Blood Tumor Mutational Burden Alone Is Not a Good Predictive Biomarker for Response to Immune Checkpoint Inhibitors in Patients With Gastrointestinal Tumors.

There has been a controversy about the predictive value of tissue-TMB-H for immune checkpoint inhibitors (ICIs) with limited data regarding blood-TMB (bTMB) in GI tumors. We aim to evaluate the predictive value of bTMB compared with MSI-H in GI tumors. Patients with unresectable/metastatic GI cancer, harboring either MSS with bTMB-H (≥10 mut/Mb) or dMMR/MSI-H who received ICI were included. We compared ICIs' efficacy between MSS-bTMB-H (N=45) versus MSI-H (N=50) in GI tumors. Ninety-five patients were identified with the majority having colorectal (49.5%) or esophagogastric (34.7%) cancers. MSS-bTMB-H group had more esophagogastric cancer and later-line ICI recipients, with no significant differences in other known prognostic variables. At a median follow-up of 9.4 months, MSI-H group showed superior ORR (58.0% vs. 26.7%), DCR (84.0% vs. 42.2%), DoR (not-reached vs. 7.6 mo), PFS (22.5 vs. 3.8 mo), and OS (Not-reached vs. 10.1 mo) compared with MSS-bTMB-H. Multivariable analysis showed that MSI-H was an independent favorable factor over MSS-bTMB-H for PFS (HR=0.31, CI 0.15-0.63, P=0.001) and OS (HR=0.33, CI 0.14-0.80, P=0.014). MSI-H group showed favorable outcomes compared with MSS-bTMB-16+ (ORR: 58.0% vs. 26.9%; DCR: 84.0% vs. 42.3%; PFS:22.5 vs. 4.0 mo) and MSS-bTMB-20+ (ORR: 58.0% vs. 31.6%; DCR: 84.0% vs. 42.1%; PFS:22.5 vs. 3.2 mo). There was no difference between MSS-bTMB10-15 compared with MSS-bTMB-16+ in ORR, DCR, and PFS, or between MSS-bTMB10-19 compared with MSS-bTMB20+. Regardless of bTMB cutoff at 10, 16, or 20, bTMB-H did not appear to be a predictive biomarker in MSS GI tumors in this retrospective analysis.

Solanidine Metabolites as Diet-Derived Biomarkers of CYP2D6-Mediated Tamoxifen Metabolism in Breast Cancer Patients.

Tamoxifen is an important antiestrogen for the treatment of hormone receptor-positive breast cancer and undergoes bioactivation by CYP2D6 to its active metabolite endoxifen. Genetic variation in CYP2D6 has been linked to endoxifen levels during tamoxifen therapy. Recent studies have suggested solanidine, a glycoalkaloid phytochemical in potatoes, undergoes CYP2D6-mediated metabolism to 4-OH-solanidine (m/z 414) and 3,4-seco-solanidine-3,4-dioic acid (SSDA; m/z 444). Using a retrospective cohort of 1,032 breast cancer patients on tamoxifen therapy, we examined the association of solanidine metabolites with CYP2D6 activity and its correlation with tamoxifen metabolism. Solanidine, 4-OH-solanidine, or SSDA was detected in 99.7% (N = 1,029) of plasma samples. Decreased solanidine metabolite ratios were found in CYP2D6 intermediate and poor metabolizers (P < 0.0001). Patients on CYP2D6 strong inhibitors had a 77.6% and 94.2% decrease in 4-OH-solandine/solanidine (P < 0.0001) and SSDA/solanidine (P < 0.0001), respectively. The ratio of endoxifen to tamoxifen was highly correlated with both 4-OH-solandine/solanidine (ρ = 0.3207, P < 0.0001) and SSDA/solanidine (ρ = 0.5022, P < 0.0001) ratios. Logistic regression modeling was used to determine that 4-OH-solanidine/solanidine and SSDA/solanidine ratios below 2.1 and 0.8, respectively, predicted endoxifen concentrations of <16 nM. In conclusion, solanidine, 4-OH-solanidine, and SSDA are diet-derived biomarkers of CYP2D6 activity. Moreover, in patients on tamoxifen therapy, 4-OH-solanidine/solanidine and SSDA/solanidine predicted endoxifen levels including the inhibitory effects of concomitantly prescribed CYP2D6-interacting medications. Accordingly, 4-OH-solanidine/solanidine or SSDA/solanidine ratio has the potential to be particularly useful prior to initiation of tamoxifen or for determining the impact of CYP2D6 drug interactions, as well as prior to switching from an aromatase inhibitor to tamoxifen.

Thirty-day risk of digoxin toxicity among older adults co-prescribed trimethoprim-sulfamethoxazole versus amoxicillin: A population-based cohort study.

IMPORTANCE: Trimethoprim-sulfamethoxazole (TMP-SMX) may increase digoxin concentration, a medication with a narrow therapeutic index. Small changes in digoxin concentration could predispose individuals to the risk of toxicity. OBJECTIVE: To characterize the risk of digoxin toxicity in older adults taking digoxin following co-prescription of TMP-SMX compared with co-prescription of amoxicillin. DESIGN, SETTINGS, AND PARTICIPANTS: Retrospective population-based cohort study in Ontario, Canada (2002-2020) using linked health care data. Participants comprised 47,961 older adults taking digoxin (58% women; median age 80 years [interquartile range 74-86]) who were newly treated with TMP-SMX (n = 10,273) compared with those newly treated with amoxicillin (n = 37,688). EXPOSURE: Co-prescription of TMP-SMX versus amoxicillin in older adults concurrently taking digoxin. MAIN OUTCOME AND MEASURE: The primary outcome was a hospital encounter (i.e., hospital admission or emergency department visit) with digoxin toxicity within 30 days of the antibiotic prescription. Inverse probability of treatment weighting on the propensity score was used to balance comparison groups on indicators of baseline health. Weighted risk ratios (RR) were obtained using modified Poisson regression and weighted risk differences (RD) using binomial regression. The number needed to harm (NNH) was calculated as 1/RD. RESULTS: A hospital encounter with digoxin toxicity occurred in 49/10,273 (0.48%) patients treated with TMP-SMX versus 32/37,688 (0.08%) in those treated with amoxicillin (weighted RR, 5.71 [95% confidence interval (CI), 3.19 to 10.24]; weighted RD, 0.39% [95% CI, 0.25% to 0.53%]; NNH 256 [95% CI, 233 to 400]). CONCLUSION AND RELEVANCE: In older adults taking digoxin, the 30-day risk of a hospital encounter with digoxin toxicity was nearly 6 times higher in those co-prescribed TMP-SMX versus amoxicillin, although the absolute risk difference was low (0.4%). Physicians should prescribe an alternative antibiotic when clinically appropriate. If TMP-SMX must be co-prescribed with digoxin (if the benefit is believed to outweigh the risk), digoxin should be dose-reduced on an individual basis.

Impact of CYP2C19 metabolizer status on esophageal mucosal inflammation, acid exposure, and motility among patients on chronic proton-pump inhibitor therapy with refractory symptoms of gastroesophageal reflux disease.

Background: The extent of disease severity remains unclear among CYP2C19 rapid and ultra-rapid metabolizers with refractory symptoms of gastroesophageal reflux disease (GERD) on chronic proton-pump inhibitors (PPIs). Aims: To determine the impact of CYP2C19 metabolizer status in relation to chronic PPI therapy with a focus on the extent of esophageal inflammation, acid exposure, and motor function. Methods: This retrospective study included 54 patients with refractory GERD symptoms who underwent CYP2C19 genotyping for PPI metabolism, esophagogastroduodenoscopy, ambulatory pH study, and high-resolution esophageal manometry. Patients were divided into three groups: normal metabolizer (NM) group, intermediate metabolizer/poor metabolizer (IM/PM) group, and rapid metabolizer/ultra-rapid metabolizer (RM/UM) group. The Chi-square test was used to analyze categorical variables, and one-way ANOVA for comparing means. Results: Rapid metabolizer/ultra-rapid metabolizer (RM/UM) group more frequently had either Los Angeles grade C or D GERD (7/19, 36.8% vs 1/21, 4.8%, P = 0.011) and metaplasia of the esophagus (9/19, 47.4% vs 2/21, 9.5%, P = 0.007) when compared to the NM group. RM/UM group were more frequently offered dilatation for nonobstructive dysphagia (8/19, 42.1% vs 3/21, 14.3%, P = 0.049) and more exhibited a hypotensive lower esophageal sphincter (LES) resting pressure compared to the NM group (10/19, 52.6% vs 4/21, 19%, P = 0.026). All three groups exhibited comparable DeMeester scores when PPIs were discontinued 72 hours before the ambulatory pH study. Conclusion: CYP2C19 RMs and UMs on chronic PPI with refractory GERD symptoms exhibited greater esophageal mucosal inflammation, as observed both endoscopically and histologically, and more were found to have hypotensive LES resting pressures and more were offered esophageal dilatation.

Magnesium and Esophageal Pain After Peroral Endoscopic Myotomy of the Esophagus: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Postoperative esophageal pain occurs in 67% of patients after peroral endoscopic esophageal myotomy (POEM). Magnesium can act as a smooth muscle relaxant. This study investigated whether intraoperative magnesium can reduce postoperative esophageal pain in patients undergoing POEM. METHODS: In this double-blind, placebo-controlled trial, 92 patients were randomized to receive either magnesium sulfate as a 50 mg.kg-1 (total body weight) bolus followed by an infusion at 25 mg.kg-1.hr-1, or 0.9% saline. Intraoperative analgesia was standardized in all patients. The primary outcome was the score from a validated, modified Esophageal Symptoms Questionnaire (ESQ) in the postanesthesia care unit (PACU). Pain scores, opioid requirements, and questionnaire scores were collected through postoperative day 1. RESULTS: ESQ scores were significantly lower in the magnesium group in the PACU (median [25th-75th], 24 [18-31] vs 35 [28-42]; median difference [95% confidence interval, CI], 10 [6-13]; P < .0001) and on postoperative day 1 (16 [14-23] vs 30 [24-35]; P < .0001). Less opioids were needed in the magnesium group in the PACU (mean ± standard deviation [SD] [99% CI], 4.7 ± 10 [1-9] mg vs 29 ± 21 [21-37] mg; P < .0001) and on postoperative day 1 (1 ± 3.7 [0-2.5] mg vs 13 ± 23 [4-23] mg; P = .0009). Pain scores were lower in the magnesium group in the PACU (0 [0-3] vs 5 [5-7]; P < .0001) and on postoperative day 1 (0 [0-2] vs 4 [3-5]; P < .0001). CONCLUSIONS: Patients undergoing POEM randomized to receive intraoperative magnesium had sustained reductions in esophageal discomfort severity and opioid requirements 24 hours after surgery.

Increased endothelial sclerostin caused by elevated DSCAM mediates multiple trisomy 21 phenotypes.

Trisomy 21 (T21), a recurrent aneuploidy occurring in 1:800 births, predisposes to congenital heart disease (CHD) and multiple extracardiac phenotypes. Despite a definitive genetic etiology, the mechanisms by which T21 perturbs development and homeostasis remain poorly understood. We compared the transcriptome of CHD tissues from 49 patients with T21 and 226 with euploid CHD (eCHD). We resolved cell lineages that misexpressed T21 transcripts by cardiac single-nucleus RNA sequencing and RNA in situ hybridization. Compared with eCHD samples, T21 samples had increased chr21 gene expression; 11-fold-greater levels (P = 1.2 × 10-8) of SOST (chr17), encoding the Wnt inhibitor sclerostin; and 1.4-fold-higher levels (P = 8.7 × 10-8) of the SOST transcriptional activator ZNF467 (chr7). Euploid and T21 cardiac endothelial cells coexpressed SOST and ZNF467; however, T21 endothelial cells expressed 6.9-fold more SOST than euploid endothelial cells (P = 2.7 × 10-27). Wnt pathway genes were downregulated in T21 endothelial cells. Expression of DSCAM, residing within the chr21 CHD critical region, correlated with SOST (P = 1.9 × 10-5) and ZNF467 (P = 2.9 × 10-4). Deletion of DSCAM from T21 endothelial cells derived from human induced pluripotent stem cells diminished sclerostin secretion. As Wnt signaling is critical for atrioventricular canal formation, bone health, and pulmonary vascular homeostasis, we concluded that T21-mediated increased sclerostin levels would inappropriately inhibit Wnt activities and promote Down syndrome phenotypes. These findings imply therapeutic potential for anti-sclerostin antibodies in T21.

Real-World Effectiveness of First Line Lenvatinib Therapy in Advanced Hepatocellular Carcinoma: Current Insights.

Lenvatinib received its initial approval in 2018 for the treatment of advanced hepatocellular carcinoma. It has since emerged as the preferred first line agent, supported by non-inferiority data from the REFLECT trial. Notably, lenvatinib exhibits a more favorable toxicity profile and a higher response rate compared to sorafenib. Despite the approval of immunotherapy in 2020, specifically the combination of atezolizumab and bevacizumab following the IMbrave150 trial, tyrosine kinase inhibitors remain an indispensable class of agents in the landscape of hepatocellular carcinoma treatment. This comprehensive review delves into various facets of lenvatinib utilization in hepatocellular carcinoma, shedding light on real-world data, addressing challenges, and providing insights into strategies to overcome these obstacles.

Evolving Standards of Care in the Management of Localized Colorectal Cancer.

The treatment of patients with localized rectal cancer is complex and requires input from a multidisciplinary team. Baseline local staging and mismatch repair protein testing are vital to develop individualized treatment plans. There are multiple options in terms of treatment modalities and sequencing, including transanal excision, short-course radiation, long-course chemoradiation, chemotherapy doublet or triplet, nonoperative management, and immune checkpoint blockade for patients with mismatch repair deficient tumors. While localized colon cancer is typically treated with surgical resection and consideration of adjuvant chemotherapy, emerging data suggest that neoadjuvant chemotherapy may be beneficial in patients with higher-risk disease. Quality-of-life considerations are imperative to prevent potential chronic effects on psychosocial health, neuropathy, fertility, and bowel, bladder, and sexual function. The omission of radiation or surgery can mitigate these toxicities without diminishing oncologic outcomes. The optimal treatment plan and sequence is not a one-size-fits-all approach but rather should be personalized to the patient's disease burden, tumor location, comorbidities, and preferences.

Infliximab Tissue Concentrations in Patients With Stable Ulcerative Colitis Are Correlated With More Durable Infliximab-associated Disease Remission.

BACKGROUND: We aimed to determine the correlation between tissue and plasma infliximab concentrations in an outpatient ulcerative colitis (UC) cohort based on histologic disease activity in addition to their relationship with long-term clinical outcomes. We assessed intraparticipant variability in infliximab concentrations between adjacent intestinal samples and the correlation between disease activity and tumor necrosis factor-α (TNF-α). METHODS: A prospective cohort study was conducted in participants with UC receiving infliximab. Blood and 2 sigmoid colon biopsies were obtained at the index colonoscopy for infliximab and TNF-α quantification. Histological disease activity was assessed. Participants were followed for 2 years for the occurrence of hospitalization, surgery, disease relapse, and infliximab discontinuation. RESULTS: A positive correlation was observed between mean plasma and uninflamed tissue infliximab concentrations only (Rs = 0.75, P = .0071). Lower mean tissue infliximab concentrations correlated with a shorter time to disease relapse vs those with higher mean tissue concentrations (Rs = 0.77, P = .032). This was not seen when using plasma infliximab concentrations. Additionally, no significant intraparticipant variability of infliximab concentrations was observed for all participants independent of disease activity. Neither plasma nor tissue TNF-α correlated with disease activity. CONCLUSIONS: These findings support data generated in patients with Crohn's disease: plasma infliximab concentrations are reflective of infliximab exposure in tissue in the UC patient in remission, but not for those with active disease. Increasing tissue concentrations in the noninflamed tissues may improve durability of infliximab. Neither plasma nor tissue TNF-α appear to correlate with UC disease activity. Larger follow-up studies would be of benefit.

Plasma infliximab concentrations are reflective of infliximab exposure in tissue in the UC patient in remission, but not for those with active disease. Increasing tissue concentrations in the noninflamed tissues may improve durability of infliximab.

Pembrolizumab Plus mFOLFOX7 or FOLFIRI for Microsatellite Stable/Mismatch Repair-Proficient Metastatic Colorectal Cancer: KEYNOTE-651 Cohorts B and D.

BACKGROUND: The phase 1b KEYNOTE-651 study evaluated pembrolizumab plus chemotherapy in microsatellite stable or mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients with microsatellite stable or mismatch repair-proficient metastatic colorectal cancer received pembrolizumab 200 mg every 3 weeks plus 5-fluorouracil, leucovorin, oxaliplatin (previously untreated; cohort B) or 5-fluorouracil, leucovorin, irinotecan (previously treated with fluoropyrimidine plus oxaliplatin; cohort D) every 2 weeks. Primary end point was safety; investigator-assessed objective response rate per RECIST v1.1 was secondary and biomarker analysis was exploratory. RESULTS: Thirty-one patients were enrolled in cohort B and 32 in cohort D; median follow-up was 30.2 and 33.5 months, respectively. One dose-limiting toxicity (grade 3 small intestine obstruction) occurred in cohort D. In cohort B, grade 3 or 4 treatment-related adverse events (AEs) occurred in 18 patients (58%), most commonly neutropenia and decreased neutrophil count (n = 5 each). In cohort D, grade 3 or 4 treatment-related AEs occurred in 17 patients (53%), most commonly neutropenia (n = 7). No grade 5 treatment-related AEs occurred. Objective response rate was 61% in cohort B (KRAS wildtype: 71%; KRAS mutant: 53%) and 25% in cohort D (KRAS wildtype: 47%; KRAS mutant: 6%). In both cohorts, PD-L1 combined positive score and T-cell-inflamed gene expression profiles were higher and HER2 expression was lower in responders than nonresponders. No association between tumor mutational burden and response was observed. CONCLUSION: Pembrolizumab plus 5-fluorouracil, leucovorin, oxaliplatin/5-fluorouracil, leucovorin, irinotecan demonstrated an acceptable AE profile. Efficacy data appeared comparable with current standard of care (including by KRAS mutation status). Biomarker analyses were hypothesis-generating, warranting further exploration. GOV IDENTIFIER: ClinicalTrials.gov; NCT03374254.

A randomized controlled trial of brief behavioral activation plus savoring for positive affect dysregulation in university students.

Rising rates of depression on university campuses accentuate the need for specific intervention. Interventions targeting disturbances in positive affect, in particular, remain sparse, yet such deficits interfere substantially with functioning and further exacerbate or maintain negative symptoms. The current study aimed to evaluate the impact of a virtual, two-session Behavioral Activation augmented with Savoring (BA + S) intervention compared to an Emotional Awareness (EA) control group in increasing positive affect. Sixty university students with low positive affect were randomized to BA + S or EA and completed 21 days of experience-sampling of positive affect. Weekly measures of positive and negative valence symptoms were assessed at baseline, sessions one and two, and at one-week follow-up. Through a prori analyses utilizing multilevel and multivariate multilevel models, our results demonstrate that daily positive affect measured via experience-sampling significantly improved in BA + S, whereas positive affect did not change for those receiving EA, though the interaction of condition and time was not significant. Furthermore, interactions in weekly variables were significant. Increases in positive valence symptoms (affect, anhedonia, etc.) were only reported for students receiving BA + S but not EA. Negative valence symptoms (affect, depression, general distress) improved in both conditions but with superior improvements in BA + S compared to EA. BA + S shows promise for a scalable and accessible intervention to university students with clinical levels of positive and negative affect. ClinicalTrials ID: NCT05234476.

Pembrolizumab Plus Binimetinib With or Without Chemotherapy for MSS/pMMR Metastatic Colorectal Cancer: Outcomes From KEYNOTE-651 Cohorts A, C, and E.

BACKGROUND: Cohorts A, C, and E of the phase Ib KEYNOTE-651 study evaluated pembrolizumab + binimetinib ± chemotherapy in microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients received pembrolizumab 200 mg every 3 weeks plus binimetinib 30 mg twice daily alone (cohort A; previously treated with any chemotherapy) or with 5-fluorouracil, leucovorin, oxaliplatin (cohort C; previously untreated) or 5-fluorouracil, leucovorin, irinotecan (cohort E; previously treated with 1 line of therapy including fluoropyrimidine + oxaliplatin-based regimen) every 2 weeks. Binimetinib dose-escalation to 45 mg twice daily was planned in all cohorts using a modified toxicity probability interval design (target dose-limiting toxicity [DLT], 30%). The primary endpoint was safety; investigator-assessed objective response rate was secondary. RESULTS: In cohort A, 1/6 patients (17%) had DLTs with binimetinib 30 mg; none occurred in 14 patients with 45 mg. In cohort C, 3/9 patients (33%) had DLTs with binimetinib 30 mg; dose was not escalated to 45 mg. In cohort E, 1/5 patients (20%) had DLTs with binimetinib 30 mg; 5/10 patients (50%) had DLTs with 45 mg. Enrollment was stopped in cohort E binimetinib 45 mg and deescalated to 30 mg; 2/4 additional patients (50%) had DLTs with binimetinib 30 mg (total 3/9 [33%] had DLTs with binimetinib 30 mg). Objective response rate was 0% in cohort A, 9% in cohort C, and 15% in cohort E. CONCLUSION: Per DLT criteria, binimetinib + pembrolizumab (cohort A) was tolerable, binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, oxaliplatin (cohort C) did not qualify for binimetinib dose escalation to 45 mg, and binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, irinotecan (cohort E) required binimetinib dose reduction from 45 to 30 mg. No new safety findings were observed across cohorts. There was no apparent additive efficacy when binimetinib + pembrolizumab was added to chemotherapy. Data did not support continued enrollment in cohorts C and E.

Circulating tumor DNA analysis guiding adjuvant treatment in resected stage III cholangiocarcinoma: a case report.

Background: Cholangiocarcinoma (CCA) is a rare and aggressive gastrointestinal cancer. Unfortunately, 60% to 70% of early-stage CCA patients experience disease recurrence after curative resection and standard adjuvant therapy. Currently, there is no reliable tool to identify CCA recurrence before radiographic detection. Longitudinal monitoring of circulating tumor DNA (ctDNA) has shown promising value in molecular identification of relapse prior to conventional surveillance in other solid tumors. However, there is a scarcity of data on ctDNA in CCA after curative surgery. Case Description: An 81-year-old male with stage 3A intrahepatic CCA achieved radiographic remission after curative resection and was started on standard adjuvant capecitabine on post-operative day (POD) 50. Tumor-informed ctDNA tested positive on two consecutive occasions, with the titer increasing from 0.16 mean tumor molecule (MTM)/mL on POD 92 to 0.80 MTM/mL on POD 183, despite being on capecitabine. carbohydrate antigen 19-9 (CA19-9) also continued to increase from 175.6 U/mL on POD 92 to 7,594.9 U/mL on POD 217. Notably, surveillance computed tomography (CT) scans showed no evidence of disease (NED) on POD 126, 186, and 211. Molecular profiling and next-generation sequencing (NGS) panels from CCA tissue revealed microsatellite instability-high (MSI-H). After extensive discussions with the patient regarding the rising ctDNA titer despite being on capecitabine for nearly 6 months, we initiated pembrolizumab on POD 224 prior to radiographic recurrence. Given the tumor is MSI-H, and the preferred toxicity profile compared to the front-line chemotherapy option for CCA, we started pembrolizumab. ctDNA became undetectable, and CA19-9 returned to the reference range with pembrolizumab. As of the last follow-up on POD 876, the patient has continued pembrolizumab without noticeable side effects, and imaging continues to show NED, with persistent negative ctDNA and normal CA19-9 levels. Conclusions: This case demonstrates the potential utility of tumor-informed ctDNA in CCA as (I) an early detection tool before radiographic recurrence; (II) a response monitoring tool as a surrogate biomarker that can guide therapy optimization; and (III) shows that early intervention with immunotherapy or potentially targeted agents based on ctDNA may lead to improved survival outcomes.

Landscape fire smoke airway exposure impairs respiratory and cardiac function and worsens experimental asthma.

BACKGROUND: Millions of people are exposed to landscape fire smoke (LFS) globally, and inhalation of LFS particulate matter (PM) is associated with poor respiratory and cardiovascular outcomes. However, how LFS affects respiratory and cardiovascular function is less well understood. OBJECTIVE: We aimed to characterize the pathophysiologic effects of representative LFS airway exposure on respiratory and cardiac function and on asthma outcomes. METHODS: LFS was generated using a customized combustion chamber. In 8-week-old female BALB/c mice, low (25 µg/m3, 24-hour equivalent) or moderate (100 µg/m3, 24-hour equivalent) concentrations of LFS PM (10 µm and below [PM10]) were administered daily for 3 (short-term) and 14 (long-term) days in the presence and absence of experimental asthma. Lung inflammation, gene expression, structural changes, and lung function were assessed. In 8-week-old male C57BL/6 mice, low concentrations of LFS PM10 were administered for 3 days. Cardiac function and gene expression were assessed. RESULTS: Short- and long-term LFS PM10 airway exposure increased airway hyperresponsiveness and induced steroid insensitivity in experimental asthma, independent of significant changes in airway inflammation. Long-term LFS PM10 airway exposure also decreased gas diffusion. Short-term LFS PM10 airway exposure decreased cardiac function and expression of gene changes relating to oxidative stress and cardiovascular pathologies. CONCLUSIONS: We characterized significant detrimental effects of physiologically relevant concentrations and durations of LFS PM10 airway exposure on lung and heart function. Our study provides a platform for assessment of mechanisms that underpin LFS PM10 airway exposure on respiratory and cardiovascular disease outcomes.

A Proposed Treatment Algorithm for Low Back Pain Secondary to Bertolotti's Syndrome.

BACKGROUND: Chronic low back pain is widely prevalent, and there are a range of conditions that may result in the low back pain. In general, treatment of low back pain starts with conservative management such as medications, physical therapy, and home exercise regimens. If conservative measures fail, a range of interventional techniques can be employed to manage back pain. An uncommonly recognized cause of back pain is Bertolotti's syndrome which is a result of back pain due to lumbosacral transitional vertebrae (LSTV). LSTV is a congenital abnormality either characterized by the lumbarization of the sacrum where the first sacral bone fails to fuse with the rest of the sacrum or the sacralization of the lumbar spine where the L5 vertebra fuses with the sacrum creating a longer sacrum. In many cases, the condition can be recognized by imaging techniques such as an x-ray, computed tomography, or magnetic resonance imaging. OBJECTIVES: To propose a treatment algorithm for patients with low back pain secondary to Bertolotti's syndrome. STUDY DESIGN: Case study and treatment algorithm proposal. METHODS: A treatment algorithm for patients with low back pain secondary to Bertolotti's Syndrome which involves starting with local anesthetic and steroid injection of the pseudo-articulation, followed by radiofrequency ablation of the pseudo-articulation, and then complete endoscopic resection of the pseudo joint. RESULTS: The proposed stepwise treatment guideline has the ability to diagnose Bertolotti's syndrome as the cause of low back pain and provide symptomatic relief. LIMITATIONS: Several limitations exist for the study including the fact that the algorithmic approach may not fit every patient. Additionally, there would be benefit in future research studies comparing each step of the algorithm with conservative measures to compare efficacy and long-term outcomes of the procedures. CONCLUSIONS: Our stepwise approach to diagnosing and managing the pain resulting from Bertolotti's syndrome is an effective method of treatment for the condition.