45 research outputs found

    Griffithsia schousboei (Ceramiaceae, Rhodophyceae), a species new to South Africa

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    A species of Griffithsia from southern Natal has been isolated into unialgal culture. Its vegetative and reproductive characters align it with G. schousboei, a species previously known only to occur in Portugal, the Mediterranean and Caribbean Seas, and south to Brazil and Ghana. This report extends the known range of this alga to Natal. Closely related species are discussed and synonymies recommended

    A serological survey of bovine babesiosis in northern and eastern Zimbabwe

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    The geographical distribution of Babesia bovis and Babesia bigemina antibodies in communal herds in northern and eastern Zimbabwe was determined using the ELISA technique. The animals in different herds in the study region had different levels of natural exposure to B. bovis (mean 32 %, range 0-79%) and B. bigemina (mean 52%, range 5-92%) infections. The majority of herds (90%) were endemically unstable for B. bigemina and 62 % were unstable for B. bovis. Natural region 5 and Manicaland province had the highest seroprevalence of B. bovis infection, while natural region 5 and Masvingo province had the highest seroprevalence of B. bigemina infection.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Australian Agency for International Development. Australian Centre for International Agricultural Research. Central Veterinary Laboratory, Harare.mn201

    Expression of FBN1 during adipogenesis:relevance to the lipodystrophy phenotype in Marfan syndrome and related conditions

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    Fibrillin-1 is a large glycoprotein encoded by the FBN1 gene in humans. It provides strength and elasticity to connective tissues and is involved in regulating the bioavailability of the growth factor TGF beta. Mutations in FBN1 may be associated with depleted or abnormal adipose tissue, seen in some patients with Marfan syndrome and lipodystrophies. As this lack of adipose tissue does not result in high morbidity or mortality, it is generally under-appreciated, but is a cause of psychosocial problems particularly to young patients. We examined the role of fibrillin-1 in adipogenesis. In inbred mouse strains we found significant variation in the level of expression in the Fbn1 gene that correlated with variation in several measures of body fat, suggesting that mouse fibrillin-1 is associated with the level of fat tissue. Furthermore, we found that FBN1 mRNA was up-regulated in the adipose tissue of obese women compared to non-obese, and associated with an increase in adipocyte size. We used human mesenchymal stem cells differentiated in culture to adipocytes to show that fibrillin-1 declines after the initiation of differentiation. Gene expression results from a similar experiment (available through the FANTOM5 project) revealed that the decline in fibrillin-1 protein was paralleled by a decline in FBN1 mRNA. Examination of the FBN1 gene showed that the region commonly affected in FBN1-associated lipodystrophy is highly conserved both across the three human fibrillin genes and across genes encoding fibrillin-1 in vertebrates. These results suggest that fibrillin-1 is involved as the undifferentiated mesenchymal stem cells transition to adipogenesis but then declines as the developing adipocytes take on their final phenotype. Since the C-terminal peptide of fibrillin-1 is a glucogenic hormone, individuals with low fibrillin-1 (for example with FBN1 mutations associated with lipodystrophy) may fail to differentiate adipocytes and/or to accumulate adipocyte lipids, although this still needs to be shown experimentally. (C) 2016 The Authors. Published by Elsevier Inc

    Sensitive and specific detection of proviral bovine leukemia virus by 5' Taq nuclease PCR using a 3' minor groove binder fluorogenic probe

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    Sensitive assays are required to detect proviral bovine leukemia virus (BLV) in donor cattle used for the in vivo preparation of Australian tick fever vaccines. 5' Taq nuclease assays using 3' minor groove binder DNA probes (TaqMan®MGB) were developed and compared to conventional PCR assays for sensitive detection of Australian BLV. Seven beef and dairy herds were screened using DNA prepared by a variety of protocols to evaluate these tests. Comparative sensitivities of PCR tests were determined by testing log10 dilutions of plasmids with inserted BLV sequences. Animals were also screened by the BLV standard agar-gel immunodiffusion test (AGID) and commercial enzyme linked immunosorbent assays (ELISA) for antibodies, and an ELISA for detecting viral antigens expressed (VAE) in lymphocyte cultures. The TaqMan®MGB assay based on the pol region was the most sensitive and specific for the detection of BLV. This is the first report of a sensitive BLV 5' Taq nuclease assay

    Comparison of a competitive inhibition ELISA and the card agglutination test for detection of antibodies to Anaplasma marginale and Anaplasma centrale in cattle

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    Objective: To compare a recently developed recombinant MSP-5 competitive inhibition ELISA with a card agglutination test for detection of antibodies to Anaplasma marginale and Anaplasma centralein Australian cattle. Materials and methods: The ELISA was compared with the card agglutination test using 208 sera from cattle in Anaplasma-free herds, 86 sera from cattle experimentally infected with A marginale or A centrale and 757 sera from cattle in areas endemic for A marginale. Results: The specificity of the ELISA, based on testing 208 sera from cattle in Anaplasma-free areas, was 99.5%, and the sensitivities for detection of antibodies to A marginale and A centrale in sera from the experimentally infected cattle were 98.0% and 100%, respectively. For the same sets of sera, the specificity of the card agglutination test was 98.6% and the sensitivities for detection of antibodies to A marginale and A centrale were 98.0% and 100%, respectively. For the 757 sera collected from cattle in areas endemic for A marginale, the agreement between the ELISA and the card agglutination test depended on the positive threshold selected for the ELISA. The maximum achievable agreement was 91.5% (kappa = 0.73; 95% confidence interval 0.66, 0.79). Conclusion: We conclude that the competitive inhibition ELISA is a useful alternative to the card agglutination test for detection of A marginale or A centrale infection in cattle. The assay should be particularly useful for epidemiological applications such as prevalence studies and control programs

    Identification of antigenic differences that discriminate between cattle vaccinated with Anaplasma centrale and cattle naturally infected with Anaplasma marginale

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    Monoclonal antibodies were raised against the vaccine strain of Anaplasma centrale used in Australia. A monoclonal antibody that reacted with an 80 kDa antigen was used to develop an A. centrale-specific fluorescent antibody test that will be useful for confirming species identity in patent infections. Another monoclonal antibody that reacted with a 116 kDa antigen was used to develop an A. centrale-specific competitive inhibition enzyme-linked immunosorbent assay (ELISA) for the serological identification of vaccinated cattle. The sensitivity of the ELISA was 100% in cattle experimentally infected with A. centrale, 97.1% in a vaccinated beef herd and 98.3% in a vaccinated dairy herd. The specificity of the ELISA was 98.6% in non-vaccinated cattle outside the Anaplasma marginale-endemic area, 97.9% in non-vaccinated cattle within the A. marginale-endemic area and 100% in cattle experimentally infected with A. marginale. The ELISA detected antibodies to A. centrale in cattle up to 9 years after vaccination with no apparent decrease in sensitivity. The assay has proved extremely valuable in Australia for investigating reported failures of multivalent live vaccines used to protect cattle against anaplasmosis and babesiosis, and should be similarly useful elsewhere in the world where these types of vaccines are used, e.g. Israel and South America

    Development of an enzyme-linked immunosorbent assay for detection of antibodies to Babesia bigemina in cattle

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    Monoclonal antibodies, directed against a 58-kDa Babesia bigemina merozoite antigen that reacted strongly with immune sera from experimentally and naturally infected cattle in Western blots, were used to develop a competitive-inhibition enzyme-linked immunosorbent assay (ELISA). As based on the testing of 70 antibody-positive sera from experimentally infected cattle and 166 antibody-negative sera collected in non-endemic areas of Australia, the sensitivity and specificity of the ELISA were 95.7% and 97.0%, respectively. In sequential sera collected from six calves during the course of experimental B. bigemina infections the ELISA detected seroconversion at about 10 days post-inoculation. The specificity of the ELISA was not affected by the presence of antibodies to B. bovis, Anaplasma marginale or Theileria buffeli. In 42 sera from cattle experimentally infected with B. bovis but negative for B. bigemina the specificity of the ELISA was 95.2%. The use of a competitive-inhibition ELISA format detecting only antibody directed against a single epitope on the 58-kDa antigen appears to have overcome many of the specificity problems that have plagued serological tests for B. bigemina in the past. The test should be useful for epidemiology studies, particularly in areas where B. bovis and B. bigemina have overlapping distributions
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