusia region (southern Spain). Acorn morphometry showed statistic significant differences between the populations with a higher acorn weight, length, and diameter in the northern provenances (TJA, GSE, CTH, CHU, APS, and PCO), while the Southern provenances (RMA, SAA, CCO, BCA, and SCA) showed lower value that even decreased with the altitude. Acorn chemical composition also showed statistic significant differences between populations. Morphometry and chemical composition data were subjected to clustering analysis, and two major clusters were detected. This analysis showed that northern populations (CTH, TJA, SCA, CHU, PCO, GSE, and APS) showed a tendency to present values highest in acorn weight (5.42?g vs. 3.21?g); acorn length (37.21?mm vs. 28.73?mm); acorn diameter (16.12?mm vs. 13.79?mm); ash (1.88% vs. 1.55%); protein (4.82% vs. 4.38%); fat (12.55% vs. 9.92%); and oleic acid (66.93 vs. 66.4%). On the contrary, Southern populations (SSA, VJA, CCO, BCA, RG, and RMA) showed a tendency to present values lowest in sugar (10.28% vs. 11.25%); energy (20,076.71?kJ/kg vs. 20,149.26?kJ/kg); palmitic (16.11% vs. 16.39%) and linoleic acids (13.07% vs. 13.11%). The populations studied here seemed to integrate acorn morphology and chemical composition related to environmental conditions of the original provenances. These data have provided biochemical markers that help establish phylogenic associations between populations and also reveal potentially account as an alternative source for dietary nutrition.     

Efficacy of albendazole and moxidectin and resistance to ivermectin against Libyostrongylus douglassii and Libyostrongylus dentatus in ostriches

Anthelmintic resistance has emerged globally as a problem amongst nematode of livestock and has been particularly well documented in equine and small ruminants. There are no studies regarding the efficacy of anthelmintics against the hematophagous nematodes in ostriches, Libyostrongylus dentatus; and just a few on L. douglassii. Here the efficacy of albendazole, ivermectin and moxidectin were evaluated against these two species in an ostrich farm in Minas Gerais state, Brazil. The feces were collected on the day of treatment and after 13days of an oral dose of albendazole (6mg/kg), or an injected dose (0.2mg/kg) of ivermectin or moxidectin. The fecal egg count reduction test and coprocultures were performed to determine possible resistance against the drugs used. An efficacy of 60% was found for ivermectin, while albendazole and moxidectin were 100% effective. Both worm species appeared to have reduced sensitivity to ivermectin.     

Increased incidence of DNA amplification in follicular than in uterine and blood samples indicates possible tropism of Neospora caninum to the ovarian follicle

This study evaluated the presence of Neospora caninum in ovarian follicle aspirates and uterine flushes obtained from N. caninum seropositive dairy cows. Ninety-two cows that aborted within the previous 90 days were sampled to determine the presence of antibodies against N. caninum. Thirteen seropositive cows were chosen for collection of blood leukocytes, uterine flushes (UF; n=12) and follicular aspirates (OPU; n=13). Samples were centrifuged and the cellular sediment from the follicular fluid, uterine flushes and blood leukocytes were used for DNA extraction and PCR. Follicular aspirates had the highest frequency of DNA amplification for N. caninum (p<0.05, 92.3%; 12/13). Whereas uterine (4/12) and blood leukocyte (5/13) samples had similar (p>0.05) rate of positive results. Nonetheless, there was no agreement between blood leukocytes and follicular samples taken from the same animal (Cohen Kappa=-0.16). Similarly, blood leukocytes and uterine results had moderate agreement between them (Cohen Kappa=0.47). This study indicates that N. caninum is present in the ovarian follicle and uterus of seropositive cows, suggesting a possible risk of neosporosis transmission between females during oocyte and embryo collection and transfer. Hence, precautions should be taken to minimize the risk of N. caninum transmission. Furthermore, the high incidence of positive results in follicle samples, that exceeded that of their paired blood leukocytes, suggests a possible tropism of N. caninum for the ovarian follicle.     

A new type of pterocarpanquinone that affects Toxoplasma gondii tachyzoites in vitro

Toxoplasma gondii, the agent of Toxoplasmosis, is an obligate intracellular protozoan able to infect a wide range of vertebrate cells, including nonprofessional and professional phagocytes. Therefore, drugs must have intracellular activities in order to control this parasite. The most common therapy for Toxoplasmosis is the combination of sulfadiazine and pyrimethamine. This treatment is associated with adverse reactions, thus, the development of new drugs is necessary. In previous studies, naphthoquinone derivatives showed anti-cancer activity functioning as agents capable of acting on groups of DNA, preventing cancer cells duplication. These derivatives also display anti-parasitic activity against Plasmodium falciparum and Leishmania amazonensis. The derivative pterocarpanquinone tested in this work resulted from the molecular hybridization between pterocarpans and naphtoquinone that presents anti-tumoral and anti-parasitic activities of lapachol. The aim of this work was to determine if this derivative is able to change T. gondii growth within LLC-MK2 cells. The drug did not arrest host cell growth, but was able to decrease the infection index of T. gondii with an IC(50) of 2.5 μM. Scanning and transmission electron microscopy analysis showed morphological changes of parasites including membrane damage. The parasite that survived tended to encyst as seen by Dolichos biflorus lectin staining and Bag-1 expression. These results suggest that pterocarpanquinones are drugs potentially important for the killing and encystment of T. gondii.     

Assessing turnover of microbial biomass phosphorus: Combination of an isotopic dilution method with a mass balance model

Microbial biomass phosphorus (P) can play an important role in P cycling and availability to plants by acting as a source (remineralization) or sink (immobilization) of phosphate ions (iP). To assess the role of the microbial P pools, both the dynamics (i.e. the turnover) and the size of the microbial P pools were studied in forest soils. Combining an isotopic dilution method with a modelling approach, we showed the existence of two pools of microbial P with different dynamics and therefore of different importance in soil P availability and cycling. In particular, we showed that the largest pool of microbial P (80%) had a fast turnover (nine days). Microbial P increased with an increase in soil organic matter and represented up to 53% of total P in contrasting forest soils. By combining these results with the turnover times of microbial P obtained in the modelling study, we evaluated that 8.5-17.3 kg P ha⁻¹ of microbial P could turn over in a few days. This suggests that microbial biomass P is a potentially significant source of available iP, and that micro-organisms can play a major role in P cycling in the forest studied here. However, microbial biomass can also be in competition with the trees since most of the remineralized P could be immobilized again in the microbial turnover.     

Results of a national survey of US veterinary college faculty regarding attitudes toward farm animal welfare

OBJECTIVE: To examine attitudes toward farm animal welfare among veterinary college faculty. DESIGN: E-mail survey. STUDY POPULATION: 157 US veterinary college faculty with large animal or food animal emphasis. PROCEDURE: Veterinarians from 27 US veterinary colleges were contacted via e-mail and asked to complete a 7-page survey relating to farm animal welfare issues. Thirty-one percent of those contacted responded. RESULTS: 71% of respondents self-characterized their attitude toward farm animal welfare as "we can use animals for the greater human good but have an obligation to provide for the majority of the animals' physiologic and behavioral needs." An additional 19% of respondents were more concerned about animal welfare than was indicated by that statement, and 10% were less concerned about farm animal welfare than was indicated by that statement. Significant relationships among demographic variables and attitude scores were observed, including more concerned attitudes among females, those with more liberal political views, and those who cited lower religiosity. No relationship between attitude and age was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinary college faculty have the opportunity to impact many stakeholders within the animal agriculture industries (eg, future veterinarians and policy makers looking for a veterinary science perspective). Results indicated that a considerable level of concern toward farm animal welfare is present in this population. Although the process of change may not be rapid, it is likely that the influence of these respondents will factor heavily into enhancing farm animal welfare.     

Reproductive characteristics of grass-fed, luteinizing hormone-releasing hormone-immunocastrated Bos indicus bulls

Two field trials were conducted in Brazil to evaluate LHRH immunocastration of Bos indicus bulls (d 0 = 2 yr of age). In Study I, 72 bulls were assigned randomly to one of three treatment groups: LHRH0-immunized, castrated, and intact. Immunized animals (n = 25) received a primary and two booster injections of ovalbumin-LHRH-7 and thioredoxin-LHRH-7 fusion proteins on d 0, 141, and 287. Twenty-three bulls were surgically castrated on d 141, and 24 served as intact controls. All animals were slaughtered on d 385, at approximately 3 yr of age. In Study II, 216 bulls were assigned randomly to the same three treatments as in Study I; however, because of a drought in the area, bulls were kept on pasture an additional year, and a fourth treatment was added, in which one-half the LHRH-immunized bulls received an additional booster on d 639 (fourth immunization). All animals in Study II were slaughtered on d 741 (4 yr of age). Luteinizing hormone-releasing hormone antibodies increased following each immunization for immunized bulls, but they were not detectable in castrate or intact animals in either study. Consequently, scrotal circumference was suppressed in immunized bulls compared with intact controls in both studies. By d 287, serum concentrations of testosterone in LHRH-immunized bulls were decreased compared with intact controls (P < 0.01). In both studies, testes and epididymal weights at slaughter were greater (P < 0.01) for intact (500 +/- 17 and 60 +/- 2 g, respectively) than for immunized bulls (173 +/- 22 and 26 +/- 2 g, respectively) and fourth immunization bulls (78 +/- 23 and 20 +/- 2 g, respectively; Study II). At the end of each study, BW was greater (P < 0.01) for intact bulls than for castrated and LHRH-immunized animals. In these two studies, the efficacy of the LHRH fusion proteins to induce an effect similar to that of surgical castration was considered 92 and 93%, respectively. These data support the concept that immunocastration of bulls at 2 yr of age was successful and that it has practical application as a tool for producing grass-fattened bulls in Brazil.     

Synthesis and in-vitro antifungal activity of 6-trifluoromethylpyrazolo[3,4-d]pyrimidines

Thirty 6-trifluoromethylpyrazolo[3,4-d]pyrimidines were synthesised and tested for antifungal activity in vitro against ten phytopathogenic fungi of different taxonomic classes. Six of the compounds had noteworthy activity against Sclerotinia minor, Corticium solani and Phoma betae. The relationships between structure and activity are discussed on the basis of the present and previous studies.     

Relationship between group II caspase activity of bovine preimplantation embryos and capacity for hatching

The occurrence of apoptosis in a fraction of blastomeres in the preimplantation embryo is well known but the consequences of this phenomenon for the developmental potential of the blastocyst has not been well established. Here we demonstrate that blastocysts with low amounts of activated group II caspase activity have increased potential for development to the hatched blastocyst stage. Bovine blastocysts produced in vitro were assayed using a non-invasive fluoregenic substrate that is cleaved by activated group II caspases (i.e., caspase-2, -3 and -7). Subsequently, blastocysts were cultured until Day 10 post-insemination and the proportion undergoing hatching determined. In Experiment 1, blastocysts were cultured without respect to stage of development (expanded or non-expanded); blastocysts classified as having low caspase activity had higher hatching rates than blastocysts with medium or high caspase activity. In Experiment 2, embryos were categorized as nonexpanded or expanded blastocysts. Caspase activity was lower and hatching rate higher for expanded blastocysts than for nonexpanded blastocysts. For nonexpanded blastocysts, embryos classified as having low caspase activity had higher hatching rates as compared to embryos with medium or high caspase activity. In conclusion, the capacity for blastocysts to undergo further development is related to degree of group II caspase activity. Conditions that enhance the incidence of apoptosis in blastocysts may reduce developmental competence. In addition, determination of caspase activity may be useful for selection of embryos for transfer into recipients.