Noncytotoxic lytic granule-mediated CD8+ T cell inhibition of HSV-1 reactivation from neuronal latency

Reactivation of herpes simplex virus type 1 (HSV-1) from neuronal latency is a common and potentially devastating cause of disease worldwide. CD8+ T cells can completely inhibit HSV reactivation in mice, with interferon-gamma affording a portion of this protection. We found that CD8+ T cell lytic granules are also required for the maintenance of neuronal latency both in vivo and in ex vivo ganglia cultures and that their directed release to the junction with neurons in latently infected ganglia did not induce neuronal apoptosis. Here, we describe a nonlethal mechanism of viral inactivation in which the lytic granule component, granzyme B, degrades the HSV-1 immediate early protein, ICP4, which is essential for further viral gene expression.     

The structure of Mercury's magnetic field from MESSENGER's first flyby

During its first flyby of Mercury, the MESSENGER spacecraft measured the planet's near-equatorial magnetic field. The field strength is consistent to within an estimated uncertainty of 10% with that observed near the equator by Mariner 10. Centered dipole solutions yield a southward planetary moment of 230 to 290 nanotesla RM3 (where RM is Mercury's mean radius) tilted between 5 degrees and 12 degrees from the rotation axis. Multipole solutions yield non-dipolar contributions of 22% to 52% of the dipole field magnitude. Magnetopause and tail currents account for part of the high-order field, and plasma pressure effects may explain the remainder, so that a pure centered dipole cannot be ruled out.     

How Raw and Gypsum Modified Bauxite Residues Affect Seed Germination,Enzyme Activities,and Root Development of Sinapis alba

Water, Air, & Soil Pollution - Isotopic effects of carbonyls were investigated using the simulation reactions of carbonyls with the cysteamine derivatization. Furthermore, variations of carbon...     

Biofilm formation vs. PCB adsorption on granular activated carbon in PCB-contaminated aquatic sediment

Purpose

Granular activated carbon (GAC) that is both an efficient polychlorinated biphenyl (PCB) adsorbent and a good growth support for microorganisms is considered suitable for in situ remediation of PCB-contaminated aquatic sediment. Here, the potential competition between biofilm formation and PCB (Aroclor 1260) adsorption on GAC in a PCB-contaminated aquatic sediment was investigated.

Materials and methods

GACs, both coated and uncoated with biofilm or PCBs, were incubated with sediment. Each was monitored for biofilm development and PCB adsorption by: (a) cryo-scanning electron microscopy, (b) real-time quantitative PCR analysis of the 16S rRNA, (c) terminal restriction fragment length polymorphism and (d) chemical analysis.

Results and discussion

Biofilm formation on the GAC by the sediment's bacteria was rapid and occurred in three stages: (1) initial adherence of discrete bacteria, (2) an increase in biomass associated with a shift in bacterial diversity and (3) exopolymeric matrix production. The density and biodiversity of the multispecies biofilm depended on the biofilm's age. The addition of Aroclor 1260 to the sediment resulted in a decrease of the biofilm biomass, whereas Aroclor 1260 previously adsorbed on the GAC prior to contact with the sediment did not influence the biofilm biomass or its formation dynamics. Similarly, a biofilm previously developed on the GAC did not significantly decrease PCB adsorption, although contact of the GAC with the sediment did hamper adsorption of the higher chlorinated PCB congeners.

Conclusions

A mature multispecies bacterial biofilm developed in 1 month on GAC in contact with aquatic sediment did not hamper PCB adsorption, and PCB adsorption did not influence biofilm formation. These findings are important for the application of remediation strategies.     

Determination of enrofloxacin stability and in vitro efficacy against Staphylococcus pseudintermedius and Pseudomonas aeruginosa in four ear cleaner solutions over a 28 day period

Chemical stability and in vitro bactericidal efficacy of 0.9% enrofloxacin‐compounded solutions were evaluated following storage at room temperature for 28 days. Chemical stability of enrofloxacin was determined by high‐performance liquid chromatography (HPLC) in five compounded solutions, including sterile water. Bactericidal efficacy was determined by spiral plating serial 10‐fold dilutions of bacteria and solutions followed by colony counts. Tris–EDTA [TrizEDTA^® (TE)], Tris–EDTA and 0.15% chlorhexidine [TrizChlor^® (TC)], 2.5% lactic acid, 0.1% salicylic acid and 0.1% parachlorometaxylenol [Epi‐Otic (EO)], and 0.1% free salicylic acid, 0.1% parachlorometaxylenol and 0.5% EDTA [Epi‐Otic Advanced (EA)] were used. High‐performance liquid chromatography was carried out with one‐step liquid/liquid extraction to detect and quantify enrofloxacin stability. Mean recoveries for compounded samples run in triplicate at 28 days were 97.7% (TE), 99.9% (TC), 98.1% (EO) and 97.8% (EA). Kruskal–Wallis analysis showed no significant difference in the percentage recovery (H = 0.0539, df = 3, P = 0.9967). American Type Culture Collection strains of Staphylococcus pseudintermedius and Pseudomonas aeruginosa were used to evaluate in vitro efficacy following 30 min incubation on days 0, 14 and 28. Consistent in vitro bactericidal efficacy of all compounded solutions, indicated by killing >2.3 × 10⁷ colony‐forming units/mL, was seen; however, bactericidal efficacy decreased for compounded TC on day 14. Pseudomonas aeruginosa was more sensitive to the ear cleaners and enrofloxacin than S. pseudintermedius. The HPLC and in vitro data suggest that 0.9% enrofloxacin compounded with sterile water, TE, EO and EA maintains chemical stability and bactericidal efficacy for 28 days.     

Continuous intravenous infusion of glucose induces endogenous hyperinsulinaemia and lamellar histopathology in Standardbred horses

Endocrinopathic laminitis is frequently associated with hyperinsulinaemia but the role of glucose in the pathogenesis of the disease has not been fully investigated. This study aimed to determine the endogenous insulin response to a quantity of glucose equivalent to that administered during a laminitis-inducing, euglycaemic, hyperinsulinaemic clamp, over 48 h in insulin-sensitive Standardbred racehorses. In addition, the study investigated whether glucose infusion, in the absence of exogenous insulin administration, would result in the development of clinical and histopathological evidence of laminitis. Glucose (50% dextrose) was infused intravenously at a rate of 0.68 mL/kg/h for 48 h in treated horses (n=4) and control horses (n=3) received a balanced electrolyte solution (0.68 mL/kg/h). Lamellar histology was examined at the conclusion of the experiment. Horses in the treatment group were insulin sensitive (M value 0.039±0.0012 mmol/kg/min and M-to-I ratio (100×) 0.014±0.002) as determined by an approximated hyperglycaemic clamp. Treated horses developed glycosuria, hyperglycaemia (10.7±0.78 mmol/L) and hyperinsulinaemia (208±26.1 μIU/mL), whereas control horses did not. None of the horses became lame as a consequence of the experiment but all of the treated horses developed histopathological evidence of laminitis in at least one foot. Combined with earlier studies, the results showed that laminitis may be induced by either insulin alone or a combination of insulin and glucose, but that it is unlikely to be due to a glucose overload mechanism. Based on the histopathological data, the potential threshold for insulin toxicity (i.e., laminitis) in horses may be at or below a serum concentration of ～200 μIU/mL.     

Persistent digital hyperthermia over a 48 h period does not induce laminitis in horses

Persistent digital hyperthermia, presumably due to vasodilation, occurs during the developmental and acute stages of insulin-induced laminitis. The objectives of this study were to determine if persistent digital hyperthermia is the principal pathogenic mechanism responsible for the development of laminitis. The potent vasodilator, ATP-MgCl(2) was infused continuously into the distal phalanx of the left forefoot of six Standardbred racehorses for 48 h via intra-osseous infusion to promote persistent digital hyperthermia. The right forefoot was infused with saline solution and acted as an internal control. Clinical signs of lameness at the walk were not detected at 0 h, 24h or 48 h post-infusion. Mean ± SE hoof wall temperatures of the left forefoot (29.4 ± 0.25°C) were higher (P<0.05) than those on the right (27.5 ± 0.38°C). Serum insulin (15.0 ± 2.89 μIU/mL) and blood glucose (5.4 ± 0.22 mM) concentrations remained unchanged during the experiment. Histopathological evidence of laminitis was not detected in any horse. The results demonstrated that digital vasodilation up to 30°C for a period of 48 h does not trigger laminitis in the absence of hyperinsulinaemia. Thus, although digital hyperthermia may play a role in the pathogenesis of laminitis, it is not the sole mechanism involved.     

Relationships between muscle growth potential,intramuscular fat content and different indicators of muscle fibre types in young Charolais bulls

Genetic selection in favor of muscle growth at the expense of fat should affect characteristics of muscles, and therefore beef quality. This study was conducted with two extreme groups of six animals selected among 64 Charolais young bulls ranked according to their genetic potential for muscle growth. Muscle characteristics were assessed in Rectus abdominis (RA, slow oxidative) and Semitendinosus (ST, fast glycolytic) muscles. Intramuscular fat content and proportions of myosin heavy chains I (slow) and IIA (fast oxido‐glycolytic) and certain indicators of oxidative metabolism (activities of citrate synthase (CS), isocitrate dehydrogenase and cytochrome‐c oxidase (COX); expression of H‐fatty acid binding protein (FABP)) were higher in RA than in ST muscle. Genetic selection for muscle growth reduced intramuscular fat content and the activities of some oxidative metabolism indicators (namely CS, COX only). The positive correlation between muscle triacylglycerol content and A‐FABP messenger RNA level (a marker of adipocyte differentiation) (r = 0.53, P < 0.05) suggests that A‐FABP may be a good marker of the ability of bovines to deposit intramuscular fat. In conclusion, the metabolic muscle characteristics which respond to the selection process in favor of muscle growth clearly differ from the muscle characteristics which allow muscle types to be differentiated.     

A systematic quantitative review of urban tree benefits,costs, and assessment methods across cities in different climatic zones

Urban trees can potentially mitigate environmental degradation accompanying rapid urbanisation via a range of tree benefits and services. But uncertainty exists about the extent of tree benefits and services because urban trees also impose costs (e.g. asthma) and may create hazards (e.g. windthrow). Few researchers have systematically assessed how urban tree benefits and costs vary across different cities, geographic scales and climates. This paper provides a quantitative review of 115 original urban tree studies, examining: (i) research locations, (ii) research methods, and (iii) assessment techniques for tree services and disservices. Researchers published findings in 33 journals from diverse disciplines including: forestry, land use planning, ecology, and economics. Research has been geographically concentrated (64% of studies were conducted in North America). Nearly all studies (91.3%) used quantitative research, and most studies (60%) employed natural science methods. Demonstrated tree benefits include: economic, social, health, visual and aesthetic benefits; identified ecosystem services include: carbon sequestration, air quality improvement, storm water attenuation, and energy conservation. Disservices include: maintenance costs, light attenuation, infrastructure damage and health problems, among others. Additional research is required to better inform public policy, including comparative assessment of tree services and disservices, and assessment of urban residents and land managers’ understanding of tree benefits and costs.