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The germplasm for modern sugarcane cultivars (Saccharum spp. hybrids)has been derived principally from S. officinarum (2n = 80), and S. spontaneum (2n = 40 to 128). Diploid gamete formation has been significant in developing cultivated sugarcane, but the cytological basis for the processes involved is not clearly understood. This research investigated microsporogenesis in nine clones of Saccharum spp. Hybrids and in S. officinarum and S. spontaneum. Diploid gamete formation occurred in all 11 lines, but was least frequent in S. spontaneum and S. officinarum which produced 0.5% and 0.8%2n gametes, respectively. In the hybrid lines, 2n gametes were formed infrequencies ranging from 0.9% to 4.4%. Cytological evidence was obtained for dyad and triad formation during microsporogenesis. Detailed analysis of chromosome behaviour at meiosis indicated that 2n male gamete formation is probably attributable to the absence of cytokinesis rather than a combination of asynchrony and non-disjunction. The clones were ranked on the basis of the frequencies with which they formed 4 × 1n microspores and the data were analysed using χ 2 tests for homogeneity. These established that theSaccharum spp. hybrids could be designated as either ‘high’ or ‘low’ frequency haploid gamete producers. Conversely, the latter group, which formed diploid gametes most frequently (2.2%–4.4%), can be described as high frequency diploid gamete producers. The identification of clones most frequently forming diploid gametes may facilitate the more rapid recovery of desirable sugarcane genotypes because such clones could be selected for preferential use in clonal improvement. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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Objective: To report an unusual manifestation of acetaminophen intoxication in a dog.
Case Summary: A Miniature Pinscher was presented for evaluation of lethargy and facial swelling after ingestion of 500–750 mg/kg of acetaminophen. Laboratory testing revealed eccentrocytes, Heinz bodies, hemoglobinemia, and a declining packed red cell volume consistent with oxidative damage to the erythrocytes. Hepatocellular damage, as monitored by serum alanine aminotransferase, was not documented. The dog responded well to therapeutic intervention, and was discharged from the hospital. The dog returned to the hospital 2 days later with clinical signs and diagnostic tests consistent with acute keratoconjunctivitis sicca, which was assumed to be due to a toxic etiology. The dog responded well to therapy, regaining normal levels of tear production within six weeks.
New or Unique Information Provided: Acetaminophen intoxication may be associated with severe erythrocytic oxidative damage in the absence of detectable hepatic injury in dogs. Acetaminophen intoxication may have the potential to cause acute keratoconjunctivitis sicca in dogs. ( J Vet Emerg Crit Care 2001; 11(2): 123–126 )  相似文献   
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Two horses were diagnosed as having Mycobacterium ulcerans infections. The first was a 21-year-old Quarterhorse-cross mare living in Mallacoota (a coastal town near the border of New South Wales and Victoria, Australia) that presented with lichenification, hair-loss and oedema on a fetlock, which subsequently ulcerated, as well as a non-healing ulcer on the wither. The second horse was a 32 year-old Standardbred gelding from Nicholson, near Bairnsdale, Victoria, that had an ulcerated lesion on its caudal thigh. Histologically, there were characteristic changes seen with M. ulcerans infections in other species, including extensive necrosis without associated granulomatous inflammation. The organisms were seen in Ziehl-Neelsen-stained smears or sections of the lesions from both horses and were isolated in culture from the first horse. A definitive diagnosis was provided by real-time polymerase chain reaction targeting the M. ulcerans-specific insertion sequence, IS2404. Delayed identification of the infectious agent in the first case led to the use of suboptimal antimicrobial therapy, resulting in failure to control the infection and the horse was subsequently euthanased. The second horse was successfully treated following surgical debulking of the centre of the lesion and one session of aggressive cryosurgery. Mycobacterium ulcerans should be considered in the differential diagnosis of unexplained lichenification with oedematous and ulcerated skin lesions in horses living in regions where this organism is endemic.  相似文献   
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