Bactericidal activity of porcine neutrophil secretions

Antimicrobial proteins in neutrophil granules exert their bactericidal activity both within the neutrophil phagolysosome and as components of neutrophil extracellular traps. This study evaluated the bactericidal activity of porcine neutrophil secretions against four bacterial pathogens of swine. Porcine neutrophils were treated with or without phorbol myristate acetate (PMA), then the resulting supernatants were incubated with Escherichia coli K-12, Streptococcus suis, Actinobacillus suis, or Pasteurella multocida, and the surviving colony forming units were enumerated. Supernatants of PMA-activated neutrophils killed an average of 95% of E. coli K-12 cells, relative to supernatants from untreated neutrophils. Inhibition of elastase activity using chloromethylketone (CMK) prior to PMA stimulation significantly reduced the bactericidal activity of the neutrophil supernatants; 57% of the PMA-induced bactericidal activity against E. coli K-12 was estimated to be elastase-dependent. The same neutrophil supernatants had lower bactericidal activity against S. suis, A. suis, and P. multocida, with 30%, 36% and 13% reduction in bacterial numbers, respectively. The cathelicidin porcine myeloid antimicrobial peptide (PMAP)-36 and lactotransferrin were among the proteins identified in the supernatants of PMA-stimulated neutrophils by mass spectrometry. These findings imply that elastase-activated proteins, such as cathelicidins, are partially responsible for the bactericidal effect of porcine neutrophil secretions, but non-elastase-dependent proteins such as lactoferrin may also contribute. Further, the secretions of activated neutrophils were effective in killing the avirulent E. coli K-12 but were less effective against the other bacteria tested, suggesting that these pathogens may have evolved mechanisms to resist neutrophil-mediated killing.     

The value of plasma fibrinogen estimations in dogs. A comparison with total leucocyte and neutrophil counts

Plasma fibrinogen levels were measured by a simple refractometry method on 552 dog blood samples submitted from clinical cases for routine haematological examination. Sixty samples with total leucocyte and neutrophil counts within the defined normal range had elevated fibrinogen levels. The majority of these samples were from animals with a disease condition. It was concluded, because of this, and because of the simplicity of the method, that fibrinogen estimations are a worthwhile addition to the routine haematological examination of dog blood.     

Performance of broiler chickens fed least-cost diets formulated to model predicted amino acid requirements

Two 3-week battery brooder experiments were conducted with male broiler chicks to investigate the use of a model equation to predict amino acid requirements. In the first experiment, chicks were fed four diet treatments based on published recommendations (Guelph, (Summers & Leeson, 1976) NRC, 1977; Maryland, (Thomas et al. 1978); AEC, 1978), two diet treatments based on model-calculated recommendations (Hurwitz et al., 1978) and one commercial chick starter. A second experiment comparing one diet treatment each for a published (NRC), model-calculated and commercial recommendation was necessiated due to updating the model. In Experiment 1, significant differences (p < 0.05) were noted in feed efficiency at 15 days in favour of birds on the commercial treatment relative to those receiving days in favour of birds on the commercial treatment relative to those receiving treatments based on published recommendations. Over the trial period, the commercial treatment and a model-based treatment supported a significantly (p < 0.05) better feed efficiency than did the other published recommendations. The model-based diet treatment of Experiment 2 resulted in significantly (p < 0.01) superior bird weights at 7 and 14 days and feed efficiency at 7 days (p < 0.01) and 14 days (p < 0.05) relative to both NRC (1977) and the commercial diet treatment. These results indicate the potential of using model-calculated amino acid recommendations for 0- to 3-week old broiler chickens.     

Serum concentrations of the third component of complement in healthy dogs and dogs with protein-losing nephropathy

OBJECTIVE: To develop a method for determining the concentration of the third component of complement (C3) in canine serum, to establish a reference range for C3 in healthy dogs, and to evaluate dogs with protein-losing nephropathy (PLN) to determine whether PLN is associated with decreased serum C3 concentrations. ANIMALS: 30 healthy dogs and 49 dogs with PLN. PROCEDURES: Serum samples were obtained from healthy dogs at the time of examination, whereas serum samples were obtained from dogs with PLN at the time of diagnosis. All samples were frozen at -70 degrees C until analyzed. Serum C3 concentrations were determined by use of a sandwich ELISA. Concentrations were expressed as the number of dilutions in which C3 could be detected. RESULTS: C3 was detectable in healthy control dogs (range, 1,920,000 to 15,400,000 dilutions; median, 9,600,000 dilutions). This represented a range of four 2-fold serum dilutions. In addition, C3 was detectable in dogs with PLN (range, 1,460,000 to 30,070,000 dilutions; median, 7,680,000 dilutions), which represented a range of six 2-fold serum dilutions. There was no significant difference in C3 concentrations between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: C3 is a critical part of the immune defense system that has not been extensively examined in veterinary medicine. An ELISA was developed for measuring C3 concentrations, and a reference range for healthy dogs was established. Significant decreases in C3 concentrations were not detected in any dog with PLN. Additional studies will be required to definitively determine the importance of serum C3 concentrations in PLN.     

Use of a multivariable model to estimate the probability of discharge in hospitalized foals that are 7 days of age or less

OBJECTIVE: To create a mathematical model to assist in early prediction of the probability of discharge in hospitalized foals < or= 7 days old. STUDY DESIGN: Prospective study. ANIMALS: 1,073 foals. PROCEDURES: Medical records from 910 hospitalized foals < or = 7 days old for which outcome was recorded as died or discharged alive were reviewed. Thirty-four variables including historical information, physical examination findings, and laboratory results were examined for association with survival. Variables associated with being discharged alive were entered into a multivariable logistic regression model. Accuracy of the model was validated prospectively on data from 163 foals. RESULTS: Factors in the final model included age group, ability to stand, presence of a suckle reflex, WBC count, serum creatinine concentration, and anion gap. Sensitivity and specificity of the model to predict live discharge were 92% and 74%, respectively, in the retrospective population and 90% and 46%, respectively, in the prospective population. Accuracy of an equine clinician's initial prediction of the foal being discharged alive was 83%, and accuracy of the model's prediction was 81%. Combining the clinician's prediction of probability of live discharge with that of the model significantly increased (median increase, 12%) the accuracy of the prediction for foals that were discharged and nonsignificantly decreased (median decrease, 9%) the accuracy of the predication for nonsurvivors. CONCLUSIONS AND CLINICAL RELEVANCE: Combining the clinician's initial predication of the probability of a foal being discharged alive with that of the model appeared to provide a more precise early estimate of the probability of live discharge for hospitalized foals.     

Disorders of the infraspinatus tendon and bursa in three horses

CASE DESCRIPTION: 3 horses with penetrating wounds to the shoulder area were examined because of forelimb lameness. CLINICAL FINDINGS: All horses had physical examination findings (decreased cranial phase of the stride, swelling in the shoulder region, and signs of pain on manipulation of the shoulder) that were suggestive of problems in the upper portion of the forelimb. Injury to the biceps tendon or bursa was the primary differential diagnosis in each instance, but no abnormalities involving those structures were found. Radiographic and ultrasonographic imaging revealed injuries to the caudal eminence of the greater tubercle of the humerus, the infraspinatus tendon, and the infraspinatus bursa. Examination with ultrasound was more sensitive than radiography at detecting both osseous and soft tissue changes. TREATMENT AND OUTCOME: All 3 horses responded favorably to treatment with antimicrobials and non-steroidal anti-inflammatory drugs. Although initial response to standing lavage was favorable in 1 horse, endoscopic lavage was later required. Standing removal of fracture fragments was performed in 2 horses. Ultrasonographic imaging was helpful in monitoring the response to treatment and changes in the affected structures. All 3 horses eventually became sound after treatment. CLINICAL RELEVANCE: Infraspinatus bursitis and tendonitis should be included in the differential diagnoses of horses with shoulder lameness. Diagnosis and monitoring should include ultrasonographic monitoring. The prognosis for return to soundness after appropriate treatment appears to be good.     

Greater sage-grouse as an umbrella species for sagebrush-associated vertebrates

Widespread degradation of the sagebrush ecosystem in the western United States, including the invasion of cheatgrass, has prompted resource managers to consider a variety of approaches to restore and conserve habitats for sagebrush-associated species. One such approach involves the use of greater sage-grouse, a species of prominent conservation interest, as an umbrella species. This shortcut approach assumes that managing habitats to conserve sage-grouse will simultaneously benefit other species of conservation concern. The efficacy of using sage-grouse as an umbrella species for conservation management, however, has not been fully evaluated. We tested that concept by comparing: (1) commonality in land-cover associations, and (2) spatial overlap in habitats between sage-grouse and 39 other sagebrush-associated vertebrate species of conservation concern in the Great Basin ecoregion. Overlap in species’ land-cover associations with those of sage-grouse, based on the ? (phi) correlation coefficient, was substantially greater for sagebrush obligates than non-obligates . Spatial overlap between habitats of target species and those associated with sage-grouse was low (mean ? = 0.23), but somewhat greater for habitats at high risk of displacement by cheatgrass (mean ? = 0.33). Based on our criteria, management of sage-grouse habitats likely would offer relatively high conservation coverage for sagebrush obligates such as pygmy rabbit (mean ? = 0.84), but far less for other species we addressed, such as lark sparrow (mean ? = 0.09), largely due to lack of commonality in land-cover affinity and geographic ranges of these species and sage-grouse.     

Catalytic inhibition of human DNA topoisomerase II by interactions of grape cell culture polyphenols

Previously, we isolated mixed polyphenolic fractions on a toyopearl matrix (TP-2 to TP-6) from grape cell cultures that were highly potent catalytic inhibitors in a human DNA topoisomerase II assay for cancer chemoprevention. The objectives of this study were to evaluate the potency of, and potential interactions between, individual fractions and some of the purified bioactive polyphenols that comprise these fractions on human DNA topoisomerase II catalytic activity. Treatments that combined anthocyanin-rich fractions (TP-2; 0.5 or 2.0 microg of dried material/mL), fractions containing catechins, procyanidin dimers, and flavanones (TP-4; 0.25 microg of dried material/mL), and/or fractions enriched with procyanidin oligomers and polymers (TP-6; 0.15 or 0.5 microg of dried material/mL) showed additive effects toward catalytic inhibition of the enzyme. Epicatechin gallate (IC50 = 0.029 microM), myricetin (0.39 microM), procyanidin B2 (PB2, 4.5 microM), and resveratrol (65.7 microM), constituents of the most bioactive mixed fraction from grape cell culture (TP-4), each individually provided potent catalytic inhibition of topoisomerase II. In addition, potentiating interactions between the PB2 and the other polyphenolic constituents mentioned above and between myricetin and resveratrol were clearly demonstrated. A synergistic interaction between myricetin and resveratrol was also confirmed with isobolographic analysis at a molar ratio of 1:70.     

Plasticization of a protein-based film by glycerol: a spectroscopic, mechanical, and thermal study

Kafirin, the seed storage protein of the cereal sorghum, is highly homologous with the maize storage protein zein. The effects of plasticisation of a kafirin film by glycerol in the absence of water were examined by a combination of spectroscopic (NMR and infrared), rheological, and calorimetric methods. The results suggest that at low glycerol levels the glycerol is absorbed onto and possibly into the protein. Increasing the level of glycerol increases the motion of the protein and changes the protein conformation. There are corresponding changes of the mechanical properties of protein films. At 40% (w/w) of glycerol, two glass transition temperatures were observed, one of which corresponded to the glass transition temperature of pure glycerol. This result indicates that at this level of plasticizer there are sufficient glycerol/glycerol interactions occurring to allow a separate glass formation process for glycerol.