Anemia amelioration by lactose infusion during trypanosomosis could be associated with erythrocytes membrane de-galactosylation

African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.     

Acute Toxicity of Gramoxone to Oreochromis niloticus (Trewavas) in Nigeria

The acute toxicity of paraquat (1,1-dimethyl-4,4-bipyridinium dichloride) to fingerlings of Oreochromis niloticus (Trewavas) was determined in 96 hr staticbioassays. During the assays opercular ventilation and tailfin movement rates of the fish were determined.Haemotological parameters of the blood and histopathology ofthe gills were observed.The 96 hr LC₅₀ of paraquat to fingerlings of O. niloticus was observed to be 11.84 mg L^-1.Histopathology of gills of the fish exposed to 12.00 mgL^-1, and 14.20 mg L^-1 showed a dose-dependentdisruption of the architecture of the lamellae, filamenthyperplasia and atrophy, leading to impairment in oxygenuptake. Other symptoms of toxicosis in exposed fish includeloss of equilibrium; agitated swimming; air gulping;haemorrhaging of the gills, pectoral and pelvic fins; periodof quiescence and finally, death.     

Effects of air exposure and agitation on quality of stored boar semen samples

The objective of this study was to investigate the effects of semen volume, air contact inside semen dose tubes, daily agitation of semen doses and extender type on semen quality, thermo-resistance and bacteria growth in extended boar semen doses preserved over 7 days of liquid storage. Ejaculates from 4 proven terminal cross-bred boars were collected using the gloved-hand technique for 4 weeks and used in the 3 × 2 × 2 factorial study. The effects of treatment (CON: 80 ml doses sealed at the top of the tube; 40HIGH: 40 ml doses sealed at top of tube, and 40LOW: 40 ml doses sealed at top of the liquid), agitation (agitated versus not agitated) and extender type (long-term versus short-term) were investigated on semen quality, thermo-resistance and bacteria growth in boar semen doses. The results of the study revealed that motility (p = .031) and viability (p = .041) in 40HIGH were lower than CON. pH (p < .001) was higher in 40HIGH compared with CON and 40LOW. Agitation did not impact motility (p = .581), progressive motility (p = .870), viability (p = .509) or morphology (p = .970), while long-term extender maintained higher motility (p = .002), progressive motility (p = .036), viability (p < .001) and normal acrosome (p < .001) than a short-term extender. VAP (p = .039) of 40HIGH was lower than CON in a thermo-resistance test. Neither treatment (p > .798, .766) nor agitation (p > .396, .476) impacted bacterial growth in this study. In conclusion, air contact negatively impacts boar semen pH and consequently sperm motility. Semen doses prepared with 80 or 40 ml volumes of extended boar semen with minimal air contact in the tubes yield more desirable semen quality and agitating boar semen doses daily does not have negative or positive effects on boar semen quality.     

Tsetse-Fliegen-Forschung in Nigeria,ihr gegenwärtiger Stand und ihre zukünftige Entwicklung

Ohne Zusammenfassung     

Gastroprotective and ulcer-healing mechanisms of ellagic acid in experimental rats

Ellagic acid (EA), a plant-derived polyphenol, exhibits antioxidant, anti-inflammatory, and gastroprotective effects. Its gastroprotective mechanisms have not been fully elucidated nor have its effects on chronic ulcer previously been described. Toward these ends, the antiulcer activities of EA were evaluated in acute (ethanol and indomethacin) and chronic (acetic acid) ulcer models in Wistar rats. In this study, oral administration of EA significantly prevented the gastric ulceration caused by ethanol, indomethacin, and acetic acid treatments. Its gastroprotective mechanism in ethanol-induced ulcer were partly due to intensification in the endogenous production of nitric oxide, an antioxidant effect by replenishing depletion of endogenous nonprotein sulfhydryls and attenuation of tumor necrosis factor-α increase, whereas in indomethacin ulcer, it is partly due to a reduction in the plasma level of leukotriene B(4). In acetic acid ulcer, promotion of ulcer-healing effects was partly due to attenuation of the elevated levels of the inflammatory cytokines TNF-α, interferon-γ, and interleukins-4 and -6. These findings suggest that ellagic acid exerts its antiulcer activity by strengthening the defensive factors and attenuating the offensive factors.     

Comparative effect of slow and rapid freezing on sperm functional attributes and oxidative stress parameters of goat spermatozoa cryopreserved with tiger nut milk extender

Comparative effect of slow and rapid freezing on sperm functional attributes and oxidative stress parameters of goat spermatozoa cryopreserved with tiger nut milk (TNM) extender was examined in this study. Pooled semen samples obtained from West African Dwarf (WAD) goat bucks were diluted with Tris‐based extenders containing different levels of TNM (0, 5, 10, 15 and 20 ml/100 ml extender). The diluted semen samples were subjected to slow and rapid freezing for a period of 7 days and thereafter evaluated for sperm functional attributes (percentage motility, acrosome integrity, membrane integrity, abnormality and livability) and oxidative stress (malondialdehyde [MDA] concentration and acrosin activity) parameters. Results showed that higher (p < 0.05) motility, livability, membrane and acrosome integrities in semen cryopreserved with slow freezing compared to rapid freezing. These parameters (motility, livability and membrane integrity) were higher (p < 0.05) in semen cryopreserved with 15% TNM in both slow and rapid freezing protocols. The results revealed that semen cryopreserved in slow freezing had lower (p < 0.05) abnormality compared to rapid freezing. Acrosin activity was higher in slow freezing compared to rapid freezing. Acrosin activity was higher at 15% TNM in both slow and rapid freezing. Lower (p < 0.05) MDA concentration was observed in semen cryopreserved using slow freezing compared to rapid freezing. The findings revealed improved post‐thaw sperm functional attributes and oxidative stress parameters of WAD goat spermatozoa cryopreserved with 15% TNM using slow freezing.     

Responses of cassava (Manihot esculenta Crantz) cultivars to in vitro-induced phosphorus stress

Rapid identification of phosphorus (P) stress-tolerant cassava varieties by in vitro and molecular screening is essential for sustainable food production. The objectives of this study were to describe morphological and molecular responses of 10 cassava cultivars to in vitro-induced P stress and identify P-stress-tolerant ones. Plantlets were raised from nodal segments on Murashige and Skoog (MS) medium containing either P or no P (control). The ?tudу was conducted as a 2 × 10 factorial arrangement using a randomized complete-block design with thrее rерliсаtе?. On P-stress medium, TMS 01/1371 did not produce roots, TMS 94/0039 produced roots after three weeks, and MM 96/1751, MM 98/3437, TMS 01/0040, TMS 30040, TMS 84/00353, TMS 91934, TMS 92B/00061, and TMS 94/0026 produced roots after six weeks. Phosphorus-stress treatment reduced number of leaves, number of roots, and number of shoots by 41.8%, 214.7%, 139.2%, respectively. Similarly, P-stress treatment decreased dry weight (DW) of TMS 01/0040, TMS 01/1371, TMS 84/00353, TMS 91934, TMS 92B/00061, and TMS94/0026 by an average of 10.2%. However, P-stress treatment increased DW of MM 96/1751, MM 98/3437 and TMS 94/0039 by an average of 8.4%; P-stress treatment had no effect on DW of TMS 30040. Expression of MeWRKY gene was higher in roots than in leaves of all cultivars by an average of 88.1%. Stress tolerance index relative to P showed that MM 96/1751, MM 98/3437, TMS 94/0039, and TMS 30040 were P-stress tolerant and therefore recommended for breeding and for production to farmers.     

Use of duckweed, Spirodela polyrrhiza L. Schleiden, as a protein feedstuff in practical diets for tilapia, Oreochromis niloticus L.

The use of solar-dried duckweed, Spirodela polyrrhiza L. Schleiden, as a dietary protein component for tilapia, Oreochromis niloticus L., reared in glass tanks was evaluated. Six isonitrogenous diets (30% crude protein) were fed to all-male tilapia fingerlings for 56 days. The fish meal protein in the diets was substituted at a rate of 5%, 10%, 20%, 30% and 100% with duckweed. A diet without the duckweed served as a control. Growth performance and nutrient utilization of fish were based on daily weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and protein productive value. There were no significant differences (P > 0.05) in growth performance and nutrient utilization of fish fed on diets containing up to 20% duckweed inclusion and the control. However, increases in dietary duckweed inclusion resulted in progressively reduced growth performance and nutrient utilization of fish. Diet without fish meal (100% duckweed) gave the poorest result. The most cost-effective diet in terms of cost per unit gain in weight of fish was obtained with 30% duckweed dietary inclusion. The result showed that solar-dried up to 30% duckweed dietary inclusion as a replacement for fishmeal in practical diets supported fish growth and was cost-effective.