Comparative cellular analysis of motor cortex in human, marmoset and mouse.

The primary motor cortex (M1) is essential for voluntary fine-motor control and is functionally conserved across mammals1. Here, using high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmoset monkeys and mice, we demonstrate a broadly conserved cellular makeup of this region, with similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. The core conserved molecular identities of neuronal and non-neuronal cell types allow us to generate a cross-species consensus classification of cell types, and to infer conserved properties of cell types across species. Despite the overall conservation, however, many species-dependent specializations are apparent, including differences in cell-type proportions, gene expression, DNA methylation and chromatin state. Few cell-type marker genes are conserved across species, revealing a short list of candidate genes and regulatory mechanisms that are responsible for conserved features of homologous cell types, such as the GABAergic chandelier cells. This consensus transcriptomic classification allows us to use patch-seq (a combination of whole-cell patch-clamp recordings, RNA sequencing and morphological characterization) to identify corticospinal Betz cells from layer 5 in non-human primates and humans, and to characterize their highly specialized physiology and anatomy. These findings highlight the robust molecular underpinnings of cell-type diversity in M1 across mammals, and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations.

Publisher Correction: Somatic APP gene recombination in Alzheimer's disease and normal neurons.

In this Article, the top label in Fig. 5d should read 'DISH 3/16' instead of 'DISH 3/17'. This error has been corrected online.

Frailty in Kidney Disease: A Comprehensive Review to Advance Its Clinical and Research Applications.

Frailty is a multi-system syndrome of decreased physiologic reserve that has been shown to strongly and independently predict morbidity and mortality. Frailty is prevalent in patients living with kidney disease and occurs earlier in individuals with kidney disease as compared to the general population. In this comprehensive review, we aim to advance the clinical and research applications of frailty in kidney disease populations. Specifically, we clarify the definition of frailty and address its common misconceptions; review the mechanisms and epidemiology of frailty in kidney disease; discuss challenges and limitations in frailty measurement; and provide updated evidence related to risk factors for frailty, its associated adverse outcomes, and interventions. We further add to the literature in this topic by highlighting potential applications of frailty measurement in care of patients with kidney disease and conclude with our recommendations for future research related to this important syndrome.

Somatic APP gene recombination in Alzheimer's disease and normal neurons.

The diversity and complexity of the human brain are widely assumed to be encoded within a constant genome. Somatic gene recombination, which changes germline DNA sequences to increase molecular diversity, could theoretically alter this code but has not been documented in the brain, to our knowledge. Here we describe recombination of the Alzheimer's disease-related gene APP, which encodes amyloid precursor protein, in human neurons, occurring mosaically as thousands of variant 'genomic cDNAs' (gencDNAs). gencDNAs lacked introns and ranged from full-length cDNA copies of expressed, brain-specific RNA splice variants to myriad smaller forms that contained intra-exonic junctions, insertions, deletions, and/or single nucleotide variations. DNA in situ hybridization identified gencDNAs within single neurons that were distinct from wild-type loci and absent from non-neuronal cells. Mechanistic studies supported neuronal 'retro-insertion' of RNA to produce gencDNAs; this process involved transcription, DNA breaks, reverse transcriptase activity, and age. Neurons from individuals with sporadic Alzheimer's disease showed increased gencDNA diversity, including eleven mutations known to be associated with familial Alzheimer's disease that were absent from healthy neurons. Neuronal gene recombination may allow 'recording' of neural activity for selective 'playback' of preferred gene variants whose expression bypasses splicing; this has implications for cellular diversity, learning and memory, plasticity, and diseases of the human brain.

Altered cell and RNA isoform diversity in aging Down syndrome brains.

Down syndrome (DS), trisomy of human chromosome 21 (HSA21), is characterized by lifelong cognitive impairments and the development of the neuropathological hallmarks of Alzheimer's disease (AD). The cellular and molecular modifications responsible for these effects are not understood. Here we performed single-nucleus RNA sequencing (snRNA-seq) employing both short- (Illumina) and long-read (Pacific Biosciences) sequencing technologies on a total of 29 DS and non-DS control prefrontal cortex samples. In DS, the ratio of inhibitory-to-excitatory neurons was significantly increased, which was not observed in previous reports examining sporadic AD. DS microglial transcriptomes displayed AD-related aging and activation signatures in advance of AD neuropathology, with increased microglial expression of C1q complement genes (associated with dendritic pruning) and the HSA21 transcription factor gene RUNX1 Long-read sequencing detected vast RNA isoform diversity within and among specific cell types, including numerous sequences that differed between DS and control brains. Notably, over 8,000 genes produced RNAs containing intra-exonic junctions, including amyloid precursor protein (APP) that had previously been associated with somatic gene recombination. These and related results illuminate large-scale cellular and transcriptomic alterations as features of the aging DS brain.

Longitudinal Evaluation of Antibody Persistence in Mother-Infant Dyads After Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Pregnancy.

BACKGROUND: There are limited data on how coronavirus disease 2019 (COVID-19) severity, timing of infection, and subsequent vaccination impact transplacental transfer and persistence of maternal and infant antibodies. METHODS: In a longitudinal cohort of pregnant women with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, maternal/infant sera were collected at enrollment, delivery/birth, and 6 months. Anti-SARS-CoV-2 spike immunoglobulin (Ig)G, IgM, and IgA were measured by enzyme-linked immunosorbent assay. RESULTS: Two-hundred fifty-six pregnant women and 135 infants were enrolled; 148 maternal and 122 neonatal specimens were collected at delivery/birth; 45 maternal and 48 infant specimens were collected at 6 months. Sixty-eight percent of women produced all anti-SARS-CoV-2 isotypes at delivery (IgG, IgM, IgA); 96% had at least 1 isotype. Symptomatic disease and vaccination before delivery were associated with higher maternal IgG at labor and delivery. Detectable IgG in infants dropped from 78% at birth to 52% at 6 months. In the multivariate analysis evaluating factors associated with detectable IgG in infants at delivery, significant predictors were 3rd trimester infection (odds ratio [OR] = 4.0), mild/moderate disease (OR = 4.8), severe/critical disease (OR = 6.3), and maternal vaccination before delivery (OR = 18.8). No factors were significant in the multivariate analysis at 6 months postpartum. CONCLUSIONS: Vaccination in pregnancy post-COVID-19 recovery is a strategy for boosting antibodies in mother-infant dyads.

Effect of Long-term Exercise Training on Physical Performance and Cardiorespiratory Function in Adults With CKD: A Randomized Controlled Trial.

RATIONALE & OBJECTIVE: The safety and efficacy of long-term exercise training in reducing physical functional loss in older adults with advanced CKD and comorbidity is uncertain. STUDY DESIGN: Multicenter, parallel group, randomized controlled trial. SETTINGS & PARTICIPANTS: Adults 55 years and older with estimated glomerular filtration rate (eGFR) of 15 to <45 mL/min/1.73 m2 enrolled from centers in Baltimore and Boston. INTERVENTION: Twelve months of in-center supervised exercise training incorporating majority aerobic but also muscle strengthening activities or a group health education control intervention, randomly assigned in 1:1 ratio. OUTCOME: Primary outcomes were cardiorespiratory fitness and submaximal gait at 6 and 12 months quantified by peak oxygen consumption (Vo2peak) on graded exercise treadmill test and distance walked on the 6-minute walk test, respectively. Secondary outcomes were changes in lower extremity function, eGFR, albuminuria, glycemia, blood pressure, and body mass index. RESULTS: Among 99 participants, the mean age was 68 years, 62% were African American, and the mean eGFR was 33 mL/min/1.73 m2; 59% had diabetes, and 29% had coronary artery disease. Among those randomized to exercise, 59% of exercise sessions were attended in the initial 6 months. Exercise was well tolerated without excess occurrence of adverse events. At 6 months, aerobic capacity was higher among exercise participants (17.9 ± 5.5 vs 15.9 ± 7.0 mL/kg/min, P = 0.03), but the differences were not sustained at 12 months. The 6-minute walk distance improved more in the exercise group (adjusted difference: 98 feet [P = 0.02; P = 0.03 for treatment-by-time interaction]). The exercise group had greater improvements on the Timed Up and Go Test (P = 0.04) but not the Short Physical Performance Battery (P = 0.8). LIMITATIONS: Planned sample size was not reached. Loss to follow-up and dropout were greater than anticipated. CONCLUSIONS: Among adults aged ≥55 years with CKD stages 3b-4 and a high level of medical comorbidity, a 12-month program of in-center aerobic and resistance exercise training was safe and associated with improvements in physical functioning. FUNDING: Government grants (National Institutes of Health). TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT01462097.

Immunogenicity of adjuvanted versus high-dose inactivated influenza vaccines in older adults: a randomized clinical trial.

BACKGROUND: Adjuvanted inactivated influenza vaccine (aIIV) and high-dose inactivated influenza vaccine (HD-IIV) are U.S.-licensed for adults aged ≥ 65 years. This study compared serum hemagglutination inhibition (HAI) antibody titers for the A(H3N2) and A(H1N1)pdm09 and B strains after trivalent aIIV3 and trivalent HD-IIV3 in an older adult population. RESULTS: The immunogenicity population included 342 participants who received aIIV3 and 338 participants who received HD-IIV3. The proportion of participants that seroconverted to A(H3N2) vaccine strains after allV3 (112 participants [32.8%]) was inferior to the proportion of participants that seroconverted after HD-IIV3 (130 participants [38.5%]) at day 29 after vaccination (difference, - 5.8%; 95%CI, - 12.9% to 1.4%). There were no significant differences between the vaccine groups in percent seroconversion to A(H1N1)pdm09 or B vaccine strains, in percent seropositivity for any of the strains, or in post-vaccination GMT for the A(H1N1)pdm09 strain. The GMTs for the post-vaccination A(H3N2) and B strains were higher after HD-IIV than after aIIV3. CONCLUSIONS: Overall immune responses were similar after aIIV3 and HD-IIV3. For the primary outcome, the aIIV3 seroconversion rate for H3N2 did not meet noninferiority criteria compared with HD-IIV3, but the HD-IIV3 seroconversion rate was not statistically superior to the aIIV3 seroconversion rate. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03183908.

Mobility in Older Adults Receiving Maintenance Hemodialysis: A Qualitative Study.

RATIONALE & OBJECTIVE: For older adults, maintaining mobility is a major priority, especially for those with advanced chronic diseases like kidney failure. However, our understanding of the factors affecting mobility in older adults receiving maintenance hemodialysis is limited. STUDY DESIGN: Descriptive qualitative study. SETTING & PARTICIPANTS: Using purposive sampling, we recruited (1) persons aged≥60 years receiving maintenance hemodialysis; and (2) care partners (≥18 years) providing regular support to an older adult receiving hemodialysis. During a single in-person home visit, we assessed mobility using the Short Physical Performance Battery (SPPB) and conducted individual one-on-one interviews regarding important personal factors related to mobility. ANALYTICAL APPROACH: Descriptive statistics were used for demographic and SPPB data. Transcripts underwent thematic coding, informed by the International Classification of Function framework of mobility. We used conceptual content analysis to inductively extract themes and subthemes. RESULTS: We enrolled 31 older adults receiving hemodialysis (42% female, 68% Black) with a mean age of 73±8 years and mean dialysis vintage of 4.6±3.5 years; their mean SPPB score was 3.6±2.8 points. Among 12 care partners (75% female, 33% Black), the mean age was 54±16 years and mean SPPB score was 10.1±2.4 points. Major themes extracted were (1) mobility represents independence; (2) mobility is precarious; (3) limitations in mobility cause distress; (4) sources of encouragement and motivation are critical; and (5) adaptability is key. LIMITATIONS: Modest sample from single geographic area. CONCLUSIONS: For older adults receiving hemodialysis, mobility is severely limited and is often precarious in nature, causing distress. Older adults receiving hemodialysis and their care partners have identified sources of encouragement and motivation for mobility, and cite an adaptable mindset as important. Future studies should conceptualize mobility as a variable condition and build on this outlook of adaptability in the development of interventions.

Submegabase copy number variations arise during cerebral cortical neurogenesis as revealed by single-cell whole-genome sequencing.

Somatic copy number variations (CNVs) exist in the brain, but their genesis, prevalence, forms, and biological impact remain unclear, even within experimentally tractable animal models. We combined a transposase-based amplification (TbA) methodology for single-cell whole-genome sequencing with a bioinformatic approach for filtering unreliable CNVs (FUnC), developed from machine learning trained on lymphocyte V(D)J recombination. TbA-FUnC offered superior genomic coverage and removed >90% of false-positive CNV calls, allowing extensive examination of submegabase CNVs from over 500 cells throughout the neurogenic period of cerebral cortical development in Mus musculus Thousands of previously undocumented CNVs were identified. Half were less than 1 Mb in size, with deletions 4× more common than amplification events, and were randomly distributed throughout the genome. However, CNV prevalence during embryonic cortical development was nonrandom, peaking at midneurogenesis with levels triple those found at younger ages before falling to intermediate quantities. These data identify pervasive small and large CNVs as early contributors to neural genomic mosaicism, producing genomically diverse cellular building blocks that form the highly organized, mature brain.

Distinct Mechanisms of Dissemination of NDM-1 Metallo-ß-Lactamase in Acinetobacter Species in Argentina.

A 4-year surveillance of carbapenem-resistant Acinetobacter spp. isolates in Argentina identified 40 strains carrying blaNDM-1 Genome sequencing revealed that most were Acinetobacter baumannii, whereas seven represented other Acinetobacter spp. The A. baumannii genomes were closely related, suggesting recent spread. blaNDM-1 was located in the chromosome of A. baumannii strains and on a plasmid in non-A. baumannii strains. A resistance gene island carrying blaPER-7 and other resistance determinants was found on a plasmid in some A. baumannii strains.

Copper regulates rest-activity cycles through the locus coeruleus-norepinephrine system.

The unusually high demand for metals in the brain, along with insufficient understanding of how their dysregulation contributes to neurological diseases, motivates the study of how inorganic chemistry influences neural circuitry. We now report that the transition metal copper is essential for regulating rest-activity cycles and arousal. Copper imaging and gene expression analysis in zebrafish identifies the locus coeruleus-norepinephrine (LC-NE) system, a vertebrate-specific neuromodulatory circuit critical for regulating sleep, arousal, attention, memory and emotion, as a copper-enriched unit with high levels of copper transporters CTR1 and ATP7A and the copper enzyme dopamine ß-hydroxylase (DBH) that produces NE. Copper deficiency induced by genetic disruption of ATP7A, which loads copper into DBH, lowers NE levels and hinders LC function as manifested by disruption in rest-activity modulation. Moreover, LC dysfunction caused by copper deficiency from ATP7A disruption can be rescued by restoring synaptic levels of NE, establishing a molecular CTR1-ATP7A-DBH-NE axis for copper-dependent LC function.

Being Precise About Precision Medicine: What Should Value Frameworks Incorporate to Address Precision Medicine? A Report of the Personalized Precision Medicine Special Interest Group.

Precision medicine is a dynamic area embracing a diverse and increasing type of approaches that allow the targeting of new medicines, screening programs or preventive healthcare strategies, which include the use of biologic markers or complex tests driven by algorithms also potentially taking account of patient preferences. The International Society for Pharmacoeconomics and Outcome Research expanded its current work around precision medicine to (1) describe the evolving paradigm of precision medicine with examples of current and evolving applications, (2) describe key stakeholders perspectives on the value of precision medicine in their respective domains, and (3) define the core factors that should be considered in a value assessment framework for precision medicine. With the ultimate goal of improving health of well-defined patient groups, precision medicine will affect all stakeholders in the healthcare system at multiple levels spanning the individual perspective to the societal perspective. For an efficient, timely and practical precision medicine value assessment framework, it will be important to address these multiple perspectives through building consensus among the stakeholders for robust procedures and measures of value aspects, including performance of precision mechanism; aligned reimbursement processes of precision mechanism and subsequent treatment; transparent expectations for evidence requirements and study designs adequately matched to the intended use of the precision mechanism and to the smaller target patient populations; recognizing the potential range of value-generation such as ruling-in and ruling-out decisions.

Risk Factors for Misuse of Prescribed Opioids: A Systematic Review and Meta-Analysis.

STUDY OBJECTIVE: Increasing opioid prescribing has been linked to an epidemic of opioid misuse. Our objective is to synthesize the available evidence about patient-, prescriber-, medication-, and system-level risk factors for developing misuse among patients prescribed opioids for noncancer pain. METHODS: We performed a systematic search of the scientific and gray literature for studies reporting on risk factors for prescription opioid misuse. Two reviewers independently reviewed titles, abstracts, and full texts; extracted data; and assessed study quality. We excluded studies with greater than 50% cancer patients, palliative patients, and illicit opioid initiation. When possible, we synthesized the effect sizes of dichotomous risk factors and their associations with opioid misuse, using inverse-variance random-effects meta-analysis. We calculated the mean difference between opioid misusers and nonmisusers for continuous risk factors. When studies lacked homogeneity, we synthesized their results qualitatively. RESULTS: Of 9,629 studies, 65 met our inclusion criteria. Among patients with outpatient opioid prescriptions, the following factors were associated with the development of misuse: any current or previous substance use (odds ratio [OR] 3.55; 95% confidence interval [CI] 2.62 to 4.82), any mental health diagnosis (OR 2.45; 95% CI 1.91 to 3.15), younger age (OR 2.19; 95% CI 1.81 to 2.64), and male sex (OR 1.23; 95% CI 1.10 to 1.36). CONCLUSION: Although clinicians should endeavor to offer alternative pain management strategies to all patients, those who are younger, are male patients, and report a history of or current substance use or mental health diagnoses were associated with a greater risk of developing opioid misuse. Clinicians should consider prioritizing alternative pain management strategies for these higher-risk patients.

Effect of Host Human Products on Natural Transformation in Acinetobacter baumannii.

Our previous data show that serum albumin can trigger natural transformation in Acinetobacter baumannii. However, extracellular matrix/basal membrane components, norepinephrine, and mucin did not have a significant effect on this process. Therefore, the effect of human products appears to be albumin specific, as both BSA and HSA have been shown to increase of natural transformation.

Increasing the Technicity Index to 92% in a Community Hospital: A 5-Year Retrospective Review.

OBJECTIVE: This study describes the observed trends in hysterectomy routes at Langley Memorial Hospital (LMH) in Langley, British Columbia, over 5 consecutive years. Associations between patient characteristics and surgical approach were explored, and approach-based surgical outcomes were evaluated using the institutional technicity index (TI), defined as the ratio of hysterectomies performed by minimally invasive surgery to all hysterectomies. METHODS: A retrospective descriptive study involving 706 women who underwent hysterectomy at LMH between January 1, 2012 and December 31, 2016 by six full-time surgeons was performed. From the patient characteristics and surgical outcomes associated with the route of hysterectomy, the annual institutional and overall rates of hysterectomy by type were calculated according to the Canadian Task Force Classification II-2. RESULTS: The TI increased from 67% to 92% from 2012 to 2016. Specifically, the proportion of hysterectomies completed by a total laparoscopic approach increased from 37% to 78%, whereas hysterectomies performed by the abdominal or laparoscopic-assisted vaginal approach decreased from 32% to 8% and from 17% to 1%, respectively. Vaginal hysterectomy rates remained constant across the study period. Minimally invasive surgery was associated with significantly reduced surgical blood loss and decreased length of hospital stay, with no difference in surgical time compared with an open approach. CONCLUSIONS: As far as the study investigators are aware, the TI at LMH is among the highest reported to date in Canada. Potential contributing factors include well-trained and experienced gynaecologic surgeons, readily available peer-to-peer mentorship, certified gynaecologic assistance, dedicated surgical staff, and consistency in the operating room set-up. Hence, achieving a high TI in a community setting is feasible without increasing the risk of surgical complications or length of surgery.

Effect of Physical Activity on Frailty: Secondary Analysis of a Randomized Controlled Trial.

Background: Limited evidence suggests that physical activity may prevent frailty and associated negative outcomes in older adults. Definitive data from large long-term randomized trials are lacking. Objective: To determine whether a long-term, structured, moderate-intensity physical activity program is associated with a lower risk for frailty and whether frailty status alters the effect of physical activity on the reduction in major mobility disability (MMD) risk. Design: Multicenter, single-blind, randomized trial. Setting: 8 centers in the United States. Participants: 1635 community-dwelling adults, aged 70 to 89 years, with functional limitations. Intervention: A structured, moderate-intensity physical activity program incorporating aerobic, resistance, and flexibility activities or a health education program consisting of workshops and stretching exercises. Measurements: Frailty, as defined by the SOF (Study of Osteoporotic Fractures) index, at baseline and 6, 12, and 24 months, and MMD, defined as the inability to walk 400 m, for up to 3.5 years. Results: Over 24 months of follow-up, the risk for frailty (n = 1623) was not statistically significantly different in the physical activity versus the health education group (adjusted prevalence difference, -0.021 [95% CI, -0.049 to 0.007]). Among the 3 criteria of the SOF index, the physical activity intervention was associated with improvement in the inability to rise from a chair (adjusted prevalence difference, -0.050 [CI, -0.081 to -0.020]). Baseline frailty status did not modify the effect of physical activity on reducing incident MMD (P for interaction = 0.91). Limitation: Frailty status was neither an entry criterion nor a randomization stratum. Conclusion: A structured, moderate-intensity physical activity program was not associated with a reduced risk for frailty over 2 years among sedentary, community-dwelling older adults. The beneficial effect of physical activity on the incidence of MMD did not differ between frail and nonfrail participants. Primary Funding Source: National Institute on Aging, National Institutes of Health.