The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) novel coronavirus 2019 (COVID-19) global pandemic has led to millions of cases and hundreds of thousands of deaths. While older adults ...appear at high risk for severe disease, hospitalizations and deaths due to SARS-CoV-2 among children have been relatively rare. Integrating single-cell RNA sequencing (scRNA-seq) of developing mouse lung with temporally resolved immunofluorescence in mouse and human lung tissue, we found that expression of SARS-CoV-2 Spike protein primer TMPRSS2 was highest in ciliated cells and type I alveolar epithelial cells (AT1), and TMPRSS2 expression increased with aging in mice and humans. Analysis of autopsy tissue from fatal COVID-19 cases detected SARS-CoV-2 RNA most frequently in ciliated and secretory cells in airway epithelium and AT1 cells in peripheral lung. SARS-CoV-2 RNA was highly colocalized in cells expressing TMPRSS2. Together, these data demonstrate the cellular spectrum infected by SARS-CoV-2 in lung epithelium and suggest that developmental regulation of TMPRSS2 may underlie the relative protection of infants and children from severe respiratory illness.
Lung organogenesis requires precise timing and coordination to effect spatial organization and function of the parenchymal cells. To provide a systematic broad-based view of the mechanisms governing ...the dynamic alterations in parenchymal cells over crucial periods of development, we performed a single-cell RNA-sequencing time-series yielding 102,571 epithelial, endothelial and mesenchymal cells across nine time points from embryonic day 12 to postnatal day 14 in mice. Combining computational fate-likelihood prediction with RNA in situ hybridization and immunofluorescence, we explore lineage relationships during the saccular to alveolar stage transition. The utility of this publicly searchable atlas resource (www.sucrelab.org/lungcells) is exemplified by discoveries of the complexity of type 1 pneumocyte function and characterization of mesenchymal Wnt expression patterns during the saccular and alveolar stages - wherein major expansion of the gas-exchange surface occurs. We provide an integrated view of cellular dynamics in epithelial, endothelial and mesenchymal cell populations during lung organogenesis.
Purpose To determine if reoperation rates are higher for patients who underwent isolated rotator cuff repair (RCR) than those who underwent RCR with concomitant biceps tenodesis using a large ...private-payer database. Methods A national insurance database was queried for patients who underwent arthroscopic RCR between the years 2007 and 2014 (PearlDiver, Warsaw, IN). The Current Procedural Terminology (CPT) 29,827 (arthroscopy, shoulder, surgical; with RCR) identified RCR patients who were subdivided into 3 groups—group 1: RCR without biceps tenodesis; group 2: RCR with concomitant arthroscopic biceps tenodesis (CPT 29827 and 29,828); group 3: RCR with concomitant open biceps tenodesis (CPT 29827 and 23,430). Reoperation rates (revision RCR, subsequent biceps surgeries) and complications at 30 days, 90 days, 6 months, and 1 year were analyzed. Multivariate logistic regression was used to compare reoperations and complications between groups. Rotator cuff tear size, whether the biceps was ruptured and whether a biceps tenotomy was performed, was not available. Results Group 1: 27,178 patients. Group 2: 4,810 patients. Group 3: 1,493 patients. More patients underwent concomitant arthroscopic than concomitant open tenodesis ( P < .001). A total of 2,509 patients underwent a reoperation for RCR or biceps tenodesis within 1 year after RCR. When adjusted for age, sex, and comorbidities, no significant differences in reoperation rates at 30 days or 90 days among the 3 groups, but significantly more patients who had a tenodesis, required a reoperation compared with those who did not have a tenodesis at 6 months and 1 year (both P < .001). Urinary tract infections were more common in patients who did not have a tenodesis, whereas dislocation, nerve injury, and surgical site infection were more common in tenodesis patients. Conclusions Higher reoperation rates at 1 year were seen in patients who had concomitant biceps tenodesis. Level of Evidence Level III, case-control database review study.
Hsp70 chaperones bind to various protein substrates for folding, trafficking, and degradation. Considerable structural information is available about how prokaryotic Hsp70 (DnaK) binds substrates, ...but less is known about mammalian Hsp70s, of which there are 13 isoforms encoded in the human genome. Here, we report the interaction between the human Hsp70 isoform heat shock cognate 71-kDa protein (Hsc70 or HSPA8) and peptides derived from the microtubule-associated protein Tau, which is linked to Alzheimer's disease. For structural studies, we used an Hsc70 construct (called BETA) comprising the substrate-binding domain but lacking the lid. Importantly, we found that truncating the lid does not significantly impair Hsc70's chaperone activity or allostery in vitro. Using NMR, we show that BETA is partially dynamically disordered in the absence of substrate and that binding of the Tau sequence GKVQIINKKG (with a KD = 500 nm) causes dramatic rigidification of BETA. NOE distance measurements revealed that Tau binds to the canonical substrate-binding cleft, similar to the binding observed with DnaK. To further develop BETA as a tool for studying Hsc70 interactions, we also measured BETA binding in NMR and fluorescent competition assays to peptides derived from huntingtin, insulin, a second Tau-recognition sequence, and a KFERQ-like sequence linked to chaperone-mediated autophagy. We found that the insulin C-peptide binds BETA with high affinity (KD < 100 nm), whereas the others do not (KD > 100 μm). Together, our findings reveal several similarities and differences in how prokaryotic and mammalian Hsp70 isoforms interact with different substrate peptides.
Marker-based dynamic functional or regression methods are used to compute joint centre locations that can be used to improve linear scaling of the pelvis in musculoskeletal models, although large ...errors have been reported using these methods. This study aimed to investigate if statistical shape models could improve prediction of the hip joint centre (HJC) location. The inclusion of complete pelvis imaging data from computed tomography (CT) was also explored to determine if free-form deformation techniques could further improve HJC estimates. Mean Euclidean distance errors were calculated between HJC from CT and estimates from shape modelling methods, and functional- and regression-based linear scaling approaches. The HJC of a generic musculoskeletal model was also perturbed to compute the root-mean squared error (RMSE) of the hip muscle moment arms between the reference HJC obtained from CT and the different scaling methods. Shape modelling without medical imaging data significantly reduced HJC location error estimates (11.4 ± 3.3 mm) compared to functional (36.9 ± 17.5 mm, p = <0.001) and regression (31.2 ± 15 mm, p = <0.001) methods. The addition of complete pelvis imaging data to the shape modelling workflow further reduced HJC error estimates compared to no imaging (6.6 ± 3.1 mm, p = 0.002). Average RMSE were greatest for the hip flexor and extensor muscle groups using the functional (16.71 mm and 8.87 mm respectively) and regression methods (16.15 mm and 9.97 mm respectively). The effects on moment-arms were less substantial for the shape modelling methods, ranging from 0.05 to 3.2 mm. Shape modelling methods improved HJC location and muscle moment-arm estimates compared to linear scaling of musculoskeletal models in patients with hip osteoarthritis.
To evaluate the effect of disposable cystoscopes on the rate of symptomatic urinary tract infections (UTI) following post-renal transplant cystoscopic stent removal.
We performed a retrospective ...study of post-renal transplant cystoscopic stent removals in our outpatient clinic from March 2019 to March 2022. Our clinic converted to disposable cystoscopes in October 2021. All outpatient, phone, and portal encounters were reviewed for 30 days following the procedure. The primary outcome was the number of post-procedural symptomatic UTI within 30 days of the procedure. Symptomatic UTI was defined as fever, dysuria, or hematuria accompanied by a positive urine culture.
A total of 323 patients had post-transplant stent removals including 123 with reusable scopes and 200 with disposable scopes. Around 1.6% (2/123) of patients with a reusable cystoscope experienced symptomatic UTI’s. They had positive urine cultures for Escherichia coli and Klebsiella. 2.0% (4/200) of patients with a disposable cystoscopy had a symptomatic UTI. The 3 types of positive urine cultures they experienced were E Coli, Klebsiella, and Enterococcus.
The conversion from reusable to disposable cystoscopes did not decrease symptomatic UTI following renal transplant stent removal.
Platelet dysregulation is drastically increased with advanced age and contributes to making cardiovascular disorders the leading cause of death of elderly humans. Here, we reveal a direct ...differentiation pathway from hematopoietic stem cells into platelets that is progressively propagated upon aging. Remarkably, the aging-enriched platelet path is decoupled from all other hematopoietic lineages, including erythropoiesis, and operates as an additional layer in parallel with canonical platelet production. This results in two molecularly and functionally distinct populations of megakaryocyte progenitors. The age-induced megakaryocyte progenitors have a profoundly enhanced capacity to engraft, expand, restore, and reconstitute platelets in situ and upon transplantation and produce an additional platelet population in old mice. The two pools of co-existing platelets cause age-related thrombocytosis and dramatically increased thrombosis in vivo. Strikingly, aging-enriched platelets are functionally hyper-reactive compared with the canonical platelet populations. These findings reveal stem cell-based aging as a mechanism for platelet dysregulation and age-induced thrombosis.
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•Aging leads to two parallel platelet specification paths from HSCs•The shortcut platelet pathway is perpetuated by highly expansive MkPs•Canonical MkPs are resilient to age-induced changes•The aging-induced shortcut path causes thrombocytosis and platelet hyper-reactivity
With advanced age, platelets generated by a differentiation pathway that shortcuts the canonical progenitor cascade to directly make megakaryotic precursor cells from hematopoietic stem cells cause thrombocytosis and are more prone to thrombosis compared with canonically derived platelets.
Obstructive sleep apnea (OSA) increases risk for cognitive decline and Alzheimer's disease (AD). While the underlying mechanisms remain unclear, hypoxemia during OSA has been implicated in cognitive ...impairment. OSA during rapid eye movement (REM) sleep is usually more severe than in non-rapid eye movement (NREM) sleep, but the relative effect of oxyhemoglobin desaturation during REM versus NREM sleep on memory is not completely characterized. Here, we examined the impact of OSA, as well as the moderating effects of AD risk factors, on verbal memory in a sample of middle-aged and older adults with heightened AD risk.
Eighty-one adults (mean age:61.7 ± 6.0 years, 62% females, 32% apolipoprotein E ε4 allele (APOE4) carriers, and 70% with parental history of AD) underwent clinical polysomnography including assessment of OSA. OSA features were derived in total, NREM, and REM sleep. REM-NREM ratios of OSA features were also calculated. Verbal memory was assessed with the Rey Auditory Verbal Learning Test (RAVLT). Multiple regression models evaluated the relationships between OSA features and RAVLT scores while adjusting for sex, age, time between assessments, education years, body mass index (BMI), and APOE4 status or parental history of AD. The significant main effects of OSA features on RAVLT performance and the moderating effects of AD risk factors (i.e., sex, age, APOE4 status, and parental history of AD) were examined.
Apnea-hypopnea index (AHI), respiratory disturbance index (RDI), and oxyhemoglobin desaturation index (ODI) during REM sleep were negatively associated with RAVLT total learning and long-delay recall. Further, greater REM-NREM ratios of AHI, RDI, and ODI (i.e., more events in REM than NREM) were related to worse total learning and recall. We found specifically that the negative association between REM ODI and total learning was driven by adults 60 + years old. In addition, the negative relationships between REM-NREM ODI ratio and total learning, and REM-NREM RDI ratio and long-delay recall were driven by APOE4 carriers.
Greater OSA severity, particularly during REM sleep, negatively affects verbal memory, especially for people with greater AD risk. These findings underscore the potential importance of proactive screening and treatment of REM OSA even if overall AHI appears low.
Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative ...coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr) and summer (July-Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.
OBJECTIVETo identify associations between preoperative psychiatric diagnoses and perioperative outcomes after RC. METHODSThe Florida Inpatient Data File was used to identify patients who underwent RC ...from 2013 to 2019. ICD-10 codes for a mood or anxiety disorder were identified and analyzed as a 3-level variable: neither, one of these, or both. Outcomes included inpatient mortality, non-home discharge, in-hospital complications, and length of stay. Mixed-effects logistic regression (accounting for clustering within hospitals) and negative binomial regression models were utilized. RESULTSWe identified 4396 RC patients, including 306 (7.0%) with a mood disorder and 389 (8.8%) with an anxiety disorder. After multivariable adjustment, there was no significant association between mood and/or anxiety disorders with mortality or the presence or number of in-hospital complications. However, a mood or anxiety disorder was significantly associated with increased odds of non-home discharge (OR 1.60, 95% CI 1.20-2.14) and longer length of stay (IRR 1.13, 95% CI 1.07-1.19); these associations were also increased among patients with both mood and anxiety disorder diagnoses (non-home discharge OR 2.66, 95% CI 1.61-4.38; length of stay IRR 1.12, 95% CI 1.01-1.24). CONCLUSIONPatients with mood and/or anxiety disorders undergoing RC had longer length of stay and increased odds of discharge to a non-home facility despite similar risks of perioperative complications. These data suggest an opportunity for perioperative intervention to address these disparities in postoperative outcomes. However, further work is needed to determine the underlying causes of these differences and to develop effective interventions.
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