Phylogenetic and sequence analyses of insect transferrins suggest that only transferrin 1 has a role in iron homeostasis.

Iron is essential to life, but surprisingly little is known about how iron is managed in nonvertebrate animals. In mammals, the well-characterized transferrins bind iron and are involved in iron transport or immunity, whereas other members of the transferrin family do not have a role in iron homeostasis. In insects, the functions of transferrins are still poorly understood. The goals of this project were to identify the transferrin genes in a diverse set of insect species, resolve the evolutionary relationships among these genes, and predict which of the transferrins are likely to have a role in iron homeostasis. Our phylogenetic analysis of transferrins from 16 orders of insects and two orders of noninsect hexapods demonstrated that there are four orthologous groups of insect transferrins. Our analysis suggests that transferrin 2 arose prior to the origin of insects, and transferrins 1, 3, and 4 arose early in insect evolution. Primary sequence analysis of each of the insect transferrins was used to predict signal peptides, carboxyl-terminal transmembrane regions, GPI-anchors, and iron binding. Based on this analysis, we suggest that transferrins 2, 3, and 4 are unlikely to play a major role in iron homeostasis. In contrast, the transferrin 1 orthologs are predicted to be secreted, soluble, iron-binding proteins. We conclude that transferrin 1 orthologs are the most likely to play an important role in iron homeostasis. Interestingly, it appears that the louse, aphid, and thrips lineages have lost the transferrin 1 gene and, thus, have evolved to manage iron without transferrins.

Perioperative goal-directed hemodynamic optimization using noninvasive cardiac output monitoring in major abdominal surgery: a prospective, randomized, multicenter, pragmatic trial: POEMAS Study (PeriOperative goal-directed thErapy in Major Abdominal Surgery).

BACKGROUND: In this study, our objective was to determine whether a perioperative hemodynamic protocol based on noninvasive cardiac output monitoring decreases the incidence of postoperative complications and hospital length of stay in major abdominal surgery patients requiring intensive care unit admission. Secondary objectives were the time to peristalsis recovery and the incidence of wound infection, anastomotic leaks, and mortality. METHODS: A randomized clinical trial was conducted in 6 tertiary hospitals. One hundred forty-two adult patients scheduled for open colorectal surgery, gastrectomy, or small bowel resection were enrolled. A hemodynamic protocol including fluid administration and vasoactive drugs based on arterial blood pressure, cardiac index, and stroke volume response was compared with standard practice. Patients were followed until hospital discharge (determined by a surgeon blinded to the study) or death. In contrast to previous studies, we designed a pragmatic trial (as opposed to explanatory trials) to mimic real practice and obtain maximal external validity for the study. RESULTS: Fluid administration was similar except for the number of colloid boluses (2.4 ± 1.8 [treated] vs 1.3 ± 1.4 [control]; P < 0.001) and packed red blood cell units (0.6 ± 1.3 [treated] vs 0.2 ± 0.6 [control]; P = 0.019). Dobutamine was used in 25% (intraoperatively) and 19.4% (postoperatively) of the treated patients versus 1.4% and 0% in the control group (P < 0.001). We have observed a reduction in reoperations in the treated group (5.6% vs 15.7%; P = 0.049). However, no significant differences were observed in overall complications (40% vs 41%; relative risk 0.99 [0.67-1.44]; P = 0.397), length of stay (11.5 [8-15] vs 10.5 [8-16]; P = 0.874), time to first flatus (62 hours [40-76] vs 72 hours [48-96]; P = 0.180), wound infection (7 vs 14; P = 0.085), anastomotic leaks (2 vs 5; P = 0.23), or mortality (4.2% vs 5.7%; P = 0.67). CONCLUSIONS: The results of our pragmatic study indicate that a perioperative hemodynamic protocol guided by a noninvasive cardiac output monitor was not associated with a decrease in the incidence of overall complications or length of stay in major abdominal surgery.