Decreasing use of pancreatic necrosectomy and NSQIP predictors of complications and mortality

BACKGROUND

Surgical pancreatic necrosectomy (SPN) is an option for the management of infected pancreatic necrosis. The literature indicates that an escalating, combined endoscopic, interventional radiology and minimally invasive surgery "step-up" approach, such as video-assisted retroperitoneal debridement, may reduce the number of required SPNs and ICU complications, such as multiple organ failure. We hypothesized that complications for surgically treated severe necrotizing pancreatitis patients decreased during the period of adoption of the "step-up" approach.

METHODS

The American college of surgeons national surgery quality improvement program database (ACS-NSQIP) was used to find SPN cases from 2007 to 2019 in ACS-NSQIP submitting hospitals. Mortality and Clavien-Dindo class 4 (CD4) ICU complications were collected. Predictors of outcomes were identified by univariate and multivariate analyses.

RESULTS

There were 2457 SPN cases. SPN cases decreased from 0.09% in 2007 to 0.01% in 2019 of NSQIP operative cases (p < 0.001). Overall mortality was 8.5% and did not decrease with time. CD4 complications decreased from 40 to 27% (p < 0.001). There was a 65% reduction in SPN cases requiring a return to the operating room. Multivariate predictors of complications were emergency general surgery (EGS, p < 0.001), serum albumin (p < 0.0001) and modified frailty index (mFI) (p < 0.0001). Multivariate predictors of mortality were EGS (p < 0.0001), serum albumin (p < 0.0001), and mFI (p < 0.04). The mFI decreased after 2010 (p < 0.001).

CONCLUSION

SPNs decreased after 2010, with decreasing CD4 complications, decreasing reoperation rates and stable mortality rates, likely indicating broad adoption of a "step-up" approach. Larger, prospective studies to compare indications and outcomes for "step up" versus open SPN are warranted.

Amino acid residue L112 in the ACTH receptor plays a key role in ACTH or α-MSH selectivity

The adrenocorticotropic hormone (ACTH) receptor, known as the melanocortin-2 receptor (MC2R), plays a key role in regulating adrenocortical function. MC2R is a subtype of the melanocortin receptor family and ACTH is only agonist for MC2R. Our previous result indicates that ACTH1-17 is the minimal peptide required for MC2R activation but DPhe7-ACTH1-17 has no activity at MC2R. In this study, we examined the molecular basis of the MC2R responsible for ligand selectivity using ACTH analogues and MC2R mutagenesis. Our results indicate that substitution of the 3TM of the MC2R with the corresponding region of the MC3R switches DPhe-ACTH1-17 from no activity to agonist. Further experiment indicates that substitution of the amino acid residue leucine to isoleucine in 112 (L112I) of the 3TM of the MC2R changes both DPhe-ACTH1-17 and ACTH1-15 from no activity to agonists. Surprisingly, mutation L112I switches α-MSH from no activity to agonist, suggesting that this residue plays a key role at MC2R for ligand ACTH or α-MSH selectivity.

The use of perioperative ketorolac in the surgical treatment of pediatric spontaneous pneumothorax

BACKGROUND

We sought to determine the effect of ketorolac on pediatric primary spontaneous pneumothorax recurrence after operation.

METHODS

The Pediatric Health Information System database was queried for patients ages 10-16years discharged in the years 2004-2014 with pneumothorax or pleural bleb and a related operative procedure. Deaths and secondary pneumothorax were excluded. Variables included demographics, chronic disease, intensive care unit admission, mechanical ventilation, and lung resection or plication. The primary variable was any ketorolac administration between post-operative day 0 and 5. Outcomes included reintervention within 1year, readmission, post-operative length of stay (LOS), and cost. Bivariate and multivariate logistic regression analyses were performed.

RESULTS

Of 1678 records that met inclusion criteria, 395 (23%) were subsequently excluded, leaving 1283 patients for analysis. Most patients had a lung resection recorded (78%) and the majority were administered ketorolac (57%); few required reintervention (20%) or readmission (18%). Mean postoperative LOS was 5.2±3.8days and mean cost was $17,649±$10,599. On bivariate analysis, ketorolac administration did not correlate with any measured outcome. On both bivariate and multivariate analysis, no variable was predictive of reintervention, and only lung resection correlated with readmission (adjusted odds ratio 0.63 [95% C.I. 0.45-0.90]).

CONCLUSION

Post-operative ketorolac administration was not associated with an increased likelihood of reintervention or readmission within 1year of operative treatment of primary spontaneous pneumothorax, suggesting that it may be used safely as part of a post-operative pain control regimen. Effects on postoperative length of stay and cost, however, were not demonstrated.

LEVEL OF EVIDENCE AND TYPE OF STUDY

Level III treatment study.

Key amino acid residue in Melanocortin-1 receptor (melanocyte α-MSH receptor) for ligand selectivity

The melanocortin-1 receptor (MC1R) is a subtype of the melanocortin receptor family and NDP-α-MSH is a non-selective agonist for MC1R. The core sequence of NDP-α-MSH, His-Phe-Arg-Trp, is important for ligand binding and biological activities at the melanocortin receptor subtypes (MCRs). A recent study indicates that Trp⁹ in NDP-α-MSH plays an important role in ligand selectivity. Deletion of Trp⁹ in NDP-α-MSH (des-Trp⁹-NDP-α-MSH) resulted in loss of agonist activity at MC4R, although remains agonist activity at MC1R. The molecular basis for this receptor ligand selectivity is unknown. In this study we examined what region of the MC1R is responsible for des-NDP-α-MSH selectivity. Our results indicate that (1) substitution of TM3 of MC4R with the corresponding region of MC1R switches des-Trp⁹-NDP-α-MSH from no activity to agonist; (2) des-Trp⁹-NDP-α-MSH exhibits agonistic activity at the L133M mutation of the MC4R; and (3) substitution of non-conserved amino acid residue M128 in TM3 of MC1R significantly reduced des-Trp⁹-NDP-α-MSH agonist activity. Our results demonstrate that amino acid residue 128 in TM3 of MC1R, or amino acid residue L133 in TM3 of the MC4R, play crucial roles in ligand des-Trp⁹-NDP-α-MSH selectivity at MC1R or MC4R.

Molecular impact of omega 3 fatty acids on lipopolysaccharide-mediated liver damage

BACKGROUND

Growing evidence suggests that omega 3 fatty acid containing lipid emulsions have a beneficial effect on parenteral nutrition associated liver disease (PNALD). However, the cellular and molecular mechanisms responsible for this effect are unclear. In this study, we investigated whether Omegaven™ fish oil emulsion could inhibit lipopolysaccharidase (LPS) mediated liver damage.

METHODS

We examined the effects of Omegaven™ and LPS alone and synergistically on hepatic paraoxonase 1 (PON1), a potent antioxidant protein, ERK1/2 activity, and TLR4 regulation.

RESULTS

LPS did not alter PON1 release from HepG2 cells but did significantly decrease PON1 protein synthesis (44%, P<0.05). Omegaven™ alone had no direct effect on PON1 release. However, it did significantly reverse LPS-mediated decrease in PON1 protein levels (control: 100%; LPS alone: 56+/4%; LPS+Omegaven™: 87+/6%, P<0.05). Furthermore, molecular analysis indicated that Omegaven™ blocked LPS-mediated increase in ERK1/2 activity (35% increase), an important LPS signal transduction pathway. TLR4, the receptor for LPS, was down-regulated in the presence of Omegaven™.

CONCLUSION

Omegaven™ may be beneficial in patients with PNAC because of its ability to reverse LPS-mediated inhibition of antioxidant promoting PON1 expression, and this activity may be in part mediated by the ERK1/2 pathway.

Dithiocarbamate-based coordination compounds as potent proteasome inhibitors in human cancer cells

Dithiocarbamates are a class of metal-chelating compounds with various applications in medicine. They have been used for the treatment of bacterial and fungal infections, possible treatment of AIDS, and most recently cancer. Their anti-tumor effects can in part be attributed to their ability to complex tumor cellular copper, leading to binding to and inhibition of the proteasome and in turn initiating tumor cell-specific apoptosis. Current chemotherapeutic agents are highly toxic and therefore their efficacy in the eradication of tumors is greatly limited. As a result many scientists have joined the quest for novel targeted therapies in hopes of reducing toxicity while maximizing potency and proteasome inhibition has become an attractive therapy in this regard. Here we discuss the origins, mechanism, and evolution of dithiocarbamates as potent proteasome inhibitors and therefore anti-cancer agents.