Safety of baclofen versus tizanidine for older adults with musculoskeletal pain.

BACKGROUND: Baclofen and tizanidine are both muscle relaxants that carry the risk for neuropsychiatric events in older adults but there is a lack of data directly comparing their safety. This study aimed to investigate the relative risk between these two medications in causing injury and delirium in older adults. METHODS: This was a retrospective cohort study that was completed in an integrated healthcare system in the United States and included patients aged 65 years or older who started baclofen or tizanidine for the treatment of musculoskeletal pain from January 2016 through December 2018. Outcomes included new incidence of injury (concussion, contusion, dislocation, fall, fracture, or other injuries) and delirium. The cohort was followed from the initiation of therapy until the first occurrence of any of the following events: end of the index drug exposure, end of health plan membership, death, or the study end date of December 31st, 2019. Descriptive statistics were used to compare baseline patient characteristics between baclofen and tizanidine treatment groups. Cox proportional hazards model was used to calculate adjusted hazard ratios (HRs) with 95% confidence intervals. RESULTS: The final study cohort included 12,101 and 6,027 older adults in the baclofen and tizanidine group respectively (mean age 72.2 ± 6.2 years old, 59% female). Older adults newly started on baclofen had a greater risk of injury (HR = 1.54, 95% CI = 1.21-1.96, P = < 0.001) and delirium (HR = 3.33, 95% CI = 2.11-5.26, p = <0.001) compared to those started on tizanidine. CONCLUSION: The results of this study suggest that baclofen is associated with higher incidences of injury and delirium compared to tizanidine when used for the treatment of musculoskeletal pain. Future studies should investigate if these risks are dose-related and include a comparison group not exposed to either drug.

A Randomized Trial Comparing Antibiotics with Appendectomy for Appendicitis.

BACKGROUND: Antibiotic therapy has been proposed as an alternative to surgery for the treatment of appendicitis. METHODS: We conducted a pragmatic, nonblinded, noninferiority, randomized trial comparing antibiotic therapy (10-day course) with appendectomy in patients with appendicitis at 25 U.S. centers. The primary outcome was 30-day health status, as assessed with the European Quality of Life-5 Dimensions (EQ-5D) questionnaire (scores range from 0 to 1, with higher scores indicating better health status; noninferiority margin, 0.05 points). Secondary outcomes included appendectomy in the antibiotics group and complications through 90 days; analyses were prespecified in subgroups defined according to the presence or absence of an appendicolith. RESULTS: In total, 1552 adults (414 with an appendicolith) underwent randomization; 776 were assigned to receive antibiotics (47% of whom were not hospitalized for the index treatment) and 776 to undergo appendectomy (96% of whom underwent a laparoscopic procedure). Antibiotics were noninferior to appendectomy on the basis of 30-day EQ-5D scores (mean difference, 0.01 points; 95% confidence interval [CI], -0.001 to 0.03). In the antibiotics group, 29% had undergone appendectomy by 90 days, including 41% of those with an appendicolith and 25% of those without an appendicolith. Complications were more common in the antibiotics group than in the appendectomy group (8.1 vs. 3.5 per 100 participants; rate ratio, 2.28; 95% CI, 1.30 to 3.98); the higher rate in the antibiotics group could be attributed to those with an appendicolith (20.2 vs. 3.6 per 100 participants; rate ratio, 5.69; 95% CI, 2.11 to 15.38) and not to those without an appendicolith (3.7 vs. 3.5 per 100 participants; rate ratio, 1.05; 95% CI, 0.45 to 2.43). The rate of serious adverse events was 4.0 per 100 participants in the antibiotics group and 3.0 per 100 participants in the appendectomy group (rate ratio, 1.29; 95% CI, 0.67 to 2.50). CONCLUSIONS: For the treatment of appendicitis, antibiotics were noninferior to appendectomy on the basis of results of a standard health-status measure. In the antibiotics group, nearly 3 in 10 participants had undergone appendectomy by 90 days. Participants with an appendicolith were at a higher risk for appendectomy and for complications than those without an appendicolith. (Funded by the Patient-Centered Outcomes Research Institute; CODA ClinicalTrials.gov number, NCT02800785.).

Vitamin B6 deficiency: a potential cause of refractory seizures in adults.

OBJECTIVE: In children, vitamin B(6) (pyridoxine) deficiency has been described as a cause of seizures that are refractory to conventional antiepileptic medications. We describe the clinical presentation of 3 adults with refractory seizures (later diagnosed with vitamin B(6) deficiency) that resolved after pyridoxine treatment. DESIGN: Case series. SETTING: Tertiary care surgical intensive care unit. PATIENTS: In the first case, a 54-year-old male with history of alcoholic cirrhosis developed new-onset seizures refractory to phenytoin and levetiracetam 8 days after liver transplantation. In the second case, a 59-year-old male with hepatitis C infection developed intracranial hemorrhage and new-onset seizures refractory to phenytoin, levetiracetam, and pentobarbital. The third patient is a 78-year-old male with a history of alcohol dependence who was admitted for an intraventricular bleed and developed new onset of refractory seizures. INTERVENTIONS: Intravenous pyridoxine followed by oral pyridoxine. MEASUREMENT AND MAIN RESULTS: In all 3 cases, seizures persisted despite escalation of conventional antiepileptic medications but resolved within 2 days of pyridoxine supplementation. In each case, low serum pyridoxal 5'-phosphate concentrations normalized with pyroxidine administration. CONCLUSIONS: Although refractory seizures caused by vitamin B(6) deficiency are rare in adults, it should be considered in critically ill adult patients with refractory seizures.

Recovery of PEX1-Gly843Asp peroxisome dysfunction by small-molecule compounds.

Zellweger spectrum disorder (ZSD) is a heterogeneous group of diseases with high morbidity and mortality caused by failure to assemble normal peroxisomes. There is no therapy for ZSD, but management is supportive. Nevertheless, one-half of the patients have a phenotype milder than classic Zellweger syndrome and exhibit a progressive disease course. Thus, patients would benefit if therapies became available and were instituted early. Recent reports indicate several interventions that result in partial peroxisome recovery in ZSD fibroblasts. To identify drugs that recover peroxisome functions, we expressed a GFP-peroxisome targeting signal 1 reporter in fibroblasts containing the common disease allele, PEX1-p.Gly843Asp. The GFP reporter remained cytosolic at baseline, and improvement in peroxisome functions was detected by the redistribution of the GFP reporter from the cytosol to the peroxisome. We established a high-content screening assay based on this phenotype assay and evaluated 2,080 small molecules. The cells were cultured in chemical for 2 days and then, were fixed and imaged by epifluorescent microscopy on a high-content imaging platform. We identified four compounds that partially recover matrix protein import, and we confirmed three using independent assays. Our results suggest that PEX1-p.G843D is a misfolded protein amenable to chaperone therapy.

A Pex7 hypomorphic mouse model for plasmalogen deficiency affecting the lens and skeleton.

Rhizomelic chondrodysplasia punctata type 1 is a peroxisome biogenesis disorder with the clinical features of rhizomelia, abnormal epiphyseal calcifications, congenital cataracts, and profound growth and developmental delays. It is a rare autosomal recessive disorder, caused by defects in the peroxisome receptor, PEX7. The pathology results from a deficiency of plasmalogens, a critical class of ether phospholipids whose functions are largely unknown. To study plasmalogens in an animal model, avoid early mortality and facilitate therapeutic investigations in this disease, we engineered a hypomorphic mouse model in which Pex7 transcript levels are reduced to less than 5% of wild type. These mice are born in expected ratios, are fertile and have a normal life span. However, they are petite and develop early cataracts. Further investigations showed delayed endochondral ossification and abnormalities in lens fibers. The biochemical features of reduced Pex7 function were reproduced in this model, including tissue plasmalogen deficiency, phytanic acid accumulation, reduced import of Pex7 ligands and consequent defects in plasmalogen biosynthesis and phytanic acid oxidation. Dietary supplementation with batyl alcohol, a plasmalogen precursor, recovered ether phospholipids in blood, but did not alter the clinical phenotype. The relatively mild phenotype of these mice mimics patients with milder PEX7 defects, and highlights the skeleton and lens as sensitive markers of plasmalogen deficiency. The role of plasmalogens in the normal function of these tissues at various ages can now be studied and additional therapeutic interventions tested in this model.

Comparison of risk adjustment methodologies in surgical quality improvement.

BACKGROUND: All hospitals are required to perform quality assurance activities. Many risk adjustment methodologies have been developed, and many medical centers use 1 or more than 1 risk adjustment program in an attempt to characterize their outcomes better rather than simply assessing unadjusted outcome statistics. The University HealthSystem Consortium (UHC) and American College of Surgeons-National Surgical Quality Improvement Program (NSQIP) both produce risk-adjusted outcome data. Our institution recognized a large disparity between our UHC and NSQIP risk-adjusted mortality. The purpose of this study was to attempt to discover the cause of that disparity. METHODS: One hundred twenty consecutive NSQIP records were matched with their UHC submissions during 2006. All patients' comorbidities and outcomes were reviewed, and the 2 systems, UHC and NSQIP, were compared for degree of discordance. RESULTS: Approximately twice the number of comorbidities per patient were documented in UHC (2.85+/-2.52) submissions compared with NSQIP (1.38+/-1.52, P < .001). The reporting of the comorbidities of hypertension, cardiac disease, pulmonary disease, and diabetes between UHC and NSQIP were similar in the percentage of patients reported as having each of those disease states, but the discordance between the 2 systems was 12%, 13%, 15%, and 5%, respectively (P < .001 in all 4). A total of 28% of patients were reported as suffering complications in NSQIP but only 11% in UHC, with a 26% rate of discordance (P < .01). Overall, 13% of patients were reported as having a surgical site infection in NSQIP, but only 1% in UHC. CONCLUSIONS: We found significant differences in the reporting of both comorbidities and outcomes between our medical center's submissions to UHC and NSQIP in a consecutive series of patients. This may be at least partially responsible for the difference in the risk-adjusted mortality for our institution, as reported by UHC and NSQIP.

The acyl-CoA synthetase "bubblegum" (lipidosin): further characterization and role in neuronal fatty acid beta-oxidation..

Acyl-CoA synthetases play a pivotal role in fatty acid metabolism, providing activated substrates for fatty acid catabolic and anabolic pathways. Acyl-CoA synthetases comprise numerous proteins with diverse substrate specificities, tissue expression patterns, and subcellular localizations, suggesting that each enzyme directs fatty acids toward a specific metabolic fate. We reported that hBG1, the human homolog of the acyl-CoA synthetase mutated in the Drosophila mutant "bubblegum," belongs to a previously unidentified enzyme family and is capable of activating both long- and very long-chain fatty acid substrates. We now report that when overexpressed, hBG1 can activate diverse saturated, monosaturated, and polyunsaturated fatty acids. Using in situ hybridization and immunohistochemistry, we detected expression of mBG1, the mouse homolog of hBG1, in cerebral cortical and cerebellar neurons and in steroidogenic cells of the adrenal gland, testis, and ovary. The expression pattern and ability of BG1 to activate very long-chain fatty acids implicates this enzyme in the pathogenesis of X-linked adrenoleukodystrophy. In neuron-derived Neuro2a cells, mBG1 co-sedimented with mitochondria and was found in small vesicular structures located in close proximity to mitochondria. RNA interference was used to decrease mBG1 expression in Neuro2a cells and led to a 30-35% decrease in activation and beta-oxidation of the long-chain fatty acid, palmitate. These results suggest that in Neuro2a cells, mBG1-activated long-chain fatty acids are directed toward mitochondrial degradation. mBG1 appears to play a minor role in very long-chain fatty acid activation in these cells, indicating that other acyl-CoA synthetases are necessary for very long-chain fatty acid metabolism in Neuro2a cells.