Evaluation of calibration curve-based approaches to predict clinical inducers and noninducers of CYP3A4 with plated human hepatocytes.

Cytochrome P450 (P450) induction is often considered a liability in drug development. Using calibration curve-based approaches, we assessed the induction parameters R3 (a term indicating the amount of P450 induction in the liver, expressed as a ratio between 0 and 1), relative induction score, Cmax/EC50, and area under the curve (AUC)/F2 (the concentration causing 2-fold increase from baseline of the dose-response curve), derived from concentration-response curves of CYP3A4 mRNA and enzyme activity data in vitro, as predictors of CYP3A4 induction potential in vivo. Plated cryopreserved human hepatocytes from three donors were treated with 20 test compounds, including several clinical inducers and noninducers of CYP3A4. After the 2-day treatment, CYP3A4 mRNA levels and testosterone 6ß-hydroxylase activity were determined by real-time reverse transcription polymerase chain reaction and liquid chromatography-tandem mass spectrometry analysis, respectively. Our results demonstrated a strong and predictive relationship between the extent of midazolam AUC change in humans and the various parameters calculated from both CYP3A4 mRNA and enzyme activity. The relationships exhibited with non-midazolam in vivo probes, in aggregate, were unsatisfactory. In general, the models yielded better fits when unbound rather than total plasma Cmax was used to calculate the induction parameters, as evidenced by higher R(2) and lower root mean square error (RMSE) and geometric mean fold error. With midazolam, the R3 cut-off value of 0.9, as suggested by US Food and Drug Administration guidance, effectively categorized strong inducers but was less effective in classifying midrange or weak inducers. This study supports the use of calibration curves generated from in vitro mRNA induction response curves to predict CYP3A4 induction potential in human. With the caveat that most compounds evaluated here were not strong inhibitors of enzyme activity, testosterone 6ß-hydroxylase activity was also demonstrated to be a strong predictor of CYP3A4 induction potential in this assay model.

Long-term results on the severity of acute appendicitis during COVID-19 pandemic.

Background: Acute appendicitis cases increased in severity following COVID-19-related restrictions in March, 2020. We investigated if similar changes occurred during Wave 2. Methods: Acute appendicitis patients during Wave 1 were grouped 8 weeks before (Group A) and after (Group B) stay-at-home restrictions were initiated on March 15, 2020. Cases in Wave 2 were grouped 8 weeks before (Group C) and after (Group D) November 6, 2020. Groups were compared to equivalent time frames in 2018/2019. Results: Group A versus B revealed 42.6% decrease (confidence interval: - 59.4 to - 25.7) in uncomplicated appendicitis and 21.1% increase (confidence interval: 4.8-37.3) in perforated appendicitis. Similar patterns were noted comparing Group C versus D without statistical significance. The changes seen in Wave 1 were significantly different than in 2018/2019. This trend continued in Wave 2. Conclusion: Similar to Wave 1, acute appendicitis cases increased in severity during wave 2 of COVID-19, but with less prominence.

Increasing incidence of complicated appendicitis during COVID-19 pandemic.

BACKGROUND: The novel coronavirus (COVID-19) strain has resulted in restrictions potentially impacting patients presenting with acute appendicitis and their disease burden. METHODS: All acute appendicitis admissions (281 patients) between 1/1/2018-4/30/2020 were reviewed. Two groups were created: 6 weeks before (Group A) and 6 weeks after (Group B) the date elective surgeries were postponed in Massachusetts for COVID-19. Acute appendicitis incidence and disease characteristics were compared between the groups. Similar time periods from 2018 to 2019 were also compared. RESULTS: Fifty-four appendicitis patients were categorized in Group A and thirty-seven in Group B. Those who underwent surgery were compared and revealed a 45.5% decrease (CI: 64.2,-26.7) in uncomplicated appendicitis, a 21.1% increase (CI:3.9,38.3) in perforated appendicitis and a 29% increase (CI:11.5,46.5) in gangrenous appendicitis. Significant differences in the incidence of uncomplicated and complicated appendicitis were also noted when comparing 2020 to previous years. CONCLUSIONS: The significant increase in complicated appendicitis and simultaneous significant decrease in uncomplicated appendicitis during the COVID-19 pandemic indicate that patients are not seeking appropriate, timely surgical care.

Continuous PTH in Male Mice Causes Bone Loss Because It Induces Serum Amyloid A.

Increased bone resorption is considered to explain why intermittent PTH is anabolic for bone but continuous PTH is catabolic. However, when cyclooxygenase-2 (COX2) is absent in mice, continuous PTH becomes anabolic without decreased resorption. In murine bone marrow stromal cells (BMSCs), serum amyloid A (SAA)3, induced in the hematopoietic lineage by the combination of COX2-produced prostaglandin and receptor activator of nuclear factor κB ligand (RANKL), suppresses PTH-stimulated osteoblast differentiation. To determine whether SAA3 inhibits the anabolic effects of PTH in vivo, wild-type (WT) and SAA3 knockout (KO) mice were infused with PTH. In WT mice, continuous PTH induced SAA3 and was catabolic for bone. In KO mice, PTH was anabolic, increasing trabecular bone, serum markers of bone formation, and osteogenic gene expression. In contrast, PTH increased all measurements associated with bone resorption, as well as COX2 gene expression, similarly in KO and WT mice. SAA1 and SAA2 in humans are likely to have analogous functions to SAA3 in mice. RANKL induced both SAA1 and SAA2 in human bone marrow macrophages in a COX2-dependent manner. PTH stimulated osteogenesis in human BMSCs only when COX2 or RANKL was inhibited. Addition of recombinant SAA1 or SAA2 blocked PTH-stimulated osteogenesis. In summary, SAA3 suppresses the bone formation responses but not the bone resorption responses to PTH in mice, and in the absence of SAA3, continuous PTH is anabolic. In vitro studies in human bone marrow suggest that SAA may be a target for enhancing the therapeutic effects of PTH in treating osteoporosis.

Compared to warfarin, direct oral anticoagulants are associated with lower mortality in patients with blunt traumatic intracranial hemorrhage: A TQIP study.

BACKGROUND: Falls represent the leading cause of traumatic brain injury in adults older than 65, with nearly one third experiencing a fall each year. Evidence suggests that up to 0.5% of anticoagulated patients suffer from intracranial hemorrhage (ICH) annually. Direct oral anticoagulants (DOACs) have become an increasingly popular alternative to warfarin for anticoagulation; however, there is a dearth of research regarding the safety of DOACs, in particular on the outcome of traumatic ICH while taking DOACs. METHODS: We queried our Trauma Quality Improvement Project registry for patients who presented with traumatic intracranial hemorrhage during anticoagulant use. Patients were grouped into those prescribed warfarin and patients prescribed DOAC medications. The groups were compared with respect to age, gender, Glasgow Coma Score (GCS) on arrival, Abbreviated Injury Scale (AIS) (head), Injury Severity Score (ISS), mortality, need for operative intervention, hospital and ICU lengths of stay, proportion of patients transfused (and their transfusion requirements), and rates of discharge to skilled nursing facility. Poisson regression was conducted to determine the relationship between mortality and treatment group while controlling for covariates (comorbidities, ISS). RESULTS: There were no differences between DOAC and warfarin groups in terms of age, gender, median ISS, median AIS head, or median admission GCS. Mechanisms of injury, median hospital and ICU lengths of stay, ICU free days, and transfusion requirements were also not significantly different.DOAC use was associated with significantly lower mortality (4.9% vs. 20.8%; p < 0.008) and a lower rate of operative intervention (8.2% vs. 26.7%; p = 0.023) when compared with warfarin. Excluding patients who died, the observed rate of discharge to skilled nursing facility was lower in the DOAC group (28.8% compared with 39.7%; p = 0.03). Multivariate Poisson regression analysis demonstrated that warfarin use was associated with an increased mortality when controlling for injury severity, and comorbidities. CONCLUSIONS: We report improved mortality and reduced rates of operative intervention in patients with traumatic ICH associated with DOACs compared with a similar group taking warfarin. We also noted an association with decreased rate of discharge to SNF in patients taking DOACs compared with warfarin. LEVEL OF EVIDENCE: Therapeutic study, level IV.