The hospital otolaryngologist: The louisiana state university experience.

OBJECTIVES/HYPOTHESIS: To describe the implementation and impact of a hospital otolaryngologist in an academic medical center setting. Our hypothesis was that the hospital otolaryngologist would increase productivity of the Louisiana State University (LSU) faculty otolaryngologists and provide more timely access to inpatient otolaryngology services. STUDY DESIGN: Retrospective clinical and administrative database review. METHODS: A comparative database review was performed with data from the year predating the initiation of the hospitalist program (2013) to the first full year after initiation of the program (2014). A clinical database review including diagnoses and procedures was also performed. RESULTS: Overall outpatient clinic relative value units for the aggregated LSU faculty increased 16% (despite the fact that the direct outpatient contribution of the hospital otolaryngologist was negligible). Overall capture of inpatient consult codes increased 128%. The hospital otolaryngologist was responsible for 84.5% of inpatient consult codes. There was a 100% increase in outpatient consult codes for the LSU faculty, of which <1% was attributed to the otolaryngology hospitalist. No significant impact was seen on length of stay over the study interval. Clinical database review of the first 2 years of the program showed 3,707 total encounters with postoperative encounters the most common. Four hundred fifty-four inpatient procedures were logged. The most common surgical procedure was tracheostomy. CONCLUSIONS: The otolaryngology hospitalist program is a viable clinical and economic model. LEVEL OF EVIDENCE: NA Laryngoscope, 1851-1857, 2018.

Macropinocytosis is the major pathway responsible for DNA transfection in CHO cells by a charge-reversal amphiphile.

The cellular uptake of a functional charge-reversal amphiphile:DNA lipoplex is described. First, pharmacological inhibitors were applied to block different endocytosis pathways. By examining the resulting transfection activities, it was found that endocytosis was the pathway leading to transfection in Chinese hamster ovary (CHO) cells. When the specific pathway of macropinocytosis was inhibited, ß-galactosidase expression was significantly depleted (90%); meanwhile the inhibition of clathrin-mediated pathway only brought a 30% decrease in expression; and the inhibition of caveolae-mediated pathway did not affect expression. Furthermore, a transfection kinetics study revealed that the cellular uptake responsible for gene expression was a slower process compared to clathrin-mediated endocytosis, consistent with fluid-phase uptake compared to receptor-mediated uptake. Next, a fluorescence colocalization study was used to visualize the DNA lipoplex uptake pathways. The colocalization of the DNA lipoplex and Cascade Blue, a fluid-phase uptake marker, was observed. Meanwhile, the colocalization of the DNA lipoplex and transferrin, a clathrin-mediated endocytosis marker, was also seen. However, no colocalization was observed with the endosome/lysosome marker Lysotracker. Our results indicate that macropinocytosis, not the commonly seen clathrin-mediated endocytosis for cationic lipids, is the major pathway leading to gene transfection in CHO cells for this charge-reversal amphiphile.

Alpha-actinin-4-mediated FSGS: an inherited kidney disease caused by an aggregated and rapidly degraded cytoskeletal protein.

Focal segmental glomerulosclerosis (FSGS) is a common pattern of renal injury, seen as both a primary disorder and as a consequence of underlying insults such as diabetes, HIV infection, and hypertension. Point mutations in the alpha-actinin-4 gene ACTN4 cause an autosomal dominant form of human FSGS. We characterized the biological effect of these mutations by biochemical assays, cell-based studies, and the development of a new mouse model. We found that a fraction of the mutant protein forms large aggregates with a high sedimentation coefficient. Localization of mutant alpha-actinin-4 in transfected and injected cells, as well as in situ glomeruli, showed aggregates of the mutant protein. Video microscopy showed the mutant alpha-actinin-4 to be markedly less dynamic than the wild-type protein. We developed a "knockin" mouse model by replacing Actn4 with a copy of the gene bearing an FSGS-associated point mutation. We used cells from these mice to show increased degradation of mutant alpha-actinin-4, mediated, at least in part, by the ubiquitin-proteasome pathway. We correlate these findings with studies of alpha-actinin-4 expression in human samples. "Knockin" mice with a disease-associated Actn4 mutation develop a phenotype similar to that observed in humans. Comparison of the phenotype in wild-type, heterozygous, and homozygous Actn4 "knockin" and "knockout" mice, together with our in vitro data, suggests that the phenotypes in mice and humans involve both gain-of-function and loss-of-function mechanisms.