Sub-cellular elemental imaging of human muscle tissues affected by neuromuscular diseases

Various types of neuromuscular diseases differ in symptoms, pathology, and clinical picture but one of their common elements is muscle weakness, which could lead to human motor activities impairment and in many cases to shortening of life span and even death due to respiratory failure. That is why it is very important to better understand the underlying causes of these diseases to be able to implement new methods of treatment more effectively. This paper presents the results of the elemental analysis of human muscular tissues affected by dystrophy and myopathy. For this purpose, the particle-induced X-ray emission method was used, which is perfectly suited for measuring light elements. The samples were analysed for differences in the elemental composition of Na, Mg, P, S, Cl, K, Fe, Zn, and Br. The results were presented in the form of elemental concentration maps and a thorough statistical analysis of the obtained data using the advanced statistical methods.

Experimental Evidence of Ciguatoxin Accumulation and Depuration in Carnivorous Lionfish

Ciguatera poisoning is a food intoxication associated with the consumption of fish or shellfish contaminated, through trophic transfer, with ciguatoxins (CTXs). In this study, we developed an experimental model to assess the trophic transfer of CTXs from herbivorous parrotfish, Chlorurus microrhinos, to carnivorous lionfish, Pterois volitans. During a 6-week period, juvenile lionfish were fed naturally contaminated parrotfish fillets at a daily dose of 0.11 or 0.035 ng CTX3C equiv. g−1, as measured by the radioligand-receptor binding assay (r-RBA) or neuroblastoma cell-based assay (CBA-N2a), respectively. During an additional 6-week depuration period, the remaining fish were fed a CTX-free diet. Using r-RBA, no CTXs were detectable in muscular tissues, whereas CTXs were measured in the livers of two out of nine fish sampled during exposure, and in four out of eight fish sampled during depuration. Timepoint pooled liver samples, as analyzed by CBA-N2a, confirmed the accumulation of CTXs in liver tissues, reaching 0.89 ng CTX3C equiv. g−1 after 41 days of exposure, followed by slow toxin elimination, with 0.37 ng CTX3C equiv. g−1 measured after the 6-week depuration. These preliminary results, which need to be pursued in adult lionfish, strengthen our knowledge on CTX transfer and kinetics along the food web.

Huffmanela spp. (Nematoda: Trichosomoididae) from Orange-spotted Grouper (Epinephelus coioides, Hamilton, 1822) at Jubail Province, on the Arabian Gulf, Saudi Arabia: A case report

This paper is conducted for identifying the parasite which collected during regular routine inspection for the hygienic condition and health status of fish in 2019 at the central fish market shops at Jubail city, Saudi Arabia. Samples from an orange spotted grouper (Epinephelus coioides) fish showed heavy black streaks between the muscle fibers that was considered unmarketable and rejected by the consumer after had been cut and prepared for sealing. The black discolorations were in the form of heavy diffused focal black spots or forming threads of variable sizes embedded in the entire whole-body musculature of the fish. These samples were subjected to parasitological and pathological evaluation. The parasitological examination of the affected muscular tissues revealed Huffmanela spp. eggs infection. The parasitic infestation was identified on the bases of the morphological and ultra-structural characters of the eggs. The histopatholgical investigation of the dark discoloration of the muscular tissues showed severe diffused multifocal granulomatous myositis reactions in the form of chronic inflammatory response accompanied with fibrous connective tissue proliferation around the eggs and larvae together with lymphocytes and macrophages aggregation. Muscular necrosis, edema and evidence of muscular regeneration were also noticed. In conclusion; this case report confirmed the occurrence of Huffmanela spp. infection in the muscles of Epinephelus coioides by using light and scanning electron microscopy.Further molecular assessment is recommended.

Raman and Fluorescence Profiles Modifications of Muscular and Adipose Tissues Exposed to Low Energy X-ray Beams

This work aims to investigate changes induced by low-energy radiation in adipose and muscular tissues employing autofluorescence and Raman spectroscopic techniques. X-ray beams expositions with 25 and 35 kV at 0.11, 1.1, and 2.1 Gy radiation dose levels were applied. Changes in Raman line intensities at specific bands assigned to collagen, proteins, and lipids were observed. Autofluorescent analysis exhibit variations in the collagen and nicotinamide adenine dinucleotide emission, resulting from the structural modifications, variations on the reduced/oxidized fluorophores equilibrium followed by radiation exposure. Results show that Raman and fluorescence spectroscopy are suitable techniques to evaluate radiation effects on biomolecules even at low radiation doses and energies.

Chitin Synthases Are Critical for Reproduction, Molting, and Digestion in the Salmon Louse (Lepeophtheirus salmonis)

Chitin synthase (CHS) is a large transmembrane enzyme that polymerizes Uridine diphosphate N-acetylglucosamine into chitin. The genomes of insects often encode two chitin synthases, CHS1 and CHS2. Their functional roles have been investigated in several insects: CHS1 is mainly responsible for synthesizing chitin in the cuticle and CHS2 in the midgut. Lepeophtheirus salmonis is an ectoparasitic copepod on salmonid fish, which causes significant economic losses in aquaculture. In the present study, the tissue-specific localization, expression, and functional role of L. salmonis chitin synthases, LsCHS1 and LsCHS2, were investigated. The expressions of LsCHS1 and LsCHS2 were found in oocytes, ovaries, intestine, and integument. Wheat germ agglutinin (WGA) chitin staining signals were detected in ovaries, oocytes, intestine, cuticle, and intestine in adult female L. salmonis. The functional roles of the LsCHSs were investigated using RNA interference (RNAi) to silence the expression of LsCHS1 and LsCHS2. Knockdown of LsCHS1 in pre-adult I lice resulted in lethal phenotypes with cuticle deformation and deformation of ovaries and oocytes in adult lice. RNAi knockdown of LsCHS2 in adult female L. salmonis affected digestion, damaged the gut microvilli, reduced muscular tissues around the gut, and affected offspring. The results demonstrate that both LsCHS1 and LsCHS2 are important for the survival and reproduction in L. salmonis.

Distribution of cysts holding Ascocotyle (Phagicola) longa metacercariae in tissues and organs of mugilid

Ascocotyle (Phagicola) longa is an etiological agent of human phagicolosis. Mugilids are the second intermediate host, the first being Heleobia australis, and mugilids predatory birds and mammals are its definitive hosts. The occurrence of cysts holding A. longa metacercariae is described in mugilids with a prevalence of up to 100%. The wide geographical distribution of A. longa and its intermediate hosts coupled with the rise in the consumption of raw or poorly cooked fish may elevate the risk of human infection. Therefore, in this study, we aimed to verify the distribution pattern of cysts holding A. longa in mugilids. The tissue and organ samples of these fish were processed in a domestic blender and examined under a stereoscopic microscope to identify the cysts holding the digenetic metacercariae. Of the 24 (100%) fish samples that were analyzed, 12 of Mugil curema and 12 of Mugil liza possessed cysts holding A. longa metacercariae. Digenetic cysts were identified to be present in the gills, heart, stomach, liver, intestines, mesentery, and muscular tissues collected from M. curema and M. liza. Conclusively, in M. curema, the cysts holding A. longa metacercariae were found to be distributed randomly throughout the fish body in almost every tissue and organ that was examined.