Gastrointestinal Parasitism In Goats - Bionomics Of The Suprapopulation And Incidence In Young Goats

The Modified Parfitt's Technique (MPT) is used to assess the concentration of infective nematode larvae on pasture which gives an indication of the infection to which grazing animals are exposed . Validation of this technique showed that it was not successful when applied in the field and variation in results occurred among different grass species . Using Panicum maximum ( Guinea ) , Setaria sphacelata var splendida ( Setaria) and Digitaria setivalva (Mardi Digit) grasses , modifications were introduced to improve the larval recovery rate . The soaking of herbage in lukewarm water ( 38'C ) instead of tap water increased the recovery rate significantly without variation between the three grasses tested.Using this improved MPT , plot trials were conducted to assess the longevity of third-stage larvae ( L3 ) of goat trichostrongyles under the forementioned grass leys . However the technique failed to recover any L3 . Reasons for this were low number of larvae , rainfall , and larval - grass/debris adherence . There is a need for further investigation into this technique

Tests on the centrifugal flotation technique and its use in estimating the prevalence of Toxocara in soil samples from urban and suburban areas of Malaysia

The influence of soil texture (silt, sand and laterite) and flotation solutions (saturated NaCl, sucrose, NaNO3 and ZnSO4) upon the recovery of Toxocara ova from seeded soil samples with the centrifugal flotation technique was investigated. Soil samples of different texture were artificially seeded with Toxocara spp. ova and subjected to a centrifugal flotation technique which used various flotation solutions. The results showed significant (P<0.001) interactions between the soil types and the flotation solutions. The highest percentage of ova recovery was obtained with silty soil (34.9−100.8%) with saturated NaC1 as the flotation solution (45.3−100.8%). A combination of washing of soil samples with 0.1% Tween 80, and flotation using saturated NaCl and a 30 min coverslip recovery period was used to study the prevalence of contamination of soil samples. Forty-six soil samples were collected from up to 24 public parks/playgrounds in urban areas of Petaling Jaya and suburban areas of Serdang. The prevalence of Toxocara species in the urban and suburban areas was 54.5% and 45.8% respectively

Studies on Acquired Immunity to Nematodirus battus Infection in Lambs

Several experiments were conducted using housed sheep with the aim of obtaining information regarding the immune response of young lambs to Nematodims battus infection, the influence of protein supplementation and the persistence of the response. Field observations were conducted also over a two year grazing period to determine the seroepidemiology of natural infections using an ELISA developed against worm antigens. Prior to commencement of the main housed experiments, the results of a preliminary trial conducted by Dr.W.D.Smith prior to commencement of this PhD research project were evaluated to assess the kinetics of worm loss following a single infection of N.battus, essential information before 'trickle infection-challenge' experiments can commence. Four groups of young lambs were infected with a single dose of 30,000 L3 and each group was killed after 7, 14, 21 or 28 days post-infection (PI). The worm burdens were significantly reduced in number after 28 days PI. Individual variation in burdens was evident after 21 days PI and therefore, in view of these findings, lambs in future experiments were killed at 9 or 10 days post-challenge (PC) to minimize between animal variation. The housed 'trickle infection-challenge' trials followed a standard infection regime. Lambs were infected with escalating doses of L3 over several weeks, treated with anthelmintic and challenged with a single dose of 30,000 L3 a week later. Challenge controls did not receive a primary trickle infection. All groups were killed on either day 9 or 10 PC to obtain worms, blood and intestinal tissue. Blood samples were taken frequently throughout the primary infection period for peripheral blood eosinophil counts and antibody level determination. Two trials were conducted to assess the influence of supplemention of an adequate basal diet with a rumen bypass protein (fish meal). Both had a similar design except for differences in the levels of dietary protein, the age of lambs and the duration of infection. Previously infected and challenge control groups were offered either a basal diet (trial 1, 132 g CP kg-1 DM; trial 2, 125 g CP kg-1 DM) or a supplemented one (trial 1, 183 g CP kg+ DM; trial 2, 178 g CP kg-1 DM CP). The results of both trials showed trends for enhancement of responsiveness without significant effects. Previous infection significantly enhanced immunity as characterized by reduced worm size and burdens, elevated antibody levels, increased numbers of tissue mast cells and eosinophils. Supplementation significantly enhanced antibody but not inflammatory responses. Re-analysis of the results showed that lambs could be segregated into high- and low- responders based on their worm burden. However, the degree of responsiveness was not reflected in the inflammatory and antibody responses studied. A trial was conducted to determine the persistence of the immune response described in the dietary trials. Six groups of lambs (3 infected, 3 challenge controls) were subjected to the standard design outlined above. An infected and control group was challenged either one, 6 or 12 weeks post-treatment and killed 10 days PC. The results showed an ability to respond without antigenic stimulus for up to 12 weeks which was expressed by retardation in development of the worm populations and also by worm expulsion. Field trials were conducted over a two year grazing period to determine any difference in serum anti-worm antibodies of lambs and ewes and whether this could be correlated to developing immunity. The use of serum fructosamine concentration as a general index of gastrointestinal damage was also investigated. The results showed that antibody responses of ewes were maintained at high levels throughout the grazing period with no indication of a periparturient relaxation in immunity. Lambs developed increasing antibody levels over time and the FEC declined when the peak levels were reached. However, lamb antibodies were significantly lower in comparison to ewes. Serum fructosamine was not altered despite periods of clinical nematodirosis

Palm tocotrienols reduce lipopolysaccharide-stimulated inflammatory responses of microglia

Introduction: The potential immunoregulatory effects of tocotrienols, the less studied form of vitamin E, had not been determined for microglia until our last publication showcased primary evidence of palm tocotrienols limiting microglia activation, explicitly by inhibiting nitric oxide (NO) production. Here we further explored the nitrite scavenging activity of the two most potent NO-reducing tocotrienol isoforms - δ-tocotrienol and Tocomin®50% (contains a spectrum of tocotrienols and α-tocopherol) based on their inhibitory effects on NO production and also their effects on CD40 (a microglial co-stimulator molecule) expression of BV2 microglia. Methods: BV2 cells were treated with two different doses of tocotrienols (δ-tocotrienol: 3.96 μg/mL and 19.80 μg/mL; Tocomin®50%:47.50 μg/mL and 237.50 μg/mL) followed by stimulation with 1μg/mL of lipopolysaccharide (LPS). A chemical scavenging assay was conducted to study the nitrite scavenging activity of δ-tocotrienol. Together with Tocomin®50%, we also determined their effects on CD40 expression of BV2 microglia via flow cytometry. Results: We demonstrate that the inhibitory effect of tocotrienols on NO production by microglia is not attributed to their nitrite scavenging activity. Additionally, tocotrienols also reduced the expression of the microglial co-stimulator molecule, CD40. Conclusions: Our data aids the further characterisation of the actions of tocotrienols on microglia, offering insight into the potential modulatory properties of palm tocotrienols on microglial inflammatory responses within the central nervous system (CNS)

Cardamonin inhibits COX and iNOS expression via inhibition of p65NF-κB nuclear translocation and Iκ-B phosphorylation in RAW 264.7 macrophage cells

Cardamonin, a chalcone isolated from the fruits of a local plant Alpinia rafflesiana, has demonstrated anti-inflammatory activity in cellular models of inflammation. In this report, we evaluated the ability of cardamonin to suppress both NO and PGE2 synthesis, iNOS and COX-2 expression and enzymatic activity, and key molecules in the NF-κB pathway in order to determine its molecular target. Cardamonin suppressed the production of NO and PGE2 in interferon-γ (IFN-γ)- and lipopolysaccharide (LPS)-induced RAW 264.7 cells. This inhibition was demonstrated to be caused by a dose-dependent down-regulation of both inducible enzymes, iNOS and COX-2, without direct effect upon iNOS or COX-2 enzyme activity. Subsequently we determined that the inhibition of inducible enzyme expression was due to a dose-dependent inhibition of phosphorylation and degradation of I-κBα, which resulted in a reduction of p65NF-κB nuclear translocation. We conclude that cardamonin is a potential anti-inflammatory drug lead that targets the NF-κB pathway

Effects of early age feed restriction and heat conditioning on heterophil/lymphocyte ratios, heat shock protein 70 expression and body temperature of heat-stressed broiler chickens

We examined the effects of early age feed restriction and heat conditioning on heterophil/lymphocyte ratios (HLR), heat shock protein (hsp) 70 expression and body temperature of heat-stressed male broiler chickens. On day (d) 1,chicks were subjected to (1) 60% feed restriction on d 4, 5, and 6 (FR); (2) exposure to 36±1°C for 1 h from d 1 to 21 (HT); (3) both FR and HT (FRHT); or (4) control. On d 35, all the birds were exposed to 39±1°C for 6 h. Subjecting chicks to FR, HT and FRHT reduced HLR response to the heat challenge. The FR and FRHT birds had improved hsp 70 response and the latter were more hyperthermic than controls during the heat exposure

LC-DAD-ESI-MS analysis of nitric oxide inhibitory fractions of tenggek burung (Melicope ptelefolia Champ. ex Benth)

Solvent–solvent fractionation of the methanolic extract of the popular Malay traditional vegetable “tenggek burung” (Melicope ptelefolia), followed by nitric oxide inhibition assay on RAW 264.7 cells revealed that the most active components reside mainly in hexane and dichloromethane fractions. Online profiling of the nitric oxide (NO) inhibitive fractions of the tenggek burung using liquid chromatography coupled diode array detection and electrospray ion-trap tandem mass spectroscopy (LC–DAD–ESI-MSn), has identified seven constituents. The compounds were identified as kokusaginine (1), compound 2, [kokusagine, (2a) or 5-methoxymaculine (2b)], 2,4,6-trihydroxy-3-prenylacetophenone (3), 2,4,6-trihydroxy-3-geranylacetophenone (4), 2,4,6-trihydroxy-3-geranylgeranylacetophenone (5), 3-[4-O-(3,7-dimethyl-2,6-octadienyl)phenyl]-2-propenoic acid (6) and 2,4,6-trihydroxy-3-farnesylgeranylacetophenone (7). The identity of compounds 1, 4 and 6 were unequivocally confirmed by isolation and spectroscopic evidences, other constituents are tentatively identified, based on their UV, MS, MSn and comparison with literature data. Kokusaginine (1) demonstrated in vitro activity on NO inhibition in murine peritoneal macrophages