Effects of saturated fatty acids with lysophospholipids on production and nutrient digestibility in lactating cows.

The objective of the experiment was to determine the effects of supplemental saturated fatty acid (SFA) sources, lysophospholipids (LPL), and their interaction on production and nutrient digestibility in lactating dairy cows. The experiment was conducted with 48 cows in a randomized complete block design. Cows were blocked (total 12 blocks) by parity and days in milk and randomly assigned to 4 dietary treatments in each block (2 × 2 factorial arrangement), i.e., 2 sources of fat supplements, C16:0 (palmitic acid, PA)- or C18:0 (stearic acid, SA)-enriched fat, with or without LPL. The experiment was conducted for 6 wk to measure daily dry matter intake and milk yield and weekly milk composition. During the last week of the experiment, spot fecal and urine samples were collected to determine total-tract nutrient digestibility. Milk samples in the last week were also collected to analyze for milk fatty acid (FA) profile. All data were analyzed using the mixed procedure of SAS where block was used as a random effect and FA, LPL, and the interaction of FA by LPL were used as fixed effects. Week and interactions of week by FA or LPL were included for production measures. Different sources of SFA did not affect dry matter intake and milk yield. However, PA increased (39.7 vs. 36.8 kg) energy-corrected milk compared with SA due to increased milk fat yield. No effect of LPL on production measures was observed. Total-tract digestibilities of dry matter, organic matter, crude protein, and total FA were not different between PA and SA, but PA increased (41.4 vs. 38.8%) neutral detergent fiber digestibility compared with SA. Supplementation of LPL increased (64.7 vs. 60.5%) total FA digestibility, especially 18-carbon FA (74.1 vs. 68.2%). An interaction of SFA by LPL was found for 16-carbon FA digestibility. The PA diet increased the concentration of 16-carbon FA in milk fat and SA increased the concentration of preformed FA (≥18 carbons). Supplementation of LPL decreased the concentration of trans-10 C18:1. No difference in N utilization and excretion among treatments was observed. In conclusion, PA was more effective in improving milk fat yield of lactating cows compared with SA. Supplementation of LPL increased digestibility of total FA, especially 18-carbon FA but did not affect production.

Removal and detoxification of pentahalogenated phenols using a photocatalytically induced enzymatic process.

Poly-halogenated phenols generated from a range of industrial processes can find their way into rivers and ground water. Here we report on a potential treatment for reducing the toxicity of these aqueous pollutants using two highly toxic penta-halogenated phenols (pentachlorophenol (PCP) and pentabromophenol (PBP)) as surrogates. Solutions were passed through a glass column packed with a silica support fused with titanium dioxide (TiO2) and horseradish peroxidase (HRP) immobilized on its TiO2/glass surface (HRP-Tglass). TiO2 photocatalysis was activated through irradiation with UVB (320 nm) which in turn activated the HRP. Two operational flow rates (0.5 and 1.25 mL min-1; hydraulic retention times (HRTs) of 20 and 8 min, respectively), tested the effect of retention time on the extent of degradation and reduction in toxicity of the treated effluent. Microtox® was used to measure the toxicity of the substrate and its by-products at both flow rates. At the highest flow rate, dehalogenation was limited (removal of 37 % chlorine and 22 % bromine) and the toxicity of the reaction products increased. At the lowest flow rate, the longer exposure time resulted in approximately 97 % and 96 % transformation of PCP and PBP, respectively, a greater degree of dehalogenation (removal of 65 % chlorine and 70 % bromine) and a substantial decrease in toxicity of the treated solutions. The higher toxicity of effluent from the higher flow rate was attributed to the initial degradation products being more toxic than the substrates. With a longer HRT, these were then further broken down to less toxic products. Additional toxicity tests (Hydra hexactinella (Hydra) and Chinese Hamster Ovary (CHO) cell toxicity were conducted on the effluent from the lowest flow rate. Both were less sensitive than the Microtox test, with Hydra proving more sensitive than CHO. The novelty of this work is the toxicity risk assessment of the products resulting from the use of a spatially separated immobilized enzyme and photooxidation system. The system was robust and showed no decrease in treatment efficacy over 10 h.

Playing God and tampering with nature: popular labels for real concerns in synthetic biology.

Public engagement in science with diverse cross-sections of the community is considered a critical aspect of responsible biotechnological innovation. While the research community shows willingness to engage with both ambivalent and supportive audiences about potentially disruptive technological advances, there is less enthusiasm for engaging with groups who hold deeply opposing views to such advances. 'Playing God' and 'tampering with nature' are popular examples of intrinsic objections often made in opposition to the development or use of novel genetic technologies. Historically appearing in arguments against the pursuit of genetically modified organisms in agriculture and food industries, intrinsic objections have previously been labelled by the science community as inconsistent, non-scientific, and vague. Now found in a range of innovation contexts, the domain of synthetic biology appears to attract such objections consistently. We present the findings from a large Australian study (N = 4593) which suggests 'playing God' objections and their variants can be multilayered and, at times, accompanied by meaningful information about risk perceptions. We use qualitative analysis of open-ended responses from an online survey to show how these objections are articulated in response to selected synthetic biology applications across environmental and health domains. Our research invites a rethink of how the synthetic biology community perceives, and engages with, people who express intrinsic objections. These people may additionally hold extrinsic concerns that may be potentially addressed, or at least reasonably considered, through dialogue. We offer some concluding remarks for engaging with publics who employ these types of arguments to communicate unease with aspects of technology development and use.

Bright carbonate veins on asteroid (101955) Bennu: Implications for aqueous alteration history.

The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu's parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.

Variations in color and reflectance on the surface of asteroid (101955) Bennu.

Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu's moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.

Oxidative stress, serotonergic changes and decreased ultrasonic vocalizations in a mouse model of Smith-Lemli-Opitz syndrome.

Smith-Lemli-Opitz syndrome is an inherited monogenic disorder in which mutations to the 7-dehydrocholesterol (7-DHC) reductase (Dhcr7) gene lead to deficits in cholesterol synthesis. As a result, many patients suffer from gross physiological and neurological deficits. The purpose of this study was to identify a potential abnormal behavioral phenotype in a compound mutant mouse model for Smith-Lemli-Opitz disease (Dhcr7 Δ3-5/T93M ) to further validate the model and to provide potential targets for future therapeutic interventions. We also sought to identify some of the underlying changes in brain function that may be responsible for behavioral differences among groups. The Dhcr7 compound mutant mice were smaller than their single mutant littermates. Both single and compound heterozygous mice made fewer ultrasonic vocalizations when separated from the dam, which may suggest a communication deficit in these animals. Striking increases of the highly oxidizable 7-DHC were observed in the compound mutant mice. 7-Dehydrocholesterol is the precursor to cholesterol and builds up because of decreased function of the mutated Dhcr7 enzyme. Additionally, several differences were noted in the serotonergic system including increased expression of the serotonin transporter and increased uptake of serotonin by isolated synaptosomes. We propose that changes to the oxidative environment during development can have a significant impact on the development of serotonergic function and that this contributes to behavioral differences observed in the mutant mice.

Timely initiation of chemotherapy: a systematic literature review of six priority cancers - results and recommendations for clinical practice.

This review evaluated the association between time-to-chemotherapy (TTC) and survival in six priority cancers. A systematic review of the literature was undertaken for papers indexed in the MEDLINE and Cochrane Library databases from the earliest index until April 2014. The methodology used has been published in a separate paper (Guidelines for timely initiation of chemotherapy: a proposed framework for access to medical oncology and haematology cancer clinics and chemotherapy services). The optimal timing of chemotherapy in breast cancer is unclear as available studies are of low quality, report inconsistent results and are limited to the adjuvant setting. However, increased TTC may have a negative prognostic impact, and delays beyond 4 weeks should be avoided. Studies suggest that the optimal timing for initiation of adjuvant chemotherapy for surgically resected colorectal cancer is 4-8 weeks post-surgery. Timing of chemotherapy for metastatic colorectal cancer does not influence survival. There is a paucity of studies to guide the timing of chemotherapy for the treatment of lymphoma and myeloma; no definitive conclusions can be drawn, and clinician discretion should be applied. The optimal timing of chemotherapy in lung cancer is unclear; however, rapid tumour growth and poor disease prognosis suggest that delays should be avoided wherever possible. The optimal timing of chemotherapy in ovarian cancer is unclear as available studies are of low level, report inconsistent results and are limited to the post-surgery setting; however, increased TTC may have a negative prognostic impact; therefore, delays beyond 4 weeks should be avoided.

A new method for measurement of subcoracoid outlet and its relationship to rotator cuff pathology at MR arthrography.

OBJECTIVE: Orthopaedic surgical studies have shown that variations in the vertical distance between the tip of the coracoid process and the supra-glenoid tubercle alter the shape of the subcoracoid outlet. Our objective was to measure the vertical distance between the coracoid tip and the supra-glenoid tubercle (CTGT) on MR and to assess whether this showed better correlation with rotator cuff pathology compared with the axial coraco-humeral distance. MATERIALS AND METHODS: A retrospective review was performed of 100 consecutive shoulder MR arthrograms. Vertical distance between the coracoid tip and the supraglenoid tubercle was measured in the sagittal oblique plane. Separate assessment was then made of tendon pathology of the subscapularis, supraspinatus and long head of biceps tendons. Axial coraco-humeral distance was then measured. Correlation between tendon abnormalities and the two measurements was then made. RESULTS: Of the 100 cases, 42 had subscapularis tendon lesions, 21 had lesions of the long head of biceps and 53 had supraspinatus tendon lesions. Mean vertical distance from the coracoid tip to supraglenoid tubercle was greater in those with lesions of any of these tendons and was statistically significant for the supraspinatus group (P = 0.005). Reduced axial coraco-humeral distance was also seen in patients with tendinopathy, although with less statistically significant difference (p = 0.059). CONCLUSION: Our results support orthopaedic studies that have shown that the vertical distance between the coracoid tip and the supraglenoid tubercle increases the incidence and risk of rotator cuff disease by altering the shape of the subcoracoid outlet.

MRI of inflammatory spondyloarthropathy following traumatic cauda equina syndrome.

BACKGROUND CONTEXT: Spondyloarthropathy has been described radiographically in patients following paralysis from spinal cord trauma. Onset of these findings after cauda equina syndrome have not been reported previously. Furthermore, the magnetic resonance documentation of its early evolution has not been recorded. PURPOSE: We report a case of early-onset spondyloarthropathy shown by magnetic resonance imaging (MRI) in a patient with cauda equina syndrome due to bilateral sacral insufficiency fractures. STUDY DESIGN: Unique case study review, one case. METHODS: Review of the clinical case notes and imaging including initial and subsequent MR imaging. RESULTS: The initial MRI of the lumbosacral spine showed bilateral sacral insufficiency fractures with a kyphotic deformity. The vertebral bodies were normal on the initial computed tomography and MRI studies, which did not reveal pre-existing features of sacroiliitis. The second MRI performed 5 months later clearly showed spondylitis at multiple vertebral levels with partial resolution 18 months post injury. CONCLUSION: Spondyloarthropathy in patients with paralysis due to spinal cord injury is well documented in the English language literature, but until now this has not been demonstrated by MRI. It is a rare complication of traumatic cauda equina syndrome that commences soon after the traumatic event and can resolve spontaneously.

Specialist integrated haematological malignancy diagnostic services: an Activity Based Cost (ABC) analysis of a networked laboratory service model.

AIMS: Specialist Integrated Haematological Malignancy Diagnostic Services (SIHMDS) were introduced as a standard of care within the UK National Health Service to reduce diagnostic error and improve clinical outcomes. Two broad models of service delivery have become established: 'co-located' services operating from a single-site and 'networked' services, with geographically separated laboratories linked by common management and information systems. Detailed systematic cost analysis has never been published on any established SIHMDS model. METHODS: We used Activity Based Costing (ABC) to construct a cost model for our regional 'networked' SIHMDS covering a two-million population based on activity in 2011. RESULTS: Overall estimated annual running costs were £1 056 260 per annum (£733 400 excluding consultant costs), with individual running costs for diagnosis, staging, disease monitoring and end of treatment assessment components of £723 138, £55 302, £184 152 and £94 134 per annum, respectively. The cost distribution by department was 28.5% for haematology, 29.5% for histopathology and 42% for genetics laboratories. Costs of the diagnostic pathways varied considerably; pathways for myelodysplastic syndromes and lymphoma were the most expensive and the pathways for essential thrombocythaemia and polycythaemia vera being the least. CONCLUSIONS: ABC analysis enables estimation of running costs of a SIHMDS model comprised of 'networked' laboratories. Similar cost analyses for other SIHMDS models covering varying populations are warranted to optimise quality and cost-effectiveness in delivery of modern haemato-oncology diagnostic services in the UK as well as internationally.

Tunneling in tocopherol-mediated peroxidation of 7-dehydrocholesterol.

The peroxidation of 7-dehydrocholesterol (7-DHC), a biosynthetic precursor to vitamin D3 and cholesterol, has been linked to the pathophysiology of Smith-Lemli-Optiz syndrome (SLOS), a devastating human disorder. In SLOS, 7-DHC plasma and tissue levels are elevated because of defects in the enzyme that convert it to cholesterol. α-Tocopherol can mediate the peroxidation of 7-DHC under certain circumstances and this prompted us to investigate the kinetic isotope effect (KIE) during this process. Thus, 9,14-d2-7-DHC was synthesized using a photochemical cyclization of deuterium-reinforced previtamin D3 (retro to its biosynthesis). Subsequently, we carried out co-oxidation of 9,14-h2-25,26,26,26,27,27,27-d7- and 9,14-d2-7-DHC in the presence of α-tocopherol under conditions that favor TMP. By monitoring the products formed from each precursor using mass spectrometry, the KIE for the hydrogen (deuterium) atom removal at C9 was found to be 21 ± 1. This large KIE value indicates that tunneling plays a role in the hydrogen atom transfer step in the tocopherol-mediated peroxidation of 7-DHC.

Free radical oxidation of cholesterol and its precursors: Implications in cholesterol biosynthesis disorders.

Free radical oxidation of cholesterol and its precursors contribute significantly to the pathophysiology of a number of human diseases. This review intends to summarize recent developments and provide a perspective on the reactivities of sterols toward free radical oxidation, the free radical reaction mechanism, and the biological consequences of oxysterols derived from the highly oxidizable cholesterol precursor, 7-dehydrocholesterol. We propose that the rigid structures, additional substituents on the double bonds, and the well-aligned reactive C-H bonds in sterols make them more prone to free radical oxidation than their acyclic analogs found in unsaturated fatty acids. The mechanism of sterol peroxidation follows some well-established reaction pathways found in the free radical peroxidation of polyunsaturated fatty acids, but sterols also undergo some reactions that are unique to these compounds. Peroxidation of 7-dehydrocholesterol gives arguably the most diverse set of oxysterol products that have been observed to date. The metabolism of these oxysterols in cells and the biological consequences of their formation will be discussed in the context of the pathophysiology of the human disease Smith-Lemli-Opitz syndrome. Considering the high reactivity of sterols, we propose that a number of other cholesterol biosynthesis disorders may be associated with oxidative stress.

Comparative analysis of enzymatically produced novel linear DNA constructs with plasmids for use as DNA vaccines.

The use of DNA to deliver vaccine antigens offers many advantages, including ease of manufacture and cost. However, most DNA vaccines are plasmids and must be grown in bacterial culture, necessitating elements that are either unnecessary for effective gene delivery (for example, bacterial origins of replication) or undesirable (for example, antibiotic resistance genes). Removing these elements may improve the safety profile of DNA for the delivery of vaccines. Here, we describe a novel, double-stranded, linear DNA construct produced by an enzymatic process that solely encodes an antigen expression cassette, comprising antigen, promoter, polyA tail and telomeric ends. We compared these constructs (called 'Doggybones' because of their shape) with conventional plasmid DNA. Using luciferase-expressing constructs, we demonstrated that expression levels were equivalent between Doggybones and plasmids both in vitro and in vivo. When mice were immunized with DNA constructs expressing the HIV envelope protein gp140, equivalent humoral and cellular responses were induced. Immunizations with either construct type expressing hemagluttinin were protective against H1N1 influenza challenge. This is the first example of an effective DNA vaccine, which can be produced on a large scale by enzymatic processes.

FK506-binding protein 1b/12.6: a key to aging-related hippocampal Ca2+ dysregulation?

It has been recognized for some time that the Ca(2+)-dependent slow afterhyperpolarization (sAHP) is larger in hippocampal neurons of aged compared with young animals. In addition, extensive studies since have shown that other Ca(2+)-mediated electrophysiological responses are increased in hippocampus with aging, including Ca(2+) transients, L-type voltage-gated Ca(2+) channel activity, Ca(2+) spike duration and action potential accommodation. Elevated Ca(2+)-induced Ca(2+) release from ryanodine receptors (RyRs) appears to drive amplification of the Ca(2+) responses. Components of this Ca(2+) dysregulation phenotype correlate with deficits in cognitive function and plasticity, indicating they may play critical roles in aging-related impairment of brain function. However, the molecular mechanisms underlying aging-related Ca(2+) dysregulation are not well understood. FK506-binding proteins 1a and 1b (FKBP1a/1b, also known as FKBP12/12.6) are immunophilin proteins that bind the immunosuppressant drugs FK506 and rapamycin. In muscle cells, FKBP1a/1b also bind RyRs and inhibits Ca(2+)-induced Ca(2+) release, but it is not clear whether FKBPs act similarly in brain cells. Recently, we found that selectively disrupting hippocampal FKBP1b function in young rats, either by microinjecting adeno-associated viral vectors expressing siRNA, or by treatment with rapamycin, increases the sAHP and recapitulates much of the hippocampal Ca(2+) dysregulation phenotype. Moreover, in microarray studies, we found FKBP1b gene expression was downregulated in hippocampus of aging rats and early-stage Alzheimer's disease subjects. These results suggest the novel hypothesis that declining FKBP function is a key factor in aging-related Ca(2+) dysregulation in the brain and point to potential new therapeutic targets for counteracting unhealthy brain aging.

Micromechanical characterisation of failure in acrylic bone cement: the effect of barium sulphate agglomerates.

Acrylic bone cement has been established as a method of fixation of load-bearing orthopaedic implants for nearly five decades, and has produced excellent long term clinical results. However, increasing patient BMI values and longer life expectancies are placing ever greater demands on joint replacements, so there is a need to further improve the performance of cemented fixation. Damage accumulation in the in vivo cement mantle due to initiation and coalescence of fatigue micro-cracks has been implicated in the aseptic loosening and failure of implants. While the effect of porosity on crack initiation processes has been widely reported, the relative influence of different radiopacifying agents is less well studied. In particular, barium sulphate radiopacifier particles have been reported to form large agglomerates within the cement that have been linked to initiation of fatigue cracks in vitro. However, there appears to be little understanding of the micromechanical aspects of cement failure due to barium sulphate agglomeration. The present study utilised micro-computed tomography (µCT) and field emission gun scanning electron microscopy (FEG-SEM), alongside mechanical testing, to provide a systematic, quantitative assessment of the effect of barium sulphate agglomeration on crack initiation processes in a conventional, vacuum-mixed acrylic cement. Three-dimensional characterisation of defect populations was performed, with agglomerates of barium sulphate particles found to be large (up to 0.37 mm equivalent spherical diameter), present at spatial densities up to 22 per mm³, and evenly distributed through each cement specimen. Fatigue cracks consistently initiated at the largest agglomerates; furthermore, fatigue life was found to scale consistently with largest defect size. As such, the tendency of barium sulphate particles to agglomerate is clearly evidenced to be detrimental to the fatigue performance of this cement in vitro. Optimisation of mixing techniques and/or cement formulations containing barium sulphate may therefore be advantageous to reduce the formation of agglomerates and their potential effects in vivo.

Does cyclical loading affect the elution of antibiotics from articulating cement knee spacers?

Two-stage revision surgery for infected total knee replacement offers the highest rate of success for the elimination of infection. The use of articulating antibiotic-laden cement spacers during the first stage to eradicate infection also allows protection of the soft tissues against excessive scarring and stiffness. We have investigated the effect of cyclical loading of cement spacers on the elution of antibiotics. Femoral and tibial spacers containing vancomycin at a constant concentration and tobramycin of varying concentrations were studied in vitro. The specimens were immersed and loaded cyclically to 250 N, with a flexion excursion of 45°, for 35 000 cycles. The buffered solution was sampled at set intervals and the antibiotic concentration was established so that the elution could be calculated. Unloaded samples were used as a control group for statistical comparison. The elution of tobramycin increased proportionately with its concentration in cement and was significantly higher at all sampling times from five minutes to 1680 minutes in loaded components compared with the control group (p = 0.021 and p = 0.003, respectively). A similar trend was observed with elution of vancomycin, but this failed to reach statistical significance at five, 1320 and 1560 minutes (p = 0.0508, p = 0.067 and p = 0.347, respectively). However, cyclically loaded and control components showed an increased elution of vancomycin with increasing tobramycin concentration in the specimens, despite all components having the same vancomycin concentration. The concentration of tobramycin influences both tobramycin and vancomycin elution from bone cement. Cyclical loading of the cement spacers enhanced the elution of vancomycin and tobramycin.

Continuous enzymatic treatment of 4-bromophenol initiated by UV irradiation.

Horseradish peroxidase (HRP) can be used for the treatment of halogenated phenolic substances. In the presence of hydrogen peroxide phenols are oxidized to form polymers which undergo partial dehalogenation. However, when immobilized, the peroxidase is subject to inactivation due to blockage of the active sites by the growing polymers and to deactivation by elevated levels of hydrogen peroxide. When HRP immobilized on a novel glass-based support incorporating titanium dioxide is subjected to UV irradiation, hydrogen peroxide is produced and the nascent polymer is removed. In this work a reactor was constructed that utilized HRP immobilized on the novel support and the in situ production of hydrogen peroxide to treat 4-bromophenol as a model substrate. The system was operated for almost 17 hours with no apparent decline in activity.

Selective gamma-ketoaldehyde scavengers protect Nav1.5 from oxidant-induced inactivation.

The cardiac sodium channel (SCN5A, Na(V)1.5) is a key determinant of electrical impulse conduction in cardiac tissue. Acute myocardial infarction leads to diminished sodium channel availability, both because of decreased channel expression and because of greater inactivation of channels already present. Myocardial infarction leads to significant increases in reactive oxygen species and their downstream effectors including lipoxidation products. The effects of reactive oxygen species on Na(V)1.5 function in whole hearts can be modeled in cultured myocytes, where oxidants shift the availability curve of I(Na) to hyperpolarized potentials, decreasing cardiac sodium current at the normal activation threshold. We recently examined potential mediators of the oxidant-induced inactivation and found that one specific lipoxidation product, the isoketals, recapitulated the effects of oxidant on sodium currents. Isoketals are highly reactive gamma-ketoaldehydes formed by the peroxidation of arachidonic acid that covalently modify the lysine residues of proteins. We now confirm that exposure to oxidants induces lipoxidative modification of Na(V)1.5 and that the selective isoketal scavengers block voltage-dependent changes in sodium current by the oxidant tert-butylhydroperoxide, both in cells heterologously expressing Na(V)1.5 and in a mouse cardiac myocyte cell line (HL-1). Thus, inhibition of this lipoxidative modification pathway is sufficient to protect the sodium channel from oxidant induced inactivation and suggests the potential use of isoketal scavengers as novel therapeutics to prevent arrhythmogenesis during myocardial infarction.