Browsing by Author "Kimaro, Wahabu"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Histomorphological damage in the small intestine of wami tilapia (oreochromis urolepis) (norman, 1922) exposed to microplastics remain long after depuration
    (MDPI, 2022) Mbugani, John J; Machiwa, John F; Shilla, Daniel A; Kimaro, Wahabu; Joseph, Dativa; Khan, Farhan R
    The histopathological effects of microplastics (MPs) in the gastrointestinal tracts of fish following long-term exposure and depuration are relatively understudied. This study investigated histomorphological damage in the small intestine of Oreochromis urolepis larvae following 65 d exposure to 38–45 μm of polyethylene microspheres (PE MPs) and after a recovery period of 60 d. Larval fish were assigned to each treatment group (control, 1, 10 and 100 PE MPs), where ingestion and degenerative changes in the small intestine were examined using a routine hematoxylin and eosin staining technique. The results highlighted significant PE MPs ingestion and retention proportional to exposure dose (χ 2 = 49.54; df = 2). Villi height and width and epithelial cell height were significantly affected and differed between treatment groups. Indices of damage to the small intestine organ (χ 2 = 47.37; df = 2; p < 0.05) and reaction patterns of villi, epithelial, goblet and cryptic glandular cells, leucocytic infiltration and blood congestion revealed significant occurrence of alteration as PE MPs exposure dose increased. After the recovery period, no PE MPs were observed, and villi height, width and epithelial cells showed recovery with no significant difference between treatment groups. Organ indices declined (χ 2 = 12; df = 2; p < 0.05) but remained significantly different between treatment groups, largely due to leucocytic infiltration (χ 2 = 9.08; df = 2; p < 0.05). The study demonstrated that microplastics induced small intestinal wall degeneration, but recovery in young fish occurred slowly. The damage likely compromised its digestive function, which may affect growth and reproduction. This requires further research.
  • No Thumbnail Available
    Item
    Time-course effects of carbendazim in the infundibulum of the japanese quail (coturnix coturnix japonica)
    (Anatomy Journal of Africa, 2016) Kimaro, Wahabu
    The present study was undertaken to establish the long-term effect of a single dose of carbendazim in the tubular region of the infundibulum of Japanese quail using scanning (SEM) and transmission (TEM) electron microscopy. At a dose of 400mg/kg bodyweight, carbendazim in sunflower oil base was administered orally to mature Japanese quails. The control group received the oil base only. The effects of carbendazim on ultrastructural features of infundibulum were examined in spatial temporal periods post-exposure. At SEM level, loos of cilia were observed from 5 days post-exposure. At TEM level, pyknosis, karyorrhexis, swollen mitochondria, dilated RER cisternae, increased number of lysosomes and vacuoles were observed from 24 hours post-exposure. Compound cilia and loos of striated rootlets were also observed. Thickening and duplication of the basal lamina were identified from 12 days post- exposure. These results suggest oviductal regression due to carbendazim toxicity and signs of epithelial recovery at later stages post-exposure.