Biohydrogenation of unsaturated fatty acids in continuous culture fermenters during digestion of orchardgrass or red clover with three levels of ground corn supplementation

Diet digestibility and outputs of biohydrogenation intermediates were assessed in a continuous culture of ruminal microorganisms. Orchardgrass or red clover harvested and frozen during spring or fall served as the primary substrates for fermentation. During 10-d incubations, fermenters were fed thawed forage (50 g of DM/d), forage (42 g/d) plus 8 g/d of corn, or forage (34 g/d) plus 16 g/d of corn. Effluents from the last 3 d of incubation were composited for analyses. Starch input increased from 5 to 27% of DM as corn input increased from 0 to 16 g/d. Corn input reduced (P < 0.01) pH, increased (P < 0.01) microbial DM yield, and increased (P = 0.01) digestibility of DM, NDF, CP, and nonstructural carbohydrates. Overall, apparent hydrogenation (percentage) of cis9-18:1, 18:2n-6, and 18:3n-3 was greater (P < 0.05) with orchardgrass than clover. Hydrogenation of cis9-18:1 and 18:2n-6 increased (P = 0.01), but hydrogenation of 18:3n-3 decreased (P = 0.01) linearly due to corn input, regardless of forage. As a result, output of trans11, cis15-18:2 also decreased (P = 0.01). Average output of cis9,trans11-18:2 was greater (P = 0.01) for clover (1.3 mg/d) compared with orchardgrass (0.6 mg/d), but corn input with either forage increased (P = 0.01) cis9,trans11-18:2 output by 205%. Output of trans11-18:1 was greater (P = 0.01) from orchardgrass compared with clover (174 vs. 90 mg/d), but corn increased (P = 0.01) trans11-18:1 output only from clover fermentations. Output of trans10-18:1 was greater (P = 0.01) in response to orchardgrass compared with clover (10 vs. 4 mg/d), but corn addition doubled the output regardless of forage type. Output of trans10,cis12-18:2, which did not differ due to forage type, increased (P = 0.01) twofold in response to corn. Cis9,cis11-18:2 was a primary conjugated isomer produced from forage fermentations, but its output decreased (P = 0.03) in response to corn input. When inputs of 18:2n-6 plus 18:3n-3 were less than 0.9% of total DM (clover), hydrogenation was low (87%). When 18:2n-6 plus 18:3n-3 inputs were from 1.2 to 1.5% of total DM (orchardgrass), hydrogenation averaged 96%. Despite greater hydrogenation, incremental additions of cis9-18:1 and 18:2n-6 from corn grain increased (P < 0.05) outputs of trans10-18:1, trans11-18:1, trans10,cis12-18:2, cis9,trans11-18:2, and trans,trans-18:2 in effluent. Results suggest that forage species alone or in combination with corn grain can alter hydrogenation and profiles of intermediates to varying degrees.     

Lymphoid neoplasia in the koala

Objective Correlation of immunophenotype with history, anatomical and morphological features of lymphoid neoplasia in the koala.
Methods Routine necropsies were performed on 51 koalas with suspected lymphoid neoplasia between 1986 and 1997 in New South Wales and Queensland. Immuno-phenotyping was by an immunoperoxidase method utilising species cross-reactive antibodies raised against human lymphocytes and an antibody raised against koala IgG. Cases were classified according to organs and tissues affected and the morphological features of neoplastic cells.
Results Twenty-six (51%) of the cases were of the T cell immunophenotype, 12 (24%) were of B cell immunopheno-type and 13 (25%) did not stain. The age and sex of koalas did not correlate with immunophenotype (P = 0.686 and P = 1.000, respectively). Thirty-two cases were leukaemic and 36 had multiple organ involvement, probably reflecting presenta tion of koalas at advanced stages of disease. Abdominal tissue involvement was most common (44 cases), followed by nodal (32), atypical (21) and cervicomediastinal (14). The T cell immunophenotype was over-represented among the leukaemic cases (P = 0.013). Generally, the T cell immunophenotype predominated except for many affected atypical tissues. Neoplastic cells were mostly of medium nuclear size with round to oval nuclei. No correlations were found for cell morphology, mitotic index and immunopheno-type.
Conclusion The prognostic value of an immunopheno-typic, anatomical and morphological basis for the classifica tion of lymphoid neoplasia in the koala currently is limited by the need to detect these neoplasms at an early age, the requirement for freshly fixed tissues and the restricted range of available cross-reacting antibodies.     

Diabetes mellitus in a koala (Phascolarctos cinereus)

Objective To describe a case of diabetes mellitus in a koala (Phascolarctos cinereus).
Design A case report with controls.
Procedures We describe clinical and laboratory findings in a 6-year-old, free-living, female koala presented with traumatic injury and subsequently found to have polydipsia, hyperglycaemia and glucosuria. Over a 5 week period, serum biochemical analyses, haematological examinations, urinal-yses, measurement of serum insulin and fructosamine concentrations, necropsy, histopathological examination of a range of tissues and immunohistochemical examination of the pancreas for insulin-containing cells were done. For reference purposes, serum insulin and fructosamine concentrations were determined in four and two healthy koalas, respectively, and three healthy koalas pancreases were examined histo-logically and immunohistochemically.
Results The koala had persistent hyperglycaemia, hyperlipidaemia, hyponatraemia, hypochloraemia and glucosuria. Serum insulin concentration of the diabetic koala was only marginally smaller than that of healthy koalas, but all concentrations were smaller than reference concentrations in dogs and people. Fructosamine concentration did not allow the diabetic koala to be distinguished from healthy koalas and concentrations of all koala analytes were greater than expected for healthy dogs and people. Histopathological examination revealed extensive degeneration of pancreatic islet cells and fatty infiltration of hepatocytes. Immunoperoxidase staining revealed decreased or absent insulin in the b cells of the affected koala.
Conclusion Clinical signs, clinicopathological results and histopathological changes were consistent with diabetes mellitus. The pathogenesis of the condition could not be determined but may have been related to the administration of a parenteral corticosteroid preparation, the stress of capture or tissue damage and inflammation.     

氧氟沙星药物的研究进展

通过对氧氟沙星药物近十年来的检测方法、药代动力学、药效学、耐药性及抗菌后效应、联合应用及毒理学、残留及残留的检测方法等六个方面的大量研究资料进行综述,详细介绍并论述了氧氟沙星药物在这些方面的最新研究成果,对氧氟沙星药物及其他喹诺酮类药物的进一步研究、开发和应用具有指导意义。     

Determination of Feeder Cell‐Based Cellular Niches Supporting the Colonization and Maintenance of Spermatogonial Stem Cells from Prepubertal Domestic Cat Testes

Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats.     

Cross-protective immunity and the serological classification system for Bacteroides nodosus

The relationship between the serological classification system for serogroup B and for serogroup H of Bacteroides nodosus and cross-protection between subgroups within these serogroups was examined. Protection against ovine footrot following vaccination was achieved against other subgroup strains provided sufficient cross-reactive antibody was induced by shared pilus antigens. Within serogroup B, better cross-protection against one subgroup was obtained with a pili vaccine than a whole cell vaccine which correlated with higher pilus antibody titres induced by the former. For serogroup H, a lack of cross-protection and serological reactivity between subgroups was demonstrated, which indicates that the prototype strain of subgroup H2 should be designated a new serogroup.     

The effect of an extended artificial photoperiod and gonadotrophin-releasing hormone infusions in inducing fertile oestrus in anoestrous mares

The occurrence of fertile oestrus early in the breeding season is of paramount importance to the Thoroughbred industry to facilitate early conception. This paper compares 2 techniques for inducing fertile oestrus in anoestrous mares using either an extended photoperiod alone or together with gonadotrophin-releasing hormone (GnRH) infusions. Eleven mares were placed under conditions of 16 h light and 8 h darkness and 5 of these were implanted with osmotic minipumps delivering approximately 100 ng GnRH/kg/h for 28 days (treated mares). The treated mares ovulated 27.7 days earlier than and conceived 32 days earlier than the 6 mares not given GnRH. GnRH-induced ovulations were followed by a competent luteal phase. The combination of GnRH pumps implanted 2 weeks before commencement of service together with extended photoperiod from July 1 has promise in assisting the stud breeder to improve reproductive efficiency on commercial stud farms.