bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lung Mechanics and Structure in Aged C57BL/6x129 Mice
Authors: Elliott Jonathan E , Omar Tanya S , Mantilla Carlos B , Sieck Gary C 
Published: November 2023

Aging‐related changes in lung mechanics of human subjects are characterized by a decrease in resistance and an increase in static compliance (decrease in elastic recoil). Together, these changes result in an increase in residual volume in the absence of an increase in total lung capacity. In C57BL/6x129 mice, it was reported that lung compliance increases with aging while elastic recoil pressure does not change. However, in these studies, “old” mice at 24 months of age were compared to “young” mice at 2 months of age, but at this younger age, alveologenesis is incomplete (completion does not occur until ~6 months of age). Accordingly, it remains to be established if the same aging‐related changes in lung mechanics are observed using fully developed adult C57BL/6x129 mice for comparison. To this end, we compared lung mechanics in C57BL/6x129 mice at 6 months (100% survival, n = 6), 18 months (90% survival, n = 6), and 24 months (75% survival, n = 6) of age. Respiratory system static mechanics (Resistance, Rrs; Compliance, Crs; Elastance, Ers) were assessed following tracheal intubation using the FlexiVent. There was a progressive aging‐related decrease in Rrs (6 month, 0.47 ± 0.02; 18 month, 0.41 ± 0.02; 24 month, 0.35 ± 0.02 cmH2O.s/ml), an increase in Crs (6 month, 0.046 ± 0.002; 18 month, 0.052 ± 0.002; 24 month, 0.062 ± 0.002 ml/cmH2O), and a decrease in Ers (6 month, 21.73 ± 1.19; 18 month, 19.30 ± 0.87; 24 month, 16.62 ± 1.25 cmH2O/ml). Additionally, lungs were fixed following tracheal instillation of 4% paraformaldehyde at 25 cmH2O. Thereafter, lungs were dehydrated, paraffin embedded, sectioned (6 μm thick), and stained (hematoxylin and eosin). Using standard stereological approaches, lung sections were analyzed in a uniform systematic but random fashion to assess alveolar morphology (measurement of average distance between alveolar walls based on mean linear intercept, Lm). There was a progressive aging‐related increase in Lm (6 month, 34 ± 2; 18 month, 40 ± 2; 24 month, 45 ± 2 μm) consistent with an aging‐related emphysematous‐like change in lung morphometry. Taken together, these results in appropriately aged C57BL/6x129 mice demonstrate an aging‐related change in lung mechanics and morphometry consistent with what is observed in aging humans. Therefore, the results of the present study confirm the use of rodent models for studying aging‐related changes in lung mechanics and morphometry.Support or Funding InformationNational Institute of Health grants R01‐AG044615 (CBM & GCS) and T32‐HL105355 (JEE).
Respiratory plasticity induced by intermittent hypoxia following mid‐cervical contusion in unanesthetized rats
Authors: Chiang Shu‐Chi , Lee Kun‐Ze 
Published: November 2023

Intermittent hypoxia has been considered as a potential approach to induce respiratory neuroplasticity. The purpose of present study was to investigate the impact of intermittent hypoxia on respiratory function following cervical contusion in unanesthetized rats. Adult male rats were received laminectomy or unilateral contusion at C3–C4 spinal cord using the MASCIS Impactor (height: 6.25 or 12.5 mm). At 4 weeks post‐injury, the breathing pattern of unanesthetized rats was measured by the whole body plethymography before, during and after 10 episodes of 5‐min hypoxia (10 % O2, 4 % CO2, balance N2) with 5‐min normoxia intervals. The result demonstrated that animals received severe cervical contusion had a lower tidal volume than uninjured animals. Hypoxia induced a significant increase in frequency and tidal volume in uninjured and contused animals. However, there is a progressive decline in the magnitude of hypoxic ventilatory response during intermittent hypoxia. Specifically, the frequency response is gradually reduced in uninjured animals, and the tidal volume response is decreased in contused animals with successive hypoxic stimuli. In addition, the tidal volume was significantly enhanced in contused rats but not uninjured rats at 30 min post‐hypoxia, suggesting intermittent hypoxia can induce long‐term facilitation of tidal volume following cervical contusion. These results demonstrated that intermittent hypoxia can induce differential forms of respiratory plasticity in uninjured vs. contused animals, and it may be a promising neurorehabilitation approach to improve respiratory function after cervical spinal cord injury.Support or Funding InformationNational Health Research Institutes (NHRI‐EX104‐10223NC), Ministry of Science and Technology (Most 102‐2320‐B‐110‐004‐MY3)
Hyperbaric Oxygen Treatment Following Mid‐Cervical Spinal Contusion Injury
Authors: Turner Sara , Hoyt Aaron , Gregory Nichole , Tester Nicole , Reier Paul , Fuller David 
Published: November 2023

Mounting evidence suggests daily hyperbaric oxygen treatment (HBOT) can enhance functional motor recovery after thoracic spinal cord injury (SCI), possibly through alterations in inflammatory signaling and reduced apoptosis at or near the lesion epicenter. The purpose of this initial study was to explore using HBOT as a rehabilitative tool after cervical spinal contusion injury. Rats were randomly divided into the following groups: 1) naïve (no prior treatment), 2) sham operated (laminectomy only), 3) lateral contusion at C3/4 (cSCI) and, 4) cSCI + daily HBOT. The HBOT consisted of a 1 hr exposure to 2.0 atmospheres of 100% O2, beginning on the day of SCI and continued for 10 days. Forelimb function was analyzed on day 10 post‐surgery using open field forelimb locomotor scoring (FLS) and a “water grooming” test. Compared to naïve and sham rats, ipsilateral forelimb function was severely disrupted following cSCI in both the untreated and HBOT‐treated groups (p<0.05). However, HBOT‐treated rats showed a 17% increase in ipsilateral forelimb joint mobility (FLS score = 4.1 ± 1.6) when compared to the untreated cSCI group (FLS score = 1.25 ± 0.25; p = 0.074). In addition, a greater proportion of HBOT‐treated cSCI animals regained the ability to groom with the ipsilateral forelimb when compared to untreated cSCI animals (Chi‐Square Test, p = 0.016). After the 10th treatment day, cervical spinal tissues (C2–C5) were harvested for analyses of mRNA gene expression. Compared to non‐treated rats, the HBOT cohort showed increased mRNA expression (p<0.05) of genes involved in axon growth/guidance, including: SLIT2, CNTN1, ABLIM1, PLXNB1, and ARHGEF12. In addition HBOT treated rats showed decreased mRNA expression (p<0.05) of genes involved in the induction of apoptosis via DR3 and DR4/5 death receptors, such as: RELA, CASP9, NFKB1A, FADD, TNFSF12, and APAF1. Our data are consistent with prior reports of improved motor function following HBOT in SCI animal models, and the mRNA data raise the possibility that HBOT may be influencing axonal growth and regeneration, as well as attenuating cell death. Thus, HBOT following spinal cord injury may have exciting rehabilitative potential.Support or Funding InformationCTSA U54‐TR001012, Craig H. Neilsen Foundation 313369 (SMFT), 1 R01 NS080180‐01A1 (DDF), State of Florida Brain and Spinal Cord Injury Research Program (DDF and PJR)
3D Printing of Customized Implants for Treatment of Orofacial Deformities and Defects
Authors: Tayebi Lobat 
Published: November 2023

Acute or refractory orofacial deformities and defects present surgeons with numerous reconstructive challenges.Such defects are currently reconstructed using microvascular free flaps, non‐vascular autogenous bone and/or skin grafts, or reconstruction with xenografts or synthetic materials. Using these methods, surgeons are constrained by the size and complexity of the defect; defects larger than 5 cm are difficult to reconstruct with these techniques, so are those defects that involve the anterior mandibular region. Lack of predictability of graft success, as well as the lack of predictability of the esthetic and functional outcome of a non‐vascular grafting makes it necessary to use a vascularized free flap in many of these cases. Such procedures are lengthy and challenging despite the improvements in the technology and the techniques. Patients experience long recovery periods and are exposed to related perioperative morbidities that increase health care costs, increase time lost from work, and negatively affect the patients’ quality of life.3D printing is currently being intensely studied by a diverse set of applications, including the development of bioengineered tissues, as well as the production of functional biomedical materials and devices for dental and orthopedic applications. Producing vascularized 3D‐printed customized implants/scaffolds that are infused with stem cells, and designed to replace many of the traditional surgical procedures can be considered as a new method to treat orofacial deformities and defects. These implants/scaffolds will be tailored to meet the patient's current condition, age, and prior medical history and designed for tension free soft tissue closure, enhanced vascularity and tissue formation, and the prevention of micromobilityWe anticipate that this method will significantly improve the quality of the life of patients affected by numerous oral and craniofacial pathologic conditions.
Assessing the Role of Saturated Fats in Adipose Tissue Inflammation
Authors: Morgan‐Bathke Maria , Faubion William , Jensen Michael 
Published: November 2023

BackgroundA multitude of studies have suggested that there is a link between obesity and inflammation. Various in vitro and animal studies have shown that saturated fatty acids are largely responsible for the induction of various pro‐inflammatory pathways. As vegetarians consume about half the amount of saturated fat as omnivores, we hypothesized that they would have less inflammation for any given amount of obesity.ObjectiveTo quantitate the inflammatory status of adipose tissue from obese vegetarians and omnivores.MethodsThe study included 8 obese vegetarians (1 male) and 8 obese omnivores matched for age, sex, and BMI. Body composition was measured by DXA. A blood sample to measure plasma free fatty acids (FFA) and abdominal and femoral subcutaneous adipose tissue biopsies to measure macrophage content, and the fatty acid composition were collected. Each participant also completed a Food Frequency Questionnaire (FFQ) to determine their average dietary intake.ResultsBy design there were no differences in age, weight, BMI, percentage body fat, fat free mass or adipocyte size between the omnivore and vegetarian group. The plasma FFA of vegetarians revealed that they had greater proportions of the polyunsaturated fatty acids linoleic, linolenic and DHA (p = 0.04, 0.05, 0.05 respectively). Surprisingly, there was no difference in the fatty acid composition of the adipose tissue samples (abdominal or femoral) between the two groups. The FFQ data showed no significant difference in total fat, protein, or carbohydrate intake between the groups. However, the omnivore group had significantly greater intake of saturated fat and cholesterol than the vegetarian group (p = 0.05, 0.04, respectively). The inflammatory status of adipose tissue was quantified by measuring macrophage content (total, pro‐inflammatory M1, and anti‐inflammatory M2 macrophages). There was no difference in total, M1 or M2 macrophage content between the vegetarian and omnivore groups. We also quantified the senescent cell population within the adipose tissue and again found no difference between the groups.ConclusionsWhile vegetarians have significantly greater proportions of polyunsaturated fatty acids in plasma FFA than omnivores, this was not true for adipose tissue fatty acid composition. As expected, omnivores consume significantly greater amounts of saturated fatty acids, but there was no difference in adipose tissue inflammatory status between the two groups when measured using flow cytometry and senescent cell population. It is possible that the burden of obesity is more important than the consumption of saturated fatty acids in terms of human adipose tissue inflammation.
Mitochondrial Respiration Regulates Proliferation, Micromotion, and Wound Healing Migration of Human Mesenchymal Stem Cells
Authors: Lee Yu Wei , Tung Tse Hua , Gomez Sofia , Lo Chun Min 
Published: November 2023

Mitochondria plays an important role in human mesenchymal stem cell (hMSC) proliferation and differentiation. Carbonyl cyanide 4‐(trifluoromethoxy) phenylhydrazone (FCCP), which uncouples mitochondrial oxidative phosphorylation from the electron transport chain, is known to increase oxygen consumption rates. In this study, hMSCs derived from umbilical cord were chronically exposed to different concentrations of FCCP. Cell proliferation and mitochondrial activities were measure by CyQUANT® NF cell proliferation assay and Seahorse XF‐24 extracellular flux analyzer respectively. Compared with control group, chronic exposure of hMSCs to 1 μM and 3 μM FCCP for two days led to approximately 10% and 60% reduction of proliferation. Furthermore, chronic exposure of hMSCs to 3 μM FCCP for 20 hours significantly reduced their mitochondrial function. Electric cell‐substrate impedance sensing (ECIS) was also used to detect the alternation of hMSC micromotion and wound healing migration in response to different concentrations of FCCP treatment for 20 hours. The variance and energy of level 1 DWT (discrete wavelet transform) detail coefficients of the measured resistance time series at 4 kHz were calculated and the results demonstrated a dose‐dependent decrease from 1 μM to 3 μM FCCP, implying the dose‐dependent reduction of cell micromotion. For wound healing migration, the recovery resistance curves were fitted by sigmoid curve and the hill slope showed a dose‐dependent decline from 0.3 μM to 3 μM FCCP, indicating the decrease in migration rate. Moreover, dose dependent incline of the inflection points from 0.3 μM to 3 μM FCCP implied the increase of the half time for wound recovery migration. If the measured capacitance time series at 40 kHz were analyzed and compared with the previous resistance results, the variance and energy of level 1 DWT detail coefficients dose‐dependently decreased from 0.1 μM to 3 μM FCCP. Together, these results demonstrate that partial uncoupling of mitochondrial oxidative phosphorylation reduces proliferation, micromotion, and wound healing migration of hMSCs.Support or Funding InformationThis work was supported by the Ministry of Science and Technology, Taiwan. (Grant number: NSC 102‐2628‐B‐010‐010‐MY3)
Effects of Dexamethasone on Tissue Engineered Skeletal Muscle Units
Authors: Larson Alexie 
Published: November 2023

Volumetric muscle loss (VML), muscular trauma that overwhelms the native repair mechanism, necessitates surgical intervention. Limitations to current VML treatments present a need for exogenous graft muscle sources. To date, engineered muscle produces forces substantially lower than native muscle, limiting its potential for repair. In this study, we examined the trophic effects of dexamethasone (DEX), a glucocorticoid that stimulates myoblast differentiation and fusion into myotubes, on our tissue engineered skeletal muscle units (SMUs). Using our established SMU fabrication protocol, muscle isolates were exposed to two DEX concentrations (10 and 25 nM). Following seeding onto a laminin‐coated Sylgard substrate, DEX addition was initiated on day 0 until the first feeding of growth media (day 4), or sustained until SMU formation as a control (days 0–20). Cell proliferation was measured with a BrdU assay (day 4), and myogenesis was observed through immunostaining for MyoD (day 4), and α‐actinin (day 11). After SMU formation (day 20), isometric tetanic force production was recorded to quantify functional improvement. The sustained addition of 10 nM DEX yielded optimal SMUs with advanced structural maturity and functionality. Though 25 nM DEX administered days 0–4 showed a 12% increase in myogenic proliferation determined by a BrdU and MyoD co‐stain at day 4, by day 11 the SMUs with sustained addition of 10 nM DEX demonstrated the greatest advancement in sarcomeric structure observed by α‐actinin immunostaining and a 2‐fold rise in myotube density determined by light microscopy analysis on day 14, compared to both 10 nM and 25 nM DEX days 0–4 groups. Additionally, the SMUs with sustained 10 nM DEX exhibited a 16% increase in force production compared to both 10 nM and 25 nM DEX days 0–4 groups. Future research will focus on further investigation of the timing of DEX addition, understanding the mechanism behind these effects and evaluating the regenerative potential of these SMUs in vivo.Support or Funding InformationSupported by NIH/NIAMS 1R01AR067744‐01
Reseeding Decellularized Porcine Ventricular Extracellular Matrix with Isolated Primary Human Atrial Cells
Authors: Muller Alison L , Haromy Alois , Freed Darren H 
Published: November 2023

As a result of pioneering research unveiling the influence of extracellular environment in determining stem/progenitor cell differentiation, a myriad of cellular scaffolds have been developed in order to optimize the delivery of these cells in a diseased environment as a technique to improve their efficacy in stem cell therapy. Although a variety of scaffolds are being studied in different contexts, the most physiologically relevant ones are those that most closely resemble the environment to be treated. Our lab has a keen interest in cardiovascular disease and has recently optimized a technique that decellularizes and reseeds isolated sections of healthy porcine ventricular tissue with primary human atrial cells. Decellularization involved a multi‐step, multi‐reagent washing process over a period of four days, after which confirmation of a lack of cells was determined by DAPI staining and subsequent western blotting looking for the absence of β‐tubulin. After decellularization, our objective was to successfully seed the decellularized tissue slices via co‐incubation of isolated primary human atrial fibroblasts (hAFs) or human c‐kit(+) cardiac progenitor cells (hCCs). These two cell types were chosen to compare how hAFs and hCCs respond differently to healthy extracellular matrix (ECM). Cells were isolated from the atrial appendage of patients undergoing open heart surgery by mincing followed by collagenase digestion and subsequent isolation of hCCs was performed using a c‐kit(+) magnetic bead isolation procedure. HAFs and hCCs were incubated separately on sections of decellularized porcine ventricular ECM over a period of 24 hours and then visualized using immunofluoresence. Collagen‐1, fibronectin, and versican antibodies were used to image the ECM structure and DAPI was used to identify cells embedded in the recellularized matrix. Successful seeding of cells was also evaluated by western blot detection of β‐tubulin in samples not prepared for immunofluorescence. In conclusion, our technique was successful in reseeding decellularized porcine ventricular extracellular matrix and can be extrapolated to detect other proteins in these tissues without having to reseed an entire decellularized heart. This can be used to compare differences among cell types and their responses between healthy and damaged or diseased cardiac ECM among different hearts or even within the same heart.Support or Funding InformationMazankowski Alberta Heart Institute University of Alberta Hospital Foundation Alberta Innovates Health Solutions
Synergistic targets between ASC‐differentiated endothelial and neural lineage cells to prevent hypoxic‐ischemic brain injury
Authors: Huang Chia‐Wei , Chang Ya‐Ju , Chien Shu , Wu Chia‐Ching 
Published: November 2023

Neonatal hypoxic‐ischemic (HI) brain injury causes disruption of neurovascular integrity and leads to life‐long functional deficit in human development. These devastating consequences can be prevented by protecting the architecture of the neurovascular unit. Our lab has demonstrated the possibility to differentiate the adipose‐derived stem cells (ASCs) into endothelial lineage cells (ELCs) or neuronal lineage cells (NLCs) via microenvironmental induction and studied the therapeutic effect of the cells by transplanting ASCs, ELCs, NLCs, or combination of ELCs and NLCs (E+N) into HI brain injured neonatal rats. The combined E+N treatment showed a significantly greater decrease of infarction and apoptotic areas, and better preservation of the neurovascular structure. The E+N combinations increased the cell migration under in vitro hypoxia microenvironment. Moreover, the transplanted ELCs and NLCs were able to engraft into host tissue and promote endogenous angiogenesis and neurogenesis. We performed the RNAseq to fish out the potential targets for the differentiated ELCs and NLCs. The ELCs, induced by endothelial growth factors and laminar shear stress, migrated and contributed to the vascular structure by activating the Akt signaling through vascular endothelial growth factor receptor 2 (VEGFR2) and neuropilin 1 (NRP1). NLCs showed better ability in preserving the neural structure. The synergistic benefits in E+N combination were revealed via the cell‐cell interactions for NRP1 signaling in ELCs and C‐X‐C chemokine receptor 4 (CXCR4) and fibroblast growth factor receptor 1 (FGFR1) signaling in NLCs. Blockage of target signals in either ELCs or NLCs diminished the synergistic interaction in cell migration, homing, and protection of neurovasculature in the HI injured brain. The results in current study pointed out the potential molecular targets for the synergistic effect between ELCs and NLCs to improve the therapeutic outcome for preserving brain integrity and function after HI injury.Support or Funding InformationThis study was supported in part by grants from the Ministry of Science and Technology (NSC102‐2320‐B‐006‐009‐MY3) and National Health Research Institute (NHRI‐EX101‐10115EC) in Taiwan.