Circulatory system of red tail catfish (Phractocephalus hemioliopterus Bloch & Schneider, 1801): a corrosion cast study

Red tail catfish, Phractocephalus hemioliopterus, in one of the popular ornamental fish. The present study is aimed to describe and visualizes the cardiovascular system of this species with corrosion cast study method. For this purpose, 10 red tail catfish with 580 gr average weight were obtained and were filled their blood vessels and heart with fluid artificial resin made on the basis of methylmetacrylate after anaesthetizing and euthanizing. For complete polymerization and hardening of the methylmetacrylate, the fish were further submersed for 12-24 hrs in water bath following by 24-48 hrs submersion in a 25% solution of KOH to full maceration. Based on the results we describe the cardiovascular system i.e. the afferent and efferent vessels of gill, different parts of the heart, ventral aorta, dorsal aorta, intestinal and gastric vessels, liver, anterior and posterior parts of the kidneys, spleen, portal and hepatic vein

Evaluation of morphologic method for the detection of nervous tissue in minced meat

Producing meat products with ingredients which are not consistent with the label is considered fraud. Due to the high economic value of meat, the use of unauthorized tissue in meat products is possible. Aside from the adulteration aspect, it is important to note that some animal tissues like the brain and the spinal cord can bear infective agents which are transmissible to humans. Based on these observations, the aim of the present study was to apply morphological method for detection of nervous tissues in minced meat. Laboratory adulterated minced beef meat; each containing 0, 5, 10, 15 and 20% of beef brain was prepared. Then each sample was divided into three parts and four paraffin embedded blocks were prepared from each part. The sections were stained using sudan black and cresyl violet and also the immunohistochemical staining with fluorescent method were applied using anti-neurofilament 200 antibody for the determination of nervous tissue. Although the neuronal cell bodies and neuronal fibers were clearly detectable in Cresyl violet staining and sudan black staining, respectively, however, staining intensity did not show any difference according to different percentages of added brain. In contrary, immunohistochemical study revealed that neurofilament 200- immunolabeling was present in all percentages of added brain samples and the intensity of the labeling varying from weak to strong consisted by the increasing the amount of brain in samples. In conclusion, the immunohistochemical technique with fluorescent method is an effective method for evaluations of additive brain tissue in minced meat with high sensitivity

Histological and mucin histochemical study of the small intestine of the Persian squirrel (Sciurus anomalus)

This article describes the histological and mucin histochemical properties of the small intestine of the Persian squirrel (Sciurus anomalus). This species is widely distributed in the Middle East and can be found as a companion animal. The histological studies revealed that the plicae circulares were not visible in the tunica mucosa. The maximum height and width of the villi were observed in the duodenum, which then decreased toward the ileum. The muscularis mucosa was scattered, whereas the tunica submucosa was composed of dense connective tissue. The lymphatic nodules were seen in the submucosa of the distal part of the jejunum and ileum, and Brunner's glands were embedded in the initial portion of the duodenum. The tunica muscularis was significantly thicker in the ileum, and the circular muscle layer was thicker than the longitudinal muscle layer throughout the entire length of the small intestine. The mucin histochemistry, which was examined using the periodic acid-Schiff (PAS) and alcian blue (AB) (pH 1.0 and 2.5) and also PAS-AB (pH 2.5) and aldehyde fuchsin-AB (pH 2.5) techniques coupled with methylation and saponification reaction for some sections, showed that the small intestine mucous content included both carboxylated and sulfated acidic mucins with few neutral mucins. The results of this study contribute to the knowledge of the histological and histochemical characteristics of the gastrointestinal tracts of exotic mammals and provide data for comparison with other mammals

Preparation and in vitro Evaluation of Injectable Alginate/Thiolated Chitosan Hydrogel Scaffold for Neural Tissue Engineering

Introduction: Spinal cord injuries are one of the main causes of disability with devastating neurological consequences and secondary conflicts in other organs. Tissue engineering and regenerative medicine have been recognized as novel, promising methods in the treatment of tissue injuries, especially in neurological damage in recent decades. Hydrogels have the advantage of compatibility with damaged tissue, and injectable hydrogels can be applied in minimally invasive surgeries. This study aimed to evaluate an injectable hydrogel-based scaffold consisting of thiolated chitosan and alginate for neural tissue regeneration. Materials and Methods: In the present study, an injectable hydrogel-based containing thiolated chitosan and alginate was prepared. Microbiology and pH tests were performed. Microstructural properties and porosity of scaffold were evaluated by scanning electron microscope (SEM). The swelling /shrinkage ratio and rates of biodegradation were also conducted. Finally, the viability of L929 cells on the scaffold was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: Thiolated chitosan/ alginate hydrogel had low pH with no contamination. SEM showed hydrogel had a porous microstructure with a mean pore diameter of 21.89 ± 0.32 μm which is suitable for cell culture. Furthermore, according to MTT test results, this hydrogel was biocompatible. Conclusion: Thiolated chitosan/ alginate hydrogel is convenient for application in neural tissue engineering based on its structural properties and its ability to support cell proliferation. According to the in vitro analysis, it can also be used as a scaffold to create a suitable environment for increasing cell viability