牛附睾和附睾液分析与牛附睾尾精子在模拟附睾液中存活试验

[目的]新鲜精液在离开生殖腺后存活时间很短.相关研究表明副睾液为精子的存活提供了特殊的环境.试验探讨和研究牛附睾精子在体外模拟附睾液中的存活试验的各因素的影响.[方法]试验对公牛附睾头部和尾部的摩尔渗透压和蛋白质浓度进行了分析,牛附睾尾部精子在不同蛋白浓度的CEP-2溶液中,在4℃条件下孵育120h.每24h做一次精子活力检测.[结果]5 d后精子活力仍然超过60;.附睾头、尾部的渗透压分别为(287.0±13.7)mOsm和(310.8±17.0)mOsm.蛋白浓度分别为(37.43±12.55)mg/mL和(50.58±11.08)mg/mL.[结论]附睾尾精子在蛋白浓度为40mg/mL,渗透压为345 mOsm时,精子存活率最高.     

Genomic hypomethylation in neoplastic cells from dogs with malignant lymphoproliferative disorders

DNA methylation is an epigenetic modification in which a methyl group is added usually to the fifth carbon position of a cytosine residue. Dysregulation of this process is an important molecular event which has been shown to be associated with neoplastic transformation and tumour progression in humans and mice. Features of methylation dysregulation in many different types of neoplasms include general genomic hypomethylation, focal hypermethylation, and altered expression of genes which encode a series of DNA (cytosine-5) methyltransferases. Interestingly, many types of neoplasia that are recognised in humans also develop spontaneously in the dog. By comparing the restriction patterns of MspI and HpaII, this study demonstrates that as in human, genomic hypomethylation is a feature of neoplastic cells in the majority of canine lymphoma cases and approximately one-third of canine leukemia cases confirming that dysregulation of the DNA methylating machinery is implicated in malignant transformation of lymphoid cells in some dogs.     

Neuronal ceroid-lipofuscinosis in Borderdale sheep

AIM: To describe the gross and histological lesions of a neurological disease in Borderdale sheep characterised clinically by blindness and circling, as a basis to its classification. METHODS: Formalin-fixed tissues were processed into paraffin wax and epoxy resin for light and electron microscopy of variously stained sections. RESULTS: Lesions were those of a lysosomal storage disease with severe neurodegeneration of the cerebral cortex. The staining reactions, autofluorescence and ultrastructure of storage material allowed the diagnosis of neuronal ceroid-lipofuscinosis associated with the accumulation of subunit-c of mitochondrial ATP synthase. CONCLUSIONS: The severity of neurodegeneration and minor differences in the ultrastructure of storage material implied that this was a different disease from other forms of ovine ceroid-lipofuscinosis that accumulate subunit-c of mitochondrial ATP synthase. An autosomal recessive mode of inheritance is considered probable. Although of only minor economic importance, this disease may be important to research into the group of ceroid-lipofuscinoses as a whole.     

γ-Amino Butyric Acid Control of Arginine Vasopressin Release from the Ewe Hypothalamus In Vitro: Sensitivity to Oestradiol

The present study aims to ascertain the influence of gamma-amino butyric acid (GABA)(A or B) receptors on arginine vasopressin (AVP) release in vitro and determine whether E(2) modulates GABA-AVP interaction. Within 10 min of ewe killing, saggital midline hypothalamic slices (from the anterior preoptic area to the mediobasal hypothalamus along with the median eminence, 2-mm thick, two per ewe) were dissected, placed in oxygenated minimum essential media (MEM)-alpha at 4 degrees C and within 2 h were singly perifused at 37 degrees C with oxygenated MEM-alpha (pH 7.4; flow rate 0.15 ml/min), either with or without E(2) (24 pg/ml). After 4-h equilibration, 10-min fractions were collected for 4 h interposed with a 10-min exposure at 60 min to a specific GABA(A or B) receptor agonist or antagonist at various doses (0.1-10 mm). GABA(A) (muscimol; no E(2), n = 7 perifusion chambers, with E(2), n = 11) or GABA(B) (baclofen; no E(2), n = 8, with E(2), n = 15) agonists (10 mm) did not influence AVP concentrations. However, AVP release increased (p < 0.05) 20-30 min after exposure to 10 mm GABA(A or B) antagonists (bicuculline, no E(2), n = 7: from 4.6 +/- 0.7 to 33.0 +/- 0.4, with E(2), n = 17: from 11.9 +/- 1.4 to 32.8 +/- 6.0; CGP52432, with E(2), n = 14: from 14.0 +/- 2.6 to 28.8 +/- 3.9 pg/ml). At the end of the collection period, hypothalamic slices responded to KCl (100 mm) with AVP efflux (p < 0.05). GABA(B) but not GABA(A) antagonist-stimulated AVP release was enhanced in the presence of E(2). In summary, AVP release is under the inhibitory influence of GABA input with further potentiation by E(2) through GABA(B) receptors in vitro.