Light and scanning electron microscopy of the eye of Siganus luridus (Rüppell, 1828).

Introduction: The morphological characteristics of eyes in fishes are highly diverse and have evolved to meet the specific visual requirements as per their habitats. These morphological features of eyes are important for researchers and ecologists. The dusky spinefoot (Siganus luridus) is a tropical teleost fish with a laterally flattened body which lives in the Mediterranean Sea. Currently, there are no histological data relating to the Siganus luridus eye. Methods: In this study, the morphology of the Siganus luridus eye was examined to enhance our understanding of its structure and its relationship to fish ecology. Detailed gross and microscopic features were recorded using light and scanning microscopy. Results: The key observations describe the main structural features of the eye of Siganus luridus, specifically, the diameter of the orbit, architecture of three tunics of eye and detailed lens description. The choroid was divided into four layers, and had a rete mirabile, consisting of numerous small blood vessels in the choroidal gland. The tapetum lucidum was observed, which is interesting since Siganus luridus is herbivore and herbivores typically lack a tapetum lucidum. Discussion: These observations shed new light on the intricate eye structure of Siganus luridus and provide valuable insights into its visual abilities and adaptations to the aquatic environment and feeding behavior.

Scanning electron microscopy and morphometric analysis of the hair in dromedaries with SEM-EDX in relation to age.

BACKGROUND: Hair characterization is critical for determining animal individuality throughout life. This study aimed to assess the morphological features of dromedary camel hair in relation to age. MATERIALS AND METHODS: Hair samples were obtained from the camel humps of 30 dromedary camels separated into three groups: G1 (n:10) aged one-year, G2 (n:10) aged 3-5 years, and G3 (n:10) at the age of 8-10 years. The hair was examined using light microscopy, SEM, and SEM-EDX. RESULTS: The Maghrebi camel had varied medulla patterns and structures across the ages. In the G1 group 75% had continuous medulla patterns and amorphous medulla structures, compared to 70% in G2, and 90% in G3. The medulla index increased with age, rising from 0.3 to 0.77%. The shaft width grew in size from G1 to G2, then fell to approximately one-third of the G2 size at G3. The cortex and cuticle widths were also determined by age, and they increased in the G1 compared to G3 camels. The shape of the cuticle scales in G1 camels was wavy, like mountain tops with irregular edges, within G2 camels the scales were particularly long, oval-shaped scales with smooth, wavy borders. The scales of the older G3 camels were quite long and rectangular. SEM-EDX spectra recognized carbon, oxygen, nitrogen, sulfur, calcium, aluminum, silicon, and potassium at the medulla and cortex. Sulfur levels were highest in the G2 samples but lowest in the G1 samples. CONCLUSION: The dromedary camel's hair structure and mineral content, particularly carbon and nitrogen, differed as camels aged.

Light and scanning electron microscopic characterization of the Egyptian buffalo hair in relation to age with analysis by SEM-EDX.

The purpose of this study was to demonstrate a relationship between the microstructure and measurements of Egyptian buffalo hair and age. The buffalo studied ranged in age from young to premature to adult (3-8 months, 1.5-3, 4-6, and 8-10 years). The hair was collected from the animals' withers. Cuticle elements were examined using scanning electron microscopy (SEM), light microscopy, and energy-dispersive X-ray (EDX) analysis. Hair shaft diameter increased with age, according to SEM and light microscopy measurements. The values of shaft diameter obtained by SEM of the same animal were 64%-67% of the values obtained by light microscopy due to shrinkage of the hair during the drying process. Additional microscopy measurements revealed that the width of the cortex and medulla increased with age, while the width of the cuticle decreased slightly. The medulla index of four different age groups ranged from 0.56 to 0.61 µm. The average distance between successive scale values increased from 4.83 µm in the young group to 8.86 µm between the ages of 8 and 10 years. The scale pattern had a distinct personality at each stage of age. The hair medulla was in the center and consisted of a mesh-like structure with large pores divided into smaller pores by septa. The cortex was a bundle of fibers that wrapped around the medulla. Light microscopy revealed small oval granules and large streak-like granules in the cortex. EDX spectra revealed that carbon, oxygen, and nitrogen were shown to be more abundant in all age groups of buffalo. In buffalo hair, oxygen was the second most abundant element after carbon. The carbon mass in the examined samples decreased slightly with age (42.31%, 39.18%, 38.88%, and 38.49%), while oxygen increased with age. We concluded that hair measurements varied with age, scale microstructure, and elements, so we estimated buffalo animals' ages up to 10 years. HIGHLIGHTS: The goal was to show a link between the microstructure and measurements of Egyptian buffalo hair and age. Hair shaft diameter increased with age, according to scanning electron microscopy (SEM) and light microscopy measurements. The hair shaft diameter obtained by light microscopy was higher than that obtained by scanning electron microscopy of the same animal; we hypothesized that the difference in hair shaft diameter measured by light microscopy and scanning electron microscopy of the same animal was due to the shrinkage of the hair during the drying process. The width of the cortex and medulla increased with age, while the width of the cuticle decreased slightly. The average distance between successive scale values increased from 4.83 µm in the young group to 8.86 µm between 8 and 10 years old. At each stage of age, the scale pattern had a distinct personality. Carbon, oxygen, and nitrogen were found to be more abundant in the hair of buffalo of all ages and were detected using energy-dispersive X-ray (EDX) spectra. After carbon, oxygen was the second most abundant element in buffalo hair. The carbon mass in the samples studied decreased slightly with age, while the oxygen mass increased. Hair measurements varied according to age, scale microstructure, and elements.

Micro-morphology of the retina of the light-adapted African catfish (Clarias gariepinus).

The current study aimed to investigate the ultrastructure of the retinal photoreceptors of the African catfish and to demonstrate their adaptation to nocturnal or diurnal visions or by the two ways. The eyes of eight adult catfish were collected during the daytime, and the retinae were separated and examined by light and transmission electron microscopy. The photoreceptors' layer appeared in contact with the retina's pigmented epithelium. Two photoreceptors were detected in cones and hidden rods. Cones predominate in light-adapted retinae. The outer segments of cones appeared between the retinal pigmented epithelium protrusions, which indicates the movement of melanosomes away from the photoreceptors as a retinomotor response of the catfish. The two types of retinal tapetum were in between cones. The first type, the cored granules, were large, spherical, and had black peripheral parts and central lucent parts, and contained some granules. The second type was Guanine crystallites of tapetum lucidum, which were small electron-lucent, and their shape varied from spherical to rectangular. Melanosomes vary in shape from spherical to elliptical. The Müller cells were darkly stained elongated cells that measured about 5.5-8.5 µm in length and 2.2-2.5 µm in width, and their microvilli appeared between the inner segments of the rods and cones. Müller cell processes were extended from the photoreceptor layer to the inner limiting membrane. Zonula occludentes appeared between the Müller cell processes and the internal segment of the rods and cones. African catfish have eyes which are adapted not only for nocturnal but also for daytime light.

Impact of Diclofenac Sodium on Tilmicosin-Induced Acute Cardiotoxicity in Rats (Tilmicosin and Diclofenac Cardiotoxicity).

To assess the influence of diclofenac sodium (DIC) treatment on tilmicosin (TIL) prompted cardiotoxicity, forty albino rats were randomly divided into four equal groups: control, TIL group (single subcutaneous injection of 75 mg/kg BW tilmicosin phosphate 30%), TIL + DIC group (single subcutaneous injection of tilmicosin phosphate 30% and then injection intramuscularly of 13.5 mg/kg BW/day for 6 days diclofenac sodium) and DIC group (intramuscular injection of 13.5 mg/kg BW/day diclofenac sodium for 6 days). Creatine kinase-MB, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, urea and creatinine significantly elevated in all treated groups, but markedly in TIL + DIC group serum. Lipid peroxidation significantly increased, and reduced glutathione significantly decreased in tissues of all groups. Several histopathological alterations were noticed in heart, liver, kidneys and lungs of all treated groups, particularly TIL + DIC group. Ultrastructurally, myocardium of TIL and TIL + DIC groups showed characteristic changes for myocardial apoptosis and degeneration. Significant differences were detected in area percentage of caspase-3 protein expression and bcl-2 immunoreactivity in cardiomyocytes, particularly in TIL + DIC group. This study is the first to indicate that one of the possible mechanisms of TIL cardiotoxicity is myocardial apoptosis. DIC amplifies TIL-induced cardiotoxicity besides its hepato-nephrotoxicity.

Hepatic damage associated with fatal zinc phosphide poisoning in broiler chicks.

Zinc phosphide (Zn3P2) is a widely used rodenticide which has the potential to cause high mortality if ingested. The present study was designed in order to explore the hepatic injury in broiler chicks that were acutely intoxicated with Zn3P2. For this purpose, a total number of 12 broiler Saso chicks were divided into two equal groups. Birds of the first group were exposed to 300 ppm Zn3P2 via food. Hepatic damage of intoxicated birds was evaluated biochemically and histologically using the transmission electron microscope and subsequently compared with another healthy non-treated controls (second group). The serum activity of aspartate aminotransferase (AST) was significantly higher in those poisoned with Zn3P2, While, activities of both Alanine aminotransferase (ALT) and Alkaline phosphatase (ALP), as well as, zinc concentration of hepatic tissue did not represented a significant difference between treated and control birds. Histological examination revealed presence of numerous heterogenic shaped mitochondria in hepatocytes of non-treated birds. Glycogen deposits were also scattered in the form of large electron dense deposits. Kupffer cell was irregular in shape and had numerous pseudopods often projected into sinusoidal lumen. In hepatic cells of intoxicated birds, mitochondrial swelling with cristolysis, few glycogen deposits, vacuoles in the cytoplasm and shrunken darkly stained nuclei are the major ultra-structural changes which were detected. It was concluded that the mitochondria could be one of the main target in hepatocytes for the toxic effect of Zn3P2 in broiler chicks.

Macro-microscopic study on the toepad of ostrich (Struthio camelus).

The ostrich foot has four toepads, two on the 3rd digit, one on the 4th digit and one at metatarso-phalangeal joint. Previous studies have not detailed the histo-morphological structure of these toepads. In this study, we have described the macroscopic and microscopic structures of the toepad of ostrich (Struthio camelus). Numerous papillae with different direction, length and thickness have been observed grossly on the ventral surface of each toepad. Histological examinations have revealed that the epidermis of the ostrich toepad, similar to other digitigrades, consists of an outer stratum corneum and an inner stratum germinativum (which is subdivided into basal, intermediate and transitional layers). The stratum corneum has several layers of flattened horny cells. The nuclei of basal cells have several mitotic figures. The cytoplasm of the stratum germinativum cells has multiple lipid droplets and multigranular bodies (in transitional cells only). Scanning electron microscopic examination revealed presence of collagen fibers in mid and deep dermis of each toepad. These fibers run parallel and connect to each other by very thin fibrils which are branched, crossed with each other in an oblique direction. Such arrangement of these collagen fibers, thin fibrils and presence of digital cushion are likely to be responsible for the protection of the underlying soft tissues and absorption of concussion.