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Having only emerged as a threat to snakes in 2006, relatively little is known of snake fungal disease’s (SFD) impacts on demographic processes, particularly survival and growth. I used data from an extensive capture-mark-recapture study to examine survival and growth in central Kentucky Queensnake (Regina septemivittata) populations. I found that diseased snakes and healthy snakes possessed similar monthly survival estimates (SFD positive 0.9687, 95% CI 0.8444 to 0.9944; SFD negative 0.8735, 95% CI 0.7518 to 0.9402) and that disease state transition probability from SFD negative to SFD positive, and SFD positive to SFD negative were also similar (N-P 0.4807, 95% CI 0.3395 to 0.6251; P-N 0.3461 95% CI 0.2523 to 0.4536). Additionally, I found that diseased snakes exhibited heightened growth rates (1.12 mm/month females, 0.91 mm/month males) compared to healthy snakes (0.73 mm/month females, 0.59 mm/month males)., © 2022 Andrew Jerome Ibach

Although autacoids primarily derived from the cyclooxygenase-2 and 5-lipoxygenase (LOX) pathways are essential mediators of inflammation, endogenous specialized proresolving mediators (SPMs) act as robust agonists of resolution. SPM biosynthesis is initiated by the conversion of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid primarily via the 12/15-LOX pathway. Although 12/15-LOX activity is prominent in the cornea, the role of SPM pathway activation during infection remains largely unknown and is the focus of the current study. Pseudomonas keratitis was induced in resistant BALB/c and susceptible C57BL/6 (B6) mice. Biosynthetic pathways for proinflammatory autacoids and SPMs were assessed. Divergent lipid mediator profiles demonstrate the importance of 15-LOX pathways in the pathogenesis of ocular infectious disease. Results indicate that an imbalance of LOX enzymatic pathways contributes to susceptibility observed in B6 mice where deficient activation of SPM circuits, as indicated by reduced 15-hydroxy-eicosatetraenoic acid and 17-hydroxydocosahexaenoic acid levels, prevented transition toward resolution and led to chronic inflammation. In sharp contrast, BALB/c mice demonstrated a well-balanced axis of 5-LOX/12-LOX/15-LOX pathways, resulting in sufficient proresolving bioactive metabolite formation and immune homeostasis. Furthermore, a novel immunoregulatory role for 15-LOX was revealed in inflammatory cells (polymorphonuclear leukocytes and macrophages), which influenced phagocytic activity. These data provide evidence that SPM circuits are essential for host defense during bacterial keratitis.-Carion, T. W., Greenwood, M., Ebrahim, A. S., Jerome, A., Suvas, S., Gronert, K., Berger, E. A. Immunoregulatory role of 15-lipoxygenase in the pathogenesis of bacterial keratitis.

Substance P neuropeptide and its receptor, neurokinin-1 receptor (NK1R), are reported to present on the ocular surface. In this study, mice lacking functional NK1R exhibited an excessive desquamation of apical corneal epithelial cells in association with an increased epithelial cell proliferation and increased epithelial cell density, but decreased epithelial cell size. The lack of NK1R also resulted in decreased density of corneal nerves, corneal epithelial dendritic cells (DCs), and a reduced volume of basal tears. Interestingly, massive accumulation of CD11c+CD11b+ conventional DCs was noted in the bulbar conjunctiva and near the limbal area of corneas from NK1R−/− mice. After ocular HSV-1 infection, the number of conventional DCs and neutrophils infiltrating the infected corneas was significantly higher in NK1R−/− than C57BL/6J mice. This was associated with an increased viral load in infected corneas of NK1R−/− mice. As a result, the number of IFN-γ–secreting virus-specific CD4 T cells in the draining lymph nodes of NK1R−/− mice was much higher than in infected C57BL/6J mice. An increased number of CD4 T cells and mature neutrophils (CD11b+Ly6ghigh) in the inflamed corneas of NK1R−/− mice was associated with an early development of severe herpes stromal keratitis. Collectively, our results show that the altered corneal biology of uninfected NK1R−/− mice along with an enhanced immunological response after ocular HSV-1 infection causes an early development of herpes stromal keratitis in NK1R−/− mice.

An alternative way of fractionating lignocellulose biomass into its individual components, hemicelluloses, lignin and cellulose, was investigated. South African Eucalyptus grandis wood chips were fractionated using a combination of hot water and alkaline treatments with or without AQ. Initially, the biomass samples were treated in hot water to remove hemicelluloses. At optimum pre-fraction conditions, the data acquired revealed that almost 12 % of the E. grandis wood biomass could be recovered as hemicelluloses. When the hemicelluloses pre-extracted biomass was further treated using sodium hydroxide with or without AQ, the data indicated that the amount of lignin and cellulose that could be recovered was 22 and 36 %, respectively (as % of the wood mass). The substrate was characterised by a higher amount of α-cellulose (91–93 %), lower kappa no (12–13), viscosity (327–450 η mg/L) and DP (1078–1536). It was then presumed that such pulp could meet end-user requirement of the dissolving pulps. Industrial acceptance of this biomass fractionation concept, however, will further require careful assessments of various options for treating and purifying the hemicelluloses and lignin in their respect streams.

The IL-2/anti–IL-2 Ab immunocomplex has recently been shown to expand the naturally occurring pool of CD4+Foxp3+ regulatory T cells (Tregs). In this study, we show that administration of the IL-2/anti–IL-2 Ab immunocomplex to C57BL/6 mice, prior to corneal HSV-1 infection, significantly increased the pool of Foxp3+ Tregs when measured at early time points postinfection. Increased numbers of Foxp3+ Tregs on days 2 and 4 postinfection resulted in a marked reduction in the development of severe herpetic stromal keratitis (HSK). When compared with corneas from the control group, corneas from the immunocomplex-treated group showed a significant reduction in the amount of infectious virus on day 2 but not on day 4 postinfection. Reduced viral load was associated with a 2-fold increase in NK cell numbers in corneas from the immunocomplex-treated group of mice. Moreover, a dramatic reduction in the influx of CD4 T cells in inflamed corneas was determined on days 7 and 16 postinfection in the immunocomplex-treated group of infected mice. Immunocomplex treatment given on days 5, 6, and 7 postinfection significantly increased Foxp3+ Tregs in draining lymph nodes and in the spleen but failed to reduce the severity of HSK. In terms of the influx of CD4 T cells and granulocytes into inflamed corneas, no significant differences were noted between both groups of mice on day 16 postinfection. Our findings demonstrate that increasing Foxp3+ Tregs early but not late postinfection in secondary lymphoid tissues is more efficacious in controlling the severity of HSK.

Psbetaeudomonas (P.) aeruginosa infection of the cornea in BALB/c mice does not result in perforation and the mice have been classified as resistant. However, regulation of this response via inflammasome activation remained untested. Therefore, BALB/c mice were infected with P. aeruginosa ATCC strain 19660 and NLRP3 and NLRC4 protein tested by ELISA. Since NLRC4 vs NLRP3 protein levels were significantly higher in the corneas of BALB/c at 1 and 5 days postinfection we used silencing to knockdown NLRC4. Silencing NLRC4 vs scrambled siRNA treatment exacerbated disease in BALB/c mice, reduced myeloperoxidase levels and elevated bacterial plate counts at 5 days postinfection. It also increased pro IL-1beta, but reduced total protein for IL-1beta and IL-18 at 5 days postinfection. Flow cytometry to identify cells affected by silencing, showed reduced caspase-1 levels in a CD11blowLy6Glow population of cells, (but not PMN or macrophages) from the infected cornea of siNLRC4 treated mice that produced less mature IL-1beta. These data provide evidence that the NLRC4 inflammasome contributes to resistance through regulation of caspase-1, IL-1beta and IL-18 in a CD11blowLy6Glow population of cells.

The purpose of this study is to evaluate the effect blocking neurokinin 1 receptor (NK1R) signaling has on the CD8 T cell response to corneal herpes simplex 1 (HSV-1) infection, using NK1R antagonist (L 760735) or NK1R−/− mice. Corneal HSV-1 infection was carried out on C57BL/6 and NK1R−/− mice. Our results showed an enhanced CD8 T cell response to corneal HSV-1 infection by NK1R−/− mice compared to C57BL/6 mice. The data illustrates that at day 5 post infection, draining lymph nodes (DLNs) in NK1R−/− mice exhibit an increased CD8 T cell IFN-γ response as measured by intracellular cytokine staining. In addition, an increased CD8 T cell proliferation is noted in NK1R−/− mouse DLNs. Interestingly, L 760735 treatment given to HSV-1 infected C57BL/6 mice did not show an increase in CD8 T cell proliferation or IFN-γ production; in comparison to infected, vehicle treated control mice. To determine the underlying cause of this discrepancy, we detected pre-existing LYVE+ vessels in unmanipulated corneas of NK1R−/− mice. This was associated with higher levels of VEGF-C protein in ocular tissue (cornea + limbal conjunctiva) of unmanipulated NK1R−/− compared to C57BL/6 mice, as measured via western blot. We recently reported a massive accumulation of CD11b and CD11c expressing cells near the limbal area in unmanipulated eyes of NK1R−/− mice [J Immunol., 2016, 197 (10) 4021–4033]. Confocal microscopy results showed VEGF-C colocalization with these cells near the limbal area in NK1R−/− mice. Since corneal lymphatics play an important role in generating the CD8 T cell response to corneal HSV-1 infection, our results suggest an enhanced CD8 T cell response in NK1R−/− mice, likely due to a notable increase in corneal lymphatics in NK1R−/− compared to C57BL/6 mice.

FOR 20 years I have been duty vet for the British Riding Clubs (BRC) at their national championships. In my first year, 14 horses were declined …

Extended reach drilling (ERD) and completion capability at the Chayvo field, Sakhalin Island, has evolved in well design and operational practices to increase well reach to over 10.5 kilometers. This is a result of disciplined redesign based on learnings acquired throughout the program and has resulted in the successful drilling of world record measured depth ERD wells. The learnings and design changes will be discussed in this paper using a recent record well, the Chayvo Z–12, as a case study. Implementation of the operator's drilling performance management process and integrated hole quality (IHQ) technology has enabled continuous improvement in overall rate of penetration (ROP) and hole quality. Impediments to higher ROP have been systematically engineered out of the drilling system while minimizing the level of risk. Bottomhole assembly (BHA) designs and operational practices have been modified to reduce vibration effects leading to poor borehole patterning and micro-doglegs, thus enabling a higher ROP with a better quality borehole. Detailed torque and drag modeling, engineering surveillance, and lubricants have also led to improved hole cleaning, lower equivalent circulating densities (ECD), and reduced friction effects required to drill and complete these wells. Chayvo completion design incorporates the use of pre-drilled liners, standalone screens, swell packers, and inflow control devices (ICDs), allowing effective zonal isolation, prevention of sand production, and flow profile control. Management of ICD placement and configuration provides the flexibility for early well life zonal isolation while maintaining cost effective non-rig intervention options for the future. The ability to effectively capture and transfer lessons learned has been a driver to the success at Chayvo. Work process and technology best practices can be rapidly integrated into operations, thereby facilitating improvement in all aspects of the drilling process.

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