Assessing the suitability of antibiotic resistance markers and the indirect ELISA technique for studying the competitive ability of selected Cyclopia Vent. rhizobia under glasshouse and field conditions in South Africa

<p>Abstract</p> <p>Background</p> <p>Symbiotic N2 fixation in legumes is constrained by many factors, including the paucity of suitable soil rhizobia To maximise growth of legume species therefore often requires the application of effective rhizobia as inoculants. But where native strains out-compete introduced rhizobia for nodule formation, it is important that the competitiveness of selected strains is tested in the field and glasshouse prior to their recommendation as commercial inoculants. However the methodology for strain identification inside nodules has often proved difficult and thus limited this field of research. In this study, the suitability of the antibiotic resistance technique (both intrinsic low-resistance fingerprinting and high-resistance marking) and the serological indirect ELISA method were assessed for their ability to detect selected Cyclopia rhizobia under glasshouse and field conditions. The four rhizobial strains that were used, namely PPRICI3, UCT40a, UCT44b and UCT61a, were isolated from wild Cyclopia species growing in the Western Cape fynbos of South Africa.</p> <p>Results</p> <p>The test strains formed two distinct groups with regard to their intrinsic resistance to the antibiotics streptomycin sulphate and spectinomycin dihydrochloride pentahydrate, making it impossible to use intrinsic antibiotic resistance to distinguish strains from within the same intrinsic resistance group. The use of strains marked with double antibiotic resistance was also investigated. A number of these strains lost their antibiotic marker tags after one plant passage; and some also lost their competitive ability. The indirect ELISA technique provided a more satisfactory method of identifying selected Cyclopia strains under both field and glasshouse conditions. The primary antibodies raised against strains UCT40a, UCT61a and UCT44b gave absorbance readings that were unambiguously negative (0.30 OD405), while those of strain PPRICI3 were ambiguous (0.50 OD405) with many false positive readings (1.0 A405). The indirect ELISA method showed a high level of analytical sensitivity in glasshouse experiments and there were no cross-reactions between the four test strains. The method was also suitable for detecting three of the four test strains in competition studies under field conditions, and can also be used to identify some strains under field conditions.</p> <p>Conclusion</p> <p>The antibiotic marker method was found unsuitable for identifying Cyclopia rhizobia in competition experiments in both glasshouse and field conditions. However, the indirect ELISA technique was found suitable for identifying these strains in glasshouse studies. The method was also appropriate for identifying strains UCT40a, UCT44b and UCT61a, but not strain PPRICI3, in field competition studies.</p

How to Implement Visual Activity Schedules for Students with Disabilities

Based on recent literature reviews on the use of Visual Activity Schedules (VAS) for students with intellectual disability and autism, the strategy has been deemed an evidence based practice. Using the literature highlighted in the recent reviews, this article provides an overview of VAS and common skills VAS has been used to teach. Additionally, the authors provide guidelines on schedules variations, creating schedules, and implementing the schedules. Finally, several examples of VAS are included

Comparison of TNFα to Lipopolysaccharide as an Inflammagen to Characterize the Idiosyncratic Hepatotoxicity Potential of Drugs: Trovafloxacin as an Example

Idiosyncratic drug reactions (IDRs) are poorly understood, unpredictable, and not detected in preclinical studies. Although the cause of these reactions is likely multi-factorial, one hypothesis is that an underlying inflammatory state lowers the tolerance to a xenobiotic. Previously used in an inflammation IDR model, bacterial lipopolysaccharide (LPS) is heterogeneous in nature, making development of standardized testing protocols difficult. Here, the use of rat tumor necrosis factor-α (TNFα) to replace LPS as an inflammatory stimulus was investigated. Sprague-Dawley rats were treated with separate preparations of LPS or TNFα, and hepatic transcriptomic effects were compared. TNFα showed enhanced consistency at the transcriptomic level compared to LPS. TNFα and LPS regulated similar biochemical pathways, although LPS was associated with more robust inflammatory signaling than TNFα. Rats were then codosed with TNFα and trovafloxacin (TVX), an IDR-associated drug, and evaluated by liver histopathology, clinical chemistry, and gene expression analysis. TNFα/TVX induced unique gene expression changes that clustered separately from TNFα/levofloxacin, a drug not associated with IDRs. TNFα/TVX cotreatment led to autoinduction of TNFα resulting in potentiation of underlying gene expression stress signals. Comparison of TNFα/TVX and LPS/TVX gene expression profiles revealed similarities in the regulation of biochemical pathways. In conclusion, TNFα could be used in lieu of LPS as an inflammatory stimulus in this model of IDRs

Embedding Science Facts in Leisure Skill Instruction Conducted by Peer Tutors

This investigation evaluated the effectiveness of using peer tutors to teach a chained leisure skill (i.e., UNO card game) to three middle school students with disabilities using a simultaneous prompting procedure within a multiple probe design. The investigation also assessed whether the students with disabilities would acquire four unrelated science core content facts presented as nontargeted information during instructive feedback. Results indicated that all students met or made progress toward criterion on the leisure skill. In addition, two of the three students acquired all four core content facts

Examination of the Evidence Base for Using Visual Activity Schedules With Students With Intellectual Disability

We conducted a comprehensive review of the literature to establish the evidence base for using visual activity schedules (VAS) with individuals with intellectual disability. Literature published after 2005 was evaluated for quality using the criteria developed by Horner et al.; a total of 14 studies were included as acceptable. Findings suggest that VAS is an evidence-based practice for teaching a variety of daily living, navigation, vocational, recreation, and academic skills to adolescents and adults with intellectual disability. Results also show increases in independence and on-task behaviors. We conclude the article by discussing limitations and recommendations for future research

Expression of the Carboxy-Terminal Portion of MUC16/CA125 Induces Transformation and Tumor Invasion

<div><p>The CA125 antigen is found in the serum of many patients with serous ovarian cancer and has been widely used as a disease marker. CA125 has been shown to be an independent factor for clinical outcome in this disease. In The Cancer Genome Atlas ovarian cancer project, MUC16 expression levels are frequently increased, and the highest levels of MUC16 expression are linked to a significantly worse survival. To examine the biologic effect of the proximal portion of MUC16/CA125, NIH/3T3 (3T3) fibroblast cell lines were stably transfected with the carboxy elements of MUC16. As few as 114 amino acids from the carboxy-terminal portion of MUC16 were sufficient to increase soft agar growth, promote matrigel invasion, and increase the rate of tumor growth in athymic nude mice. Transformation with carboxy elements of MUC16 was associated with activation of the AKT and ERK pathways. MUC16 transformation was associated with up-regulation of a number of metastases and invasion gene transcripts, including IL-1β, MMP2, and MMP9. All observed oncogenic changes were exclusively dependent on the extracellular “ectodomain” of MUC16. The biologic impact of MUC16 was also explored through the creation of a transgenic mouse model expressing 354 amino acids of the carboxy-terminal portion of MUC16 (MUC16^c354). Under a CMV, early enhancer plus chicken β actin promoter (CAG) MUC16^c354 was well expressed in many organs, including the brain, colon, heart, kidney, liver, lung, ovary, and spleen. MUC16^c354 transgenic animals appear to be viable, fertile, and have a normal lifespan. However, when crossed with p53-deficient mice, the MUC16^c354:p53^+/- progeny displayed a higher frequency of spontaneous tumor development compared to p53^+/- mice alone. We conclude that the carboxy-terminal portion of the MUC16/CA125 protein is oncogenic in NIH/3T3 cells, increases invasive tumor properties, activates the AKT and ERK pathways, and contributes to the biologic properties of ovarian cancer.</p></div