Comparison of sampling and culture methods for the diagnosis of Tritrichomonas foetus infection in bulls

abstract: Sampling methods for preputial secretions and culture methods for T. foetus were compared in a 2-by-2 factorial experiment. 14 bulls were confirmed as infected by repeated weekly sampling and culture on Diamond's medium over the course of 10 months. In a 6-week test of alternative methods of diagnosis, the bulls were randomly assigned to have their preputial contents sampled weekly either by washing or by scraping of the preputial membrane. The samples were cultured on Claussen's medium and in InPouch packets at 37°C in air for 7 days. The results were compared by McNemar's χ² test for symmetry. Washing yielded 69 positive cultures from 84 samples whereas scraping yielded 65 from 83. These differences were not statistically significant. InPouch culture detected 73 of 83 samples from positive bulls, whereas Claussen's medium detected 61 of 83. The difference in sensitivity between the two culture methods was highly significant, with the InPouch method 'missing' 2 positive samples that were detected by Claussen's medium and Claussen's medium missing 14 positive samples that were detected by InPouch culture

Discovery of Small Molecule Splicing Modulators of Survival Motor Neuron-2 (SMN2) for the Treatment of Spinal Muscular Atrophy (SMA)

Spinal muscular atrophy (SMA), a rare neuromuscular disorder, is the leading genetic cause of death in infants and toddlers. SMA is caused by the deletion or a loss of function mutation of the survival motor neuron 1 (SMN1) gene. In humans, a second closely related gene SMN2 exists, however it codes for a less stable SMN protein. In recent years, significant progress has been made toward disease modifying treatments for SMA by modulating SMN2 pre-mRNA splicing. Herein, we describe the discovery of LMI070 / branaplam, a small molecule that stabilizes the interaction between the spliceosome and SMN2 pre-mRNA. Branaplam (1) originated from a high-throughput phenotypic screening hit, pyridazine 2, and evolved via multi-parameter lead optimization. In a severe mouse SMA model, branaplam treatment increased full-length SMN RNA and protein levels, and extended survival. Currently, branaplam is in clinical studies for SMA

SMN2 splice modulators enhance U1-pre-mRNA association and rescue SMA mice

Spinal muscular atrophy (SMA), which results from the loss of expression of the survival of motor neuron-1 (SMN1) gene, represents the most common genetic cause of pediatric mortality. A duplicate copy (SMN2) is inefficiently spliced, producing a truncated and unstable protein. We describe herein a potent, orally active, small-molecule enhancer of SMN2 splicing that elevates full-length SMN protein and extends survival in a severe SMA mouse model. We demonstrate that the molecular mechanism of action is via stabilization of the transient double-strand RNA structure formed by the SMN2 pre-mRNA and U1 small nuclear ribonucleic protein (snRNP) complex. The binding affinity of U1 snRNP to the 5′ splice site is increased in a sequence-selective manner, discrete from constitutive recognition. This new mechanism demonstrates the feasibility of small molecule-mediated, sequence-selective splice modulation and the potential for leveraging this strategy in other splicing diseases