The dynamics of human bone marrow adipose tissue in response to feeding and fasting.

BACKGROUNDAdipocytes were long considered inert components of the bone marrow niche, but mouse and human models suggest bone marrow adipose tissue (BMAT) is dynamic and responsive to hormonal and nutrient cues.METHODSIn this study of healthy volunteers, we investigated how BMAT responds to acute nutrient changes, including analyses of endocrine determinants and paracrine factors from marrow aspirates. Study participants underwent a 10-day high-calorie protocol, followed by a 10-day fast.RESULTSWe demonstrate (a) vertebral BMAT increased significantly during high-calorie feeding and fasting, suggesting BMAT may have different functions in states of caloric excess compared with caloric deprivation; (b) ghrelin, which decreased in response to high-calorie feeding and fasting, was inversely associated with changes in BMAT; and (c) in response to high-calorie feeding, resistin levels in the marrow sera, but not the circulation, rose significantly. In addition, TNF-α expression in marrow adipocytes increased with high-calorie feeding and decreased upon fasting.CONCLUSIONHigh-calorie feeding, but not fasting, induces an immune response in bone marrow similar to what has been reported in peripheral adipose tissue. Understanding the immunomodulatory regulators in the marrow may provide further insight into the homeostatic function of this unique adipose tissue depot.FUNDINGNIH grant R24 DK084970, Harvard Catalyst/The Harvard Clinical and Translational Science Center (National Center for Advancing Translational Sciences, NIH, award UL 1TR002541), and NIH grants P30 DK040561 and U19 AG060917S1.

Sex and Race-Ethnic Disparities in Door-to-CT Time in Acute Ischemic Stroke: The Florida Stroke Registry.

Background Less than 40% of acute stroke patients have computed tomography (CT) imaging performed within 25 minutes of hospital arrival. We aimed to examine the race-ethnic and sex differences in door-to-CT (DTCT) ≤25 minutes in the FSR (Florida Stroke Registry). Methods and Results Data were collected from 2010 to 2018 for 63 265 patients with acute ischemic stroke from the FSR and secondary analysis was performed on 15 877 patients with intravenous tissue plasminogen activator-treated ischemic stroke. Generalized estimating equation models were used to determine predictors of DTCT ≤25. DTCT ≤25 was achieved in 56% of cases of suspected acute stroke, improving from 36% in 2010 to 72% in 2018. Women (odds ratio [OR], 0.90; 95% CI, 0.87-0.93) and Black (OR, 0.88; CI, 0.84-0.94) patients who had strokes were less likely, and Hispanic patients more likely (OR, 1.07; CI, 1.01-1.14), to achieve DTCT ≤25. In a secondary analysis among intravenous tissue plasminogen activator-treated patients, 81% of patients achieved DTCT ≤25. In this subgroup, women were less likely to receive DTCT ≤25 (0.85, 0.77-0.94) whereas no significant differences were observed by race or ethnicity. Conclusions In the FSR, there was considerable improvement in acute stroke care metric DTCT ≤25 in 2018 in comparison to 2010. However, sex and race-ethnic disparities persist and require further efforts to improve performance and reduce these disparities.

Targeting Microglial Polarization to Improve TBI Outcomes.

Traumatic Brain Injury (TBI) is still the worldwide leading cause of mortality and morbidity in young adults. Improved safety measures and advances in critical care have increased chances of surviving a TBI, however, numerous secondary mechanisms contribute to the injury in the weeks and months that follow TBI. The past 4 decades of research have addressed many of the metabolic impairments sufficient to mitigate mortality, however, an enduring secondary mechanism, i.e. neuroinflammation, has been intractable to current therapy. Neuroinflammation is particularly difficult to target with pharmacological agents due to lack of specificity, the blood brain barrier, and an incomplete understanding of the protective and pathologic influences of inflammation in TBI. Recent insights into TBI pathophysiology have established microglial activation as a hallmark of all types of TBI. The inflammatory response to injury is necessary and beneficial while the death of activated microglial is not. This review presents new insights on the therapeutic and maladaptive features of the immune response after TBI with an emphasis on microglial polarization, followed by a discussion of potential targets for pharmacologic and non-pharmacologic treatments. In aggregate, this review presents a rationale for guiding TBI inflammation towards neural repair and regeneration rather than secondary injury and degeneration, which we posit could improve outcomes and reduce lifelong disease burden in TBI survivors.

Genotype-Phenotype Correlation for Predicting Cochlear Implant Outcome: Current Challenges and Opportunities.

The use and utility of cochlear implantation has rapidly increased in recent years as technological advances in the field have expanded both the efficacy and eligible patient population for implantation. This review aims to serve as a general overview of the most common hearing disorders that have favorable auditory outcomes with cochlear implants (CI). Hearing loss in children caused by congenital cytomegalovirus infection, syndromic conditions including Pendred Syndrome, and non-syndromic genetic conditions such as hearing impairment associated with GJB2 mutations have shown to be successfully managed by CI. Furthermore, cochlear implantation provides the auditory rehabilitation for the most common etiology of hearing loss in adults and age-related hearing loss (ARHL) or presbycusis. However, in some cases, cochlear implantation have been associated with some challenges. Regarding implantation in children, studies have shown that sometimes parents seem to have unrealistic expectations regarding the ability of CI to provide auditory rehabilitation and speech improvement. Given the evidence revealing the beneficial effects of early intervention via CI in individuals with hearing disorders especially hearing loss due to genetic etiology, early auditory and genetic screening efforts may yield better clinical outcomes. There is a need to better understand genotype-phenotype correlations and CI outcome, so that effective genetic counseling and successful treatment strategies can be developed at the appropriate time for hearing impaired individuals.

Generalized granuloma annulare associated with essential thrombocythemia.

The only myeloproliferative neoplasm associated with generalized granuloma annulare (GA) is chronic myelogenous leukemia (CML). We present the first reported case of GA in a patient with essential thrombocythemia (ET). Future work investigating the shared pathophysiology of GA-associated CML and ET may improve our understanding of GA pathophysiology and treatment.

Role of microRNAs in inner ear development and hearing loss.

The etiology of hearing loss tends to be multi-factorial and affects a significant proportion of the global population. Despite the differences in etiology, a common physical pathological change that leads to hearing loss is damage to the mechanosensory hair cells of the inner ear. MicroRNAs (miRNAs) have been shown to play a role in inner ear development and thus, may play a role in the development or prevention of hearing loss. In this paper, we review the mechanism of action of miRNAs in the auditory system. We present an overview about the role of miRNAs in inner ear development, summarize the current research on the role of miRNAs in gene regulation, and discuss the effects of both miRNA mutations as well as overexpression. We discuss the crucial role of miRNAs in ensuring normal physiological development of the inner ear. Any deviation from the proper function of miRNA in the cochlea seems to contribute to deleterious damage to the structure of the auditory system and subsequently results in hearing loss. As interest for miRNA research increases, this paper serves as a platform to review current understandings and postulate future avenues for research. A better knowledge about the role of miRNA in the auditory system will help in developing novel treatment modalities for restoring hearing function based on regeneration of damaged inner ear hair cells.