Presence of Leptin and Its Receptor in the Hypothalamus,Uterus and Ovaries of Swine Females Culled with Distinct Ovarian Statuses and Parities

Leptin acts on energy metabolism, affecting reproductive functions through activation of its receptors in the brain and in reproductive organs. This study compared the presence of leptin and its receptor (ObR‐b) in hypothalamus neurons, endometrial glands and oocytes of culled swine females across ovarian statuses and parities. Immunohistochemistry was done in samples of uterus, ovaries and hypothalamus from 28 culled females, using polyclonal antibodies antileptin and ObR‐b. Immunolabelling was compared for sows categorized by parity at culling (0, 1, 2–4 and <4) and ovarian status (luteal and follicular phases of the oestrous cycle and with cysts). Immunolabelling for leptin and ObR‐b in neurons and oocytes was weaker in females with cysts (p < 0.05) than in those at the follicular phase. In endometrial glands, leptin immunolabelling was less intense in females with cysts (p < 0.05), but immunolabelling for ObR‐b was similar across ovarian statuses (p > 0.05). In sows culled with 2–4 parities, leptin immunolabelling in neurons and endometrial glands was more intense than in nulliparous females (p < 0.05). In comparison with sows culled at greater parities, ObR‐b immunolabelling for nulliparous females was less intense in endometrial glands and in oocytes (p < 0.05), but more intense in neurons (p < 0.05). Thus, in swine, the presence of leptin and ObR‐b varies across parities and is more intense in the uterus, ovaries and hypothalamus of females that were cycling before culling than in those having cystic ovaries.     

Radioactive gold-198 seeds for the treatment of squamous cell carcinoma in the eyelid of a cat

A 19-year-old, speyed, domestic short-hair cat was presented with an eyelid tumour of 3 months duration. Ophthalmic examination revealed a large, raised, ulcerated and bleeding mass affecting the left lower eyelid. The mass was 12 mm x 10 mm in size, extended to the medial canthus and had eroded 10 mm of eyelid margin. Mandibular lymph nodes were not palpably enlarged. A diagnosis of squamous cell carcinoma was confirmed by histologic examination. Due to involvement of more than half the lower eyelid, it was decided that treatment with radioactive gold-198 seeds was appropriate. Nine radioactive gold-198 seeds were implanted, delivering a minimum tumour dose of 65 Gy. Three weeks postoperatively the mass had resolved, with only a small scab remaining. After a further 3 weeks, there was no evidence of the eyelid tumour. Although approximately 7 mm of eyelid margin was absent, this did not cause any clinical signs other than mild conjunctivitis. There was no evidence of the tumour 10 months postoperatively, when the cat was euthanased for unrelated disease.     

Field evaluation of a mixture of albendazole sulphoxide and levamisole against Ostertagia and Trichostrongylus spp in sheep

The efficacy of a mixture of albendazole sulphoxide and levamisole, 3.6 and 8.25 mg/kg respectively, at single and double dose rates, was compared with the recommended dose rate of each anthelmintic alone. The comparison was conducted on groups of 6 to 14-week-old lambs on 22 farms, 16 of which had evidence of multiple resistance to benzimidazole and levamisole. A single dose of the mixture reduced mean egg counts by 95% on half the farms with multiple resistance and on all the remaining farms. Consequently, the mixture should be included in an assessment of effective anthelmintics on farms to determine its value for nematode control. A double dose rate of mixture was effective on all but 4 farms. Reductions caused by the mixture were due to the additive actions of the drugs on 18 of 22 farms; synergistic action was noted on only 3 farms. It was concluded that the mixture of albendazole sulphoxide and levamisole offered many farmers an effective anthelmintic for use in preventive control programs. Recommendations for such programs include annual rotation of effective anthelmintics as a means of delaying selection for drug resistance.     

Effects of Growth Hormone on In Situ Culture of Bovine Preantral Follicles are Dose Dependent

The objective of this study was to evaluate different concentrations of growth hormone (GH) on the development of bovine preantral follicles cultured included in the ovarian tissue (in situ) on the rates of morphologically normal, viable, primordial and developing follicles, as well as the oocyte and follicle diameter and ultrastructural analysis. Ovarian fragments collected from cows with no cross‐breeds defined were cultured in situ for 1 and 7 days in minimal essential medium (α‐MEM+) supplemented with different concentrations of recombinant human GH (0, 10, 25, 50 ng/ml). The ovarian fragments non‐cultured (control) and cultured were processed for classic histology, mechanical isolation and electron transmission microscopy (MET). The parameters underwent anova (Tukey′s and Dunnett′s tests) and chi‐square test (χ²). After 7 days of culture, the treatment with 50 ng/ml GH showed no differences with fresh control (p > 0.05) and had greater effectiveness than in the 0, 10 and 25 ng/ml GH concentrations of the morphologically normal follicles. Regarding the primordial follicles, a reduction was observed in the 50 ng/ml GH concentration concomitant with the significant increase in developing follicles, differing from both the fresh control and the other GH concentrations tested. In addition, 50 ng/ml GH showed a larger follicle and oocyte diameter when compared to the other treatments cultured. Similar structures were ultrastructurally observed in the control group, 50 ng/ml GH. Follicles cultured in 10 ng/ml GH showed nuclear invagination, vacuoles and lesioned basal membrane. Hence, it is concluded that 50 ng/ml GH is the most effective concentration for the development of preantral follicles cultured in situ.     

Purification of secretory immunoglobulin A from milk of the brushtail possum (Trichosurus vulpecula)

AIM: To identify and purify secretory immunoglobulin A (sIgA), a key effecter molecule in mucosal immune responses, from milk of the brushtail possum (Trichosurus vulpecula).

METHODS: Milk samples were collected from female possums with pouch young, and clarified by centrifugation and precipitation methods. The clarified fraction was purified by gel filtration and affinity chromatography to yield sIgA. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting techniques were used to assess the purity of the final product, and to identify the heavy (H) chain, light (L) chain and secretory component (SC) of possum sIgA.

RESULTS: Immunoblotting, using antibodies raised against cloned possum sIgA SC and H-chain, and a synthetic peptide fragment of the H-chain, confirmed the identity of the purified protein. The N-terminal amino acid sequence of purified possum sIgA showed strong homology to reported sequences of H-chain variable regions of marsupial immunoglobulins.

CONCLUSIONS: Milk was shown to be a convenient source of mucosal secretion containing sIgA, and a process involving 2 precipitation and 2 chromatography steps produced purified sIgA. This IgA preparation will prove useful for the generation of sIgA-specific immunological reagents for measurement of immune responses in the development of mucosal-based vaccines for biological control of possums.     

水稻纹枯病生防菌株的筛选、鉴定及其防治效果

为获得对水稻纹枯病有生防潜力的菌株,从湖北省恩施土家族苗族自治州植物根际土壤中分离获得菌株,筛选对水稻纹枯病菌有拮抗作用的菌株,并测定其发酵液的抑菌活性、抑菌谱及生物学特性;基于形态学特征、生理生化特征及分子生物学特征对其进行分类鉴定,并通过离体叶片、室内盆栽和田间试验进一步评价其生防潜力。结果显示,从根际土壤中共分离获得162株菌株,其中生防菌株E12对水稻纹枯病菌的抑制率最高,达94.93%,且该菌株对常见的12种植物病原菌均有抑制作用,抑制率在59.84%~93.14%之间;生防菌株E12能分泌蛋白酶、嗜铁素和淀粉酶,具有固氮及形成生物被膜的能力;结合形态学特征、生理生化特征及分子生物学特征,将菌株E12鉴定为越南伯克霍尔德氏菌Burkholderia vietnamiensis;生防菌株E12处理离体水稻叶片后,其相对病斑长度较对照显著减小,对水稻纹枯病的室内盆栽和田间防治效果分别为62.51%和67.78%。表明越南伯克霍尔德氏菌E12在防控水稻纹枯病方面有较好的潜力。