Effects of moderately oxidized dietary lipid and the role of vitamin E on the development of skeletal abnormalities in juvenile Atlantic halibut (Hippoglossus hippoglossus)

A study was conducted to characterize the effects of oxidized marine fish oil (MFO) on skeletal development in juvenile Atlantic halibut (Hippoglossus hippoglossus) and to determine the role of vitamin E on their bone health and antioxidant defense mechanisms. Juvenile halibut (4.5 ± 0.1 g) were fed six experimental diets containing untreated (peroxide value (POV)  =0.6 meq kg^− 1), mod`rately oxidized (POV = 7.5 meq kg^− 1) and highly oxidized (POV = 15 meq kg^− 1) MFO either with or without α-tocopherol acetate (0 or 300 IU kg^− 1) supplementation for 14 weeks. No significant effects on growth, survival, hepatosomatic indices, or hematocrit were observed among the dietary treatments. Fish fed diets without vitamin E and highly oxidized dietary lipids showed increased hepatic malonaldehyde concentrations indicating a response to oxidative stress. Both muscle and liver α-tocopherol concentrations were significantly lower in fish fed diets without vitamin E supplementation. Alkaline phosphatase levels in serum and bone were increased when vitamin E was present within the diet indicating higher bone formation activity by osteoblasts. Oxidized lipids and lack of dietary vitamin E significantly increased saturated and decreased polyunsaturated hepatic fatty acids. Liver lipids of fish fed diets without vitamin E also exhibited a lower ratio of 22:6n-3 to 22:5n-3 and n-3 fatty acids. The most frequent skeletal deformity observed was scoliosis, spanning the cephalic/prehemal regions, as well as the anterior hemal region of the vertebral column, which increased the frequency according to elevated levels of oxidized dietary lipid. Lordosis was also observed, with no specific pattern along the vertebral column. The pattern and type of abnormalities observed were similar to those reported in an earlier study in halibut from a commercial hatchery.     

Measuring the height of the fishing line and its effect on shrimp catch and bycatch in an ocean shrimp (Pandalus jordani) trawl

The relationship between fishing line height (FLH), shrimp catch and bycatch in a semi-pelagic ocean shrimp (Pandalus jordani) trawl was investigated using a newly developed recording inclinometer. The inclinometer was effective at measuring FLH and indicating trawl performance deficits. FLH was determined to be stable during a haul and also between hauls within a given footrope and groundline configuration. FLH was readily adjusted with simple modifications to the footrope “dropper” chains. Inclinometer data showed that FLH can be unequal between double-rigged nets of identical configuration. Shrimp catch and the bycatch of flatfish and juvenile rockfish varied inversely with FLH, suggesting FLH can be adjusted to equalize the catch of shrimp, flatfish and juvenile rockfish between two double-rigged shrimp nets.     

Recreational scuba diving in a groundwater ecosystem: Disturbance mechanisms,ecological impacts and stakeholder perceptions

1. Ecological damage by scuba divers has been extensively studied in marine ecosystems, particularly coral reefs, whereas the impacts on freshwater environments such as groundwater springs is unknown. In the Silfra groundwater fissure in Iceland, a vast increase in diver entries has occurred during the last decade, prompting concerns over potential ecosystem impacts and visitor carrying capacity.
2. Here, a mixed‐method approach was used to assess the impacts of scuba diving in Silfra. (a) Divers were recorded under water to observe the mechanisms of diver‐related disturbances, (b) benthic material was collected along transects in Silfra and the undisturbed fissure Flosagjá to compare biofilm biomass and zoobenthic communities between and within fissures, and (c) the perceptions and experiences of stakeholders surrounding the dive tourism in Silfra were explored.
3. Underwater observations showed that 91.4% of the divers caused at least a single disturbance, resulting in biofilm detachments and/or sediment stirring. Diver fins caused the most frequent disturbances, predominantly through fin‐generated currents but also by directly contacting the substrate. Benthic biofilm biomass was lower in Silfra than Flosagjá and exhibited a negative correlation with dive‐use. Some disturbance‐tolerant zoobenthic groups exhibited moderate to strong correlations with dive‐use.
4. All stakeholders had negative perceptions towards increasing diver entries, but although entry limitation could improve tourism quality, disturbance might only minimally be reduced as springs like Silfra may be particularly sensitive.
5. Springs are characteristically stable and uniform environments that can be vulnerable to disturbance. Their use for scuba diving should be carefully managed through a holistic approach and an active collaboration between all stakeholders.

     

Myosins 1 and 6, myosin light chain kinase,actin and microtubules cooperate during antibody-mediated internalisation and trafficking of membrane-expressed viral antigens in feline infectious peritonitis virus infected monocytes

Monocytes infected with feline infectious peritonitis virus, a coronavirus, express viral proteins in their plasma membranes. Upon binding of antibodies, these proteins are quickly internalised through a new clathrin- and caveolae-independent internalisation pathway. By doing so, the infected monocytes can escape antibody-dependent cell lysis. In the present study, we investigated which kinases and cytoskeletal proteins are of importance during internalisation and subsequent intracellular transport. The experiments showed that myosin light chain kinase (MLCK) and myosin 1 are crucial for the initiation of the internalisation. With co-localisation stainings, it was found that MLCK and myosin 1 co-localise with antigens even before internalisation started. Myosin 6 co-localised with the internalising complexes during passage through the cortical actin, were it might play a role in moving or disintegrating actin filaments, to overcome the actin barrier. One minute after internalisation started, vesicles had passed the cortical actin, co-localised with microtubules and association with myosin 6 was lost. The vesicles were further transported over the microtubules and accumulated at the microtubule organising centre after 10 to 30 min. Intracellular trafficking over microtubules was mediated by MLCK, myosin 1 and a small actin tail. Since inhibiting MLCK with ML-7 was so efficient in blocking the internalisation pathway, this target can be used for the development of a new treatment for FIPV.     

Effect of treatment with a cationic antiviral compound on acute infection with bovine viral diarrhea virus

Bovine viral diarrhea virus (BVDV) is a widespread bovine pathogen capable of causing disease affecting multiple body systems. Previous studies have shown 2-(2-benzimidazolyl)-5-[4-(2-imidazolino)phenyl]furan dihydrochloride (DB772) effectively prevents BVDV infection in cell culture. The aim of this project was to assess the efficacy of DB772 for the prevention of acute BVDV infection. Four calves seronegative to BVDV were treated with DB772 and another 4 calves were treated with diluent only on the same dosing schedule. Each calf was subsequently challenged intranasally with BVDV. Virus was isolated consistently from untreated calves on days 4 to 8, while treated calves remained negative by virus isolation during this period. Azotemia was exhibited by all treated calves on day 4 resulting in the euthanasia of 1 calf on day 10 and the death of another on day 13. Virus was isolated from the 2 remaining treated calves on day 14 or 21. On day 21, both remaining treated calves and all 4 untreated calves had anti-BVDV antibody titers > 1:2048. This pilot study indicates that DB772 temporarily prevented acute disease due to BVDV, but carries a significant concern of renal toxicity.     

Lacticin 481: in vitro reconstitution of lantibiotic synthetase activity

The lantibiotic lacticin 481 is synthesized on ribosomes as a prepeptide (LctA) and posttranslationally modified to its mature form. These modifications include dehydration of serines and threonines, followed by intramolecular addition of cysteines to the unsaturated amino acids, which generates cyclic thioethers. This process breaks eight chemical bonds and forms six newbonds and is catalyzed by one enzyme, LctM. We have characterized the in vitro activity of LctM, which completely processed a series of LctA mutants, displaying a permissive substrate specificity that holds promise for antibiotic engineering.     

The genetic landscape of the childhood cancer medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor of children. To identify the genetic alterations in this tumor type, we searched for copy number alterations using high-density microarrays and sequenced all known protein-coding genes and microRNA genes using Sanger sequencing in a set of 22 MBs. We found that, on average, each tumor had 11 gene alterations, fewer by a factor of 5 to 10 than in the adult solid tumors that have been sequenced to date. In addition to alterations in the Hedgehog and Wnt pathways, our analysis led to the discovery of genes not previously known to be altered in MBs. Most notably, inactivating mutations of the histone-lysine N-methyltransferase genes MLL2 or MLL3 were identified in 16% of MB patients. These results demonstrate key differences between the genetic landscapes of adult and childhood cancers, highlight dysregulation of developmental pathways as an important mechanism underlying MBs, and identify a role for a specific type of histone methylation in human tumorigenesis.     

Erwinia carotovora subsp.atroseptica infection promotes verticillium wilt development in potato in Israel

Summary The interaction betweenErwinia carotovora subsp.atroseptica (Eca) andVerticillium dahliae and its effect on symptom development in potato cultivars showing different degrees of resistance to them was examined over two seasons in irrigated fields in a hot, dry climate. Four cultivars were used: Cara, highly resistant to blackleg and tolerant to Verticillium wilt; Pentland Crown also resistant to blackleg but susceptible to Verticillium wilt; Désirée, moderately susceptible to blackleg but tolerant to Verticillium wilt; and Maris Bard, susceptible to both diseases. Seed tubers were inoculated with Eca immediately after harvest in Scotland, to simulate natural infection, and then planted in Israel in soil naturally infested byV. dahliae. In Verticillium tolerant cultivars, Eca infection increased the rate of colonization byV. dahliae and significantly enhanced symptom development, as assessed by suppression of plant height and wilt symptoms. This report is a portion of the Ph.D. thesis of the senior author in Ben-Gurion University of the Negev.     

The effect of photodynamic therapy on squamous cell carcinoma in a murine model: evaluation of time between intralesional injection to laser irradiation

Successful treatment of naturally occurring periocular squamous cell carcinoma (SCC) in horses with photodynamic therapy (PDT) has been performed by injecting residual tumor with verteporfin and applying laser irradiation immediately following injection. This study used a murine model to evaluate the influence of time between intralesional injection of verteporfin to laser irradiation on tumor growth inhibition with PDT. Mice were randomized into six groups (n=10/group). Each tumor was injected with either 0.1mg/cm(3) of verteporfin (Tx) or 5% dextrose in water (C). Tx and C groups 1, 2, and 3 were irradiated at 1, 30, and 180min after injection. Wilcoxon-rank sum test (P< or =0.05) was performed to determine the relative change in tumor volume (RCTV) between groups. Statistical significance was demonstrated between treatment groups. Although verteporfin-PDT treated mice in Tx1 and Tx2 demonstrated a lower RCTV compared to C1 and C2 mice, the differences were not statistically significant.