Phylogenetic evidence for recombination in SAG5 locus in Toxoplasma gondii

The present study evaluated the hypothesis that genetic diversity in SAG5 genes was generated by recombination events. Three lines of evidence suggested that recombination occurred in SAG5 genes in T. gondii. The permutation test revealed strong signature of intragenic recombination, pairwise comparisons of nucleotide sequences of SAG5 genes revealed that SAG5A alleles have chimerical structures composed of segments derived through recombination events between different alleles, and phylogenetic trees reconstructed based on SAG5 sequences using neighbor-joining and maximum parsimony methods, showed statistically well-supported consensus clusters of T. gondii strains specific to each SAG5 gene. Topological discrepancies between trees based on the N-terminal variable domain and C-terminal conserved domain sequences, were observed, suggesting intragenic recombinetion between SAG5A and SAG5B/C genes. The results showed that recombination within SAG5 in T. gondii was a major evolutionary mechanism generating both allelic variation at SAGS locus and contributing to genotypic diversity and to emergence of new T. gondii variants, allowing them to evade the host immune defence mechanism

Continual measurements of cardiac haemodynamic parameters and internal carotid blood flow by Khalil thermodilution catheter

This study develops a simple method which others almost immediate information of the cardiac hemodynamic parameters. It can be repeated as required without any noticeable discomfort to the patient. The structure of the used catheter, and the procedure are presented

new heart model for better biological system simulation

An electronic nonlinear time varying capacitance is designed to simulate the human myocardial performance which cannot be easily programmed on an analog computer. This design makes feasible the use of RLC circuit model for the Pressure-Flow dynamics of the Cardiovascular System with a large number of segments without being limited by the size of the analog computer. The model can be interconnected to the analog computer for studying related problems. Nonlinearity in the suggested model allows for mechanical heart failure to be detected. Systolic time is made variable with heart rate to mirnic reality. Time scale is introduced to allow for the study of slow phenomena like myocardial hypertrophy