Perioperative Multimodal Pain Management Approach in Older Adults With Polytrauma.

INTRODUCTION: The use of intravenous (IV) acetaminophen (APAP) postoperatively in older adults may be a beneficial strategy. We implemented a multimodal pain management approach in our hospital in 2015, with IV APAP being the first-line therapy. MATERIALS AND METHODS: This was a retrospective, single-center, observational cohort study of polytrauma, orthopedic surgical patients aged ≥50 y. Patients admitted in 2017, postimplementation of pain protocol, were categorized as the exposed patients. Patients in the year 2014 served as the historical cohort. The two primary outcomes evaluated were postoperative opioid consumption in morphine milligram equivalents (MMEs) and patient pain scores. RESULTS: In total, 121 eligible patients were identified for this study; 22 historical control patients and 99 exposed patients. We observed a significant reduction in postoperative opioid use up to 48 h postoperatively (20.9 ± 27 versus 4.3 ± 12.4 MME [P < 0.05] at 24 h and 19.8 ± 31.2 versus 2.1 ± 11.3 MME [P < 0.05] at 48 h, respectively). The mean opioid consumption remained significantly lower in patient subgroup of age ≥74 y with no difference in the mean pain scores (1.5 ± 1.5 versus 1.9 ± 1.6 [P = 0.48] at 24 h and 1.5 ± 1.8 versus 2.0 ± 1.5 [P = 0.21] at 48 h postoperatively in the historical versus exposed cohort, respectively). Exposed patients had a shorter hospital length of stay than control patients (5.0 [3, 7] versus 6.5 [5, 9.5] d; P = 0.01). CONCLUSIONS: The use of multimodal pain management with IV APAP as first-line therapy was associated with reduced opioid use in the perioperative setting for older adults with polytrauma.

Anticancer peptide PNC-27 adopts an HDM-2-binding conformation and kills cancer cells by binding to HDM-2 in their membranes.

The anticancer peptide PNC-27, which contains an HDM-2-binding domain corresponding to residues 12-26 of p53 and a transmembrane-penetrating domain, has been found to kill cancer cells (but not normal cells) by inducing membranolysis. We find that our previously determined 3D structure of the p53 residues of PNC-27 is directly superimposable on the structure for the same residues bound to HDM-2, suggesting that the peptide may target HDM-2 in the membranes of cancer cells. We now find significant levels of HDM-2 in the membranes of a variety of cancer cells but not in the membranes of several untransformed cell lines. In colocalization experiments, we find that PNC-27 binds to cell membrane-bound HDM-2. We further transfected a plasmid expressing full-length HDM-2 with a membrane-localization signal into untransformed MCF-10-2A cells not susceptible to PNC-27 and found that these cells expressing full-length HDM-2 on their cell surface became susceptible to PNC-27. We conclude that PNC-27 targets HDM-2 in the membranes of cancer cells, allowing it to induce membranolysis of these cells selectively.

The penetratin sequence in the anticancer PNC-28 peptide causes tumor cell necrosis rather than apoptosis of human pancreatic cancer cells.

BACKGROUND: PNC-27 and PNC-28 are p53-derived peptides from the human double minute (hdm-2) binding domain attached to penetratin. These peptides induce tumor cell necrosis of cancer cells, but not normal cells. The anticancer activity and mechanism of PNC-28 (p53 aa17-26-penetratin) was specifically studied against human pancreatic cancer. METHODS: MiaPaCa-2 cells were treated with PNC-28. Necrosis was determined by measuring lactate dehydrogenase (LDH) and apoptosis as assayed for measuring elevation of proapoptotic proteins. PNC-29, an unrelated peptide, and hdm-2-binding domain p53 aa12-26 without penetratin (PNC-26) were used as controls. Since there is evidence that penetratin is required for tumor cell necrosis, we tested "naked" p53 peptide without penetratin by transfecting a plasmid that encodes p53 aa17-26 segment of PNC-28 into MiaPaCa-2 and an untransformed rat pancreatic acinar cell line, BMRPA1. Time-lapse electron microscopy was employed to further elucidate anticancer mechanism. RESULTS: Treatment with PNC-28 does not result in the elevation of proapoptotic proteins found in p53-induced apoptosis, but elicits rapid release of LDH, indicative of tumor cell necrosis. Accordingly, we observed membrane pore formation and dose-dependent killing. In direct contrast, transfected MiaPaCa-2 cells underwent apoptosis, and not necrosis, as evidenced by expression of high levels of caspases-3 and 7 and annexin V with background levels of LDH. CONCLUSION: These results suggest that PNC-28 may be effective in treating human pancreatic cancer. The penetratin sequence appears to be responsible for the fundamental change in the mechanism of action, inducing rapid necrosis initiated by membrane pore formation. Cancer cell death by apoptosis was observed in the absence of penetratin.

Site-specific phosphorylation of raf in cells containing oncogenic ras-p21 is likely mediated by jun-N-terminal kinase.

In a study of interactions between the raf-MEK-MAPK (ERK) and JNK-jun pathways, we found previously that JNK can induce phosphorylation of raf but not vice versa. In this study, we investigate the nature of the JNK-induced phosphorylation of raf. In in vitro experiments in which immunobead-bound raf is phosphorylated by activated JNK, we find strong phosphorylation signals at raf-Ser259 and Ser338. The Ser259 phosphorylation is surprising since it is associated with inhibition of migration of raf to the cell membrane where it can interact with ras-p21. We also find that in oocytes induced to mature with oncogenic ras-p21, which induces high levels of phosphorylated JNK and MAPK, the same pattern of phosphorylation of raf occurs. In contrast, in oocytes induced to mature with insulin, which requires activation of wild-type ras-p21, phosphorylation of raf-Ser338 but not raf-Ser259 occurs. In oncogenic ras-transformed human pancreatic cancer MIA-PaCa-2 cells, phosphorylation of both raf serines occurs. Treatment of these cells with the ras peptide, PNC-2 attached to a penetrating sequence that blocks JNK and MAPK phosphorylation and induces tumor cell necrosis, results in a marked decrease in phosphorylation of raf-Ser259, but not that of raf-Ser338. These results suggest that oncogenic ras-p21 induces phosphorylation of both raf-Ser259 and Ser338 and that raf-Ser 259 phosphorylation may be effected by activated JNK.

The anti-cancer peptide, PNC-27, induces tumor cell lysis as the intact peptide.

PURPOSE: PNC-27, a peptide that contains an HDM-2-binding domain from p53 attached to a membrane-penetrating peptide on its carboxyl terminal end, is cytotoxic to cancer, but not normal, cells. It forms transmembrane pores in the cancer cell membrane. Our purpose is to determine if the whole peptide or critical fragments induce pore formation in cancer cells. METHODS: We have prepared PNC-27 with a green fluorescent label on its amino terminus and a red fluorescent label on its carboxyl terminus and treated MCF-7 breast cancer cells and untransformed MCF-10-2A breast epithelial cells with this double-labeled peptide to determine if combined yellow fluorescence occurs in the membrane of the cancer cells during cancer cell killing. RESULTS: At 30 min, there is significant combined punctate yellow fluorescence, indicative of intact peptide, in the cell membrane of cancer cells that increases during cancer cell lysis. MCF-10-2A cells show initial (30 min) uniform combined yellow membrane fluorescence that subsequently disappears. Unlike the cancer cells, these untransformed cells remain viable. CONCLUSIONS: PNC-27 induces cancer cell membrane lysis by acting as the whole peptide, not fragments. The punctate yellow fluorescence is due to interaction of PNC-27 with intramembrane targets of MCF-7 cells that do not exist in the membrane of the untransformed cell line. This interaction increases the lifetime of PNC-27. Absence of these targets in the membranes of the untransformed MCF-10-2A cells results in initial uniform fluorescence of the double-labeled peptide in their membranes after which the peptide is degraded.

The role of the assistant in laparoscopic surgery: important considerations for the apprentice-in-training.

Laparoscopic surgery is a dynamic and integral component of surgical training. In many surgical programs, the surgeon-in-training gradually incorporates the knowledge and skill-sets through a variable spectrum of assistant/ apprentice instruction with different surgical mentors. As a result, this lack of formal and/or standardized instruction may be inconsistent with a structured educational process. In the year 2008, with widespread applications for minimally invasive techniques and technology, contributions from skilled assistants are now increasingly more important for effective and safe operative conduct. Incorporating these challenges into a balanced educational process remains no easy matter. The authors believe the assistant's role is vital to all aspects of laparoscopic surgery, no matter how routine or complex. Laparoscopic assistants should participate and contribute directly in the (a) preoperative evaluation and preparation, (b) patient positioning, (c) operative suite arrangement, (d) trocar placement, plus important (e) intraoperative maneuvers contingent upon acquired mastery of laparoscopic skills. Understanding these principles plus effective administration of various duties allows for the apprentice in training to progress to more complex procedures and eventual primary surgeon responsibility. In this report, the role of the laparoscopic assistant/apprentice is reviewed, with particular attention focused on requisite fundamentals for evolving laparoscopic surgeons. To date, there are few publications within the world literature that directly address these observations. Important considerations delineating the expectations and goals for the assistant/apprentice, as well as the mentor, during laparoscopic training are provided.