The role of methadone in cardiac surgery for management of postoperative pain

Background

This retrospective study evaluated the efficacy and safety of intraoperative methadone compared with short-acting opioids.

Methods

Patients undergoing cardiac surgery with cardiopulmonary bypass (n=11 967) from 2018 to 2023 from a single health system were categorised into groups based on intraoperative opioid administration: no methadone (Group O), methadone plus other opioids (Group M+O), and methadone only (Group M).

Results

Patients in Groups M and M+O had lower mean pain scores until postoperative day (POD) 7 compared with Group O after adjusting for covariates (P<0.01). Both Groups M and M+O had lower total opioid administered compared with Group O for all days POD0-POD6 (all P<0.001). The median number of hours until initial postoperative opioid after surgery was 2.55 (inter-quartile range [IQR]=1.07-5.12), 6.82 (IQR=3.52-12.98), and 7.0 (IQR=3.82-12.95) for Group O, Group M+O, and Group M, respectively. The incidence of postoperative complications did not differ between groups.

Conclusions

Intraoperative administration of methadone was associated with better pain control without significant side-effects after cardiac surgery.

Surgical Site Infections in Open and Laparoscopic Operations in Rooms With Open-floor Drainage Systems

INTRODUCTION

Surgical site infections are common postoperative complications. Some operating rooms have open-floor drainage systems for fluid disposal during endourologic cases, although nonendoscopy cases are not always allowed in these rooms. We hypothesized that operating rooms with open-floor drainage systems would not materially affect risk of surgical site infections for patients undergoing open and laparoscopic procedures.

METHODS

Patients who had surgical site infections from 2016 through 2020 were identified from data of the National Surgical Quality Improvement Program. Patients without surgical incisions, with open wounds, and with surgical site infections at surgery were excluded. The primary outcome was surgical site infection occurrence within 30 days of surgery. Multilevel multivariable logistic regression was used to estimate the observed-to-expected surgical site infection ratio for each operating room (2 with and 23 without open-floor drainage systems).

RESULTS

We identified 8,419 surgical cases, of which 802 (9.5%) were performed in operating rooms with open-floor drainage systems; 166 patients (2.0%) had surgical site infections. Of the surgical site infections, 7 (4.2%) occurred in operating rooms with open-floor drainage systems. Surgical specialty, American Society of Anesthesiologists physical status, higher case acuity, dyspnea, immunosuppression, longer surgical duration, and wound classification were associated with surgical site infections (P < .05 for all). The observed-to-expected ratios of surgical site infections occurring in the 2 operating rooms with open-floor drainage systems were 0.85 and 1.15. The odds ratio of surgical site infections for urologic cases performed in room with vs without open-floor drainage systems was 1.30 (P = .65).

CONCLUSIONS

Urology operating room designs often include open-floor drainage systems for water-based cases. These drainage systems were not associated with an increased risk of surgical site infections.

Identification of abscission checkpoint bodies as structures that regulate ESCRT factors to control abscission timing

The abscission checkpoint regulates the ESCRT membrane fission machinery and thereby delays cytokinetic abscission to protect genomic integrity in response to residual mitotic errors. The checkpoint is maintained by Aurora B kinase, which phosphorylates multiple targets, including CHMP4C, a regulatory ESCRT-III subunit necessary for this checkpoint. We now report the discovery that cytoplasmic abscission checkpoint bodies (ACBs) containing phospho-Aurora B and tri-phospho-CHMP4C develop during an active checkpoint. ACBs are derived from mitotic interchromatin granules, transient mitotic structures whose components are housed in splicing-related nuclear speckles during interphase. ACB formation requires CHMP4C, and the ESCRT factor ALIX also contributes. ACB formation is conserved across cell types and under multiple circumstances that activate the checkpoint. Finally, ACBs retain a population of ALIX, and their presence correlates with delayed abscission and delayed recruitment of ALIX to the midbody where it would normally promote abscission. Thus, a cytoplasmic mechanism helps regulate midbody machinery to delay abscission.

When a cell divides, it must first carefully duplicate its genetic information and package these copies into compartments housed in the two new cells. Errors in this process lead to genetic mistakes that trigger cancer or other harmful biological events.

Quality control checks exist to catch errors before it is too late. This includes a final ‘abscission’ checkpoint right before the end of division, when the two new cells are still connected by a thin membrane bridge. If cells fail to pass this ‘no cut’ checkpoint, they delay severing their connection until the mistake is fixed.

A group of proteins called ESCRTs is responsible for splitting the two cells apart if nothing is amiss. The abscission checkpoint blocks this process by altering certain proteins in the ESCRT complex, but exactly how this works is not yet clear.

To find out more, Strohacker et al. imaged ESCRT factors in a new experimental system in which the abscission checkpoint is active in many cells. This showed that, in this context, certain ESCRT components were rerouted from the thread of membrane between the daughter cells to previously unknown structures, which Strohacker et al. named abscission checkpoint bodies. These entities also sequestered other factors that participate in the abscission checkpoint and factors that contribute to gene expression.

These results are key to better understand how cells regulate their division; in particular, they provide a new framework to explore when this process goes wrong and contributes to cancer.

Germ cell defects and hematopoietic hypersensitivity to gamma-interferon in mice with a targeted disruption of the Fanconi anemia C gene

Fanconi anemia (FA) is an autosomal recessive chromosome instability syndrome characterized by progressive bone marrow (BM) failure, skeletal defects, and increased susceptibility to malignancy. FA cells are hypersensitive to DNA cross-linking agents, oxygen and have cell cycle abnormalities. To develop an animal model of the disease we generated mice homozygous for a targeted deletion of exon 9 of the murine FA complementation group C gene (fac). Mutant mice had normal neonatal viability and gross morphology, but their cells had the expected chromosome breakage and DNA cross-linker sensitivity. Surprisingly, male and female mutant mice had reduced numbers of germ cells and females had markedly impaired fertility. No anemia was detectable in the peripheral blood during the first year of life, but the colony forming capacity of marrow progenitor cells was abnormal in vitro in mutant mice. Progenitor cells from fac knock-out mice were hypersensitive to interferon gamma. This previously unrecognized phenotype may form the basis for BM failure in human FA.

Cloning and characterization of a human cDNA (INPPL1) sharing homology with inositol polyphosphate phosphatases

We have cloned a novel human cDNA, INPPL1 (GenBank Accession No. L36818), which maps to 11q23. The corresponding mRNA is 4657 nt in length and is widely expressed in both fetal and adult tissues. An open reading frame of 3441 nt encodes a putative polypeptide that shares several domains with inositol triphosphate phosphatases. Several polymorphisms have been mapped to the 3'-untranslated region, yet the putative coding region showed no polymorphisms in nine independent cDNA samples.

The Ashkenazi Jewish Fanconi anemia mutation: incidence among patients and carrier frequency in the at-risk population

Fanconi anemia (FA) is an autosomal recessive disease for which at least four complementation groups exist. Recently the gene that corrects the defect in Fanconi anemia complementation group C cells (FACC) has been cloned. We have previously identified a common mutation in the FACC gene, which accounts for a majority of FA cases in Ashkenazi Jewish individuals. We here describe the use of allele-specific oligonucleotide (ASO) hybridization to determine the frequency of this mutation among additional Jewish FA patients and to determine the carrier frequency in the Jewish population. The common IVS4 + 4A-->T allele was found on 19/23 (83%) Jewish FA chromosomes, indicating that it is indeed responsible for most cases of FA among Ashkenazi Jews. The carrier frequency was 2/314 for Jewish individuals and the mutant allele was not detected in 130 non-Jewish controls.

A common mutation in the FACC gene causes Fanconi anaemia in Ashkenazi Jews

Fanconi anaemia is an autosomal recessive disease for which four known complementation groups exist. Recently, the gene defective in complementation group C (FACC) has been cloned. In order to determine the fraction of Fanconi anaemia caused by FACC mutations, we used reverse transcription PCR and chemical mismatch cleavage (CMC) to examine the FACC cDNA in 17 FA cell lines. 4/17 patients (23.5%) had mutations in this gene. Two Ashkenazi-Jewish individuals were homozygous for an identical splice mutation. Three additional Jewish patients bearing this allele were found upon screening 21 other families. We conclude that a common mutation in FACC accounts for the majority of Fanconi anaemia in Ashkenazi-Jewish families.

Large scale screen for transposon insertions into cloned genes

We describe a method of screening for transposon insertions in or near Drosophila loci that correspond to cloned DNA sequences. We mobilize a modified P element transposon that carries a bacterial plasmid origin of replication and a drug-resistance marker. The genomic sequences flanking each transposon insertion site can then be rescued as a plasmid in Escherichia coli. Libraries of such plasmids, representing pools of transposon-mutagenized individuals, are used as hybridization probes against cloned sequences to determine whether a transposon has inserted next to a particular site in the genome. The number of loci that can be screened simultaneously by this procedure is quite large. We have screened an array of cDNA clones representing almost 700 distinct loci against libraries representing 760 mutagenized flies, and we obtained hybridization signals to 7 different cDNAs. Three of these events have been analyzed in detail and represent genuine insertions near genomic sequences that correspond to the cDNAs.

Resolution of the isoenzymes of soybean lipoxygenase using isoelectric focusing and chromatofocusing

Isoelectric focusing in thin-layer polyacrylamide gels has been applied to the analysis of the enzymes involved in the formation and destruction of peroxides in soybeans [Glycine max (L.)], lipoxygenases and peroxidases, respectively. As a result of differences in pH optima for catalytic activity, lipoxygenases were selectively detected by adjusting the pH employed for activity-specific staining. Type-1 lipoxygenase was revealed not only by staining based on the conversion of linoleic acid to hydroperoxide but also by two stains based on the reduction of the hydroperoxide. These methods were found to be suitable for the analysis and characterization of isoenzyme patterns in different soybean cultivars. A substantial difference in the distribution of lipoxygenases maximally active near pH 7 was observed for cultivars Provar and Vickery. A similar degree of separation of the isoenzymes was achieved on a larger scale using chromato-focusing in the pH range 7.4-5.0.