The Role of Protocadherin γ in Adult Sensory Neurons and Skin Reinnervation.

The clustered protocadherins (cPcdhs) play a critical role in the patterning of several CNS axon and dendritic arbors, through regulation of homophilic self and neighboring interactions. While not explored, primary peripheral sensory afferents that innervate the epidermis may require similar constraints to convey spatial signals with appropriate fidelity. Here, we show that members of the γ-Pcdh (Pcdhγ) family are expressed in both adult sensory neuron axons and in neighboring keratinocytes that have close interactions during skin reinnervation. Adult mice of both sexes were studied. Pcdhγ knock-down either through small interfering RNA (siRNA) transduction or AAV-Cre recombinase transfection of adult mouse primary sensory neurons from floxed Pcdhγ mice was associated with a remarkable rise in neurite outgrowth and branching. Rises in outgrowth were abrogated by Rac1 inhibition. Moreover, AAV-Cre knock-down in Pcdhγ floxed neurons generated a rise in neurite self-intersections, and a robust rise in neighbor intersections or tiling, suggesting a role in sensory axon repulsion. Interestingly, preconditioned (3-d axotomy) neurons with enhanced growth had temporary declines in Pcdhγ and lessened outgrowth from Pcdhγ siRNA. In vivo, mice with local hindpaw skin Pcdhγ knock-down by siRNA had accelerated reinnervation by new epidermal axons with greater terminal branching and reduced intra-axonal spacing. Pcdhγ knock-down also had reciprocal impacts on keratinocyte density and nuclear size. Taken together, this work provides evidence for a role of Pcdhγ in attenuating outgrowth of sensory axons and their interactions, with implications in how new reinnervating axons following injury fare amid skin keratinocytes that also express Pcdhγ.SIGNIFICANCE STATEMENT The molecular mechanisms and potential constraints that govern skin reinnervation and patterning by sensory axons are largely unexplored. Here, we show that γ-protocadherins (Pcdhγ) may help to dictate interaction not only among axons but also between axons and keratinocytes as the former re-enter the skin during reinnervation. Pcdhγ neuronal knock-down enhances outgrowth in peripheral sensory neurons, involving the growth cone protein Rac1 whereas skin Pcdhγ knock-down generates rises in terminal epidermal axon growth and branching during re-innervation. Manipulation of sensory axon regrowth within the epidermis offers an opportunity to influence regenerative outcomes following nerve injury.

High-Throughput, Label-Free Detection of DNA Origami in Single-Cell Suspensions Using origamiFISH-Flow.

Structural DNA nanotechnology enables custom fabrication of nanoscale devices and promises diverse biological applications. However, the effects of design on DNA nanostructure (DN)-cell interactions in vitro and in vivo are not yet well-characterized. origamiFISH is a recently developed technique for imaging DNs in cells and tissues. Compared to the use of fluorescent tags, origamiFISH offers label-free and structure-agnostic detection of DNs with significantly improved sensitivity. Here, the origamiFISH technique is extended to quantify DNs in single-cell suspensions, including in nonadherent cells such as subsets of immune cells, via readout by flow cytometry. This method, referred to as origamiFISH-Flow, is high-throughput (e.g., 10 000 cells per second) and compatible with immunostaining for concurrent cell-type and cell-state characterization. It is shown that origamiFISH-Flow provides 20-fold higher signal-to-noise ratio for DN detection compared to dye labeling approaches, leading to the capture of >25-fold more DN+ cells under single-picomolar DN uptake concentrations. Additionally, the use of origamiFISH-Flow is validated to profile the uptake of various DN shapes across multiple cell lines and splenocytes, as well as to quantify in vivo DN accumulation in lymphoid organs. Together, origamiFISH-Flow offers a new tool to interrogate DN interactions with cells and tissues, while providing insights for tailoring their designs in bio-applications.

Percutaneous left atrial appendage occlusion and risk of stroke, hospitalized bleeding and death in Medicare beneficiaries.

PURPOSE: Among patients with atrial fibrillation (AF), a nonpharmacologic option (e.g., percutaneous left atrial appendage occlusion [LAAO]) is needed for patients with oral anticoagulant (OAC) contraindications. Among beneficiaries in the Medicare fee-for-service coverage 20% sample databases (2015-18) who had AF and an elevated CHA2DS2-VASc score, we assessed the association between percutaneous LAAO versus OAC use and risk of stroke, hospitalized bleeding, and death. METHODS: Patients undergoing percutaneous LAAO were matched to up to five OAC users by sex, age, date of enrollment, index date, CHA2DS2-VASc score, and HAS-BLED score. Overall, 17 156 patients with AF (2905 with percutaneous LAAO) were matched (average ± SD 78 ± 6 years, 44% female). Cox proportional hazards model were used. RESULTS: Median follow-up was 10.3 months. After multivariable adjustments, no significant difference for risk of stroke or death was noted when patients with percutaneous LAAO were compared with OAC users (HRs [95% CIs]: 1.14 [0.86-1.52], 0.98 [0.86-1.10]). There was a 2.94-fold (95% CI: 2.50-3.45) increased risk for hospitalized bleeding for percutaneous LAAO compared with OAC use. Among patients 65 to <78 years old, those undergoing percutaneous LAAO had higher risk of stroke compared with OAC users. No association was present in those ≥78 years. CONCLUSION: In this analysis of real-world AF patients, percutaneous LAAO versus OAC use was associated with similar risk of death, nonsignificantly elevated risk of stroke, and an elevated risk of bleeding in the post-procedural period. Overall, these results support results of randomized trials that percutaneous LAAO may be an alternative to OAC use for patients with contraindications.

Association of diabetes and glycemic control with left atrial function: The Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND AND AIMS: Although glycemic status is associated with impaired cardiac structure and function, less is known on left atrial (LA) function across the glycemic spectrum. We evaluated the association of diabetes and glycemic control with LA function in a community-based cohort of older adults. METHODS AND RESULTS: This cross-sectional analysis included 5075 participants from the Atherosclerosis Risk in Communities Study (mean age 75.5 years, 58 % women, and 20 % Black adults) with echocardiographic strain data for LA reservoir, conduit, and contractile function. Multivariable linear regression was used to assess associations of diabetes status and glycemic control with LA function. In participants without diabetes, we used ordinal linear regression to evaluate associations of fasting glucose and HbA1c with LA function. Compared to individuals with a normal fasting glucose, prevalent diabetes was associated with 0.68 % lower LA conduit function (95 % confidence interval (CI): 1.11 to -0.25) and prediabetes a 0.47 % reduction (95 % CI: 0.85 to -0.09) in fully adjusted analyses. Persons with diabetes and high HbA1c (HgbA1c ≥ 7 % vs <7 %) had 1.05 % lower LA conduit function (95 % CI: 1.63, -0.48). Among individuals without diagnosed diabetes, higher fasting glucose, but not HbA1c, was significantly associated with worse LA conduit function. No significant associations were observed for LA reservoir and contractile function. CONCLUSIONS: A history of diabetes, prediabetes, and higher fasting glucose levels in persons without diabetes were associated with worse LA conduit function. Corroborative research is needed in prospective cohorts as well as studies that explore underlying mechanisms.

Left Atrial Mechanical Dysfunction and the Risk for Ischemic Stroke in People Without Prevalent Atrial Fibrillation or Stroke : A Prospective Cohort Study.

BACKGROUND: Atrial myopathy-characterized by changes in left atrial function and size-may precede and promote atrial fibrillation (AF) and cardiac thromboembolism. In people without prior AF or stroke, whether analysis of left atrial function and size can improve ischemic stroke prediction is unknown. OBJECTIVE: To evaluate the association of echocardiographic left atrial function (reservoir, conduit, and contractile strain) and left atrial size (left atrial volume index) with ischemic stroke and determine whether these measures can improve the stroke prediction achieved by CHA2DS2-VASc score variables. DESIGN: Prospective cohort study. SETTING: ARIC (Atherosclerosis Risk in Communities) study. PARTICIPANTS: 4917 ARIC participants without prevalent stroke or AF. MEASUREMENTS: Ischemic stroke events (2011 to 2019) were adjudicated by physicians. Left atrial strain was measured using speckle-tracking echocardiography. RESULTS: Over 5 years, the cumulative incidences of ischemic stroke in the lowest quintiles of left atrial reservoir, conduit, and contractile strain were 2.99% (95% CI, 1.89% to 4.09%), 3.18% (CI, 2.14% to 4.22%), and 2.15% (CI, 1.09% to 3.21%), respectively, and that of severe left atrial enlargement was 1.99% (CI, 0.23% to 3.75%). On the basis of the Akaike information criterion, left atrial reservoir strain plus CHA2DS2-VASc variables was the best predictive model. With the addition of left atrial reservoir strain to CHA2DS2-VASc variables, 11.6% of the 112 participants with stroke after 5 years were reclassified to higher risk categories and 1.8% to lower risk categories. Among the 4805 participants who did not develop stroke, 12.2% were reclassified to lower and 12.7% to higher risk categories. Decision curve analysis showed a predicted net benefit of 1.34 per 1000 people at a 5-year risk threshold of 5%. LIMITATION: Underascertainment of subclinical AF. CONCLUSION: In people without prior AF or stroke, when added to CHA2DS2-VASc variables, left atrial reservoir strain improves stroke prediction and yields a predicted net benefit, as shown by decision curve analysis. PRIMARY FUNDING SOURCE: National Heart, Lung, and Blood Institute of the National Institutes of Health.

Deep terminal negative of the P wave in V1 and incidence of ischemic stroke: The atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Deep terminal negative of the P wave in V1 (DTNPV1) is a marker of left atrial remodeling. We aimed to evaluate the association of DTNPV1 with incident ischemic stroke. METHODS: The Atherosclerosis Risk in Communities study is a prospective community-based cohort study. All participants at visit 4 (1996-1998) except those with prevalent stroke, missing covariates, and missing or uninterpretable ECG were included. DTNPV1 was defined as the absolute value of the depth of the terminal negative phase >100 µV in the presence of biphasic P wave in V1. Association between DTNPV1 as a time-dependent exposure variable and incident ischemic stroke was evaluated. The accuracy of the prediction model consisting of DTNPV1 and CHA2DS2-VASc variables in predicting ischemic stroke was analyzed. RESULTS: Among 10,605 participants (63 ± 6 years, 56% women, 20% Black), 803 cases of ischemic stroke occurred over a median follow-up of 20.19 years. After adjusting for demographics, DTNPV1 was associated with an increased risk of stroke (HR 1.96, [95% CI 1.39-2.77]). After further adjusting for stroke risk factors, use of aspirin and anticoagulants, and time-dependent atrial fibrillation, DTNPV1 was associated with a 1.50-fold (95% CI 1.06-2.13) increased risk of stroke. When added to the CHA2DS2-VASc variables, DTNPV1 did not significantly improve stroke prediction as assessed by C-statistic. However, there was improvement in risk classification for participants who did not develop stroke. CONCLUSION: DTNPV1 is significantly associated with higher risk of ischemic stroke. Since DTNPV1 is a simplified electrocardiographic parameter, it may help stroke prediction, a subject for further research.

Venous thromboembolism mortality and trends in older US adults, 2011-2019.

Venous thromboembolism (VTE) affects 1.2 million people per year in the United States. With several clinical changes in diagnosis and treatment approaches in the past decade, we evaluated contemporary post-VTE mortality risk profiles and trends. Incident VTE cases were identified from the 2011-2019 Medicare 20% Sample, which is representative of nearly all Americans aged 65 and older. The social deprivation index was linked from public data; race/ethnicity and sex were self-reported. The all-cause mortality risk 30 days and 1 year after incident VTE was calculated in demographic subgroups and by prevalent cancer diagnosis status using model-based standardization. Risks for major cancer types, risk differences by age, sex, race/ethnicity, and socio-economic status (SES), and trends over time are also reported. The all-cause mortality risk among older US adults following incident VTE was 3.1% (95% CI 3.0-3.2) at 30 days and 19.6% (95% CI 19.2-20.1) at 1 year. For cancer-related VTE events, the age-sex-race-standardized risk was 6.0% at 30 days and 34.7% at 1 year. The standardized 30-day and 1-year risks were higher among non-White beneficiaries and among those with low SES. One-year mortality risk decreased 0.28 percentage points per year (95% CI 0.16-0.40) on average across the study period, with no trend observed for 30-day mortality risk. In sum, all-cause mortality risk following incident VTE has decreased slightly in the last decade, but racial and socio-economic disparities persist. Understanding patterns of mortality among demographic subgroups and in cancer-associated events is important for targeting efforts to improve VTE management.

Burdens of disease and caregiver burden in complex vascular malformations.

INTRODUCTION: Vascular malformations (VMs) are rare diseases that affect a wide age range of patients and require complicated care and management. The strain these conditions put on patients and their caretakers is not well understood. This study aims to characterize those burdens in young adult patients and parents of patients with VMs to improve communication, health-related quality of life, and caregiver burden. METHODS: We performed semi-structured interviews with patients and parents of patients with VMs. Interviews were conducted via telephone or video-call software, recorded, and transcribed. The transcriptions were analyzed to identify burden themes through multiple rounds of codebook development and refinement. The final codebook was applied to all interviews. RESULTS: Twenty-five young adult patients and 34 parent interviews were performed and led to the identification of four primary themes of disease burden that showed up in almost every interview: burdens of the disease process, logistical and financial burdens, psychological and emotional burdens, and social burdens. Persistent uncertainty was prominent and exacerbated all other burdens as well. DISCUSSION: We found that patients and parents struggle with burdens in a wider breadth of life experiences than have been previously characterized in the literature. They feel stressors of isolation, struggles with their identity, and even traumatic experiences from prior medical encounters. It is critical for providers of these patients and families to be aware of the burdens that they face outside of the immediate medical context. Acknowledging and providing space to address these burdens has the potential to greatly improve therapeutic relationships.

Association of abnormal p-wave parameters with brain MRI morphology: The atherosclerosis risk in communities neurocognitive study (ARIC-NCS).

BACKGROUND: Recent evidence indicates that abnormal P-wave parameters (PWPs)-ECG markers of atrial myopathy-are associated with incident dementia, independent of atrial fibrillation (AF) and clinical ischemic stroke. However, the mechanisms remain unclear and may include subclinical vascular brain injury. Hence, we evaluated the association of abnormal PWPs with brain MRI correlates of vascular brain injury in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). METHODS: ARIC-NCS participants who underwent 3T brain MRI scans in 2011-2013 were included. PWPs were measured from standard 12-lead ECGs. Brain MRI outcomes included cortical infarcts, lacunar infarcts, cerebral microhemorrhages, brain volumes, and white matter disease (WMD) volume. We used weighted multivariable logistic and linear regression to evaluate the associations of abnormal PWPs with brain MRI outcomes. RESULTS: Among 1715 participants (mean age, 76.1 years; 61% women; 29% Black), 797 (46%) had ≥1 abnormal PWP. After multivariable adjustment, including adjusting for prevalent AF, abnormal P-wave terminal force in lead V1 (aPTFV1) and prolonged P-wave duration (PPWD) were associated with increased odds of both cortical (OR 1.41; 95% CI, 1.14 to 1.74 and OR 1.30; 95% CI, 1.04 to 1.63, respectively) and lacunar infarcts (OR 1.36; 95% CI, 1.15 to 1.63 and OR 1.37; 95% CI, 1.15 to 1.65, respectively). Advanced interatrial block (aIAB) was associated with higher odds of subcortical microhemorrhage (OR 2.04; 95% CI, 1.36 to 3.06). Other than a significant association between aPTFV1 with lower parietal lobe volume, there were no other significant associations with brain or WMD volume. CONCLUSION: In this exploratory analysis of a US community-based cohort, ECG surrogates of atrial myopathy are associated with a higher prevalence of brain infarcts and microhemorrhage, suggesting subclinical vascular brain injury as a possible mechanism underlying the association of atrial myopathy with dementia.

Developing a Quality Assurance Framework for Neuro-Ophthalmology Using a Multisite Data Registry.

BACKGROUND: Quality assurance (QA) in neuro-ophthalmology (NOPH) is often lacking. We aimed to assess the quality of referral assessment and time to consult for common neuro-ophthalmological conditions by implementing a quality-assurance registry, NODE (Neuro-ophthalmology Database), in a tertiary neuro-ophthalmology clinic. Australian standardized triage categories, namely, P1 (consult ≤30 days), P2 (consult ≤30-60 days), and P3 (consult ≤60-90 days), were developed and validated for neuro-ophthalmological conditions. METHODS: We collected data from NODE on 676 patients at the Alfred Hospital, Melbourne and developed a consensus on the assignation of NOPH conditions to triage categories using a modified Delphi approach. A panel of 7 experienced neuro-ophthalmologists scored conditions and assignation to triage categories. Consensus was considered when ≥75% of the panel strongly agreed or agreed. We analyzed the mean days from referral to triage and from triage to the initial consultation and compared that with the developed triage category standard. RESULTS: Most patients presenting to the service were female (64%). Common diagnoses were idiopathic intracranial hypertension (IIH) (19%), optic neuropathy (ON) (14%), nonspecific headaches (11%), cranial nerve defects (CND) (8%), and papilledema (7%). Consensus on triage category assignment was reached after 2 rounds of scoring from expert panel members. The mean time from referral to triage was performed in <5 days for all the common diagnosis at the NOPH clinic. The mean days (±SD) from P1 category triage to initial consult for IIH was 15 (±12) days, acute ON 16 (±14) days, CND was 20 (±15) days, and papilledema was 20 (±19) days. The mean days from P2 triage to initial consultant for nonspecific headaches was 22 (±20) days and for EOMD was 48 (±22) days. The mean time (days) from P3 triage to initial consultant for nonocular myasthenia gravis was 38 days (±29) days and for visual snow was 54 (±31) days. CONCLUSIONS: We have established a consensus agreement on triage categories for neuro-ophthalmological conditions, which can be further validated using a larger panel of experts. We established a NOPH registry that will serve as a framework to benchmark quality of care between NOPH services. Data from our NOPH registry demonstrated that most conditions are appropriately triaged and seen.

Heat generated during dental treatments affecting intrapulpal temperature: a review.

INTRODUCTION: Heat is generated and transferred to the dentine-pulp complex during various dental procedures, such as from friction during cavity preparations, exothermic reactions during the polymerisation of restorative materials and when polishing restorations. For in vitro studies, detrimental effects are possible when intra-pulpal temperature increases by more than 5.5°C (that is, the intra-pulpal temperature exceeds 42.4°C). This excessive heat transfer results in inflammation and necrosis of the pulp. Despite numerous studies stating the importance of heat transfer and control during dental procedures, there are limited studies that have quantified the significance. Past studies incorporated an experimental setup where a thermocouple is placed inside the pulp of an extracted human tooth and connected to an electronic digital thermometer. METHODS: This review identified the opportunity for future research and develop both the understanding of various influencing factors on heat generation and the different sensor systems to measure the intrapulpal temperature. CONCLUSION: Various steps of dental restorative procedures have the potential to generate considerable amounts of heat which can permanently damage the pulp, leading to pulp necrosis, discoloration of the tooth and eventually tooth loss. Thus, measures should be undertaken to limit pulp irritation and injury during procedures. This review highlighted the gap for future research and a need for an experimental setup which can simulate pulp blood flow, temperature, intraoral temperature and intraoral humidity to accurately simulate the intraoral conditions and record temperature changes during various dental procedures.

The prospective association between periodontal disease and brain imaging outcomes: The Atherosclerosis Risk in Communities study.

AIM: We investigate if periodontal disease is prospectively associated with cerebrovascular and neurodegenerative markers of dementia and Alzheimer's pathology. MATERIALS AND METHODS: N = 1306 participants (Visit 5 mean age = 76.5 [standard deviation = 5.4] years) in the Atherosclerosis Risk in Communities study with completed dental exams at Visit 4 underwent brain magnetic resonance imaging scans at Visit 5 while N = 248 underwent positron emission tomography scans. Participants were classified as edentulous or, among the dentate, by the modified Periodontal Profile Class. Brain volumes were regressed on periodontal status in linear regressions. Cerebrovascular measures and ß-amyloid positivity were regressed on periodontal status in logistic regressions. RESULTS: Periodontal disease was not associated with brain volumes, microhaemorrhages, or elevated ß-amyloid. Compared with periodontally healthy individuals, odds ratios [95% confidence interval] for all-type infarcts were 0.37 [0.20, 0.65] for severe tooth loss and 0.56 [0.31, 0.99] for edentulous participants. CONCLUSIONS: Within the limitations of this study, periodontal disease was not associated with altered brain volumes, microhaemorrhages, or ß-amyloid positivity. Tooth loss was associated with lower odds of cerebral infarcts.

Association of Echocardiographic Measures of Left Atrial Function and Size With Incident Dementia.

Importance: Atrial myopathy-characterized by alterations in left atrial (LA) function and size-is associated with ischemic stroke, independent of atrial fibrillation (AF). Electrocardiographic markers of atrial myopathy are associated with dementia, but it is unclear whether 2-dimensional echocardiographic (2DE)-defined LA function and size are associated with dementia. Objective: To examine the association of LA function and size with incident dementia. Design, Setting, and Participants: The Atherosclerosis Risk in Communities (ARIC) study is a community-based prospective cohort. An exploratory, retrospective analysis was conducted. ARIC centers are located in Forsyth County, North Carolina; Jackson, Mississippi; Washington County, Maryland; and suburban Minneapolis, Minnesota. For this analysis, visit 5 (2011-2013) served as the baseline. Participants without prevalent AF and stroke and who had 2DEs in 2011-2013 were included and surveilled through December 31, 2019. Exposures: LA function (reservoir strain, conduit strain, contractile strain, emptying fraction, passive emptying fraction, and active emptying fraction), and LA size (maximal and minimal volume index) as evaluated by 2DE. Main Outcomes and Measures: Dementia cases were identified using in-person and phone cognitive assessments, hospitalization codes, and death certificates. Cox proportional hazards models were used. Results: Among 4096 participants (mean [SD] age, 75 [5] years; 60% women; 22% Black individuals), 531 dementia cases were ascertained over a median follow-up of 6 years. Dementia incidence for the lowest LA quintile was 4.80 for reservoir strain, 3.94 for conduit strain, 3.29 for contractile strain, 4.20 for emptying fraction, 3.67 for passive emptying fraction, and 3.27 for active emptying fraction per 100 person-years. After full-model adjustments, there were statistically significant associations between measures of LA function and dementia; the hazard ratios (HRs) from the lowest vs highest quintile for reservoir strain were 1.98 (95% CI, 1.42-2.75); for conduit strain, 1.50 (95% CI, 1.09-2.06); for contractile strain, 1.57 (95% CI, 1.16-2.14); for emptying fraction, 1.87 (95% CI, 1.31-2.65); and for active emptying fraction, 1.43 (95% CI, 1.04-1.96). LA passive emptying fraction was not significantly associated with dementia (HR, 1.26 [95% CI, 0.93-1.71]). Dementia incidence for the highest LA maximal volume index quintile was 3.18 per 100 person-years (HR for highest vs lowest quintile, 0.77 [95% CI, 0.58-1.02]) and for the highest minimal volume index quintile was 3.50 per 100 person-years (HR for the highest vs lowest quintile, 0.95 [95% CI, 0.71-1.28]). Both measures were not significantly associated with dementia. These findings were robust to sensitivity analyses that excluded participants with incident AF or stroke. Conclusions and Relevance: In this exploratory analysis of a US community-based cohort, several echocardiographic measures of lower LA function were significantly associated with an increased risk of subsequent dementia. Measures of LA size were not significantly associated with dementia risk. These findings suggest that impaired LA function may be a risk factor associated with dementia.

Association of Carotid Intima-Media Thickness with Brain MRI Markers in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS).

OBJECTIVE: Elevated carotid intima-media thickness (cIMT) and carotid plaque are markers of arterial injury and may be linked to structural brain injury. We hypothesized cIMT or presence of carotid plaque at midlife are associated with presence of infarcts and cerebral microbleeds, greater white matter hyperintensity (WMH) volume, and smaller regional brain volumes in late-life. METHODS: We included 1,795 Atherosclerosis Risk in Communities (ARIC) Study participants (aged 57±6 years, 57% female, 23% Black) with carotid ultrasounds in 1990-1992 and brain MRI scans in 2011-2013. Weighted linear regression was used for brain volume outcomes, while logistic regression was used for infarcts and cerebral microbleeds. RESULTS: After multivariable adjustments, the highest cIMT quintile was associated with smaller deep gray matter (ß [95% CI]: -0.11 [-0.22, -0.01]) and cortical volume in a temporal-parietal meta region of interest (ROI) (ß [95% CI]: -0.10 [-0.20, -0.01]) in late-life. Similarly, those with carotid plaque had smaller regional brain volumes than those without (ßs [95% CIs]: -0.05 [-0.12, 0.03] and -0.06 [-0.13, 0.01] for deep gray matter and temporal-parietal meta ROI). No significant relations were observed with WMH volume, infarcts, or cerebral microbleeds. CONCLUSION: Over a median follow-up of 21 years, greater midlife cIMT and presence of carotid plaque were associated with smaller deep gray matter volume and cortical volume in a meta ROI involving temporal and parietal lobe regions typically involved in neurodegeneration, including Alzheimer's disease, in later life. Contrary to our hypothesis, associations between measures of arterial injury and markers of vascular brain injury were null.

The γ-Protocadherins Regulate the Survival of GABAergic Interneurons during Developmental Cell Death.

Inhibitory interneurons integrate into developing circuits in specific ratios and distributions. In the neocortex, inhibitory network formation occurs concurrently with the apoptotic elimination of a third of GABAergic interneurons. The cell surface molecules that select interneurons to survive or die are unknown. Here, we report that members of the clustered Protocadherins (cPCDHs) control GABAergic interneuron survival during developmentally-regulated cell death. Conditional deletion of the gene cluster encoding the γ-Protocadherins (Pcdhgs) from developing GABAergic neurons in mice of either sex causes a severe loss of inhibitory populations in multiple brain regions and results in neurologic deficits such as seizures. By focusing on the neocortex and the cerebellar cortex, we demonstrate that reductions of inhibitory interneurons result from elevated apoptosis during the critical postnatal period of programmed cell death (PCD). By contrast, cortical interneuron (cIN) populations are not affected by removal of Pcdhgs from pyramidal neurons or glial cells. Interneuron loss correlates with reduced AKT signaling in Pcdhg mutant interneurons, and is rescued by genetic blockade of the pro-apoptotic factor BAX. Together, these findings identify the PCDHGs as pro-survival transmembrane proteins that select inhibitory interneurons for survival and modulate the extent of PCD. We propose that the PCDHGs contribute to the formation of balanced inhibitory networks by controlling the size of GABAergic interneuron populations in the developing brain.SIGNIFICANCE STATEMENT A pivotal step for establishing appropriate excitatory-inhibitory ratios is adjustment of neuronal populations by cell death. In the mouse neocortex, a third of GABAergic interneurons are eliminated by BAX-dependent apoptosis during the first postnatal week. Interneuron cell death is modulated by neural activity and pro-survival pathways but the cell-surface molecules that select interneurons for survival or death are unknown. We demonstrate that members of the cadherin superfamily, the clustered γ-Protocadherins (PCDHGs), regulate the survival of inhibitory interneurons and the balance of cell death. Deletion of the Pcdhgs in mice causes inhibitory interneuron loss in the cortex and cerebellum, and leads to motor deficits and seizures. Our findings provide a molecular basis for controlling inhibitory interneuron population size during circuit formation.

Single-molecule level structural dynamics of DNA unwinding by human mitochondrial Twinkle helicase.

Knowledge of the molecular events in mitochondrial DNA (mtDNA) replication is crucial to understanding the origins of human disorders arising from mitochondrial dysfunction. Twinkle helicase is an essential component of mtDNA replication. Here, we employed atomic force microscopy imaging in air and liquids to visualize ring assembly, DNA binding, and unwinding activity of individual Twinkle hexamers at the single-molecule level. We observed that the Twinkle subunits self-assemble into hexamers and higher-order complexes that can switch between open and closed-ring configurations in the absence of DNA. Our analyses helped visualize Twinkle loading onto and unloading from DNA in an open-ringed configuration. They also revealed that closed-ring conformers bind and unwind several hundred base pairs of duplex DNA at an average rate of ∼240 bp/min. We found that the addition of mitochondrial single-stranded (ss) DNA-binding protein both influences the ways Twinkle loads onto defined DNA substrates and stabilizes the unwound ssDNA product, resulting in a ∼5-fold stimulation of the apparent DNA-unwinding rate. Mitochondrial ssDNA-binding protein also increased the estimated translocation processivity from 1750 to >9000 bp before helicase disassociation, suggesting that more than half of the mitochondrial genome could be unwound by Twinkle during a single DNA-binding event. The strategies used in this work provide a new platform to examine Twinkle disease variants and the core mtDNA replication machinery. They also offer an enhanced framework to investigate molecular mechanisms underlying deletion and depletion of the mitochondrial genome as observed in mitochondrial diseases.

High eosinophil counts predict decline in FEV1: results from the CanCOLD study.

INTRODUCTION: The aim of this study was to examine the association between blood eosinophil levels and the decline in lung function in individuals aged >40 years from the general population. METHODS: The study evaluated the eosinophil counts from thawed blood in 1120 participants (mean age 65 years) from the prospective population-based Canadian Cohort of Obstructive Lung Disease (CanCOLD) study. Participants answered interviewer-administered respiratory questionnaires and performed pre-/post-bronchodilator spirometric tests at 18-month intervals; computed tomography (CT) imaging was performed at baseline. Statistical analyses to describe the relationship between eosinophil levels and decline in forced expiratory volume in 1 s (FEV1) were performed using random mixed-effects regression models with adjustments for demographics, smoking, baseline FEV1, ever-asthma and history of exacerbations in the previous 12 months. CT measurements were compared between eosinophil subgroups using ANOVA. RESULTS: Participants who had a peripheral eosinophil count of ≥300 cells·µL-1 (n=273) had a greater decline in FEV1 compared with those with eosinophil counts of <150 cells·µL-1 (n=430; p=0.003) (reference group) and 150-<300 cells·µL-1 (n=417; p=0.003). The absolute change in FEV1 was -32.99 mL·year-1 for participants with eosinophil counts <150 cells·µL-1; -38.78 mL·year-1 for those with 150-<300 cells·µL-1 and -67.30 mL·year-1 for participants with ≥300 cells·µL-1. In COPD, higher eosinophil count was associated with quantitative CT measurements reflecting both small and large airway abnormalities. CONCLUSION: A blood eosinophil count of ≥300 cells·µL-1 is an independent risk factor for accelerated lung function decline in older adults and is related to undetected structural airway abnormalities.

Hospital Safety-Net Burden Is Associated With Increased Inpatient Mortality and Perioperative Complications After Colectomy.

BACKGROUND: Colectomies are common yet costly, with high surgical-site infection rates. Safety-net hospitals (SNHs) carry a large proportion of uninsured or Medicaid-insured patients, which has been associated with poorer surgical outcomes. Few studies have examined the effect of safety-net burden (SNB) status on colectomy outcomes. We aimed to quantify the independent effects of hospital SNB and surgical site infection (SSI) status on colectomy outcomes, as well as the interaction effect between SSIs and SNB. METHODS: We used the Healthcare Cost and Utilization Project's State Inpatient Databases for California, Florida, New York, Maryland, and Kentucky. We included 459,568 colectomies (2009 to 2014) for analysis, excluding patients age <18 y and rectal cases. The primary and secondary outcomes were inpatient mortality and complications, respectively. RESULTS: Adjusting for patient, procedure, and hospital factors, colectomy patients were more likely to die in-hospital at high-burden SNHs (adjusted OR [aOR]: 1.38, 95% confidence interval [CI]: 1.25-1.51, P < 0.001), compared with low SNB hospitals and to experience perioperative complications (aOR: 1.12, 95% CI: 1.04-1.20, P < 0.01). Colectomy patients with SSIs also had greater odds of in-hospital mortality (aOR: 1.92, 95% CI: 1.83-2.02, P < 0.001) and complications (aOR: 3.65, 95% CI: 3.55-3.75, P < 0.001) compared with those without infections. Patients treated at SNHs who developed a SSI were even more likely to have an additional perioperative complication (aOR: 4.33, 95% CI: 3.98-4.71, P < 0.001). CONCLUSIONS: Our study demonstrated that colectomy patients at SNHs have poorer outcomes, and for patients with SSIs, this disparity was even more pronounced in the likelihood for a complication. SNB should be recognized as a significant hospital-level factor affecting colectomy outcomes, with SSIs as an important quality metric.

Effects of walking speeds and durations on plantar skin blood flow responses.

BACKGROUND: Various walking speeds and durations in daily life cause different levels of ischemia of plantar tissues. It is unclear what walking speeds and durations significantly affect plantar tissue viability and risks for foot ulcers in non-diabetics and diabetics. OBJECTIVE: The aim of this study was to establish the normal response of plantar skin blood flow to different speeds and durations of walking exercise in non-diabetics that would be needed to quantify impaired responses in diabetics. METHOD: Laser Doppler flowmetry was used to measure plantar skin blood flow of the first metatarsal head in 12 non-diabetics. A 3 × 2 factorial design, including 3 speeds (slow at 3 km/h, moderate at 6 km/h, and fast at 9 km/h) and 2 durations (10 and 20 min), was used in this study. Skin blood flow after walking was expressed as a ratio of skin blood flow before walking. The 3 × 2 two-way analysis of variance (ANOVA) with repeated measures was used to examine the main effects of speeds and durations and their interaction. RESULT: The walking speed significantly affected skin blood flow responses (p < 0.01). Walking at 9 km/h significantly increased plantar skin blood flow (5.71 ±â€¯1.89) compared to walking at 6 km/h (2.1 ±â€¯0.29) and 3 km/h (1.16 ±â€¯0.14), especially at 20-minute walking duration (p < 0.01). The walking duration showed a trend of significance on affecting skin blood flow responses (p = 0.06). There was no significant interaction between walking speeds and durations (p > 0.05). CONCLUSIONS: Our results provide the first evidence that walking speeds affect plantar skin blood flow and a fast walking speed (9 km/h) significantly increases plantar skin blood flow compared to moderate (6 km/h) and slow (3 km/h) walking speeds.

Racial, Ethnic, and Gender Diversity in Pediatric Anesthesiology Fellowship and Anesthesiology Residency Programs in the United States: Small Reservoir, Leaky Pipeline.

BACKGROUND: The critical question of racial and gender diversity in pediatric anesthesia training programs has not been previously explored. The primary objective of this study was to evaluate trends by race/ethnicity and gender in pediatric anesthesiology fellowship training programs in the United States for the years 2000 to 2018. METHODS: Demographic data on pediatric anesthesiology fellows and anesthesiology residents were obtained from the self-reported data collected for the Journal of the American Medical Association's annual report on Graduate Medical Education for the years 2000 to 2018. Diversity was assessed by calculating the proportions of trainees per year by gender and racial/ethnic groups in pediatric anesthesiology fellowship and anesthesiology residency programs. Logistic regression equations were developed to estimate the annual growth rate of each racial/ethnic groups. RESULTS: The number of pediatric anesthesiology fellows increased from 57 trainees in 2000-2001 to 202 in 2017-2018 at an average rate of 9 fellows per year (95% confidence interval [CI], 8-10). These increases were primarily due to white trainees (54.4%-63.4%) as the proportions of black (7.0%-4.5%), Asian (26.3%-21.3%), and other minority (12.3%-10.9%) trainees have remained low. The number of anesthesiology residents increased from 3950 trainees in 2000-2001 to 5940 in 2017-2018 at an average rate of 99 residents per year (95% CI, 88-111). Within all anesthesiology trainees, these increases were due to white trainees (55.7%-61.3%) as the proportion of black (5.0%-6.0%), Asian (25.8%-24.1%), and other minority trainees (8.2%-8.5%) has remained fairly constant over the time period. Despite the overall lower proportion of female anesthesiology residents (range: 27.0%-37.5%), a steady increase in the number of women in pediatric anesthesiology fellowship programs has reversed the gender imbalance in this population as of 2010. CONCLUSIONS: While historic gains have been made in gender diversity in pediatric anesthesiology, there is persistent underrepresentation of black and Hispanic trainees in pediatric anesthesiology. It appears that their low numbers in anesthesiology residency programs (the reservoir) may be partly responsible. Efforts to increase ethnic/racial diversity in pediatric anesthesiology fellowship and anesthesiology residency training programs are urgently needed.