Therapeutic Intervention with Dietary Chitosan Nanoparticles Alleviates Fish Pathological and Molecular Systemic Inflammatory Responses against Infections

Marine bio-sourced chitosan nanoparticles (CSNP) are antimicrobial and immunomodulatory agents beneficial for fish medicine. Herein, dietary CSNP was investigated for the amelioration of the systemic inflammatory responses of an induced fish model. One hundred and forty-four rainbow trout were assigned to one pathogen-free and non-supplemented group (negative control), and three challenged groups: non-supplemented (positive control), CSNP-preventive, and CSNP-therapeutic. After a feeding experiment extended for 21 days, the organosomatic indices (OSI) and molecular aspects were assessed. After a challenge experiment extended for further 28 days, CSNP-therapeutic intervention was assessed on fish survival and systemic inflammatory responses on pathology, histo-morphology, and molecular aspects. With CSNP administration, OSI nonsignificantly decreased and the relative expression of targeted inflammatory-mediator genes was significantly increased. The CSNP-therapeutic fish showed an RPS of 80% as compared to the positive control group, and CSNP-therapeutic administration retained the highest gene expression augmentation up to 28 days after the challenge. Notably, the splenic reticulin fibers framework of the CSNP-therapeutic group retained the highest integrity among the groups during the infection. After recovery, reticulin fibers density in the CSNP-therapeutic samples was significantly higher than in the negative control group, which indicates high innate immunity. Thus, CSNP showed promising biotherapeutic features enhancing fish resistance against infections.     

Immunohistochemical localization of distinct angiotensin II AT1 receptor isoforms in the kidneys of the Sprague-Dawley rat and the desert rodent Meriones crassus

Employing a purified lgG fraction of a polyclonal anti-AT1 receptor anti-body, raised against a synthetic octapeptide encompassing residues 14-21 of the first extracellular domain of the AT1 polypeptide, selective AT1 receptor expression was immunohistochemically demonstrable within renal structures in Sprague-Dawley (SD) rats and the desert rodent Meriones crassus. In both animal models, prominent AT1 receptor labelling was evident in renal vascular elements, particularly cortical inter-lobular arteries (IA) as well as vasa recta bundles in the inner stripe of the outer medulla. Less intense labelling was observed among peritubular capillary endothelia within the deep cortex, and at both the outer stripe and the inter-bundle regions of the inner stripe of the outer medulla. The binding of the anti-peptide anti-body was, however, lacking among glomeruli and, except for the intense labelling confined to basement membranes of Bowman's capsule of deep nephrons, was virtually absent in all renal tubular structures of both animal models. Structural assessment of the expressed AT1 receptors by two-dimensional Western blotting revealed that a spectrum of structurally distinct AT1 receptor isoforms is expressed in the renal tissues of both animal models. This spectrum was constituted by isoforms of equal size (70 kDa) but distinct pls in SD rats, and of both different sizes (67-73 kDa) and isoelectric points in M. crassus. In either species, the charge and/or size heterogeneity of AT1 receptor isoforms may be attributed in part to differential post-translational glycosylation mechanisms of the AT1 receptor polypeptide backbone. The potential for the differential glycosylation state of AT1 receptors to alter recognition properties may add another level of complexity to tissue-specific and/or species-specific mechanisms underlying angiotensin II interactions in the kidney.     

Evaluation of Egyptian sheep production systems: I. Breed crosses and management systems

Our objective was to evaluate life-cycle performance of flocks of two Egyptian breeds, Rahmani (R) and Ossimi (O), and their crosses with Finnish Landrace (F) in two management systems. Management systems were one mating season per year (1M) and three mating seasons per 2 yr (3M). Breeds and crosses studied included purebred R and O, F1 crosses 1/2F-1/2R (FR) and 1/2F-1/2O (FO), and inter se matings of 1/4 F-3/4 R (RFR) and 1/4 F-3/4 O (OFO). A dynamic computer model was used to simulate animal performance and enterprise efficiency and profit. Two measures of lifecycle feed conversion (biological efficiency) were computed: kilograms of TDN input per kilograms of empty body weight output (TDN/EBW) and kilograms of TDN input per kilogram of carcass lean output (TDN/CLN). Profit was measured as gross margin (income minus variable costs per ewe per year, GM/EWE). Input parameters for the model were obtained from published results and analyses of data collected from experimental flocks of the same genetic stocks in Egypt. Profit for FR and RFR was 42 and 6% higher in 1M than in 3M. However, profit for all other genetic types was 4 to 8% greater in 3M than in 1M. Breed rankings changed depending on the measure of evaluation (i.e., biological efficiency or profit). Maximization of system output did not necessarily improve efficiency. Under accelerated lambing systems, greater overhead costs associated with labor and feed offset gains in ewe productivity. Genetic stocks should be matched to resources and management systems.     

Effects of different carbon sources and dietary protein levels in a biofloc system on growth performance,immune response against white spot syndrome virus infection and cathepsin L gene expression of Litopenaeus vannamei

A 5‐week study was performed to evaluate the effect of spoilage date extract (SDE) as the biofloc carbon source on Litopenaeus vannamei (5.4 ± 0.3 g) performance. The two levels of dietary protein (15% and 25% crude protein) and two carbohydrate sources (molasses‐M and SDE‐P) were tested including: M15, M25, P15 and P25. The minimum (0.2 ± 0.0 mg/L) and the maximum (0.5 ± 0.0 mg/L) of total ammonia nitrogen were observed in the P15 and M25 groups respectively. The highest protein efficiency ratio (6.1 ± 0.3) and protein productive value (112.3 ± 5.8%) were found in the P15 group (p < 0.05). No significant difference was found between biofloc treatments in the expression of cathepsin L gene in hepatopancreas (p > 0.05). The number of total haemocyte count (THC), semigranular cells (SGC) and granular cells (GC) of shrimp in SDE‐based biofloc treatments was relatively higher than those in molasses‐based biofloc treatments. Following the white spot syndrome virus (WSSV) challenge, a significant decrease in THC, SGC, GC and hyaline cell values was observed in all treatments (p = 0.001). Plasma biochemical parameters were significantly influenced by dietary protein levels, biofloc carbon sources as well as WSSV challenge test. In conclusion, SDE successfully could be used as an alternative carbon source for establishing a biofloc system in L. vannamei production.     

Further studies on the propagation of cauliflower

Use of carefully lifted, decapitated cauliflower plants with 6 to 7 leaves per se, eliminated the need of the rooting of shoots and provided seeds in reduced time. Previously, shoots obtained from decapitated and de-leafed plants were rooted and allowed to produce seeds. This latter method did not assure that seed would be available in time for the following season's planting.     

Genetic diversity among sumac (Rhus coriaria L.) accessions collected from five areas of Iran

Genetic Resources and Crop Evolution - Sumac (Rhus coriaria L.) has been used in human nutrition as an herbal drug to treat different diseases for centuries. In recent years, the genetic...     

Amantadine: neuromuscular blockade by suppression of ionic conductance of the acetylcholine receptor

Amantadine hydrochloride decreases the sensitivity of denervated mammalian muscle to iontophoretically applied acetylcholine. The drug depresses the amplitude of the end-plate current and reverses the slope of the relation between half-decay time and membrane potential suggesting that it alters the ionic conductance that is mediated by the acetylcholine receptor. Binding studies confirm that amantadine acts on the ion conductance modulator rather than the acetylcholine receptor.     

Natural enemies and seasonal abundance of the blackmargined aphid (Monellia caryella) in pecan orchards in Israel

The blackmargined aphid,Monellia caryella (Fitch), exhibited a seasonal pattern with early and late peaks of the population in pecan orchards at Newe Ya’ar in the Yizre’el Valley. A similar pattern was not observed at Kibbutz Sede Eliyyahu in the Bet She’an Valley, where there was a single peak, late in the season. The occurrence of natural enemies indicated that spiders and lacewing eggs were the predators most commonly associated with population fluctuations of the aphid. In most cases the rate of increase of the blackmargined aphid was highest late in the season.     

Sublethal effects of nine insecticides on Drosophila suzukii and its major pupal parasitoid Trichopria drosophilae

Background

Although the pupal parasitoid Trichopria drosophilae is used in conservative and augmentative biocontrol of Drosophila suzukii infestations, current pest management strategies mostly rely on multiple insecticide applications. In this context, the aim of the study was to investigate the baseline toxicity of nine insecticides on D. suzukii larvae and their multiple sublethal effects (LC₁₀) on immature stages of the pest feeding on contaminated diet and T. drosophilae developing within the intoxicated host.

Results

Chlorpyriphos and azadirachtin showed the lowest and the highest LC₁₀, the values of which were 9.78 × 10¹³ and 1.46 × 10³ times lower than their recommended label field rate, respectively. Among tested insecticides, imidacloprid, malathion and dimethoate were the only treatments that did not affect the juvenile development time of D. suzukii, while spinosad and the organophosphates chlorpyriphos and dimethoate did not influence fly pupal size. No sublethal effects were recorded on T. drosophilae degree of infestation (DI) and juvenile development time. On the contrary, cyazypyr and dimethoate negatively affected the success of parasitism (SP) and the number of progeny of the pupal parasitoid, in association with malathion for the first parameter and spinosad for the fertility. Compared to the untreated control, more female progeny emerged following azadirachtin exposure, while dimethoate caused the opposite effect. Imidacloprid, lambda-cyhalothrin and spinetoram decreased hind tibia length of emerged parasitoids.

Conclusion

This study provides new insights on the (eco)toxicological profile of nine insecticides and new information needed to support the deployment of T. drosophilae in the field within the sustainable management techniques against D. suzukii. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.