AMPK governs lineage specification through Tfeb-dependent regulation of lysosomes.

Faithful execution of developmental programs relies on the acquisition of unique cell identities from pluripotent progenitors, a process governed by combinatorial inputs from numerous signaling cascades that ultimately dictate lineage-specific transcriptional outputs. Despite growing evidence that metabolism is integrated with many molecular networks, how pathways that control energy homeostasis may affect cell fate decisions is largely unknown. Here, we show that AMP-activated protein kinase (AMPK), a central metabolic regulator, plays critical roles in lineage specification. Although AMPK-deficient embryonic stem cells (ESCs) were normal in the pluripotent state, these cells displayed profound defects upon differentiation, failing to generate chimeric embryos and preferentially adopting an ectodermal fate at the expense of the endoderm during embryoid body (EB) formation. AMPK(-/-) EBs exhibited reduced levels of Tfeb, a master transcriptional regulator of lysosomes, leading to diminished endolysosomal function. Remarkably, genetic loss of Tfeb also yielded endodermal defects, while AMPK-null ESCs overexpressing this transcription factor normalized their differential potential, revealing an intimate connection between Tfeb/lysosomes and germ layer specification. The compromised endolysosomal system resulting from AMPK or Tfeb inactivation blunted Wnt signaling, while up-regulating this pathway restored expression of endodermal markers. Collectively, these results uncover the AMPK pathway as a novel regulator of cell fate determination during differentiation.

Episodic and Chronic Migraine in Primary Care.

OBJECTIVE: To inform migraine care model development by assessing differences between patients with chronic migraine (CM) and episodic migraine (EM) in the current state of treatment, disability, patient satisfaction, and quality improvement opportunities. BACKGROUND: Efficient and focused use of scarce resources will be needed to address challenges within large populations of migraine patients. METHODS: We deployed a cross-sectional survey study of randomly selected migraine patients within a community primary care practice. RESULTS: There were 516 survey respondents (516/1804 [30%] response rate). CM patients were more likely than EM patients to report care from a neurologist (76/110 [69%] vs 229/406 [56%]; P = .0026), and higher disability according to the Migraine Disability Assessment and Headache Impact Test - 6 questionnaires (P < .0001). CM patients were less likely than EM patients to report overall satisfaction with care (16/110 [38%] vs 156/406 [66%], P = .0002), satisfaction with access to care (17/110 [33%] vs 176/406 [68%], P < .0001), and advice they needed (16/110 [31%] vs 160/406 [62%], P < .0001). Most patients with migraine had been offered triptan medications 377/516 (78%). Overall, 156/516 (31%) of individuals were currently taking any medication for migraine prevention, and 208/516 (40%) including botulinum toxin injections. CM patients were more likely to be taking preventive medication (39/110 [36%] vs 117/406 [29%], P = .0191) and report familiarity with the diagnosis of medication-overuse headache than patients with EM (80/110 [81%] vs 256/406 [69%], P = .0178). CONCLUSIONS: We observed differences between patients with chronic and EM and expected care delivery improvement opportunities for migraine patients in primary care. CM patients report higher levels of disability and less satisfaction with access to perceived needed medical advice and care. These findings support the need to further develop and study novel care models to efficiently and effectively deliver high-quality care and expertise in limited supply to a diverse migraine population.

Neuroimaging utilization and findings in headache outpatients: Significance of red and yellow flags.

Background Neuroimaging for headache commonly exceeds published guideline recommendations and may be overutilized. Methods We conducted a retrospective cross-sectional study of all outpatient community patients at Mayo Clinic Rochester who underwent a neuroimaging study for a headache indication in 2015. We assessed the neuroimaging utilization pattern, clinical application of red flags, and concordance with neuroimaging guidelines. Results We identified 190 outpatients who underwent 304 neuroimaging studies for headache. The median age was 46.5 years (range 18-91 years), 65% were female, and most reported no prior history of headache (n = 97, 51%). A minority of patients had prior brain imaging studies (n = 44, 23%) and neurological consultations for headache (n = 29, 15%). Few studies were ordered after consultation with a neurologist (n = 14, 7%). Seventy-seven percent of patients were documented to have a "red flag" justifying the imaging study. Abnormal neuroimaging findings were found in 3.1% of patients with warning flags (5/161); carotid dissection (n = 3) and reversible cerebral vasoconstrictive syndrome (n = 2). An estimated 35% of patients were imaged against guidelines. Conclusions The prevalence of serious causes of headache in a community practice was low despite the presence of a documented red flag symptom. Inadequate understanding or application of red flags may be contributing to recommendations to image patients against current guidelines. Interventions to reduce unnecessary neuroimaging of patients with headache need to be designed and implemented.

Impact of Multiple Chronic Conditions in Patients Hospitalized with Stroke and Transient Ischemic Attack.

BACKGROUND: The prevalence and clinical impact of chronic conditions (CCs) have increasingly been recognized as an important public health concern. We evaluated the prevalence of coexisting CCs and their association with 30-day mortality and readmission in hospitalized patients with stroke and transient ischemic attack (TIA). METHODS: In a retrospective study of patients aged ≥18 years hospitalized for first-ever stroke and TIA, we assessed the prevalence of coexisting CCs and their predictive value for subsequent 30-day mortality and readmission. RESULTS: Study cohort comprised 6771 patients, hospitalized for stroke (n = 4068) and TIA (n = 2703), 51.4% men, with mean age of 68.2 years (standard deviation: ±15.6), mean number of CCs of 2.9 (±1.7), 30-day mortality rate of 8.6% (entire cohort), and 30-day readmission rate of 9.7% (in 2498 patients limited to Olmsted and surrounding counties). In multivariable models, significant predictors of (1) 30-day mortality were coexisting heart failure (HF) (odds ratio [OR]: 1.45, 95% confidence interval [CI]: 1.09-1.92), cardiac arrhythmia (OR: 1.74, 95% CI: 1.40-2.17), coronary artery disease (CAD) (OR: 1.64, 95% CI: 1.29-2.08), cancer (OR: 1.67, 95% CI: 1.31-2.14), and diabetes (HR: 1.28, 95% CI: 1.01-1.62); and (2) 30-day readmission (n = 2498) were CAD (OR: 1.50, 95% CI: 1.09-2.07), cancer (OR: 1.46, 95% CI: 1.01-2.10), and arthritis (OR: 1.62, 95% CI: 1.09-2.40). CONCLUSIONS: In patients hospitalized with stroke and TIA, CCs are highly prevalent and influence 30-day mortality and readmission. Optimal therapeutic and lifestyle interventions for CAD, HF, cardiac arrhythmia, cancer, diabetes, and arthritis may improve early clinical outcome.

A spatially and temporally restricted mouse model of soft tissue sarcoma.

Soft tissue sarcomas are mesenchymal tumors that are fatal in approximately one-third of patients. To explore mechanisms of sarcoma pathogenesis, we have generated a mouse model of soft tissue sarcoma. Intramuscular delivery of an adenovirus expressing Cre recombinase in mice with conditional mutations in Kras and Trp53 was sufficient to initiate high-grade sarcomas with myofibroblastic differentiation. Like human sarcomas, these tumors show a predilection for lung rather than lymph node metastasis. Using this model, we showed that a prototype handheld imaging device can identify residual tumor during intraoperative molecular imaging. Deletion of the Ink4a-Arf locus (Cdkn2a), but not Bak1 and Bax, could substitute for mutation of Trp53 in this model. Deletion of Bak1 and Bax, however, was able to substitute for mutation of Trp53 in the development of sinonasal adenocarcinoma. Therefore, the intrinsic pathway of apoptosis seems sufficient to mediate p53 tumor suppression in an epithelial cancer, but not in this model of soft tissue sarcoma.

Electronic Consultations in a Community Neurology Practice: A Retrospective Study Informing Best Practice.

Objective: To describe our practice of electronic consultations (e-consults) and assess safety and risk factors for subsequent face-to-face consultations. Patients and Methods: A retrospective cohort study of all e-consults completed in a community neurology practice between May 5, 2018, and June 31, 2019, was completed. Clinical and demographic variables were compared between the successful and unsuccessful (defined by presence of subsequent face-to-face consultation) cohorts. Hazard ratios (HR) were calculated using Cox regression model. Kaplan-Meier probability analysis (with 95% CIs) of subsequent face-to-face consultation was performed. Case examples highlighting potential harm were summarized. Results: In total, 302 e-consults were reviewed. The most frequent referrals were for headache (n=125, 41.4%), dysesthesia (n=40, 13.2%), and abnormal imaging finding (n=27, 8.9%). The most common e-consult questions were for treatment (57.6%) and diagnostic evaluation (48.0%) recommendations. Moreover, 24.8% (n=75) of e-consults were followed by face-to-face consultations, with primary risk factors including female sex (HR, 1.9), referral for headache (HR, 1.7), and final diagnosis of migraine (HR, 2.0) or long-term migraine (HR, 5.0). Potential harm related to delayed diagnosis/treatment was identified in 6 (2.0%) patients with migraine and 4 (1.3%) without migraine presenting to emergency department. Conclusion: Utilization of e-consults may safely improve access to neurologic expertise and prevent the need for some visits, which may have required a face-to-face visit. In patients with chronic migraine, e-consults should be considered short-term and followed by face-to-face consultation as soon as access allows. Neurologists performing e-consults should be able to triage patients to face-to-face consultation, particularly when diagnosis is uncertain or the neurologic examination may help guide appropriate testing.

Tissue-specific p19Arf regulation dictates the response to oncogenic K-ras.

The ability of oncogenes to engage tumor suppressor pathways represents a key regulatory mechanism that can limit the outgrowth of incipient tumor cells. For example, in a number of settings oncogenic Ras strongly activates the Ink4a/Arf locus, resulting in cell cycle arrest or senescence. The capacity of different cell types to execute tumor suppressor programs following expression of endogenous K-ras(G12D) in vivo has not been examined. Using compound mutant mice containing the Arf(GFP) reporter and the spontaneously activating K-ras(LA2) allele, we have uncovered dramatic tissue specificity of K-ras(G12D)-dependent p19(Arf) up-regulation. Lung tumors, which can arise in the presence of functional p19(Arf), rarely display p19(Arf) induction. In contrast, sarcomas always show robust activation, which correlates with genetic evidence, suggesting that loss of the p19(Arf)-p53 pathway is a requisite event for sarcomagenesis. Using constitutive and inducible RNAi systems in vivo, we highlight cell type-specific chromatin regulation of Ink4a/Arf as a critical determinant of cellular responses to oncogenic K-ras. Polycomb-group complexes repress the locus in lung tumors, whereas the SWI/SNF family member Snf5 acts as an important mediator of p19(Arf) induction in sarcomas. This variation in tumor suppressor induction might explain the inherent differences between tissues in their sensitivity to Ras-mediated transformation.

Posttraumatic Ruptured Axillary Mononeuropathy Without Shoulder Dislocation in an American Football Player: A Case Report and Review of the Literature.

ABSTRACT: A high school-aged right-handed adolescent boy presented with a 5-mo history of persistent proximal right arm weakness and numbness after an American football stinger injury without a documented history of a shoulder dislocation or humeral fracture. He developed diffuse deltoid muscle atrophy, persistent shoulder abduction weakness, and reduced pinprick sensation confined to the axillary distribution over 5 mos. Needle electromyography demonstrated dense fibrillation potentials and no voluntary activation in all three deltoid muscle heads, indicating a severe posttraumatic ruptured axillary mononeuropathy. The patient then underwent a complex three-cable sural nerve graft repair for attempted reinnervation of the axillary-innervated muscles. Isolated axillary nerve injuries are usually associated with anterior shoulder dislocations; however, a severe isolated persistent axillary mononeuropathy from a ruptured axillary nerve may occur in trauma patients without a clear history of shoulder dislocation. These patients may present with only mild persistent weakness of shoulder abduction. Electrodiagnostic testing to fully assess axillary nerve function should still be considered to identify patients with high-grade nerve injuries that may benefit from sural nerve grafting. The rapid recovery of our patient's initial symptoms with persistent severe axillary injury suggests a unique vulnerability of the nerve due to the neuroanatomy and possibly other factors.

Migraine Patient Care Model Preferences in a Community Practice.

Background and Objectives: Developing high-value care models with limited resources for large populations of individuals with migraine requires advanced understanding of patient preferences for care delivery methods. In this study, we aimed to inform the development of migraine care models by assessing patient preferences for types of care delivery and determining differences based on migraine frequency and disability. Methods: We analyzed unpublished data from a cross-sectional survey of 516 randomly selected individuals with migraine within a community practice associated with Mayo Clinic, Rochester, MN. Results: Individuals with chronic migraine, compared with those with episodic migraine, were more likely to prefer a visit with a neurologist (p = 0.0005), synchronous telephone conference with primary care provider (PCP) and neurologist (p = 0.0102), and a written migraine action plan in the medical record (p = 0.0343). Compared with those with mild/no disability, individuals with moderate-to-severe disability were more likely to prefer a visit with a neurologist (p < 0.0001), synchronous video or telephone conference with PCP and neurologist (p < 0.0001), PCP communication with neurologist (p = 0.0099), electronic message to primary care team with access to neurologist (p = 0.0216), and written action plan in the medical record (p = 0.0011). Collectively, individuals most preferred telephone follow-up and least preferred communications with a nurse or pharmacist or generalized education (all p < 0.001). Discussion: We observed differences in migraine care delivery preferences between migraine frequency and level of migraine disability. Observations support development of care pathways that include a written migraine action plan, primary care-neurology collaboration including nontraditional interactions, and prioritization of traditional neurology consultation for the most disabled patients.