Stimulation of the bronchus-associated lymphoid tissue of goats and its effect on in vitro colonization by Pasteurella haemolytica

Twenty goats of about 7 months of age were divided into five groups. The goats in groups 1 and 2 were exposed once, using an intranasal spray to 2 ml of an inoculum containing 10⁶ colony-forming units/ml of living or dead Pasteurella haemolytica A2, respectively. The goats in groups 3 and 4 were similarly exposed twice at a 2-week interval. Group 5 was the untreated control. The number and size of the bronchus-associated lymphoid tissue (BALT) in goats exposed twice to either living or dead organisms were significantly (p>0.05) increased compared with those exposed once and with the unexposed control. In vitro colonization by living P. haemolytica A2 onto the lung tissue in which the BALT had been stimulated by two exposures of either living or dead organisms was significantly (p>0.05) reduced. The study indicates that stimulation of the respiratory mucosal immunity may prevent P. haemolytica A2 infection.     

The induction of Hsp70 synthesis by non‐lethal heat shock confers thermotolerance and resistance to lethal ammonia stress in the common carp,Cyprinus carpio (Linn)

Exposure to heat‐shock protein (Hsp) stimulating factors induces Hsp accumulation and confers tolerance to lethal ammonia stress on the common carp Cyprinus carpio. This study investigated whether a non‐lethal heat shock bestowed similar protective effects against ammonia and induced thermotolerance, both thought to be rendered by increased amounts of Hsps. The 30‐min lethal temperature (30 min LHT) and 1‐h lethal ammonia concentration (1 h LCT) for this species occurred at 41°C and 14.2 mg/L NH₃ respectively. Heating juvenile carp (5 cm) from 28°C to 32, 34 and 38°C, with a subsequent 8‐h recovery period augmented tolerance to lethal heat and ammonia perturbation by two to threefold as compared with animals held at 28°C. Protection occurred in conjunction with Hsp70 accumulation in gills, substantiating the role of this Hsp in enhancing the stress tolerance of common carp.     

Responses to Low P-Supply in Breeding Lines of White Clover (Trifolium Repens L.) Reveals Two Tiers of Responses

Four breeding lines (BLs) of white clover, which range in terms of their disposition to increase biomass in response to low or high phosphate (P) levels in soil, were evaluated further when grown hydroponically. BL 45 increased both fresh and dry weight in response to P-deprivation, while BL 49 displayed the same significant stimulation in response to sufficient P. However, when compared these lines did not accumulate any significantly higher levels of P, and all four lines showed the same changes to root:shoot ratio in response to P-deprivation, as well as the induction of both soluble and cell-wall-associated acid phosphatase activity. These results confirm that there is no direct relationship between growth (as an increase in biomass) and acid phosphatase activity and further some responses to P-deprivation may be common to all genetic backgrounds suggesting that they are not part of the intricate mechanisms governing these responses.     

The ameliorative effect of ascorbic acid on the oxidative status,live weight and recovery rate in road transport stressed goats in a hot humid tropical environment

The ameliorative effect of ascorbic acid (AA) on live weight following transportation is vital in animal husbandry. This study investigated the influence of AA on live weight, rectal temperature (rt), and oxidative status of transport stressed goats in a hot humid tropical environment. Twenty‐four goats were divided into four groups, A, B, C and D of six animals each. Group A were administered AA 100 mg/kg intramuscularly 30 min prior to 3.5 h transportation. Group B was administered AA following transportation. Group C were transported but not administered AA as positive controls while group D were not transported but were administered normal saline as negative controls. Live weight, rt and blood samples were collected before, immediately post‐transport (pt), 24 h, 3 days, 7 days and 10 days pt. Plasma was used for malondialdehyde (MDA) analysis while hemolysates were used for superoxide dismutase (SOD) analysis. There was minimal live weight loss in group A compared to groups B and C. Group A recorded reduced MDA activities and increased SOD activities compared to groups B and C which recorded significantly high MDA activities. This study revealed that AA administration ameliorated the stress responses induced by transportation in animals in hot humid tropical environments. The administration of AA to goats prior to transportation could ameliorate stress and enhance productivity.     

The Effects of Dexamethasone on the Response of Bronchus-associated Lymphoid Tissue to Intranasal Administration of Formalin-killed Pasteurella haemolytica A2 in Goats

A trial was conducted to observe the immediate and chronic effects in goats of dexamethasone administration on the bronchus-associated lymphoid tissue (BALT) response to intranasal administration of formalin-killed Pasteurella haemolytica A2. Twenty-four goats were divided into four groups. Those in group 1 were injected intramuscularly with 1 mg/kg dexamethasone on three consecutive days, followed by intranasal exposure to formalin-killed P. haemolytica A2 one day after the last dexamethasone treatment. The goats in group 2 were similarly injected with dexamethasone followed by intranasal exposure to formalin-killed P. haemolytica A2 21 days after the last dexamethasone treatment. The animals in group 3 were exposed intranasally to formalin-killed P. haemolytica A2 without prior dexamethasone treatment. The animals in group 4 were untreated controls. The intranasal exposures to formalin-killed P. haemolytica A2 were repeated 2 weeks later. Intranasal exposure to formalin-killed P. haemolytica 1 day after dexamethasone treatment further reduced the number and size of BALT compared to the untreated control. Significantly (p<0.01) more reduction of BALT occurred in goats exposed to formalin-killed P. haemolytica A2 21 days after dexamethasone treatment. On the other hand, intranasal exposure of goats without prior dexamethasone treatment stimulated the BALT compared to the untreated controls.     

Efficacy of papain-based wound cleanser in promoting wound regeneration

A new invention, papain-based wound cleanser is formulated by incorporating papain, a proteolytic enzyme extracted from Carica papaya into the formulation. This cleanser is invented to simplify the methods in wound management by combining wound cleansing and wound debridement using a single formulation. This study describes the preparation and preclinical study of papain-based wound cleanser in accelerating wound healing. In this study, papain-based wound cleanser was used to treat wound incision on Sprague-Dawley rats while distilled water and Betadine were used as negative and positive control. Twenty-seven clinically healthy white rats were randomly divided into three groups and treated accordingly until the 21st day post-incision. Wound reduction rates and histological analysis were obtained to asses the healing pattern. Rats treated with papain-based wound cleanser showed a progressive wound healing based on the wound reduction rates and histological analysis when compared with rats treated with distilled water and Betadine. Better collagen deposition and presence of skin organelles in rats treated with papain-based wound cleanser demonstrated its efficacy in promoting wound healing. In addition to its wound healing effect, papain-based wound cleanser is also integrated with antibacterial properties which make it a complete package for wound management. However, further studies should be carried out to ensure its safety for human usage.     

Efficacy of an inactivated recombinant vaccine encoding a fimbrial protein of Pasteurella multocida B:2 against hemorrhagic septicemia in goats

This study was carried out to determine the antibody responses and protective capacity of an inactivated recombinant vaccine expressing the fimbrial protein of Pasteurella multocida B:2 following intranasal vaccination against hemorrhagic septicemia in goats. Goats were vaccinated intranasal with 10⁶ CFU/mL of the recombinant vaccine (vaccinated group) and 10⁶ CFU/mL of pET32/LIC vector without fimbrial protein (control group). All three groups were kept separated before all goats in the three groups were challenged with 10⁹ CFU/mL of live pathogenic P. multocida B:2. During the course of study, both serum and lung lavage fluid were collected to evaluate the antibody levels via enzyme-linked immunosorbent assay. It was found that goats immunized with the inactivated recombinant vaccine developed a strong and significantly (p < 0.05) higher specific IgA and IgG responses in both serum and lung lavage fluid samples compared to the control and unvaccinated groups. Following intratracheal challenge, the rate of isolation was 17% for the vaccinated group, 67% for the control group and 100% for the unvaccinated group. However, none of the goat from the vaccinated group had P. multocida B:2 in the liver, tonsil and heart. Therefore, the study revealed that an inactivated recombinant vaccine significantly provides significant protection against high dose challenge and enhances the stimulation of the local and systemic immunities.     

Cellular and humoral responses in the respiratory tract of goats following intranasal stimulation using formalin-killed Pasteurella haemolytica A2

A study to determine the immunoglobulin and cellular responses in the respiratory tract of goats following intranasal exposures to formalin-killed Pasteurella haemolytica A2 was carried out. Forty-two goats were divided into two groups. Goats in Group 1 were subjected to double intranasal exposures to formalin-killed P. haemolytica A2 while goats in Group 2 were the unexposed control. Prior to and at weekly intervals post-exposure, three goats from each group were killed, serum samples were collected while the lungs were flushed with 50 ml normal saline before the right apical lobes were fixed in 10% buffered formalin. Both serum and lung lavage fluid were subjected to enzyme-linked immunosorbent assay (ELISA) to determine the levels of IgA, IgM and IgG while the formalin-fixed tissues were examined histologically. IgA levels in the lung lavage fluid increased rapidly to reach a significantly (p < 0.05) high level as early as Week 2 post-exposure and remained significantly (p < 0.05) high throughout the study period. The IgM levels increased at an intermediate rate to reach a significantly (p < 0.05) high level at Week 3 post-exposure before they decreased to an insignificant (p > 0.05) level the following week and the weeks thereafter. IgG levels increased gradually and only reached a significantly (p < 0.01) high level at Weeks 5 and 6 of the study. The size of the bronchus-associated lymphoid tissue (BALT) and the number of lymphocytes in BALT increased significantly from Week 2 and remained high thereafter. However, differences in the numbers of BALT were insignificant (p > 0.05) initially before becoming significantly (p < 0.05) high at Weeks 5 and 6. The BALT responses were parallel to those of imunoglobulins in the lung lavage fluid.