RÉSUMÉ
Gastric residual volume (GRV) has been widely used in clinical practice for a long time as an essential indicator of gastrointestinal motility and enteral nutrition tolerance. Recent studies have questioned the rationality of monitoring GRV routinely in critically ill patients. A "one size fits all" principle is not an optimal solution in the clinical practice of enteral nutrition in critically ill patients because of the huge heterogeneity of the intensive care unit (ICU) population. Each method of monitoring GRV has advantages and disadvantages. With the widespread clinical application of harmless monitoring technologies such as ultrasound, the gastric suctioning method maybe used less and less. The management of enteral nutrition focuses on identifying the factors and triggers of gastric retention, attempting to solve them from the perspective of prevention and elimination of high-risk factors for aspiration and analysis of pathophysiological mechanisms, eliminating all negative hindering factors, and actively promoting the concept of "creating conditions for enteral nutrition". As a critical nutrition management team, it is necessary to pay attention to the continuous improvement of enteral nutrition management culture and rationally use diversified management strategies, which may be more important than monitoring GRV.
RÉSUMÉ
A promising genetic marker, sag5b, was cloned and expressed and the difference of the genes between highly virulent strain (RH) and less virulent strain(Prugniaud) of Toxoplasma gondii was compared. The PCR-generated product of sag5b was subcloned into T easy vector and plasmid pET28a consecutively. The fusion expression was induced by IPTG and identified by SDS-PAGE and Western blotting. The immunoreactivity of recombinant SAG5B was identical to that of native SAG5B on the membrane of tachyzoites of RH strain. The brains of mice infected with Prugniaud strain of T. gondii were homogenated. Sag1 was successully cloned by PCR from both RH strain tachyzoites and the homogenized brain tissues of mice infected with low virulent strain of Prugniaud,whereas sag5b was only detected in RH strain but not in Prugniaud strain, indicating that sag5b could be used as a genetic marker for differentiation of strain virulence. Expression and vaccination of the virulence-associated gene into mice failed to induce obvious protective immunity against the challenge of RH strain.