Systolic time intervals assessed by 2-D echocardiography and spectral Doppler in the horse

In the present study, the ‘acoustic windows’ for the measurement of the left ventricular systolic time intervals is studied by means of 2‐D echocardiography and cardiac Doppler ultrasonography, and the normal values in the horse (n = 112) are determined. The left ventricular isovolumetric contraction time, the pre‐ejection period (PEP), as well as the left ventricular ejection time (LVET) have been measured, and the values of the left ventricular total electromechanical systole (LVTES) and the PEP‐to‐LVET ratio have been calculated. It has been established that the most suitable window for the measurement of the aforementioned indices in 2‐D echocardiography is the right parasternal window in a view in short axis at the level of the cardiac base to measure the aortogram. In Doppler ultrasonography, the preferred window is the left parasternal using the five chambers apical view. The following values have been acquired: PEP = 0.071 ± 0.01 s; LVET = 0.532 ± 0.097 s; LVTES = 0.6 ± 0.1 s and PEP‐to‐LVET = 0.138 ± 0.025 measured by 2‐D echocardiography and PEP = 0.068 ± 0.009 s; LVET = 0.527 ± 0.076 s; LVTES = 0.598 ± 0.098 s and PEP‐to‐LVET = 0.131 ± 0.01 measured by Doppler ultrasonography.     

Neural encoding of olfactory recognition memory

Our work with both sheep and mouse models has revealed many of the neural substrates and signalling pathways involved in olfactory recognition memory in the main olfactory system. A distributed neural system is required for initial memory formation and its short-term retention-the olfactory bulb, piriform and entorhinal cortices and hippocampus. Following memory consolidation, after 8 h or so, only the olfactory bulb and piriform cortex appear to be important for effective recall. Similarly, whereas the glutamate-NMDA/AMPA receptor-nitric oxide (NO)-cyclic GMP signalling pathway is important for memory formation it is not involved in recall post-consolidation. Here, within the olfactory bulb, up-regulation of class 1 metabotropic glutamate receptors appears to maintain the enhanced sensitivity at the mitral to granule cell synapses required for effective memory recall. Recently we have investigated whether fluctuating sex hormone levels during the oestrous cycle modulate olfactory recognition memory and the different neural substrates and signalling pathways involved. These studies have used two robust models of social olfactory memory in the mouse which either involve social or non social odours (habituation-dishabituation and social transmission of food preference tasks). In both cases significant improvement of learning retention occurs when original learning takes place during the proestrus phase of the ovarian cycle. This is probably the result of oestrogen changes at this time since transgenic mice lacking functional expression of oestrogen receptors (ERalpha and ERbeta, the two main oestrogen receptor sub-types) have shown problems in social recognition. Therefore, oestrogen appears to act at the level of the olfactory bulb by modulating both noradrenaline and the glutamate/NO signalling pathway.     

Anaplasma marginale: lack of cross-protection between strains that share MSP1a variable region and MSP4

In Mexico, there are no commercial alternatives for the immunoprophylaxis of bovine Anaplasmosis, a disease responsible for great economic losses. Blood derived Anaplasma marginale used for immunizing susceptible cattle has shown promising results for homologous protection and controversial results against unrelated strains. The present study examined, under controlled conditions, the cross-protective potential of an immunogen composed of blood derived A. marginale of three strains against challenge with strains not included in the immunogens. Groups 1 and 2 were immunized with blood derived Anaplasma from strains Mexico, Morelos and Yucatan, group 4 with strains Morelos, Veracruz and Yucatan, two more groups (2 and 5) of equal conditions were inoculated with an adjuvant alone. Groups 1, 4 and 5 were challenged with Mexico strain; groups 2 and 3 were challenge-inoculated with strain Veracruz; groups 3 and 5 with strains Veracruz and Mexico as controls. Only animals in group 1, immunized and challenged with strain Mexico showed adequate protection. Both groups challenged with strains not included in the immunogens developed poor protection, while all the controls had to be treated to prevent death.     

Biometrical, biological, biochemical and molecular characteristics of Meloidogyne incognita isolates and related species

Meloidogyne incognita is one of the most polyphagous species of root-knot nematodes occurring in Brazil and worldwide. Eight M. incognita isolates were studied, representing two enzymatic phenotypes (esterase and malate desydrogenase: I1/N1, I2/N1) and four cryptic Meloidogyne sp.1 (S2/N1) isolates, representing one cytological type (3n?=?40–46). Three M. hispanica isolates (Hi3/N1, 2n?=?32–36) and two of an atypical Meloidogyne sp.2 (S2a/N3, 3n?=?40–44) were included in this study for comparison. All isolates were tested with three M. incognita-specific molecular markers. The primer pairs B06F/R, miF/R and incK14F/R amplified three species-specific fragments of 1,200?bp, 955?bp and 399?bp, respectively for M. incognita and Meloidogyne sp.1 isolates. No amplification occurred in the M. hispanica and Meloidogyne sp.2 isolates, except with primers miF/R (1,650?bp). The genetic variability of the Meloidogyne spp. isolates was evaluated, using RAPD and ISSR markers. The phylogenetic analyses revealed two strongly supported monophyletic clades: clade I, consisting of M. hispanica and the atypical Meloidogyne sp.2 isolates, and clade II, clustering together all M. incognita and the Meloidogyne sp.1 isolates. Considering the biometrical, cytological and molecular approaches, it was possible to conclude that the isolates with three enzymatic phenotypes (I1/N1, I2/N1 and S2/N1) presented the characteristics described for M. incognita. Some correlations were detected between the isozymatic phenotypes and the tree topology (S2a/N3, Hi3/N1, I1/N1, S2/N1), but no strict correlation could be observed for the phenotype I2/N1 and one isolate of S2/N1. Morphologically, the Msp.2 isolates differ from M. incognita and M. hispanica by the female stylet features presenting straight cone tip and round pear shaped knobs, posteriorly sloping. The results of this study suggested that the Msp.2 isolates with phenotypes S2aN3 belong to a new or an unidentified species closely related to M. hispanica.     

Interleukin-8 as a prognostic serum marker in canine mammary gland neoplasias

Mammary gland tumors in female dogs are an excellent model for the clinic-pathological, diagnostic and prognostic investigation of mammary neoplasias. Prognostic and predictive markers are effective in research and routine diagnosis. Interleukins play a fundamental role in cancer, with a particular function in tumor growth, invasion and metastatic potential. Interleukin-8 (IL-8) is known to possess tumorigenic and pro-angiogenic properties, and its overexpression is seen in a number of human tumors. IL-8 serum levels were determined and correlated with the clinic-pathological features and clinical evolution of mammary gland neoplasias in female dogs. IL-8 was measured by an immunoenzymatic assay in 30 female dogs with mammary neoplasias within a 12 month follow-up and in 50 control animals. The correlation between IL-8 concentration and clinical parameters was investigated. A statistically significant difference in the IL-8 serum levels was found in tumor-bearing dogs compared to the controls. In addition, when the individual parameters were evaluated, IL-8 content showed a positive correlation with the tumor progression, lymph node involvement, recurrence and death. Single and multivariate analyses showed associations between tumor recurrence, metastasis, high clinical staging and high IL-8, and also with the death risk. This was also consistent with the high IL-8 content in dogs showing tumor recurrence and metastasis. IL-8 superexpression has been detected in a number of human tumors, usually associated with a poor prognostic. Besides promoting angiogenesis, IL-8 is strongly related with the metastatic phenotype of mammary tumor cells. High IL-8 concentration was found in mammary gland cancer patients with advanced disease stages. Our results show that IL-8 can be used as a non-invasive prognostic marker for mammary gland cancer, and can be useful for the prediction of disease progression and recurrence in dogs with mammary neoplasias. The increased level of this cytokine acts as an independent prognostic marker of survival and the identification of animals with the poor prognostic.     

Studies of enzymatic oxidation of TMP-fibers and lignin model compounds by a Laccase–Mediator-System using different 14C and 13C techniques

In this work, the results of the enzymatic oxidation of TMP-fibers (thermomechanical pulp) and a well-structured lignin model compound, the dehydropolymer (DHP), were investigated by different ¹⁴C and ¹³C methods, caused by a Laccase–Mediator-System (LMS). These methods are the nuclear magnetic resonance spectroscopy (¹³C-NMR) with DHP (unmarked) and the determination of the ¹⁴CO₂ release of ¹⁴C-marked DHP and TMP-fibers. The ¹³C-NMR measurements were chosen to analyze the structural changes of the LMS-treated DHP model compounds and TMP-fibers qualitatively and quantitatively. The data of ¹⁴CO₂ release give an explanation of the demethylation of DHP and TMP-fibers. The effect of the LMS is shown by comparing the results in respect of DHP and TMP-fibers, which were only treated with laccase and of an inactivated LMS as the control. Comparing the results of the ¹³C-NMR method, in particular the use of the Mediator during the enzymatical treatment, showed significant changes in the structure of the DHP. Also, the TMP-fibers were materially influenced by the LMS. The analysis of the ¹⁴CO₂ release data of the ¹⁴C-marked DHP and TMP-fibers revealed that the rate of ¹⁴CO₂ increases in the ¹⁴C-2 atom as well as in the O¹⁴CH₃ group within the first hour of Laccase–Mediator incubation. Therefore, the ¹⁴CO₂ release from the DHP was higher than from the TMP-fibers.     

Diversity and abundance of arbuscular mycorrhizal fungi spores under different coffee production systems and in a tropical montane cloud forest patch in Veracruz, Mexico

We evaluate the arbuscular mycorrhizal fungi (AMF) community as measured by spores in different coffee production systems (at the depth of 0?C15?cm). In addition, we analyze the similarities between the AMF communities in coffee production systems and those that occur in a tropical montane cloud forest patch in order to evaluate the capacity of coffee production systems to preserve the native AMF community. We carried out four samplings in five coffee production systems representative of a vegetation structure gradient, and in a forest. From 120 soil samples, 33 morphospecies were detected. In all the sites, the dominant morphospecies were Glomus clarum and Glomus sp. 3. We found no significant difference in AMF spore richness between sites. Diversity was similar in most of the coffee production systems. Significant differences were only detected in spore abundance; during the dry season the forest, shaded traditional rustic system and shaded simple system presented the highest spore abundance. With the exception of one species exclusive to the forest, the coffee production systems all share the same AMF species as the forest. The coffee production systems with the greatest similarity to cloud forest were the shaded traditional rustic system and the shaded simple system. It is suggested that control of weeds and fertilization could be important factors influencing the composition and abundance of AMF spores in coffee production systems.