Determination and quantification of the in vitro activity of Aloe marlothii (A. Berger) subsp. marlothii and Elephantorrhiza elephantina (Burch.) skeels acetone extracts against Ehrlichia ruminantium

An Ehrlichia ruminantium culture system was utilized for the anti-rickettsial evaluation of two ethnoveterinary plants, Elephantorrhiza elephantina and Aloe marlothii. Well-established E. ruminantium cultures were incubated with the plant leaf acetone extracts and compared to oxytetracycline and untreated controls. Effectivity was established by comparing the percentage parasitised cells and the calculation of both EC50 and extrapolated EC90 in microg/ml. The plant extracts were also screened for antibacterial activity using bioautography. Elephantorrhiza elephantina and A. marlothii demonstrated anti-ehrlichial activity with an EC50 of 111.4 and 64.5 microg/ml and EC90 of 228.9 and 129.9 microg/ml, respectively. The corresponding EC50 and EC90 for oxytetracycline was 0.29 and 0.08 microg/ml. Both plants appeared to produce their inhibitory activity by a similar mechanism, unrelated to that of the tetracyclines. Both the plant acetone extracts demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus (ATCC strains).     

Alternative eucalypts for commercial pulpwood production at moderately dry sites in the warm temperate zone of KwaZulu-Natal,South Africa

During 2001, a series of four site–taxa interaction trials was established in the warm temperate (mean annual temperature range 16–19 °C) forestry climatic zone of KwaZulu-Natal (KZN), South Africa. The main objective was to investigate the commercial forestry potential of a range of alternative Eucalyptus and Corymbia taxa for moderately dry (mean annual precipitation < 850 mm) sites within the zone. At rotation end, all trials received final standing tree measurements. At one of the sites (Rockvale), trees of eight promising alternative taxa were felled, stem measurements and wood samples taken, and wood and fibre productivities determined. On the basis of tree growth and wood and fibre production, C. citriodora subsp. variegata, C. henryi, E. badjensis, E. benthamii and E. dorrigoensis (listed alphabetically) demonstrated the greatest potential as commercial alternatives for moderately dry sites in the KZN warm temperate zone. The majority of these taxa showed strong site specificity. Eucalyptus benthamii was the only taxon showing high growth adaptability to the entire range of site conditions applied in the series. The non-susceptibility of C. citriodora subsp. variegata and C. henryi to the current topical insect pests Thaumastocoris peregrinus, Leptocybe invasa and Glycaspis brimblecombei elevates the appeal of these taxa as potential alternative planting choices for moderately dry sites within lower altitude (<1 100 m asl) areas of the climate zone. The matching of the most promising alternative taxa in the series to the range of sites encountered in moderately dry areas of the KZN warm temperate forestry zone is discussed in this paper.     

Necrotizing fasciitis: a review

Necrotizing fasciitis is a rapidly spreading, bacterial, soft-tissue infection reported in both humans and dogs. A review of the pathophysiology, clinical findings, diagnosis, and treatment of necrotizing fasciitis is presented, with the goal of familiarizing veterinarians with this uncommon but potentially fatal condition. A case report highlighting the fulminant course of this disease is also included.     

Does the renal portal valve exist in a raptor species? A study aimed at further evaluating the mechanism of toxicity of diclofenac in vultures

Diclofenac has been responsible for the deaths of millions of vultures on the Asian subcontinent. While the pathology of toxicity is well described, the mechanism of toxicity remains elusive. However, it was postulated that toxicity could be related to the unique avian renal vascular structure known as the renal portal valve and that that diclofenac altered valve functionality with subsequent renal ischaemia. While plausible, the valva renalis portalis has only been described in a small number of other bird species such as the chicken (Gallus domesticus), the domestic duck (Anas platyrhynchos domesticus) and ostrich (Struthio camelus) but not a raptor. The aim of this study was to evaluate the renal anatomy and related vasculature of the Cape griffon vulture (Gyps coprotheres) (CGV), a species sensitive to the toxic effects of diclofenac, using gross anatomy, histology and vascular casting. The vasculature of the vulture was found to be almost identical to that of the domestic chicken with the valva renalis portalis present in the v. iliaca externa between the v. renalis renalis cranialis and the v. renalis caudalus. The valve was ring-shaped with finger-like processes and histologically was composed of smooth muscle. The valve was also well vascularized and was associated with a nerve plexus. Based on the findings of this study, the proposed mechanism of toxicity is anatomically possible.     

玉米F1杂交种对黄曲霉菌穗腐病和黄曲霉毒素积累的抗性

黄曲霉毒素是由黄曲霉菌(Aspergillus flavus Link:Fr)产生的一种致癌毒素.由黄曲霉毒素造成的严重污染影响玉米籽粒的销售和运输.试验目的是:(1)测定由理想的抗病玉米自交系导致F1 对黄曲霉菌和黄曲霉毒素积累的相对抗性,而不考虑杂种优势类型.(2)通过双列分析分析该自交系的遗传基础.(3)找出哪个自交系在分子标记图谱和育种程序中是最理想的抗性资源.在所有组合中,将两个重要自交系和6个暂定与降低穗腐病和抑制黄曲霉毒素产生有关的自交系进行杂交.对其F1杂交种进行了为期两年的评价.中丝期20～24 d后,用针板法将黄曲霉菌分离菌的分生孢子混合物接种果穗.在接种区将各小区的果穗按可见穗腐病百分率进行分级.用间接竞争ELISA测定收获果穗的黄曲霉毒素B1水平.测得抗病自交系×抗病自交系F1对穗腐病和黄曲霉毒素积累的抗性水平最高,它们与许多自交系×已知抗性的自交系F1没有显著差异.双列分析表明所有杂交种和自交系Tex6和Oh516的穗腐病黄曲霉毒素水平的一般配合力(GCA)效应高度显著.结果表明在多种遗传背景下,Tex6和Oh516位分子标记图谱测定和抗性育种程序中是最理想的抗病资源.