Cloning and characterization of an 11S legumin, Car i 4, a major allergen in pecan

Among tree nut allergens, pecan allergens remain to be identified and characterized. The objective was to demonstrate the IgE-binding ability of pecan 11S legumin and characterize its sequential IgE-binding epitopes. The 11S legumin gene was amplified from a pecan cDNA library and expressed as a fusion protein in Escherichia coli. The native 11S legumin in pecan extract was identified by mass spectrometry/mass spectrometry (MS/MS). Sequential epitopes were determined by probing the overlapping peptides with three serum pools prepared from different patients' sera. A three-dimensional model was generated using almond legumin as a template and compared with known sequential epitopes on other allergenic tree nut homologues. Of 28 patients tested by dot blot, 16 (57%) bound to 11S legumin, designated Car i 4. MS/MS sequencing of native 11S legumin identified 33 kDa acidic and 20-22 kDa basic subunits. Both pecan and walnut seed protein extracts inhibited IgE binding to recombinant Car i 4, suggesting cross-reactivity with Jug r 4. Sequential epitope mapping results of Car i 4 revealed weak, moderate, and strong reactivity of serum pools against 10, 5, and 4 peptides, respectively. Seven peptides were recognized by all three serum pools, of which two were strongly reactive. The strongly reactive peptides were located in three discrete regions of the Car i 4 acidic subunit sequence (residues 118-132, 208-219, and 238-249). Homology modeling of Car i 4 revealed significant overlapping regions shared in common with other tree nut legumins.     

Cardiopulmonary effects of dexmedetomidine in sevoflurane-anesthetized sheep with and without nitric oxide inhalation

OBJECTIVE: To determine whether inhaled nitric oxide (NO) prevents pulmonary hypertension and improves oxygenation after i.v. administration of a bolus of dexmedetomidine in anesthetized sheep. ANIMALS: 6 healthy adult sheep. PROCEDURE: In a crossover study, sevoflurane-anesthetized sheep received dexmedetomidine (2 microg/kg, i.v.) without NO (DEX treatment) or with inhaled NO (DEX-NO treatment). Cardiopulmonary variables, including respiratory mechanics, were measured before and for 120 minutes after bolus injection of dexmedetomidine. RESULTS: Dexmedetomidine induced a transient decrease in heart rate and cardiac output. A short-lived increase in mean arterial pressure (MAP) and systemic vascular resistance (SVR) was followed by a significant decrease in MAP and SVR for 90 minutes. Mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance increased transiently after dexmedetomidine injection. The Pao2 was significantly decreased 3 minutes after injection and reached a minimum of (mean +/- SEM) 13.3 +/- 78 kPa 10 minutes after injection. The decrease in Pao2 was accompanied by a sudden and prolonged decrease in dynamic compliance and a significant increase in airway resistance, shunt fraction, and alveolar dead space. Peak changes in MPAP did not differ between the 2 treatments. For the DEX-NO treatment, Pao2 was significantly lower and the shunt fraction significantly higher than for the DEX treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Inhalation of NO did not prevent increases in pulmonary arterial pressures induced by i.v. administration of dexmedetomidine. Preemptive inhalation of NO intensified oxygenation impairment, probably through increases in intrapulmonary shunting.     

The Eucalyptus stem canker pathogen Teratosphaeria gauchensis represents distinct genetic groups in Africa and South America

Teratosphaeria gauchensis (Capnodiales) causes a serious stem canker disease on commercially propagated Eucalyptus species in South America. Recently, this pathogen was detected for the first time in Africa. Very little is known regarding the biology or origin of T. gauchensis, but it has been suggested that it is native to South America. The aim of this study was to compare isolates from Africa and South America using microsatellite markers. Bayesian analysis conducted in STRUCTURE, principal coordinates analysis and a UPGMA dendrogram revealed two distinct genetic groups for these isolates. The South American isolates were more genetically diverse than those from Africa. Patterns of genetic diversity in Africa suggest that T. gauchensis could have been introduced into Zimbabwe before spreading north‐eastwards. The existence of the two genetic groups and high haplotype richness associated with the South American and Zimbabwean populations suggest that it will be more difficult to reduce the impact of disease caused by T. gauchensis in these regions than in those areas where there is limited genetic diversity.     

Copper systematics in arc magmas and implications for crust-mantle differentiation

Arc magmas are important building blocks of the continental crust. Because many arc lavas are oxidized, continent formation is thought to be associated with oxidizing conditions. On the basis of copper's (Cu's) affinity for reduced sulfur phases, we tracked the redox state of arc magmas from mantle source to emplacement in the crust. Primary arc and mid-ocean ridge basalts have identical Cu contents, indicating that the redox states of primitive arc magmas are indistinguishable from that of mid-ocean ridge basalts. During magmatic differentiation, the Cu content of most arc magmas decreases markedly because of sulfide segregation. Because a similar depletion in Cu characterizes global continental crust, the formation of sulfide-bearing cumulates under reducing conditions may be a critical step in continent formation.     

Global seabird response to forage fish depletion--one-third for the birds

Determining the form of key predator-prey relationships is critical for understanding marine ecosystem dynamics. Using a comprehensive global database, we quantified the effect of fluctuations in food abundance on seabird breeding success. We identified a threshold in prey (fish and krill, termed "forage fish") abundance below which seabirds experience consistently reduced and more variable productivity. This response was common to all seven ecosystems and 14 bird species examined within the Atlantic, Pacific, and Southern Oceans. The threshold approximated one-third of the maximum prey biomass observed in long-term studies. This provides an indicator of the minimal forage fish biomass needed to sustain seabird productivity over the long term.     

Multiple tooth resorption in an Italian greyhound

An Italian greyhound was presented three times during a two-year period for dental prophylaxis due to periodontal disease. Clinical examination revealed lesions on several teeth. Radiographs revealed extensive resorptive root lesions. On histological examination, the presence of odontoclasts and signs of boney remodeling of the roots confirmed the resorptive nature of the lesions. Given the extent of the lesions, and poor prognosis with conservative treatment alone, teeth affected by the most severe resorption were extracted at each visit using a flap technique combined with alveolar vestibular osteotomy. Dental resorptive lesions are rarely detected in the dog but may be more frequent than previously thought. The routine use of dental radiographs can be used to reveal these lesions in the dog.     

Population structure of Chrysoporthe austroafricana in southern Africa determined using Vegetative Compatibility Groups (VCGs)

Chrysoporthe austroafricana is one of the most damaging pathogens of Eucalyptus trees in southern Africa. It also occurs on non‐native Tibouchina granulosa trees and native Syzygium species. Additional isolates of the pathogen from previously unstudied countries in the region have become available from survey studies. The aim of this study was to use VCGs to consider the diversity in populations of isolates collected in various countries in southern Africa (Malawi, Mozambique, Namibia, South Africa and Zambia) and from different hosts. We also wanted to determine whether there are shared VCGs among these countries and hosts in southern Africa and establish a VCG tester strain database. Results showed a high diversity amongst isolates from different countries and hosts, but suggested little movement of VCGs among countries or hosts based on the available isolates. A total of 108 VCG tester strains were identified for southern Africa.     

Maximizing the use of supplemental amino acids in corn-soybean meal diets for 20- to 45-kilogram pigs

Four experiments were conducted to determine the Lys requirement, the maximum amount of supplemental Lys that does not decrease growth performance, and to determine the order of limiting AA beyond Lys, Thr, Trp, and Met in a corn-soybean meal diet for 20- to 45-kg pigs. All experiments were conducted for 27 to 28 d with purebred or crossbred barrows and gilts, which were blocked by initial BW. Treatments were replicated with 4 to 6 pens of 4 to 6 pigs per pen. In all experiments, pigs and feeders were weighed on d 0, 14, and 27 or 28. At the beginning and end of all experiments, blood samples were obtained from all pigs to determine plasma urea N (PUN) concentrations. In Exp. 1, 0.830, 0.872, 0.913, and 0.955% standardized ileal digestible (SID) Lys was fed, whereas 0.747, 0.788, 0.830, 0.872, and 0.913% SID Lys was fed in Exp. 2. Broken-line analysis requirement estimates could not be estimated from any response variable in Exp. 1, but in Exp. 2, using ADG and PUN, the estimated SID Lys requirement was 0.83%. In Exp. 3, 0, 0.118, 0.191, 0.264, and 0.335% supplemental Lys was added to achieve 0.83% SID Lys in all diets, and Thr, Trp, and Met were supplemented to maintain Thr:Lys, Trp:Lys, and TSAA:Lys of 0.65, 0.18, and 0.60, respectively. Based on ADG, ADFI, and G:F, up to 0.23% supplemental Lys can be added along with supplemental Thr, Trp, and Met without negatively affecting growth performance; PUN was linearly decreased (P < 0.001) by supplemental Lys. In Exp. 4, treatments were 1) positive control (PC) without supplemental AA, 2) negative control (NC) with 0.335% supplemental Lys + 0.140% l-Thr + 0.035% l-Trp + 0.117% dl-Met, 3) NC + 0.044% l-Val, 4) NC + 0.021% l-Ile, and 5) NC + 0.044% l-Val + 0.021% l-Ile. Individual addition of Val and Ile did not improve (P > 0.10) ADG or G:F compared with the NC. The combined addition of Val + Ile resulted in ADG that was intermediate between the PC and NC diets but not different from either diet (P > 0.10); G:F was not improved (P > 0.10) to that observed in pigs fed the PC diet. The PUN was not different (P > 0.10) among pigs fed diets with supplemental AA but less (P < 0.10) than pigs fed the PC. The results of this research indicate that the Lys requirement for 20- to 45-kg pigs is 0.83% SID Lys, up to 0.23% supplemental Lys (0.29% l-Lys·HCl or 0.45% l-Lys·SO(4)) can be added along with supplemental Thr, Trp, and Met without negatively affecting growth performance, and another AA besides Val and Ile may be limiting growth performance in a corn-soybean meal diet with 0.335% supplemental Lys.     

Computed tomography features of bronchial and non-bronchial collateral arterial circulation development in a dog diagnosed with multiple chronic pulmonary thrombi

A 5 year-old female Lhasa Apso was diagnosed with a large right pulmonary artery thrombus, multiple smaller pulmonary thrombi, and pulmonary hypertension. In addition, thoracic computed tomography angiography revealed numerous periesophageal arterial vessels, tortuous and dilated bronchial arteries, and an enlarged tortuous left phrenic artery, consistent with systemic bronchial and non-bronchial collateral arterial circulation development. These features of chronic pulmonary arterial thrombi have not been described in dogs but are recognized in people. One year after the diagnosis, the dog was still alive and there were no clinical signs reported.