Familial episodic ataxia in lambs

Abstract

HISTORY: A similar episodic neurological disorder occurred in new born lambs on two unrelated properties involving disparate breeds of sheep. Because of the number of lambs born, cross-breeding and the fact it occurred in some mating groups and not others, a dominant mode of inheritance was, initially and separately, suspected in each case. The sires of affected lambs were apparently normal. Whereas one was New Zealand Romney, the other was a composite breed with East Friesian genetics, but both rams originated from the same source property. To investigate the pathogenesis of the disorder these two rams were acquired and mated with unrelated sheep, under experimental conditions in a more controlled environment.

CLINICAL FINDINGS: A proportion of lambs born to both sires exhibited a similar neurological disorder. Some lambs were noted to be abnormal at birth, both on home properties and in the experimental flock. They tended to adopt a head and neck extended posture and were slow to get to their feet and suckle when they then became more or less normal. When forced to move, they and other more robust lambs elicited an asymmetric gait, base-wide extensor hypertonia (hypometria) of thoracic limbs and flexor hypertonia (hypermetria) of pelvic limbs. In some there was nystagmus. After several metres of asymmetric ataxic gait they would fall to one side, sometimes adopting a sitting position. Recovery usually occurred in one to several minutes. As lambs aged, it became more difficult to elicit the episodes of dysfunction and by 6 months of age they appeared normal.

DIAGNOSIS: The disorder was diagnosed as a dominant familial episodic cerebellovestibular ataxia inherited as a dominant trait, with incomplete penetration of observed clinical signs and variable expressivity.

CLINICAL RELEVANCE: A proportion of affected lambs are likely to die in the neonatal period so the specific nature of the disorder may go unrecognised. Because of incomplete penetrance and varying expressivity, many of the lambs carrying this mutation will survive without showing clinical signs and may enter breeding flocks, where the disorder may be perpetuated and contribute to neonatal deaths.     

The Effects of Sample Size on the Outcome of Ovarian Tissue Cryopreservation

Cryopreservation of ovarian tissue is known to affect follicular survival. Several variables may be responsible for this. Little attention has focused on the effect of the size of the fragment to be cryopreserved. This study was conducted to assess the effect of the size of the tissue on follicular histology after freezing with 1,2-propanediol. Histological evaluations were performed of control and cryopreserved tissue. Fragments were cut 10 × 3 × 2 mm³ (2 mm group) or 10 × 3 × 4 mm³ (4 mm group). Percentages of normal follicles in control fragments cut into 2 and 4 mm slices were 56% and 34%, respectively. The relative risks to obtain normal follicles in the 2 mm and the 4 mm fragments after cryopreservation were 0.63 and 0.47, respectively. Freezing reduced follicle survival to a significantly greater extent in the larger tissue fragments. There is an increased risk of damage to primary and primordial follicles, when the tissue slices are cut with all dimensions larger than 2 mm.     

Environmental conditions and isozyme polymorphism in Chenopodium album L.

Electrophoretic variations within four enzyme systems (α-esterase, acid phosphatase, malate dehydrogenase and leucine amino peptidase), were studied for various garden and field populations of Chenopodium album. A correlation was found between the degree of polymorphism for the electrophoretic traits and environmental conditions. The amount of phenotypic polymorphism is very high in gardens, intermediate in an untreated and, low in herbicide-treated fields and nil for a triazine resistant population in a maize (Zea mats L.) monoculture. Furthermore, the tetraploid versus hexaploid ratio is higher within garden populations. Higher variability in garden populations is due, in part, to a high proportion of polymorphic phenotypes, and in part to a low effect of selection pressure in such types of habitat. Although there is a difference between phenotypes of populations from acid soils and those from more basic ones, we cannot be sure that the variation of polymorphism is due only to selection.     

从肿头综合征鸡分离出产Vero毒素E.coli

本研究从哈尔滨郊区某鸡场肿头综合征（ Ｓ Ｈ Ｓ）鸡分离出 ３ 株血清型为 Ｏ７８ 的埃希氏大肠杆菌（ Ｅ．ｃｏｌｉ）,从鞍山 Ｓ Ｈ Ｓ病料分离出 １ 株血清型为 Ｏ８ 的 Ｅ．ｃｏｌｉ。并证实这 ４ 株 Ｅ．ｃｏｌｉ 能够对 Ｖｅｒｏ 细胞产生毒性作用,与产 Ｖｅｒｏ 毒素的 Ｅ．ｃｏｌｉ一致。对哈尔滨市郊 Ｓ Ｈ Ｓ病鸡做病理组织学观察,主要变化为头部皮下组织,头盖骨气室及鼻粘膜下纤维素性化脓性炎症,水肿和大肠杆菌性肉芽肿,心、肝、肾等器官炎症变化并有大量异嗜性粒细胞和细菌团块。     

ANTIVIRAL EFFECTS OF BACTERIOCIN AGAINST ANIMAL-TO-HUMAN TRANSMITTABLE MUTATED SARS-COV-2: A SYSTEMATIC REVIEW

• Identification of bacteriocin sources• Classification of bacteriocins• Antiviral pathways of bacteriocinsThe COVID-19 infections caused by SARS-CoV-2 have resulted in millions of people being infected and thousands of deaths globally since November 2019. To date, no unique therapeutic agent has been developed to slow the progression of this pandemic. Despite possessing antiviral traits the potential of bacteriocins to combat SARS-CoV-2 infection has not been fully investigated. This review summarizes the mechanisms by which bacteriocins can be manipulated and implemented as effective virus entry blockers with infection suppression potential properties to highly transmissible viruses through comprehensive immune modulations that are potentially effective against COVID-19. These antimicrobial peptides have been suggested as effective antiviral therapeutics and therapeutic supplements to prevent rapid virus transmission. This review also provides a new insight into the cellular and molecular alterations which have made SARS-CoV-2 self-modified with diversified infection patterns. In addition, the possible applications of antimicrobial peptides through both natural and induced mechanisms in infection prevention perspectives on changeable virulence cases are comprehensively analyzed. Specific attention is given to the antiviral mechanisms of the molecules along with their integrative use with synthetic biology and nanosensor technology for rapid detection. Novel bacteriocin based therapeutics with cutting-edge technologies might be potential substitutes for existing time-consuming and expensive approaches to fight this newly emerged global threat.     

Pathological changes in the mammary gland and biochemical changes in milk of the goat following oral dosing with leaf of the Avocado (Persea americana)

Two varieties of avocado leaves (Persea americana var Guatemalan and var Mexican) were administered to lactating goats. The Mexican variety was without effect. The Guatemalan variety in doses exceeding 20 g fresh leaf per kg bodyweight, produced damage to the mammary gland with decreased milk production. The lesions were characterised by oedema and reddening, with clots in the large ducts. Microscopically, there was widespread degeneration and necrosis of the secretory epithelium, the necrotic cells sloughing into the lumen. There was no significant cellular inflammatory response. Concentrations of antitrypsin in the milk, indicating changes in vascular permeability, increased rapidly 15 h after a single high dose, coinciding with palpable oedema. Concentrations of NAGase, indicating cell damage, increased after 24 h. Goats given multiple doses followed a similar pattern but the initial response was delayed. The toxic principle, and its mode of action in selectively damaging mammary secretory cells, remains to be determined.