bluuebunny/crossref_metadata_2025 huggingface dataset:
Thoracopelvic Covariation Across Ontogeny in Humans
Authors: Zaleski Sarah
Published: May 2022

Clarifying human thoracopelvic covariation patterns can contribute to an understanding of body shape evolution. Previous research has shown that although adult human males and females share a common thoracopelvic covariation pattern, males tend to exhibit mediolaterally wide thoraces and narrow pelves, and females tend to exhibit mediolaterally narrow thoraces and wide pelves (2020 Am J Phys Anthropol 173(3) 514‐534). The current study tests for sex differences in thoracopelvic covariation across ontogeny.

I analyzed decedent computed tomography data from the Center for Forensic Imaging at the University of New Mexico with a sample of 44 females and 48 males, aged 0‐21 years. I used SlicerMorph to collect three‐dimensional landmark coordinate data representing thoracic and pelvic shapes as well as R geomorph and Morpho for geometric morphometric analyses. After separate Generalized Procrustes Analyses on the pelvis and thorax, I analyzed thoracopelvic covariation with two‐block partial least squares analysis. To compare covariation magnitudes, I tested effect sizes of sex‐specific two‐block partial least squares. I assessed sex‐specific covariation patterns by projecting the male data into the female two‐block partial least squares analysis and then comparing the slopes of sex‐specific data via major axis regressions and the smatr R package.

Results from the two‐block partial least squares analyses indicate significant covariation between the thorax and pelvis in females and males (p=0.001). The first latent variables explain 94.47% and 94.40% of the total covariation in the female and male samples, respectively. In both sexes, as the thorax becomes less pyramidal and more barrel‐shaped with development, the pelvis becomes more anteroposteriorly elongated. The sex‐specific two‐block partial least squares analyses do not exhibit significantly different magnitudes of thoracopelvic covariation. Slope comparison between sexes does not indicate significantly different patterns of thoracopelvic covariation.

Previous research suggests that adult thoracopelvic covariation is driven by sex differences. The current study shows that subadult thoracopelvic covariation tracks with growth and development in both sexes, which is expected in the ontogenetic sample. Subadult females and males do not exhibit significantly different magnitudes nor patterns of thoracopelvic covariation. Processes such as sagittal balance of the upper body over the pelvis may influence thoracopelvic covariation.
Discovery of novel human long‐noncoding RNAs (lncRNAs) associated with inflammation
Authors: Chini Avisankar , Mandal Subhrangsu
Published: May 2022

Noncoding RNAs are emerging class of transcripts which appear to play critical roles in various cellular processes including cell signaling and metabolism. Recent studies from our laboratory demonstrate that, long noncoding RNA (lncRNA) HOTAIR, which is well‐known as a transcriptional repressor, regulates cytokine expression, glucose metabolism during inflammation in macrophages via regulation of NF‐kB activation. Recently, to identify, lncRNAs that are associated with inflammation and immune signaling, we stimulated human monocyte (THP1 cells) derived macrophage with lipopolysaccharide (LPS) and analyzed the global transcriptome expression using RNAseq analysis. These studies demonstrated that, along with inflammatory protein coding genes and cytokines, a series of lncRNA expressions were significantly induced upon LPS‐stimulation of macrophages, suggesting their potential roles in inflammation and immune signaling. We termed these lncRNAs as LinfRNAs (Long‐noncoding inflammation associated RNA). Importantly, many of these hLinfRNA (human LinfRNAs) expression are also induced by live E.coli exposure, further suggesting their roles in inflammation and immune response. Application of NF‐kB signaling inhibitor suppressed the expression of most hLinfRNAs (LinfRNAs in Human), suggesting their potential regulation via NF‐kB signaling. The structure function of most these hLinfRNAs remains unknown and we are in the process of functional characterization of selected hLinfRNAs (such as hLinfRNA1) in inflammation and immune signaling in human. Understanding their function may help in early diagnosis and can be the key to potential therapeutic target for several inflammation associated diseases, including cardiovascular disease, autoimmune diseases, obesity, diabetes, inflammatory bowel disease, and cancer.
NAD+ Flux and Resiliency in Aged Mice
Authors: McReynolds Melanie R.
Published: May 2022

NAD+ is an essential coenzyme found in all living cells. NAD+ concentrations decline during aging, but whether this reflects impaired production or accelerated consumption remains unclear. Here we employed isotope tracing and mass spectrometry to probe NAD+ metabolism across tissues in aged mice. In 25‐month‐old mice, we observe modest tissue NAD+ depletion (median decrease ~30%) without significant changes in circulating NAD+ precursors. Isotope tracing showed unimpaired synthesis of circulating nicotinamide from tryptophan, and maintained flux of circulating nicotinamide into tissue NAD+ pools. Although absolute NAD+ biosynthetic flux was maintained in most tissues of aged mice, fractional tissue NAD+ labeling from infused labeled nicotinamide was modestly accelerated, consistent with increased activity of NAD+ consuming enzymes. Long‐term calorie restriction partially mitigated age‐associated NAD+ decline despite decreasing NAD+ synthesis, suggesting that calorie restriction reduces NAD+ consumption. Acute inflammatory stress induced by LPS decreased NAD+ by impairing synthesis in both young and aged mice. Thus, age‐related decline in NAD+ is relatively subtle and driven by increased NAD+ consumer activity rather than impaired production.
Effect of Aquatic Exercise Training on Left Ventricular Afterload in in Middle‐aged and Older Normotensives: Evaluation by Polar coordinate description
Authors: Sugawara Jun , Fukuie Marina , Yamabe Takuya , Hoshi Daisuke , Hashitomi Tatsuya , Nomura Yosuke
Published: May 2022

Regular aerobic physical activity has been recommended to prevent the age‐related increase in cardiovascular disease risks. However, the effect of in‐water aerobic exercise training (e.g., swimming, head‐out aquatic exercise) on the aortic augmentation index (AIx), an index of left ventricular afterload, is inconsistent. Recently, there has been a gaining recognition about the limitations of dimensionless ratio‐based metrics, including AIx (=augmentation pressure [AP]/pulse pressure [PP]). The single‐use of ratio would provide incomplete information relative to the “content” of the two components: since AP is a component of PP, the training‐induced change in AP might be masked by the corresponding change in PP. Accordingly, using the newly proposed companion metrics of AIx by polar coordinate description, we determined the effect of head‐out aquatic exercise training on left ventricular afterload in middle‐aged and older adults. We evaluated aortic hemodynamics in 15 normotensives (62±10 y.o., four men) before and after a 15‐week aquatic exercise course. Aortic hemodynamics were estimated from brachial arterial pressure waveforms via the general transfer function method. Companion metrics of AIx (AIxC=√{AP2+PP2}) were calculated as measures of arterial load. The participation rate in the training course was 86 %. Aortic systolic blood pressure (SBP) decreased after the training course (from 112±8 to 108±11 mmHg, P=0.02). AIxC also decreased (from 45±7 to 42±7 mmHg2, P=0.01). In contrast, AIx remained unchanged (from 47±10 to 45±11 %, P=0.148) presumably due to parallel changes in AP (from 19±5 to 17±5 mmHg, P=0.002) and PP (from 41±6 to 39±6 mmHg, P=0.01). These findings suggest that head‐out aquatic exercise training might lower the left ventricular afterload in middle‐aged and older normotensives. The newly introduced companion metric may provide better insight into underlying physiology.
Effects of pharmacologic interventions on hypertension attenuation and growth factors in animal model
Authors: Moustafa Ahmed S. , Spencer Shauna‐Kay , Bowles Teylor , Griffin Ashley , Wallace Kedra
Published: May 2022

Studies in hypertensive models of pregnancy have reported improvement in pregnancy outcomes and mean arterial pressure (MAP) after administration of various pharmacological agents. Circulating anti‐angiogenic and placental growth factors are often used as biomarkers for placental dysfunction, however the effect of pharmacological intervention to reduce hypertension on placental function is still not clear. Therefore our objective was to determine if attenuation of hypertension during a hypertensive pregnancy is associated with an improvement in placental function. To address this question we used placentas that were collected from previous pharmacological studies and stored at ‐80°C. Timed‐pregnant Sprague Dawley rats arrived on gestational day (GD) 11 and either remained normotensive (NP) or were implanted with a mini‐osmotic pump on GD12 infusing sFlt‐1 and sEng (4.7 & 7ug/kg respectively). Rats were treated with 5mg/kg ABT‐627 (blockade of the ETAreceptor), 5mg/kg Tempol (TEM, superoxide dismutase mimetic), 2mg/kg Orencia (T‐cell depletion), 500ng/kg of MFL4 (neutralization of FasL) or 100pg/day IL‐17 soluble RC (blockade of the IL‐17) for variable times during pregnancy. On GD19 MAP was measured, pups were weighed and organs were stored for future use. Placentas (n=4‐5) were homogenized and assayed in individual ELISAs for the following growth factors: sFlt‐1, PlGF, VEGF and sEng. As expected pharmacological treatments significantly decreased MAP relative to hypertensive rats (p=0.005). When the placental sFlt‐1/PlGF ratio was evaluated it was only significantly decreased in response to TEM (p=0.05). sEng was significantly decreased in rats receiving either Orencia (p=0.004) or IL‐17RC (p=0.003). There were no statistically significant differences between hypertensive rats and treated rats in any other individual factors (p>0.05). Additionally, there was a negative correlation between MAP and pup weight (r=‐0.24, p=0.03) and placental weight (r=‐0.24, p=0.03). However there was not a significant positive correlation was found between MAP and the sFlt‐1/PlGF ratio (r = 0.12, p=0.38). Collectively these data indicate that while the selected pharmacological interventions were effective at lowering the blood pressure, the effect on growth factors associated with placental dysfunction was variable. In conclusion, the role of different pharmacological interventions on improving placental dysfunction remains unclear suggesting the need for further studies to evaluate the impact of other pharmacological interventions on placental dysfunction and pregnancy outcomes.
Impact of Redox Modification on PKA Substrate Selection
Authors: Gay Naudia M. , Ekhator Ese S. , Delva‐Wiley Jeannette , Newman Robert H.
Published: May 2022

Protein kinases regulate multiple signaling pathways involved in health and disease. For instance, cyclic adenosine monophosphate‐dependent protein kinase (PKA) controls a diverse set of cellular functions, including gene expression, cell cycle progression, metabolism, and apoptosis. Dysregulation of PKA has been linked to many diseases, including diabetes, cancer, and neurodegenerative disorders. PKA is a tetramer consisting of two regulatory and two catalytic subunits. Cyclic AMP binding to the regulatory subunits leads to dissociation of the catalytic subunits, unleashing them to phosphorylate serine and threonine residues on their target substrates. Previous studies suggest that the alpha isoform of the PKA catalytic subunit (PKA Cα) is oxidized on C199 within the P+1 substrate binding region. We hypothesized that, by modifying the substrate selectivity of PKA Cα, oxidation may regulate which pathway is activated in response to a given signal. Specifically, we investigated the impact of redox modification on the substrate selection of PKA Cα. To this end, we used fluorescence polarization (FP) spectroscopy to assess the ability of oxidized and reduced forms of PKA Cα to bind a variety of model peptide ligands (e.g., PKI, Kemptide, and CREBtide). The binding of each ligand was monitored under equilibrium binding conditions and the apparent equilibrium binding parameters (i.e., KD,app) were determined for each kinase‐ligand pair. These studies suggest that H2O2‐dependent oxidation of PKA Cα alters its interactions with some ligands while having little effect on others. To gain further insights into the factors driving the differential changes in the interaction between PKA Cα and its ligands, we are currently using surface plasmon resonance (SPR) to measure changes in the apparent rate constants, kon,app and koff,app, as well as KD,app. Together, these studies offer important insights into the mechanisms of crosstalk between redox and phosphorylation‐dependent signaling at the level of kinase substrate selection and have implications for kinase regulation during normal and pathological states. Interestingly, the site of oxidation is highly conserved among AGC kinase family members. Therefore, in the future, we will use a multipronged approach to explore the impact of redox modification on the substrate selection of other AGC family members, such as PKA Cβ and AKT1, in neuronal signaling and the etiology of various diseases.
Membrane Phosphoinositides Stabilize GPCR‐arrestin Complexes and Provide Temporal Control of Complex Assembly and Dynamics
Authors: Janetzko John , Kise Ryoji , Barsi‐Rhyne Benjamin , Siepe Dirk H. , Heydenreich Franziska M. , Masureel Matthieu , Kawakami Kouki , Garcia K. C. , von Zastrow Mark , Inoue Asuka , Kobilka Brian K.
Published: May 2022

Binding of arrestin to phosphorylated G protein‐coupled receptors (GPCRs) is crucial for gating signaling. Once internalized some GPCRs remain stably associated with arrestin, while others interact transiently; this difference affects signaling and recycling behaviors of these GPCRs. Using cell‐based and in vitro biophysical assays we examined the role of membrane phosphoinositides (PIPs) in arrestin recruitment and GPCR‐arrestin complex dynamics. We find that GPCRs broadly stratify into two groups, one which requires PIP‐binding for arrestin recruitment and one that does not. Plasma membrane PIPs potentiate an active conformation of arrestin and stabilize GPCR‐arrestin complexes by promoting a core‐engaged state of the complex. As allosteric modulators of GPCR‐arrestin complex dynamics, membrane PIPs allow for additional conformational diversity beyond that imposed by GPCR phosphorylation alone. The dependance on membrane PIPs provides a mechanism for arrestin release from transiently associated GPCRs, allowing their rapid recycling, while explaining how stably associated GPCRs are able to engage G proteins at endosomes.
Effects of Modulating Multivalent Ligand Binding Accessibility & Affinity on Liquid‐Liquid Phase Separation
Authors: Galagedera Sarasi K. , Dao Thuy P. , Castaneda Carlos A.
Published: May 2022

Elucidating the molecular rules of ligand‐induced phase transitions is essential to determining the regulation of the formation and disassembly of biomolecular condensates. Ubiquitin‐binding shuttle protein Ubiquilin‐2 (UBQLN2) undergoes liquid‐liquid phase separation (LLPS) in vitro and colocalizes into stress‐induced cytoplasmic puncta in vivosuch as stress granules.[1] A recent study from our lab indicated that ubiquitin (Ub), and compact polyUb chains such as K48‐ & K11‐Ub4 can inhibit UBQLN2 LLPS by binding to phase separation‐driving UBQLN2 stickers whereas more extended chains such as K63‐ & M1‐Ub4 can promote UBQLN2 phase separation over a large Ub:UBQLN2 range by acting as a multivalent ligand scaffold.[2] Using a designed tetrameric ubiquitin construct (HOTag6‐Ub) that resembles a multi‐monoubiquitinated substrate, we further probed how alterations to the stickers and spacers of the HOTag6‐Ub ligand can modulate UBQLN2 phase behavior. Using turbidity and microscopy experiments, we obtained phase diagrams for LLPS driven by heterotypic interactions between UBQLN2 and HOTag6‐Ub. We discovered that, by changing the length and flexibility of the linker that tethers the Ub units to HOTag6, we can tune UBQLN2 LLPS. Single‐ and double‐point mutations to the Ub hydrophobic binding surface (I44 & V70 “stickers”) decreased the binding affinity between Ub and UBQLN2, thereby leading to changes in the shape of HOTag6‐Ub/UBQLN2 phase diagrams. Using nuclear magnetic resonance spectroscopy (NMR), microscopy and UV‐Vis spectroscopic methods we demonstrated that linker conformation, linker flexibility, and interactions with the Ub binding surface are driving factors of UBQLN2/HOTag6‐Ub co‐phase separation. Overall, our findings highlight how multivalent ligands can tune phase separation behavior of protein systems.

[1] Dao, T. P., Kolaitis, R.‐M., Kim, H. J., O’Donovan, K., Martyniak, B., Colicino, E., Hehnly, H., Taylor, J. P., and Castañeda, C. A. (2018). Ubiquitin Modulates Liquid‐Liquid Phase Separation of UBQLN2 via Disruption of Multivalent Interactions. Mol. Cell 69, 965‐978.

[2] Dao, T. P., Yang, Y., Cosgrove, M. S., Hopkins, J. B., Ma, W., Castaneda, C. A. (2021). Mechanistic insights into the enhancement or inhibition of phase separation by polyubiquitin chains of different lengths or linkages. bioRxiv 2021.11.12.467822; doi: https://doi.org/10.1101/2021.11.12.467822.
Effects of Metabolic Syndrome and SIRT1 Mutation on Store‐Operated Ca2+ Entry in Peripheral Blood Mononuclear Cells in Ossabaw Miniature Swine
Authors: Thamba Aish , Royer Chris , Collett Jason , Byrd James , Alloosh Mouhamad , Coutts Alex , Basile David , Sturek Michael
Published: May 2022

Background

Metabolic syndrome (MetS) impairs sarco‐endoplasmic reticulum Ca2+ ATPase (SERCA) activity that may decrease the ER Ca2+ store and increase store‐operated Ca2+ entry (SOCE) in a variety of cell types. Similar Ca2+ signaling via SOCE causes fibrosis, vascular disease, and may trigger immunogenic (type 1) diabetes by action on peripheral blood mononuclear cells (PBMCs). Sirtuin 1 (SIRT1) is a deacetylase that maintains healthy metabolism and generally attenuates vascular disease. SIRT1 impairment exacerbates MetS and vascular disease by hyper‐acetylation of SERCA, decreasing its activity and thereby potentially increasing SOCE.

Hypothesis

The SIRT1 mutation made in Ossabaw miniature swine would mimic the mutation found in humans and increase PBMC SOCE.

Methods

Using CRISPR/Cas9 methodology a point mutation (SIRT1L100P) was made in Ossabaw miniature swine to mimic the naturally occurring mutation in humans and decrease SIRT1 activity, thereby resulting in hyperacetylation of Ca2+transporters and impaired function. Four groups of pigs were used to analyze genotype and diet interactions: wild type lean, SIRT1 lean, wild type MetS, and SIRT1 MetS. Pigs were age 4 months at the start and fed normal chow (lean) or atherogenic diet (MetS) for 7 months. PBMCs were isolated and Ca2+ was measured with fura‐2. The ER Ca2+store was depleted by 10‐5M cyclopiazonic acid to inhibit SERCA in a Ca2+‐free extracellular solution to fully deplete the ER Ca2+store and then Ca2+ was returned to the solution to induce maximal SOCE. Cells were recovered in Ca2+‐free solution to partially re‐fill the ER Ca2+ store, then Ca2+ returned to the solution to observe submaximal SOCE.

Results

Both MetS diet groups (wild type MetS, SIRT1 MetS) showed impaired glucose tolerance. Fasting glucose in SIRT1 mutants was not different from wild type pigs, thus SIRT1 does not cause immunogenic diabetes at this early stage. Robust coronary atherosclerosis was shown by angiography, intravascular ultrasound, and gross imaging in MetS groups, but there was no additive or synergistic effect of SIRT1 mutation. There was no effect of MetS or SIRT1 mutation on maximal SOCE. Two‐way ANOVA showed that MetS diet increased submaximal SOCE (p<0.009), but there was no effect of SIRT1 genotype on submaximal SOCE (p=0.266). The percentage of PBMCs that responded to partial ER Ca2+ depletion was 45% in lean pigs compared to 81% in wild type and 63% in SIRT1 pigs fed MetS diet.

Conclusion

SIRT1L100P mutation is likely to require longer duration to manifest robust effects on PBMC SOCE that were found with MetS diet. PBMC activation and can be easily studied longitudinally in the SIRT1L100P mutant swine model due to the ease of blood sampling.
Carbon Nanoparticles Induce Changes in ER‐Stress Gene Expression Levels and Organelle Morphology
Authors: Rogers Ann E. , Brewster Jay L.
Published: May 2022

Ultrafine carbon black (CB) nanoparticles constitute a major component of air pollution. These particles are capable of distribution from the lungs and accumulate in diverse tissues with complex toxicological affects upon cells and organ systems. Accumulated nanoparticles can activate elevated reactive oxygen species, stress signaling, and apoptosis. In this study, cell lines from varied organ systems were assessed for nanoparticle accumulation, and for stress signaling from the endoplasmic reticulum (ER), a key regulator of cellular apoptosis. In this study, ultrafine CB particulates were generated using sonication, and shown by atomic force microscopy to display sizes in a 20‐50nm range. To examine the capacity for CB to accumulate and activate stress signaling from the endoplasmic reticulum, RAW264.7 mouse macrophages and SVEC4 mouse endothelial cells were used. The accumulation of CB was evaluated over a 48‐hour period. Incorporated particulates were purified from cell lysates via centrifugation, and then measured with absorbance readings (A595). CB was hypothesized to enter all cells in a dose and time dependent manner. In RAW264.7 macrophages, particles accumulated gradually over time, with significant accumulation detected after 2 hours of exposure with CB doses of 50, 100, and 200 ug/ml with a peak absorbance reading of 0.9 Au/ 2x105 cells. In SVEC4 endothelial cells, particles gradually accumulated up to 24 hours before decreasing with intracellular carbon black incorporation peaking at 0.4 Au/ 2x105 cells; significant accumulation was detected at 24 hours of exposure with a dose of 100 ug/ml, and after 6 hours of exposure with a dose of 200 ug/ml. Stress signaling from the ER results in predictable changes in gene expression for several genes and pre‐mRNA splicing of Xbp1. To assess ER signaling in the presence of CB, cells were treated for a 24‐hour period. Assessment of Unfolded Protein Response (UPR) branch activation was determined using qRT‐PCR to assess levels of gene expression in RAW and SVEC4 cells at low and high concentrations of carbon black. The level of ER stress was hypothesized to be dependent on cell type. Analysis revealed RAW264.7 cells to display higher levels of ER stress signaling than SVEC4 cells, consistent with the observed differences in nanoparticle accumulation in these cell lines. An additional measure of CB toxicity was provided through the assessment of ER and mitochondrial morphology. To label organelles, cells were transfected with plasmids carrying engineered fluorescent proteins targeted to the ER (red fluorescent protein) and the mitochondria (green fluorescent protein). SVEC4 endothelial cells were transfected and treated with carbon back for 24 hours. Fluorescent microscopy data revealed CB‐induced changes in both organelles, altering morphology and distribution. These results demonstrate CB‐induced cellular dysfunction and suggest that certain cell types may be more susceptible to air pollution.
The Role of Sox9 in Regulating Joint Development through a Gdf5 Enhancer
Authors: Damoah Ruth‐Love , Pira Charmaine U. , Cooper Allen M. , Shankel Matthew , Oberg Kerby C.
Published: May 2022

Sox transcription factors are involved in a number of developmental processes including joint formation. Sox9, Sox5, and Sox6 (the Sox‐trio) form a complex that promotes chondrogenesis. In joint‐associated cells, Sox9 may give rise to a subpopulation of cells expressing growth differentiation factor 5 (Gdf5). Gdf5, a secreted morphogen critical to joint development, regulates cartilage growth and tissue differentiation. Osteoarthritis (OA) is condition characterized by articular cartilage degradation and is a leading cause of disability worldwide. Gdf5 dysregulation has been identified as a risk factor for OA, and in the joints of OA patients, the Sox‐trio are downregulated. The link between Sox, Gdf5, and joint development is not fully understood. We previously identified an enhancer for Gdf5, known as Gdf5‐Associated Regulatory Region (GARR), and have identified possible Sox9 and 5/6 binding sites within GARR by in silico analysis. Thus, we hypothesized that Sox9 is required for Gdf5 upregulation through GARR, while other Sox transcription factors (Sox5/6) enhance or stabilize this interaction. To test this hypothesis, we analyzed publicly available single cell RNA sequencing (scRNA‐seq) data from mouse embryo (E12‐5‐E15.5) knee joints. Analysis revealed a strong correlation between Gdf5 and Sox9. Sox9 was upregulated in Gdf5 positive cells. Sox5 and 6 were upregulated in Gdf5 positive cells but had a lower correlation to Gdf5 expression indicating a weaker or indirect/secondary role in Gdf5 regulation. We also compared the activity of the wildtype GARR enhancer‐reporter construct to constructs with mutated Sox binding sites in developing chicken limbs to determine the role of these sites on enhancer activity. We found that in developing chicken embryo limbs, constructs with mutated Sox9 binding sites had a marked decrease in enhancer activity in the elbow but not in the autopod. Mutation of predicted Sox5/6 binding sites did not seem to affect activity relative to the non‐mutated control in the forelimb joints. Our findings suggest that Sox9 is a key regulator of elbow development through GARR‐mediated expression of Gdf5. The correlations identified in the transcriptomic data may be relevant only to the elbow and knee joints. Alternatively, the Sox transcription factors may be acting though other Gdf5‐associated enhancers in the autopod joints. Further investigation of enhancer activity in the presence of various combinations of Sox5/6/9 will throw more light on how they collectively affect Gdf5 expression as well as joint development and OA progression.
Border zone repolarization duration as a predictor of early ischemic ventricular fibrillation
Authors: Tsvetkova Alena , Ovechkin Alexey , Azarov Jan , Bernikova Olesya
Published: May 2022

Ventricular fibrillation (VF) is a dangerous complication of acute myocardial infarction. Within an episode of acute ischemia, VFs are clustered into early (1A) and delayed (1B) phases based on different mechanisms. Our previous work demonstrated that prolonged repolarization duration in the border zone predisposed to VF development. A prolongation of action potential duration in the affected area is a frequent though not inevitable change at the very beginning of ischemia. However, the role of this phenomenon in arrhythmogenesis is unclear. The objective of the present study was to evaluate an association between early (1A phase) VF with repolarization duration in the border zone in an experimental porcine myocardial infarction model.

Myocardial ischemia was induced in 19 anesthetized domestic pigs by ligation of the left anterior descending (n=9) or left circumflex (n=10) coronary arteries. Epicardial mapping was done with a 64‐lead epicardial array placed on the affected area with adjacent regions. Recordings were done in the baseline state and during ischemia with a custom‐designed system (16 bits; bandwidth 0.05 to 1000 Hz; sampling rate 4000 Hz). Local activation time (AT) and end of repolarization time (RT) were measured in each epicardial lead as the instants of a dV/dt minimum during QRS‑complex and dV/dt maximum during T‑wave, respectively. Activation‐repolarization interval (ARI, a surrogate for action potential duration) was taken as a rate‐corrected difference between RT and AT. Dispersion of repolarization (DOR) was calculated as a difference between the latest and earliest RTs throughout all recorded epicardial leads.

Ten early VF episodes developed during first minutes of ischemia (1‐8 min). In logistic regression analysis, VF incidence was associated with ARI duration in the border zone (regression coefficient 1.02, 95% CI 1.003‐1.037, p=0.023), but not DOR (regression coefficient 1.005, 95%CI 0.990‐1.021, p=0.508) during first ten minutes of ischemia. In multivariate logistic regression analysis (baseline ARI duration vs the fact of ARI prolongation), VF incidence was associated only with the baseline ARI duration (regression coefficient 1.025, 95%CI 1.007‐1.044, p=0.005).

Our data demonstrated the role of the prolonged repolarization duration in the development of 1A phase VF, which was independent of DOR and related to its baseline duration. Since the border zone is by definition at least partly accessible for blood flow, it may present a target for VF prevention therapy in a setting of acute myocardial ischemia.
The effect of disease‐causing DVL1 mutations on chondrogenesis in chicken limb mesenchyme
Authors: Bonaparte Kywana , Richman Joy M.
Published: May 2022

The Wingless (WNT) signaling pathway is a key regulator of skeletal development. Perturbations in WNT signaling are associated with several skeletal disorders, including Robinow syndrome (RS). RS is a rare skeletal dysplasia characterized by deficiencies in facial and limb skeletogenesis. All identified pathogenic variants of RS occur in genes of the WNT signaling pathway. The majority of autosomal dominant RS patients (DRS) cases are attributed to mutations in Dishevelled‐1 (DVL1) (OMIM#1807000) and Dishevelled‐3 (DVL3) (OMIM#616894), a cytoplasmic phosphoprotein. All RS DVL1variants have frameshift mutation in the penultimate exon that substitutes an abnormal peptide for the C‐terminus of the protein. Previous research in our lab has shown the expression of avian‐ specific retroviruses containing human wild‐type DVL1 and RS DVL1 variants in the limb of the chicken embryo in vivo disrupts cartilage formation. In order to examine the possible role of WNT signaling in the dysregulation of chondrogenesis caused by DVL1, high‐density cultures of chicken limb mesenchyme were treated with DVL1 viruses and either TCS JNK6o, which antagonizes non‐canonical, JNK signaling or XAV939, a canonical pathway antagonist. Cultures were grown for eight‐days stained with Alcian blue for cartilage. The area occupied by cartilage was analyzed using two‐way ANOVA with Tukey’s post‐hoc test (Graphpad Prism v9.3). In the absence of drug treatment, wtDVL1 and RS DVL11519ΔTvariant significantly increased chondrogenesis compared to GFP controls (Fig. 1A,B). Cultures treated with TCS6o (Fig. 1A) did not significantly increase cartilage compared to non‐treated controls culture. The combination of wtDVL1 with TCS6o synergistically increased chondrogenesis. This suggests 1) that endogenous non‐canonical WNT signaling is not required for chondrogenesis, 2) that wtDVL1 has a degree of JNK signaling that when antagonized increases chondrogenesis and 3) that the variants are not interacting with JNK signaling. When canonical signaling was antagonized (Fig. 1B), chondrogenesis was significantly increased for all virus types compared to GFPcontrols. However, the effect of XAV939 on the DVL11519ΔT variant‐infected cultures did not further increase chondrogenesis over the virus alone. This suggest that endogenous canonical WNT signaling represses chondrogenesis and but the variant may have altered ability to respond to a decrease in canonical signaling. Misregulation of canonical and non‐canonical WNT signaling is tied to abnormal chondrogenesis and could be contributing to the shortened limbs observed in RS patients.
Role(s) of Acetylation in human pathogen Helicobacter pylori
Authors: Rao Desirazu N.
Published: May 2022

Helicobacter pyloris (H.pylori) a Gram‐negative bacterium whose infection of the human stomach triggers a chronic gastritis that can evolve into a series of severe pathologies such as gastroduodenal ulcers and cancer. H.pylori infects more than 50% of world population. Its amazing diversity and variability are major contributors to this success by allowing the emegence of new alleles. The bacterium lacks SOS response, DNA mismatch repair system, has a huge repertoire of restriction‐modification systems and is highly competent. These characteristics compelled us to investigate its all‐possible regulatory system (s). Acetylation‐a post‐translational modification has been proven to be a major regulatory machinery in prokaryotic physiology Acetylome analysis of different strains of H. pylori showed the presence of prominent and strain specific protein acetylation. Mass‐spectrometry based analysis showed that acetylated proteins participate in diverse biological processes such as metabolic pathways, transcription, translation, cell signalling and motility. In addition, acetylome analysis showed that two Cag pathogenicity island proteins. Cag 7, Cag 14, UvrD helicase involved in nucleotide excision repair, DNA methyltransferase‐ HPyAVIA, and DprA‐ involved in Natural Transformation process were acetylated. HP0935, a putative N‐acetyltransferase belonging to the GNAT superfamily was identified as possible protein acetyltransferase. It was observed that HP0935 acetylates L‐amino acids such as arginine and methionine at Nα amino group and lysine at both Nα and Nε amino group. Mutational and pH analysis of HP0935 suggest that a possible catalytic mechanism involves deprotonation of amino group of substrates by conserved water molecule followed by nucleophilic attack of deprotonated amino group on Ac‐CoA. Furthermore, Tyr127 act as a general acid that protonates the leaving thiolate anion of Coenzyme A. It was observed that ATPase and helicase activity of HPUvrD was regulated by both enzymatic (HP0935) and non‐enzymatic (Ac‐CoA) acetylation while the methyltransferase activity of M. HPyAVIA was enhanced only by enzymatic (HP0935) acetylation. These observations suggest acetylation of several key proteins plays a role in pathogenesis and in Natural transformation of H. pylori.
Estimates of Probabilities of Successful Development of Pain Medications: An Analysis of Pharmaceutical Clinical Development Programs from 2000 to 2020
Authors: Maher Dermot P. , Wong Chi Heem , Siah Kien Wei , Lo Andrew W.
Published: May 2022

Background

The authors estimate the probability of successful development and duration of clinical trials for medications to treat neuropathic and nociceptive pain. The authors also consider the effect of the perceived abuse potential of the medication on these variables.

Methods

This study uses the Citeline database to compute the probabilities of success, duration, and survivorship of pain medication development programs between January 1, 2000, and June 30, 2020, conditioned on the phase, type of pain (nociceptive vs. neuropathic), and the abuse potential of the medication.

Results

The overall probability of successful development of all pain medications from phase 1 to approval is 10.4% (standard error, 1.5%). Medications to treat nociceptive and neuropathic pain have a probability of successful development of 13.3% (standard error, 2.3%) and 7.1% (standard error, 1.9%), respectively. The probability of successful development of medications with high abuse potential and low abuse potential are 27.8% (standard error, 4.6%) and 4.7% (standard error, 1.2%), respectively. The most common period for attrition is between phase 3 and approval.

Conclusions

The authors’ data suggest that the unique attributes of pain medications, such as their abuse potential and intended pathology, can influence the probability of successful development and duration of development.

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Melanocytic Nevus With Elastophilic Features
Authors: Tran Tien Anh N.
Published: May 2022

In dermal melanocytoses such as blue nevus or nevus of Ota, an ultrastructural study has demonstrated an intimate relationship between the dendritic melanocytes and the dermal elastic fibers with elongated cytoplasmic processes of the melanocytes aligning lengthwise along the axis of the elastic fibers in longitudinal sections and encircling the elastic fibers in cross-sections. Such a close arrangement has not been reported in common melanocytic nevi. The current case described a similar arrangement between the melanocytes and the dermal elastic fibers in a usual intradermal melanocytic nevus. Of note, as the melanocytes matured with descent, the deep melanocytes were arranged in single cells embracing the elastic fibers, imparting a signet-ring cell/phagocytosis appearance. A Verhoeff—van Gieson stain showed hypertrophy of the melanocyte-associated elastic fibers compared with the elastic fibers in the dermal background, suggesting a paracrine or juxtracrine interaction between the melanocytes and the dermal cellular components. Because of the distinctive affinity of the melanocytes to the dermal elastic fibers in this melanocytic lesion, the term melanocytic nevus with elastophilic features is suggested for this peculiar melanocytic variant.
A Case of Tofacitinib-Induced Lymphomatoid Papulosis With Ocular Involvement
Authors: Knapp Calvin , Steele Eric , Mengden-Koon Stephanie , Williams Todd , Fett Nicole
Published: May 2022

Janus kinase (JAK) inhibitors are being prescribed with increasing regularity in dermatology. We report on a patient who initiated treatment with tofacitinib for refractory erythema elevatum diutinum and subsequently developed a novel cutaneous outbreak characterized by firm violaceous papules on the trunk and extremities along with conjunctival injection and periorbital inflammation. Biopsy of affected tissue from both the cutaneous and ophthalmologic sources demonstrated increased numbers of CD30+ large atypical cells amid a mixed inflammatory cell infiltrate, consistent with lymphomatoid papulosis. A review of the literature reveals a plausible mechanism for the induction of persistent JAK signaling in the presence of a JAK inhibitor. We discuss this mechanism in depth because it pertains to this patient and recommend continued vigilance with the use of these immunologic agents.
Metastasis to the Oral Cavity: Report of 12 Cases
Authors: Lourenço Silvia V. , Florezi Giovanna P. , Smitter Anabel S. , Bologna Sheyla B. , Nico Marcello M. S.
Published: May 2022

Oral cavity is not a common route for metastatic dissemination; metastasis to the oral region may affect soft tissues and jawbones, accounting for approximately 1% of all oral malignant neoplasms. The diagnosis of metastatic lesions to the oral cavity is usually challenging to clinicians and pathologists because of their complexity and rarity. We present a series of 12 metastatic neoplasms to the oral cavity that were detected previously or after the diagnosis of the primary tumor. All tumors were of epithelial origin with primary sites in the esophagus (2 cases), colon (2 cases), bladder, lungs, liver, larynx, skin, uterus, prostate, and adrenal gland, each with one case. The commonest site of the metastatic masses in the oral cavity was the gingiva, frequently presented as a vegetating, friable mass. The clinical examination and histopathologic analysis of the lesions were central to establishing the final diagnosis of the tumors. Metastatic masses to the oral cavity should always be considered as differential diagnosis of benign-looking lesions, especially in patients with previous history of a malignant disease. Biopsy is mandatory to establish an accurate diagnosis.
Associations Between Diaper Need and Child Sleep in Under-resourced Families
Authors: Shaffer Emma , Porter Sallie , Condon Eileen , Zha Peijia , Caldwell Barbara A.
Published: May 2022

Objective:

Sleep is critical for child health, but factors related to poverty create barriers to the achievement of healthful sleep. In this study, we examined the associations of insufficient diaper supply, a measure of material hardship, with child sleep.

Methods:

This cross-sectional study included 129 parents of very young children. Each participant responded to an online material hardship assessment and the Brief Infant Sleep Questionnaire–Revised. Multiple linear regression was used to analyze the relationship between diaper need and sleep.

Results:

Controlling for family and socioeconomic variables, diaper need was associated with disrupted, shorter sleep periods (β = −11.95, p < 0.001) and lower total sleep scores (β = −6.49, p = 0.004). High diaper need was associated with parent perception of poor sleep (β = −7.28, p = 0.017).

Conclusion:

The findings suggest that an inadequate supply of diapers adversely affects children's sleep. Further research should evaluate how screening and connecting families to resources may improve pediatric sleep.
The Modified Sternoplasty: A Novel Surgical Technique for Treating Mediastinitis
Authors: Kachel Erez , Arazi Mattan , Grosman-Rimon Liza , Yehezkeel Shachar , Rimon Jordan , Gohari Jacob , Shinfeld Amihay , Sternik Leonid , Raanani Ehud , Moshkovitz Yaron
Published: May 2022

Deep sternal wound infection (DSWI) is one of the most complex and devastating complications post cardiac surgery. We present here the modified sternoplasty, a novel surgical technique for treating DSWI post cardiac surgery. The modified sternoplasty includes debridement and sternal refixation via bilateral longitudinal stainless-steel wires that are placed parasternally along the ribs at the midclavicular or anterior axillary line, followed by six to eight horizontal stainless-steel wires that are anchored laterally and directly into the ribs. On top of that solid structure, wound reconstruction is performed by the use of bilateral pectoralis muscle flaps followed by subcutaneous tissue and skin closure. We reported mortality rates and length of hospitalization of patients who underwent the modified sternoplasty. In total, 68 patients underwent the modified sternoplasty. Two of these critically ill patients died (2.9%). The average length of hospitalization from the diagnosis of DSWI was 24.63 ± 22.09 days. The modified sternoplasty for treating DSWI is a more complex surgery compared with other conventional sternoplasty techniques. However, this technique was demonstrated to be more effective, having a lower rate of mortality, and having a length of hospitalization lower than or comparable to other techniques previously reported in the literature.
Primary Monocanalicular Stent Intubation for Children With Congenital Nasolacrimal Duct Obstruction: Surgical Outcome and Risk Factors
Authors: Katowitz William R. , Prat Daphna Landau , Munroe Christiana E. , Revere Karen , Khatib Lama , Hua Peiying , Ying Gui-Shuang , Binenbaum Gil
Published: May 2022

Purpose:

To determine the risk factors impacting the surgical success of primary monocanalicular stent intubation for congenital nasolacrimal duct obstruction (CNLDO).

Methods:

This is a retrospective interventional case series of patients 18 years and younger treated more than a 12-year period with monocanalicular stent intubation with inferior turbinate fracture for CNLDO by a single surgeon. Patients with dacryocystoceles, dacryocystitis, Down syndrome and previous tear duct surgery were excluded. An intraoperative grading scale of tear duct stenosis, date of stent removal, stent length, and postoperative symptoms were recorded. Surgical success was defined as the complete resolution of symptoms.

Results:

One thousand four hundred sixty-nine stents were placed in 1,001 pediatric participants (533 unilateral, 468 bilateral). The mean age at surgery was 1.86 years (0.1–18.07). The mean follow up was 34.99 months (0.43–134.3) with mean in-office stent removal at 3.41 months (0.63–36.9). Early stent loss occurred in 14.8% intubations (217/1,469). The overall success rate was 92.4% (1,357/1,469 eyes). Subjects less than the age of 4 years had a success rate of 92.8% (1,296/1,397) compared with 84.7% (61/72) in children more than 4. In multivariable analysis, bilateral surgery, severe tear duct stenosis, and early stent loss were significantly associated with higher risk of surgical failure.

Conclusions:

Severe tear duct stenosis, early stent loss, and bilateral surgery were significant risk factors for surgical failure. While the success rate stratified by age at surgery suggested a lower success after the age of 4. Primary monocanalicular stent intubation is an effective and safe treatment for CNLDO sparing a child the need for multiple staged surgeries.
Nursing Students' Home Care Learning Delivered in an Innovative 360-Degree Immersion Experience
Authors: Woodworth Julie A.
Published: May 2022

Background:

Health care is delivered to patients in the community, frequently in their own homes. New graduates need to be prepared for this unique nursing role to care for patients in the home health setting.

Purpose:

The purpose of this study was to assess student satisfaction with an innovative pedagogy to teach home health nursing using an immersion experience. The immersion experience delivered the home health nursing activity using 360-degree footage and zoom in pictures presented via a web platform.

Methods:

This study used a descriptive cross-sectional design with convenience sampling of 81 nursing students enrolled in the third semester of an associate degree program. Data were collected through an online survey eliciting anonymous feedback.

Results:

Participant feedback revealed this new pedagogy engaged nursing students and received overwhelmingly positive responses. A review of student feedback through written comments provided further support that this immersion experience exceeded expectations.

Conclusion:

The 360-degree immersion home care experience provided problem-based learning that positively impacted student self-reported satisfaction and perceived learning.