Evaluation of metoclopramide and ranitidine on the prevention of gastroesophageal reflux episodes in anesthetized dogs

This research aimed to evaluate the effect of metoclopramide and ranitidine in the prevention of gastroesophageal reflux episodes during anesthetic procedures. Ninety healthy female dogs were submitted to elective ovariosalpingohisterectomy, randomly divided into three groups of 30 animals. The control group received only the anesthetic protocol. The metoclopramide group received an intravenous bolus of 1mg/kg, and continuous infusion (1 mg/kg/h intravenously) immediately after anesthetic induction. The ranitidine group received an intravenous bolus of 2 mg/kg, 6 h before anesthesia. Anesthesia (acepromazine, propofol and isofluorane) was standardized and the esophageal pH variations were recorded. Esophagoscopy was carried out after surgery. No difference (p<0.05) was verified in the reflux episodes between the groups. Seven animals presented reflux. Metoclopramide in bolus and continuous infusion, as well as ranitidine, 6 h before anesthesia, did not influence the reduction of the incidence of gastroesophageal reflux.     

Anti-Helicobacter pylori activity of Terminalia macroptera root

The root of Terminalia macroptera Guill. & Perr. (Combretaceae) is widely used in African traditional medicine to treat various infectious diseases, including stomach-associated diseases. This study investigates the in vitro activity of T. macroptera root extract against reference strains and clinical isolates of H. pylori and attempts to localize the extract bioactivity. T. macroptera hydroethanol (80% V/V) root extract (Tmr) activity was tested against three standard strains and sixty two clinical strains of H. pylori. Tmr liquid-liquid partition fractions were screened against twenty H. pylori strains. Qualitative analysis of Tmr and its fractions was performed by HPLC-UV/DAD. The antibiotic characterization of the H. pylori strains revealed that 20% of the tested clinical isolates were resistant to at least two of the three antibiotics belonging to the main groups of antibiotics used in multi-therapy to eradicate H. pylori infections. In contrast, Tmr showed anti-H. pylori activity against the majority (92%) of the tested strains (MIC(50) and MIC(90)=200 μg/ml). The Tmr water liquid-liquid fraction (Tmr-3) and the precipitate obtained from this fraction (Tmr-5) were the most active tested samples, showing a MIC(50) of 100 μg/ml. The present work proves the in vitro activity of T. macroptera against H. pylori, thus confirming the utility of this traditional medicinal plant to treat stomach complaints due to H. pylori infection. The main compounds of Tmr and of Tmr-3 were the ellagitannins terchebulin and punicalagin. These compounds can be considered as markers of T. macroptera root active extracts against H. pylori.     

Genetic Diversity in South American Colletotrichum gloeosporioides Isolates from Stylosanthes guianensis, a Tropical Forage Legume

The degree of genetic diversity of 127 Colletotrichum gloeosporioides isolates from Stylosanthes guianensis genotypes in South America was measured at the molecular level by random amplified polymorphic DNA (RAPD) with nine arbitrary primers of 10 bases, and by restriction fragment length polymorphism (RFLP) with a non-LTR (long terminal repeats) retrotransposon DNA sequence. The RAPD products revealed scorable polymorphism among the isolates, and a total of 80 band positions were scored. Sixty-three of the 127 isolates were clustered into 13 distinct lineages usually correlating with geographic origin. Where isolates from various regions were clustered together, most had identical host genotype origin. The pathogen population sampled from Carimagua, Colombia, a long-time Stylosanthes breeding and selection site, with a savanna ecosystem, was highly diverse. A set of 12 S. guianensis genotype differentials was used to characterize pathogenic variability of 104 isolates and their virulence patterns were grouped into 57 pathotypes. However, when they were tested on four Australian differentials, they grouped into 11 pathotypes. As shown in previous studies, no strict correlations existed between genetic diversity measured by RAPD or RFLP, and pathotype defined by pathogenicity pattern on the differentials. Southern blot analysis of the 127 isolates revealed 23 hybridizing fragments, resulting in 41 fingerprint patterns among the 127 isolates. Relationships between RFLP and RAPD variables were examined using Spearman's Rank Correlation Coefficient, which showed that the two measures of genotypic variation are in agreement.     

Environmental Interactions between Different Tree Species and Mung Bean (Vigna radiata (L.) Wilczek) in Hedgerow Intercropping Systems in Sri Lanka

Annual crops grown in association with contour hedgerows often show yield reductions. This paper quantifies the variation of above- and below-ground environmental factors in hedgerow intercrops involving six different tree species ( Calliandra calothyrus , Desmodium ransonii , Flemingia c ongesta , Gliricidia sepium , Cassia spectabilis and Tithonia diversifolia ) and thereby shows the effects of tree hedges on mung bean ( Vigna radiata ). Compared to a sole crop of mung bean, most hedgerow intercrops removed greater soil nitrogen, whereas all removed lower soil phosphorus. Mung bean closer to the hedgerows had lower N and P, indicating competitive capture of nutrients by hedges. Most hedgerow intercrops had greater top-soil water because of their shading effect, especially near hedgerows. However, greater absorption by tree root systems decreased subsoil water near hedgerows late in the season. Soil temperature was lower in most hedgerow intercrops than in the control and increased with increasing distance from hedges. During initial stages of mung bean growth, radiation interception of intercrops was greater than that of the control, especially closer to hedgerows. However, after the first month, radiation interception of the sole crop was either equal to or greater than that of hedgerow intercrops. There was significant variation between tree species in all these environmental factors. Gliricidia , which allowed greater mung bean yields, also allowed greater nutrient capture by mung bean, greater top-soil water availability, lower extraction of subsoil water and lower soil temperatures.     

The recombinant isolate of cucurbit aphid-borne yellows virus from Brazil is a polerovirus transmitted by whiteflies

The severe yellowing disease (amarelão) on melon plants is a serious problem in Brazil, although the causative agent remained unknown for a long time. Recently, recombinant isolates of cucurbit aphid-borne yellows virus (CABYV) were reported as the possible causative agents of this disease on melon plants. Although aphids are known to be the vectors of the common type of CABYV isolates, almost no aphid colony was observed in the major melon fields in Brazil with high incidence of the severe yellowing disease. In contrast, whiteflies are often abundant. Based on this observation, the hypothesis of the transmission of recombinant CABYV by whiteflies was evaluated. After thorough transmission experiments, we found that this recombinant CABYV isolate was transmitted by the whitefly Bemisia tabaci MEAM1, but not by Aphis gossipii. Furthermore, the host response by whitefly-based inoculation in cucurbits and other indicator plants showed differences in host range when compared to the common type of CABYV. Due to its transmissibility by the whitefly and the distant relationship of the P3/P5 protein to CABYV, the name “cucurbit whitefly-borne yellows virus” is proposed for this recombinant CABYV. This is the second report of polerovirus transmission by the whitefly B. tabaci, following the report of pepper whitefly-borne vein yellows virus.     

Early settlement and growth of stocked European glass eels in a fragmented watercourse

One of the actions that has been implemented to support the recovery of the panmictic population of European eel is stocking of waterbodies where natural recruitment is low or null. However, growth conditions of the stocked eels can vary greatly. This circumstance emphasises the importance to determine ideal habitat conditions to contribute to the success of stocking actions and, consequently, to increase the production of silver eels. This study aims to evaluate the early settlement and growth of stocked glass eels in the upper reaches of a fragmented river. Stocking was carried out, in 2014, at three sites of an inland tributary of the Mondego river basin (Central Portugal), and its monitoring was conducted during the following two years, until 2016, along with the collection of environmental and hydromorphological parameters. The results showed a successful dispersion throughout the study area. Growth varied spatially, although environmental parameters have not clearly explained this variation, but overall with high growth rates and a positive allometric growth in this early stage of stocking, suggesting a good condition of the stocked individuals. This study showed that these upper reaches of fragmented watercourses, a shared feature amongst most European rivers that are currently inaccessible for natural recruitment, may be suitable habitats for eel stocking.     

Tissue distribution of Leishmania chagasi and lesions in transplacentally infected fetuses from symptomatic and asymptomatic naturally infected bitches

Visceral leishmaniasis (VL) is primarily transmitted by an invertebrate vector, but transmission in the absence of the vector has been reported. Vertical transmission of VL has been described in man and dogs. The aim of this study was to evaluate the distribution of Leishmania amastigotes in fetal organs and histopathologic changes associated with parasitism and to determinate the frequency of transplacental transmission and potential of vertical transmission by symptomatic and asymptomatic pregnant bitches. Symptomatic (n = 4) and asymptomatic (n = 4) pregnant bitches, serologically and parasitologically positive for Leishmania sp., carrying a total of 53 fetuses (26 from symptomatic and 27 from asymptomatic bitches) were selected at the Veterinary Hospital of the National University of Asuncion, Paraguay. Samples of placenta and fetal organs such as liver, spleen, lymph nodes, bone marrow, kidney and heart were histologically evaluated and processed for immunodetection of amastigotes and PCR. There were no lesions compatible with VL in fetal tissues in spite of the presence of amastigotes, particularly in lymphoreticular tissues. However, fetal hepatocytes had marked degenerative changes that were independent of the presence of amastigotes in liver. Twenty-six out of 53 placentas (13 symptomatic and 13 asymptomatic) and a total of 17 fetuses out of 53 (nine symptomatic and eight asymptomatic) were PCR positive. Together these findings indicate a high frequency of transplacental transmission and no differences in the potential of transmission when symptomatic were compared to asymptomatic pregnant bitches.     

Efficiency of the Spermatogenesis in Zebu Bulls (bos taurus indicus)

The objective of the research was to evaluate the efficiency of the spermatogenesis through the morphology of the testicular parenchyma in bulls of different zebu breeds. We used testicular fragments from bull of the breeds Nelore (n = 10), Polled Nelore (n = 6), Gyr (n = 5), Guzerat (n = 5) and Tabapuã (n = 5). The tissue was perfused with Karnovsky solution, included in glycol methacrylate and stained with toluidine blue–sodium borate 1%. Animals of the Nelore breed presented higher population of primary spermatocyte in pre‐leptotene/leptotene (38.30) and in pachytene (38.14) and round spermatids (113.30), higher yield of spermatogonia mitosis (21.2) and higher daily spermatic production per gram of testicular parenchyma (32.8 × 10⁶) than those from breeds Gyr, Guzerat and Tabapuã and higher general yield of spermatogenesis (62.4) than breeds Gyr and Tabapuã. There was no significant difference in any of the evaluated parameters between breeds Nelore and Polled Nelore. The rate of Sertoli cells did not vary between the studied breeds. Apparently, the genetic selection applied to the breeds has been improving the yield in the spermatogenic process by decreasing cellular loss, although it did not increase the support capacity of the Sertoli cells.     

Nitrogen maintenance requirements and potential for nitrogen retention of pullets in growth phase

Experiments were conducted to estimate daily N maintenance requirements (NMRs) and the genetic potential for daily N retention (NR_maxT) of pullets in growth phase. Three nitrogen balance trials were conducted, and a total of 48 Hy‐line W‐36 pullets were used in each trial in age periods (starter: 14–28, grower: 56–70 and developer: 98–112 days). The treatments consisted of six graded levels of nitrogen in the diets (L1 = 8, L2 = 16, L3 = 24, L4 = 32, L5 = 40 and L6 = 48 g N/kg of feed), formulated using the dilution technique. The regression analyses between nitrogen intake and nitrogen excretion were performed to fit the exponential function and to determine the NMR. The daily NMRs that were estimated at 294, 331 and 355 mg/BW_kg^0.67 for the initial, grower and developer periods, respectively, were applied for further calculation of NR_maxT as the threshold value of the function between N intake and daily N balance. The NR_maxT was estimated by a statistical procedure following several iteration steps by the Levenberg–Marquardt algorithm until the sum of the squares of the residual was minimized. The NR_maxT was estimated at 3,200, 2,633 and 1,826 mg/BW_kg^0.67 for starter, grower and developer periods respectively. The determined model parameters were the precondition for modelling of the amino acid requirement based on an exponential N‐utilization model and depended on performance and dietary amino acid efficiency. This procedure will be further developed and applied in the subsequent study.