Fentanyl in the labor epidural impacts the results of intrapartum and postpartum maternal and neonatal toxicology tests.

BACKGROUND: A positive urine fentanyl toxicology test may have considerable consequences for peripartum individuals, yet the extent to which fentanyl administration in a labor epidural may lead to such a positive test is poorly characterized. OBJECTIVE: This study aimed to quantify the extent to which neuraxial fentanyl in labor neuraxial analgesia can lead to a positive peripartum maternal or neonatal urine toxicology test. STUDY DESIGN: We performed a prospective cohort study of pregnant participants planning a vaginal delivery with neuraxial analgesia. Participants with a history of substance use disorder, hypertension, or renal or liver disease were excluded. A urine sample was collected before initiation of neuraxial analgesia, each time the bladder was emptied during labor, and up to 4 times postpartum. Neonatal urine was collected once. Urine fentanyl testing was performed using 2 common toxicology testing methods, namely immunoassay and liquid chromatography with tandem mass spectrometric detection. RESULTS: A total of 33 maternal-infant dyads yielded a total of 178 urine specimens. All maternal specimens were negative for fentanyl using liquid chromatography with tandem mass spectrometric analysis and immunoassay before initiation of neuraxial analgesia. Intrapartum, 26 of 30 (76.7%) participants had positive liquid chromatography with tandem mass spectrometry results for fentanyl or its metabolites, and 12 of 30 (40%) participants had positive immunoassay results. Postpartum, 19 of 21 (90.5%) participants had positive liquid chromatograph with tandem mass spectrometric results, and 13 of 21 (61.9%) had a positive immunoassay result. Of the 13 neonatal specimens collected, 10 (76.9%) were positive on liquid chromatography with tandem mass spectrometry analysis, the last of which remained positive 29 hours and 50 minutes after delivery. CONCLUSION: Neuraxial fentanyl for labor analgesia may lead to positive maternal and neonatal toxicology tests at various times after epidural initiation and cessation and at different rates depending on the testing method used. Caution should be used in interpreting toxicology test results of individuals who received neuraxial analgesia to avoid false assumptions about nonprescribed use.

Cannabis positivity rates in 17 emergency departments across the United States with varying degrees of marijuana legalization.

BACKGROUND: Many states in the United States have progressed towards legalization of marijuana including decriminalization, medicinal and/or recreational use. We studied the impact of legalization on cannabis-related emergency department visits in states with varying degrees of legalization. METHODS: Seventeen healthcare institutions in fifteen states (California, Colorado, Connecticut, Florida, Iowa, Kentucky, Maryland, Massachusetts, Missouri, New Hampshire, Oregon, South Carolina, Tennessee, Texas, Washington) participated. Cannabinoid immunoassay results and cannabis-related International Classification of Diseases (ninth and tenth versions) codes were obtained for emergency department visits over a 3- to 8-year period during various stages of legalization: no state laws, decriminalized, medical approval before dispensaries, medical dispensaries available, recreational approval before dispensaries and recreational dispensaries available. Trends and monthly rates of cannabinoid immunoassay and cannabis-related International Classification of Diseases code positivity were determined during these legalization periods. RESULTS: For most states, there was a significant increase in both cannabinoid immunoassay and International Classification of Diseases code positivity as legalization progressed; however, positivity rates differed. The availability of dispensaries may impact positivity in states with medical and/or recreational approval. In most states with no laws, there was a significant but smaller increase in cannabinoid immunoassay positivity rates. CONCLUSIONS: States may experience an increase in cannabis-related emergency department visits with progression toward marijuana legalization. The differences between states, including those in which no impact was seen, are likely multifactorial and include cultural norms, attitudes of local law enforcement, differing patient populations, legalization in surrounding states, availability of dispensaries, various ordering protocols in the emergency department, and the prevalence of non-regulated cannabis products.

Transformation by Tribbles homolog 2 (Trib2) requires both the Trib2 kinase domain and COP1 binding.

Tribbles homolog 2 (Trib2) is a pseudokinase that induces acute myelogenous leukemia (AML) in mice and is highly expressed in a subset of human AML. Trib2 has 3 distinct regions, a proline-rich N-terminus, a serine/threonine kinase homology domain, and a C-terminal constitutive photomorphogenesis 1 (COP1)-binding domain. We performed a structure-function analysis of Trib2 using in vitro and in vivo assays. The N-terminus was not required for Trib2-induced AML. Deletion or mutation of the COP1-binding site abrogated the ability of Trib2 to degrade CCAAT/enhancer-binding protein-α (C/EBP-α), block granulocytic differentiation, and to induce AML in vivo. Furthermore, COP1 knockdown inhibited the ability of Trib2 to degrade C/EBP-α, showing that it is important for mediating Trib2 activity. We also show that the Trib2 kinase domain is essential for its function. Trib2 contains variant catalytic loop sequences, compared with conventional kinases, that we show are necessary for Trib2 activity. The kinase domain mutants bind, but cannot efficiently degrade, C/EBP-α. Together, our data demonstrate that Trib2 can bind both COP1 and C/EBP-α, leading to degradation of C/EBP-α. Identification of the functional regions of Trib2 that are essential to its oncogenic role provides the basis for developing inhibitors that will block Trib functions in cancer.

Impact of marijuana legalization on cannabis-related visits to the emergency department.

BACKGROUND: Cannabis is widely used in the United States despite federal laws. In US states that have progressed toward legalization, there have been various reported impacts on cannabis-related emergency department (ED) visits. However, studies on the impact of legalization in Massachusetts (MA) EDs are lacking. METHODS: Cannabinoid immunoassay (THC IA) results and cannabis-related ICD-10 codes were obtained for consecutive patient ED visits at two academic medical centers in Boston, MA over the following legalization periods (January 2012-December 2019): decriminalized (DEC), before medical dispensaries (MED BD), medical dispensaries available (MED DISP), before recreational dispensaries (REC BD) and recreational dispensaries available (REC DISP). Trends and monthly positivity rates for THC IA and ICD-10 codes were determined for these legalization periods. RESULTS: There was an increase in both THC IA (p < .0001) and cannabis-related ICD-10 codes (p < .0001) in the ED as legalization progressed at both institutions. Positivity rates significantly increased by 7% for THC IA and 0.4% for ICD-10 codes. Increases in THC IA positivity were seen in females, patients aged 30-39, older adults (>59 years), and those in the highest income tertile. There was an increasing trend in amphetamine positivity and decreasing trend in opiate positivity in patients with positive THC IA. Unlike THC IA, significant trends per patient demographics were not seen with ICD-10 codes. CONCLUSIONS: Legalization of marijuana in MA has led to an increase in cannabis use as indicated by both increasing rates of positive THC IA results, in older adults, as well as increasing cannabis-related ICD-10 codes. Data suggest a steady increase in THC use associated with legalization that was not associated with an increase in opiate, fentanyl, or cocaine use. We recommend using ED THC IA positivity, an objective laboratory measure, to monitor THC use and the impact of state-specific progression in cannabis legalization.

Validation and Implementation of an Ordering Alert to Improve the Efficiency of Monoclonal Gammopathy Evaluation.

OBJECTIVES: To evaluate the use of a provider ordering alert to improve laboratory efficiency and reduce costs. METHODS: We conducted a retrospective study to assess the use of an institutional reflex panel for monoclonal gammopathy evaluation. We then created a clinical decision support (CDS) alert to educate and encourage providers to change their less-efficient orders to the reflex panel. RESULTS: Our retrospective analysis demonstrated that an institutional reflex panel could be safely substituted for a less-efficient and higher-cost panel. The implemented CDS alert resulted in 79% of providers changing their high-cost order panel to an order panel based on the reflex algorithm. CONCLUSIONS: The validated decision support alert demonstrated high levels of provider acceptance and directly led to operational and cost savings within the laboratory. Furthermore, these studies highlight the value of laboratory involvement with CDS efforts to provide agile and targeted provider ordering assistance.

Crystal structure of the catalytic core of human DNA polymerase kappa.

We present the crystal structure of the catalytic core of human DNA polymerase kappa (hPolkappa), the first structure of a human Y-family polymerase. hPolkappa is implicated in the proficient extension of mispaired primer termini on undamaged DNAs, and in the extension step of lesion bypass. The structure reveals a stubby "fingers" subdomain, which despite its small size appears to be tightly restrained with respect to a putative templating base. The structure also reveals a novel "thumb" subdomain that provides a basis for the importance of the N-terminal extension unique to hPolkappa. And, most surprisingly, the structure reveals the polymerase-associated domain (PAD) juxtaposed on the dorsal side of the "palm" subdomain, as opposed to the fingers subdomain. Together, these properties suggest that the hPolkappa active site is constrained at the site of the templating base and incoming nucleotide, but the polymerase is less constrained following translocation of the lesion.

FAD-linked mutations in presenilin 1 alter the length of Abeta peptides derived from betaAPP transmembrane domain mutants.

gamma-Secretase is an enzymatic activity responsible for the final cleavage of the amyloid precursor protein leading to the production of the amyloid beta-peptide (Abeta). gamma-Secretase is likely an aspartyl protease, since its activity can be inhibited by both pepstatin and active-site directed aspartyl protease inhibitors. Recent work has indicated that presenilins 1 and 2 may actually be the gamma-secretase enzymes. Presenilin (PS) mutations, which lead to an increase in the production of a longer form of Abeta, are also the most common cause of familial Alzheimer's disease (FAD). Therefore, in an attempt to better characterize the substrate preferences of gamma-secretase, we performed experiments to determine how FAD-linked mutations in PS1 would affect the generation of Abeta peptides from full length precursor substrates that we have previously demonstrated to be proteolytically cleaved at alternative sites and/or by enzymatic activities that are pharmacologically distinct. Presenilin mutations increased the production of Abeta peptides from sites distal to the primary cleavage site ('longer' peptides) and in several cases also decreased production of 'shorter' peptides. These results support a model in which the FAD-linked mutants subtly alter the conformation of the gamma-secretase complex to favor the production of long Abeta.

Challenges with serum protein electrophoresis in assessing progression and clinical response in patients with Waldenström macroglobulinemia.

Accurate determination of the immunoglobulin (Ig) M paraprotein concentration is crucial to evaluating response in patients with Waldenström macroglobulinemia (WM). In most clinical laboratories, M-spike quantitation is performed by serum protein electrophoresis, which is the same method used to quantitate IgG and IgA paraproteins in patients with multiple myeloma (MM). However, the migration pattern and propensity of IgM paraproteins to form higher-order complexes in serum makes laboratory evaluation of samples from patients with WM especially challenging. We review examples of patients whose IgM paraprotein is particularly ill-suited to M-spike quantitation by serum protein electrophoresis: a case of "sticky M," a case of IgM multimers that cannot be resolved, and a case of an IgM in the ß region. In these and similar cases, a method other than M-spike quantitation, such as IgM heavy chain nephelometry, should be considered in laboratory evaluation of paraprotein concentration.

Comparative response assessment by serum immunoglobulin M M-protein and total serum immunoglobulin M after treatment of patients with Waldenström macroglobulinemia.

Serum immunoglobulin (Ig) M monoclonal protein determined by electrophoresis (sIgM-MP) and total serum IgM (sIgM) by nephelometry are widely used for response assessment in Waldenström macroglobulinemia (WM), although have not been compared for predicting changes in underlying disease burden. We, therefore, compared these serum markers with changes in bone marrow (BM) and extramedullary disease for 73 patients who were rituximab naive and treated with a rituximab-containing regimen. By linear regression analysis, reductions in sIgM-MP and sIgM showed moderate correlation with BM disease involvement (r = 0.4051 and r = 0.4490, respectively), and did not differ from one another as estimators of BM disease response (P = .3745). Neither sIgM-MP nor sIgM showed a strong correlation with BM disease response in patients with low (<1000 mg/dL) or high (>5000 mg/dL) IgM levels and extramedullary disease response. sIgM-MP and sIgM, therefore, are comparable response markers in WM. Development of newer, more accurate surrogate response markers are needed to better delineate treatment outcomes in patients with WM and with low or high IgM levels, and extramedullary disease.

Serial serum free light chain measurements do not detect changes in disease status earlier than electrophoretic M-spike measurements in patients with intact immunoglobulin myeloma.

BACKGROUND: Serum free light chains (SFLC) are used to manage patients with light chain or hyposecretory myeloma, and may also be useful in patients with intact immunoglobulin myeloma (IIMM), because their shorter half-life may enable earlier indication of relapse/response than electrophoretic M-spikes or heavy chain (IgGA) immunonephelometry. METHODS: One thousand five SFLC, M-spike, and IgGA concentrations were compared at multiple time points during the treatment of 17 myeloma patients, followed over 7.7-63.4 months. Changes in these analytes were evaluated in context with changes in disease status and treatment. RESULTS: 14/17 (82%) patients showed synchrony between M-spike, IgGA, and SFLC measurements. SFLC changes preceded M-spike/IgGA in 1 patient, and lagged behind M-spike/IgGA in 2 patients. In eight patients, SFLC showed short-term fluctuations unaccompanied by changes in M-spike, IgGA, or clinical treatment. CONCLUSIONS: In 16/17 intact immunoglobulin myeloma patients tested frequently over ~3 years, SFLC performed no better than M-spike and did not add value to conventional serum electrophoresis.

Human DNA polymerase kappa encircles DNA: implications for mismatch extension and lesion bypass.

Human DNA polymerase kappa (Pol kappa) is a proficient extender of mispaired primer termini on undamaged DNAs and is implicated in the extension step of lesion bypass. We present here the structure of Pol kappa catalytic core in ternary complex with DNA and an incoming nucleotide. The structure reveals encirclement of the DNA by a unique "N-clasp" at the N terminus of Pol kappa, which augments the conventional right-handed grip on the DNA by the palm, fingers, and thumb domains and the PAD and provides additional thermodynamic stability. The structure also reveals an active-site cleft that is constrained by the close apposition of the N-clasp and the fingers domain, and therefore can accommodate only a single Watson-Crick base pair. Together, DNA encirclement and other structural features help explain Pol kappa's ability to extend mismatches and to promote replication through various minor groove DNA lesions, by extending from the nucleotide incorporated opposite the lesion by another polymerase.