Research progress on gut health of farmers teleost fish: a viewpoint concerning the intestinal mucosal barrier and the impact of its damage

Reviews in Fish Biology and Fisheries - The intestinal mucosal barrier plays a critical role in the maintenance of host health. In farmed teleost fish, the intestinal epithelium is challenged by a...     

Application of an optimized marker amplification protocol in immunohistochemistry — a valuable tool for visualizing antigenic sites of low signal strength or sparse distribution

Amplification of immunohistochemical markers received considerable attention during the 1980s and 1990s. The amplification approach was largely abandoned following the development of antigen retrieval and reporter amplification techniques, because the latter were incorporated more easily into high throughput automated procedures in industrial and diagnostic laboratories. There remain, however, a number of instances where marker amplification still has much to offer. Consequently, we examined experimentally the utility of an optimized marker amplification technique in diagnostically relevant tissue where either the original signal strength was low or positive sites were visible, but sparsely distributed. Marker amplification in the former case not only improved the visibility of existing positive sites, but also revealed additional sites that previously were undetectable. In the latter case, positive sites were rendered more intense and therefore more easily seen during low magnification examination of large areas of tissue.     

EFFECT OF VITAMIN E SUPPLEMENTATION AND PARTIAL SUBSTITUTION OF POLY- WITH MONO-UNSATURATED FATTY ACIDS IN PIG DIETS ON MUSCLE,AND MICROSOME EXTRACT a-TOCOPHEROL CONCENTRATION AND LIPID OXIDATION

The experiment was organized in a 3×2 factorial arrangement with three dietary fat blends and a basal (20 mg kg^?1 diet) or supplemented (220 mg kg^?1) level of α-tocopheryl acetate. Dietary vitamin E and monounsaturated to polyunsaturated fatty acid ratio (dietary MUFA/PUFA) affected muscle α-tocopherol concentration (α-tocopherol [log μg g^?1]=0.18 (±0.105)+0.0034 (±0.0003)·dietary α-tocopherol [mg kg^?1 diet] (P<0.0001)+0.39 (±0.122)·dietary MUFA/PUFA (P<0.0036)). An interaction between dietary α-tocopherol and dietary MUFA/PUFA exists for microsome α-tocopherol concentration (α-tocopherol [log μg g^?1]=1.14 (±0.169) (P<0.0001)+0.0056 (±0.00099)·dietary α-tocopherol [mg kg^?1 diet] (P<0.0001)+0.54 (±0.206)·dietary MUFA/PUFA (P<0.0131)?0.0033 (±0.0011)·dietary α-tocopherol [mg kg^?1)]×dietary MUFA/PUFA (P<0.0067)), and hexanal concentration in meat (hexanal [ng·g^?1]=14807.9 (±1489.8)?28.8 (±10.6) dietary α-tocopherol [mg·kg^?1] (P<0.01)?8436.6 (±1701.6)·dietary MUFA/PUFA (P<0.001)+24.0 (±11.22)·dietary α-tocopherol·dietary MUFA/PUFA (P<0.0416)). It is concluded that partial substitution of dietary PUFA with MUFA lead to an increase in the concentration of α-tocopherol in muscle and microsome extracts. An interaction between dietary α-tocopherol and fatty acids exists, in which at low level of dietary vitamin E inclusion, a low MUFA/PUFA ratio leads to a reduction in the concentration of α-tocopherol in microsome extracts and a concentration of hexanal in meat above the expected values.     

Subcutaneous injection of visible implant elastomer in sterlet (Acipenser ruthenus Linnaeus, 1758): a study on compatibility and retention

The purpose of this study was to mark endangered sterlet (Acipenser ruthenus) with visible implant elastomer (VIE) in order to assess mortality, compatibility, retention, persistence and histological reactions resulting from this tagging technique. It was hypothesized there would be only minor effects on the fishes' health, and assumed that acute effects would be more pronounced than long‐term effects. On 11 September 2013, 20 specimens were tagged ventrally with visible implant elastomer, 20 received a subcutaneous injection with 0.9% NaCl solution, and another 20 served as untreated control. Mean total length was 28.0 ± 1.8 cm and mean body mass 64.1 ± 12.0 g. The sterlets were kept in four 4,000‐L tanks filled with 2,400‐L water. Acute effects were monitored for 95 days, where fish were held at temperatures between 2.4°C and 15.2°C, reflecting outdoor conditions. Chronic effects were examined 282 days post‐tagging through histological sections of the tagging region in five sterlets. During the first 95 days of observation, tag retention was 100%. No signs of incompatibility were detected. Body mass did not significantly differ between VIE‐tagged fish and controls. At day 282 post‐tagging, however, distinct tissue reactions were visible at the tagging sites of nine fish. Histological examination of five fish revealed a variable degree of infiltration with leukocytes in the areas around the elastomer, which did not necessarily correspond with the externally visible degree of inflammation. After medical treatment, the lesions healed without complications, whereas the retention rate of the VIE tags was 5%. According to the findings, the tag location rather than the tag itself was responsible for the externally visible irritations, indicating that the ventral subcutis of sterlet is not a suitable site, even for small VIE tags in long‐term studies. The results of this study also suggest that VIE marking should in general be critically evaluated before application in field studies.     

Quirks of dye nomenclature. 5. Rhodamines

Rhodamines were first produced in the late 19^th century, when they constituted a new class of synthetic dyes. These compounds since have been used to color many things including cosmetics, inks, textiles, and in some countries, food products. Certain rhodamine dyes also have been used to stain biological specimens and currently are widely used as fluorescent probes for mitochondria in living cells. The early history and current biological applications are sketched briefly and an account of the ambiguities, complications and confusions concerning dye identification and nomenclature are discussed.     

Quirks of dye nomenclature. 6. Malachite green

Malachite green was discovered independently by two researchers in Germany in the 19^th century and found immediate employment as a dye and a pigment. Subsequently, other uses, such as staining biological specimens, emerged. A much later application was the control of fungal and protozoan infections in fish, for which the dye remains popular, although illegal in many countries owing to a variety of toxicity problems. In solution, malachite green can exist as five different species depending on the pH. The location of the positive charge of the colored cation on a carbon atom or a nitrogen atom is still debated. The original names of this dye, and their origins, are briefly surveyed.     

The maize α-zein promoter can be utilized as a strong inducer of cellulase enzyme expression in maize kernels

Transgenic Research - Expression of recombinant proteins in plants is a technology for producing vaccines, pharmaceuticals and industrial enzymes. For the past several years, we have produced...     

Anatomical defences against bark beetles relate to degree of historical exposure between species and are allocated independently of chemical defences within trees

Conifers possess chemical and anatomical defences against tree‐killing bark beetles that feed in their phloem. Resins accumulating at attack sites can delay and entomb beetles while toxins reach lethal levels. Trees with high concentrations of metabolites active against bark beetle‐microbial complexes, and more extensive resin ducts, achieve greater survival. It is unknown if and how conifers integrate chemical and anatomical components of defence or how these capabilities vary with historical exposure. We compared linkages between phloem chemistry and tree ring anatomy of two mountain pine beetle hosts. Lodgepole pine, a mid‐elevation species, has had extensive, continual contact with this herbivore, whereas high‐elevation whitebark pines have historically had intermittent exposure that is increasing with warming climate. Lodgepole pine had more and larger resin ducts. In both species, anatomical defences were positively related to tree growth and nutrients. Within‐tree constitutive and induced concentrations of compounds bioactive against bark beetles and symbionts were largely unrelated to resin duct abundance and size. Fewer anatomical defences in the semi‐naïve compared with the continually exposed host concurs with directional differences in chemical defences. Partially uncoupling chemical and morphological antiherbivore traits may enable trees to confront beetles with more diverse defence permutations that interact to resist attack.     

Mapping of the KHSRP gene to a region of conserved synteny on human chromosome 19p13.3 and mouse chromosome 17

The K homology-type splicing regulatory protein, KSRP, activates splicing through intronic splicing enhancer sequences. It is highly expressed in neural cells and is required for the neural-specific splicing of the c-src N1 exon. In this study, we mapped the gene (gene symbols KHSRP and Khsrp) to human chromosome 19 by using radiation hybrid panels and to mouse chromosome 17 by studying an interspecific backcross panel. Human KHSRP is a positional candidate gene for familial febrile convulsion and Cayman type cerebellar ataxia. Comparative analysis of the human and mouse genomes indicates that the KHSRP gene is located in regions of conserved synteny between the two species.