Inflammatory Activity of Epithelial Stem Cell Variants from Cystic Fibrosis Lungs Is Not Resolved by CFTR Modulators.

Rationale: CFTR (cystic fibrosis transmembrane conductance regulator) modulator drugs restore function to mutant channels in patients with cystic fibrosis (CF) and lead to improvements in body mass index and lung function. Although it is anticipated that early childhood treatment with CFTR modulators will significantly delay or even prevent the onset of advanced lung disease, lung neutrophils and inflammatory cytokines remain high in patients with CF with established lung disease despite modulator therapy, underscoring the need to identify and ultimately target the sources of this inflammation in CF lungs. Objectives: To determine whether CF lungs, like chronic obstructive pulmonary disease (COPD) lungs, harbor potentially pathogenic stem cell "variants" distinct from the normal p63/Krt5 lung stem cells devoted to alveolar fates, to identify specific variants that might contribute to the inflammatory state of CF lungs, and to assess the impact of CFTR genetic complementation or CFTR modulators on the inflammatory variants identified herein. Methods: Stem cell cloning technology developed to resolve pathogenic stem cell heterogeneity in COPD and idiopathic pulmonary fibrosis lungs was applied to end-stage lungs of patients with CF (three homozygous CFTR:F508D, one CFTR F508D/L1254X; FEV1, 14-30%) undergoing therapeutic lung transplantation. Single-cell-derived clones corresponding to the six stem cell clusters resolved by single-cell RNA sequencing of these libraries were assessed by RNA sequencing and xenografting to monitor inflammation, fibrosis, and mucin secretion. The impact of CFTR activity on these variants after CFTR gene complementation or exposure to CFTR modulators was assessed by molecular and functional studies. Measurements and Main Results: End-stage CF lungs display a stem cell heterogeneity marked by five predominant variants in addition to the normal lung stem cell, of which three are proinflammatory both at the level of gene expression and their ability to drive neutrophilic inflammation in xenografts in immunodeficient mice. The proinflammatory functions of these three variants were unallayed by genetic or pharmacological restoration of CFTR activity. Conclusions: The emergence of three proinflammatory stem cell variants in CF lungs may contribute to the persistence of lung inflammation in patients with CF with advanced disease undergoing CFTR modulator therapy.

Cloning a profibrotic stem cell variant in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible, and rapidly fatal interstitial lung disease marked by the replacement of lung alveoli with dense fibrotic matrices. Although the mechanisms initiating IPF remain unclear, rare and common alleles of genes expressed in lung epithelia, combined with aging, contribute to the risk for this condition. Consistently, single-cell RNA sequencing (scRNA-seq) studies have identified lung basal cell heterogeneity in IPF that might be pathogenic. We used single-cell cloning technologies to generate "libraries" of basal stem cells from the distal lungs of 16 patients with IPF and 10 controls. We identified a major stem cell variant that was distinguished from normal stem cells by its ability to transform normal lung fibroblasts into pathogenic myofibroblasts in vitro and to activate and recruit myofibroblasts in clonal xenografts. This profibrotic stem cell variant, which was shown to preexist in low quantities in normal and even fetal lungs, expressed a broad network of genes implicated in organ fibrosis and showed overlap in gene expression with abnormal epithelial signatures identified in previously published scRNA-seq studies of IPF. Drug screens highlighted specific vulnerabilities of this profibrotic variant to inhibitors of epidermal growth factor and mammalian target of rapamycin signaling as prospective therapeutic targets. This profibrotic stem cell variant in IPF was distinct from recently identified profibrotic stem cell variants in chronic obstructive pulmonary disease and may extend the notion that inappropriate accrual of minor and preexisting stem cell variants contributes to chronic lung conditions.

Body image and disordered eating behaviors in Hispanic/Latino Youth: Findings from the Hispanic Community Health Study/Study of Latino Youth.

BACKGROUND: Prevalence of certain disordered eating behaviors is higher among Hispanic youth compared to non-Hispanics. Understanding the role of body image and social attitudes towards weight in disordered eating may inform treatment in Hispanic youth. METHODS: We analyzed data from the Hispanic Community Health Study/Study of Latino Youth (SOL Youth). Our sample included 1,463 children aged 8-16 years from four sites (Bronx, Chicago, Miami, San Diego) assessed in 2011-2014. Body image discrepancy score was calculated as the difference between perceived ideal body image and actual body image using two numbered visual graphs: adolescent (n = 728) or child (n = 735), each with slightly different scales. Questionnaires measured influences from social attitudes toward weight and disordered eating behaviors. Three disordered eating behaviors (dieting, overeating, and compensatory behaviors) were analyzed as the dependent variable. Logistic regression models adjusted for age, sex, acculturative stress, and field center to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI). RESULTS: Mean body image discrepancy score was -0.79 for adolescents (SE = 0.08) and -0.50 for children (SE = 0.05), with a negative score signifying a perceived actual body image larger than their ideal. Body image discrepancy was strongly associated with dieting (dieting ≥5 times/year aOR = 0.64, 95% CI 0.53, 0.77) and compensatory behaviors (aOR = 0.65, 95% CI 0.50, 0.85) among adolescents, and was strongly associated with overeating among children (aOR = 0.74, 95% CI 0.61, 0.91). Significant associations were not observed with social attitudes towards weight. CONCLUSIONS: Associations observed with body image discrepancy and disordered eating behaviors can inform interventions in Hispanic/Latino youth, which should consider acculturative stress.

Flap Reconstruction for Pressure Ulcers: An Outcomes Analysis.

BACKGROUND: Historically, complication rates after pressure ulcer reconstruction utilizing flap coverage have been high. Patients undergoing operations for pressure ulcer coverage typically have multiple risk factors for postoperative complications. The purpose of this study was to examine a large patient series in the pressure ulcer population to uncover objective evidence of the linkage between risk factors and outcomes after flap coverage. METHODS: This study was a retrospective chart review of patients who underwent flap reconstruction for a pressure ulcer between 1997 and 2015. The characteristics of patients were analyzed to determine those who had complications such as pressure ulcer recurrence, wound dehiscence, and wound infection. RESULTS: All patients (N = 276) underwent flap coverage of their pressure ulcers. The overall complication rate was 58.7% (162 patients). Wound dehiscence was the most common complication (31.2%), and the pressure ulcer recurrence rate was 28.6%. Multivariate regression for pressure ulcer recurrence revealed that body mass index <18.5 [relative risk (RR) 3.13], active smoking (RR 2.33), and ischial pressure ulcers (RR 3.46) were independent risk factors for pressure ulcer recurrence. Ischial pressure ulcers (RR 2.27) and preoperative osteomyelitis (RR 2.78) were independent risk factors for wound dehiscence. Diabetes was an independent risk factor for wound infection (RR 4.34). CONCLUSIONS: Our retrospective analysis revealed numerous factors that are associated with high rates of major postoperative complications. Risk factors must be taken into account when offering flap coverage, and risk-reducing strategies must be implemented in patients before pressure ulcer reconstruction.

Analysis of polyethylene glycol (PEG) fusion in cultured neuroblastoma cells via flow cytometry: Techniques & optimization.

Polyethylene glycol (PEG) has long been used as a membrane fusogen, but recently it has been adopted as a technique for peripheral nerve repair. Vertebrate models using PEG fusion have shown improved outcomes when PEG is applied during repair of severed peripheral nerves. The cellular mechanism of PEG fusion in the peripheral nerve repair model has not previously been assessed via flow cytometry. PEG fusion was assessed in this experiment by dying B35 rat neuroblastoma cells with different color fluorescent labels. The different color cells were combined and PEG was applied in concentrations of 50%, 75% and 100%. The amount of cell fusion was assessed via flow cytometry as the percentage of double positive cells. Results showed increasing fusion and decreasing viability with increasing concentrations of PEG.

Two castes sizes of leafcutter ants in task partitioning in foraging activity / Participação de dois tamanhos de castas de operárias de formigas cortadeiras no particionamento de tarefas da atividade de forrageamento

ABSTRACT: Task partitioning in eusocial animals is most likely an evolutionary adaptation that optimizes the efficiency of the colony to grow and reproduce. It was investigated indirect task partitioning in two castes sizes; this involves task partitioning in which the material transported is not transferred directly from one individual to another, but where it is dropped by one ant to be picked up by another. In two separate approaches, it was confirmed previous results pertaining to leaf caching activities among Atta colombica with task partitioning activities involving leaf dropping among Atta sexdens rubropilosa , in which there is a correlation between the size of an individual ant and the leaf fragment it transports. It was also suggested that this correlation exists only in individual ants that cut and transport (CaT) the same fragment to the nest. When task partitioning occurs and individual ants transporting (T) leaf fragments cut by other ants, the correlation becomes looser or disappears. We also observed that CaT ants are smaller than T ants.

RESUMO: Particionamento de tarefas em animais eusociais é provavelmente uma adaptação evolutiva, que otimiza a eficiência de forrageio da colônia, gerando maior capacidade de crescimento e reprodução. Nós investigamos o particionamento indireto de tarefas, com o envolvimento de castas de dois tamanhos distintos. Assim, o material coletado por uma formiga não era transportado diretamente ao ninho, nem transferido diretamente de um indivíduo para outro, mas sim descartado por uma formiga e coletado por outra. Em duas abordagens distintas, nós confirmamos em Atta sexdens rubropilosa resultados anteriores relativos à ocorrência deste particionamento indireto de tarefas, observado em Atta colombica . Mostramos também que, assim como em Atta colombica , há uma correlação entre os tamanhos da formiga e do fragmento de folha transportado quando esta corta e transporta este fragmento ao ninho (CaT). Mais ainda, confirmamos em Atta sexdens que, quando o particionamento de tarefas ocorre e as formigas apenas transportam o fragmento de folhas (T) cortadas por outras formigas, a correlação desaparece. Nós também descrevemos que as formigas CaT são menores do que as T.