1,721,010 research outputs found
The generalized effect of BMP-2 on oxidative phosphorylation
Full text linkBone Morphogenetic Proteins (BMPs) belong to the Transforming Growth Factor Beta superfamily of growth factors. While BMP signaling has been shown to induce skeletogenic differentiation of mesenchymal stem cells and be involved in the formation of ectopic bone and ossification, BMPs also are involved in the differentiation of many other tissues including neurogenic tissues. Prior studies from our laboratory showed that BMP-2 induction of chondrogenic differentiation of the C3H10T1/2 murine mesenchymal stem cell line was associated with increased oxidative metabolism. This study was performed to test the hypothesis that BMP-2 promotes increased oxidative metabolism during the differentiation of other types of cells. Using the neurogenic cell line, SH-SY5Y, this study examined whether cellular differentiation induced by BMP-2 also was associated with increased oxidative phosphorylation in non-mesenchymal stem cells.
SH-SY5Y cells were grown in growth medium (DMEM/F12 with 10% FBS, 1% Penicillin/Streptomycin, L-glutamine, and non-essential amino acids). Cells were plated appropriately at differing seeding densities (Day 0), treated one time with ± 200ng/mL BMP-2 two days after plating and analyzed on Day 4. Oxidative metabolism was measured using a Seahorse XF Analyzer that measures oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). BMP-2 induction of neural cell differentiation was assayed by quantifying dendrite communication between neurons and decreased proliferative capacity as assessed by overall culture DNA contents. Mitochondrial density after BMP-2 treatment was examined using vital mitochondrial labeling.
Groups treated with BMP-2 contained significantly less DNA content than control groups (p=0.006). BMP-2 treated cells had on average more dendritic interactions with one or two and more processes than control groups (p=0.396; p=0.872), while there were a larger percentage of cells not treated with BMP-2 that had zero dendritic interactions (p=0.470). All parameters of oxidative metabolism were increased in cells treated with BMP-2. More specifically, basal respiration and ATP production were significantly increased in BMP-2 treated cells (p=0.031; p=0.010).
SH-SY5Y cells were significantly affected by BMP-2 treatment in both DNA content and oxidative phosphorylation. The diminished DNA content with BMP-2 treatment is consistent with the known decrease in cellular proliferation that is associated with neural cell differentiation. While there were small increases in dendritic interactions these were not significant and are inclusive for demonstrating BMP-2’s effect on neural differentiation. Upregulation of oxidative phosphorylation indicated after BMP-2 treatment was validated by the substantial increases in metabolic parameters associated with BMP-2 treatment. Through the utilization of the neural cell line, SH-SY5Y, this research suggests a more generalized functionality of BMP-2 in upregulation of oxidative metabolism as well as differentiation non-specific to bone and chondrocyte cell lineage
Demographic variation in bone-marrow derived mesenchymal stem cell analytes
Full text linkOsteoporosis is a systemic skeletal disease that affects millions of people worldwide. There are many possible etiologies for osteoporosis, including inherent variables like genetics and sex, and lifestyle variables like diet and exercise. Characterized by low bone mass and increased fracture risk, the disease places a burden on both the patients and the healthcare industry. Therefore, it is vital that research determine the mechanisms by which the risk factors affect BMD so that better diagnosis and treatment options may be developed. The purpose of this study was to examine the relationship between various osteoporosis risk factors and biochemical markers of osteogenic cell activity derived from bone-marrow MSCs. It was hypothesized postmenopausal white women, having the greatest risk for osteoporosis, would have elevated hydroxyproline and decreased ALP, indicative of greater bone resorption. Acetabular reamings were collected from 26 patients (15 males and 11 females) undergoing total hip arthroplasty at Boston Medical Center. MSCs from the reamings were plated and underwent osteoinduction into osteoblasts. The cells were then harvested and assayed for various indicators of cell growth and bone cell activity, such as DNA, ALP, and hydroxyproline. Our hypothesis was generally supported in that postmenopausal white women did have less ALP, an indicator of bone deposition, than premenopausal women and postmenopausal African American women. Additional findings and directions for future studies are further discussed in this paper
Effects of exercise on movement-evoked pain in knee osteoarthritis and factors related to treatment responses
No full textOBJECTIVE: To investigate the effect of a 12-week exercise-based physical therapy on movement-evoked pain (MEP) in knee osteoarthritis (OA) and assess the relations between baseline psychological factors and treatment responses based on MEP.
BACKGROUND: Pain during movement (i.e., MEP) is one of the most common complaints amongst people with knee OA, which induces greater functional challenges during daily activities. Although the worsening of pain during exercise appears to hinder activity-based treatment adherence, the assessments of MEP tend to be overlooked in the pain management in knee OA.
METHODS: The data analyzed in this study was from the parent study, Wearable Sensors in Knee Osteoarthritis (WESENS-OA) study, a longitudinal, single-arm clinical trial of a 12-week exercise intervention in people with symptomatic knee OA. In the WESENS-OA (n = 60), participants self-reported pain intensity during the nominated activity as well as psychological symptoms (Center for Epidemiologic Studies Depression Scale), cognitive pattern (Pain Catastrophizing Scale), and central sensitization (Central Sensitization Inventory). Pain intensity during functional tasks and strength testing were collected during the laboratory visits. Three characteristics of MEP outcomes were assessed: (1) pain during the nominated activity, (2) functional MEP, and (3) exercise MEP. The participants reported the pain intensity during the nominated activity that is most troublesome due to their knee pain weekly using the 11-point numerical rating scale (NRS, range: 0-10). Pain intensity during or immediately after functional tasks (i.e., 6-minute walking, chair stand, climbing the staircase, range: 0-10) and strength testing (i.e., maximal voluntary isometric contractions of knee extensors and flexors, isokinetic knee flexion-extension at 60°/s and 120°/s each, range: 0-10) were evaluated to measure functional MEP or exercise MEP, respectively. MEP index score (i.e., maximum pain corrected for baseline pain) was reported as the outcome. Mixed model repeated measures (MMRM) analysis was utilized to evaluate the effect of an exercise intervention on the change in movement-evoked pain from baseline to 12 weeks, and least square means with the standard error were reported simultaneously. Each participant’s treatment response was determined by comparing the change in MEP from baseline to Week 12. A participant with a difference of ≥ 2 points in NRS for pain-nominated activity was classified as a responder, and for functional MEP and exercise MEP, treatment responder classification was done based on the hierarchical agglomerative clustering analysis. After dichotomizing participants, using binomial regression, the relative risk (RR) was reported to explore the predictive ability of CSI, CES-D, and PCS on treatment response based on MEP.
RESULTS: For pain during nominated activity, the mean difference (MD) from baseline to Week 6 was -1.72 with 95% CI (-2.35 to -1.08; P <0.0001), and the difference at Week 12 was -2.41 with 95% CI (-2.92 to -1.89; P <0.0001). For functional MEP, MD with 95% CI at Week 6 was -0.34 (-0.52 to -0.16; P = 0.0003), and at Week 12 was -0.44 (-0.58 to -0.31; P<0.0001). Unlike the other MEP measures, for exercise MEP, MD was measured at one timepoint, at Week 12, which was -0.58 with 95% CI (-0.88 to -0.27; P = 0.003). Our secondary analysis did not provide evidence that baseline measures of CSI, CES-D, and PCS were associated with the treatment response based on the change in MEP measures after the exercise intervention.
CONCLUSION: In conclusion, our study strongly supports the effect of exercise on reduction in three measures of MEP—pain during nominated activity, functional MEP, and exercise MEP. Our hypothesis to confirm the predictive ability of psychological factors on treatment response based on MEP was not reached, with insufficient evidence to substantiate such a notion. However, our findings hold strength to pioneer discovering the underlying mechanism of understudied MEP in knee OA.2026-02-28T00:00:00
Cost-effectiveness in healthcare: a comprehensive review on economic evaluations and methodological variations addressing chronic non-traumatic upper extremity pain
No full text2024OBJECTIVE: The demand for the effective and quality delivery of medical services continues to grow considerably creating a strain on the finite resources available for healthcare. As a result, the integration of economic evaluations within the healthcare sector is becoming more valuable as a tool for deciphering the value of clinical interventions. Analyzing the associated costs and outcomes for alternative healthcare interventions can reveal the relative effectiveness of these interventions in treating prevalent health conditions. Notably, chronic musculoskeletal pain, particularly painful non-traumatic upper extremity conditions (PNUC), afflicts an appreciable amount of individuals in society. The presented thesis proposes the usefulness of a cost-effectiveness analysis (CEA) in providing insight for the practical implementation of interventional treatment in attenuating chronic upper extremity pain.
METHODS: Within healthcare, a CEA is most relevant due to the expression of outcome measurements in natural units pertaining to mortality and morbidity. Recognizing the central facets of a CEA will help researchers conceptualize the pragmatic application of this instrument. A brief review of the existing literature informed the relevance and structural tailoring of a CEA in healthcare specifically. Highlighting key methods and measures for potential translation in an ongoing Mass General Hospital (MGH) Center for Health Outcomes and interdisciplinary Research (CHOIR) study was accomplished.
RESULTS: Key components of a structured CEA were chosen such as the Incremental Cost-Effectiveness Ratio that relates the costs and outcomes of relative interventions statistically. Particular methods address the varying type of costs and their associated outcomes were suggested such as the adoption of a Human Capital and Quality-adjusted life year approach, respectively. Next, the validity of measurements for these methods were considered and subsequently suggested such as the utilization of published cost databases and survey questionnaires.
DISCUSSION: The next steps for economic evaluations include designing solutions to enhance the quality of methodological variations for increased comparability. Applying an economic evaluation at MGH CHOIR to address the effectiveness of a mind-body intervention will reveal the extent to which the quality of life for patients with PNUC has been altered. Future directions include extending this evaluation to a broader range of varying healthcare conditions to further investigate the beneficiary nature of varing interventional treatments. Fostering the implementation of cost evaluations in hospitals will maximize healthcare expenditure and further bridge the gap in creating effective long-term care
Impacts of hypophosphatemia on gene expression needed for bone fracture repair
Full text linkBone fractures are one of the most common injuries in the United States, encompassing 6.2 million incidences, and costing the healthcare system roughly $20 billion annually. The majority of this cost falls upon a unique type of fracture known as a non-union fracture, defined by incomplete healing after 9 months. The economic burden in combination with the frequency by which these incidences occur offer a unique opportunity for research and improvement in the healthcare field.
Previous research on the fracture repair process showed that dietary deficiency led to delayed healing producing a rachitic-like effect on the endochondral bone formation process that occurs during fracture healing. This research will build off the understanding of hypophosphatemia on bone fracture repair utilizing a unique temporal clustering approach to assess changes in the transcriptomic expression within callus tissues of control fed and dietary phosphate restricted animals.
Using a temporal cluster modeling technique developed by our group (Lu et al. 2019), twelve clusters were generated for the gene expression data extracted from the callus tissues of B6 strain mice at time points 3, 5, 7, 10, 14, 18-, 21-, 28-, and 35-days post fracture, in, control and phosphate restricted dietary groups. Groupings of clusters were used to establish the temporal expression patterns over the time course of healing and identify the movement of genes that changed their temporal expression patterns between the control and phosphate restricted diets. Biological process categories were established for each cluster, grouping using both Ingenuity Pathway Analysis (IPA) and the NIH DAVID Bioinformatics Database ontology assessment programs. Genes based on their association with four key tissue developmental processes in fracture repair, skeletogenesis, myogenesis, vasculogenesis, and neurogenesis were analyzed.
The analysis showed shifts to later peak expression times for all four categories. Further analysis illuminated three specific regulatory pathways that were significantly impacted by hypophosphatemia, Hippo and WNT signaling pathways and the circadian rhythm pathway while oxidative phosphorylation was both shifted and showed reduced expression. The shifts in expression time and level of these pathways demonstrate their importance to bone fracture repair and their impacts on mesenchymal stem cell differentiation.
From the data analysis it is clear that limiting dietary phosphate results in impaired mesenchymal stem cell differentiation caused by delayed Hippo and WNT signaling. Further it is evident that the processes of skeletogenesis, myogenesis, vasculogenesis, and neurogenesis are heavily interconnected, often showing overlapping genes through all four processes. Based on these shifts and impairments in specific signaling we identified novel mechanisms by which hypophosphatemia can impair fracture callus growth and development and delay healing
Fracture nonunion etiology, diagnosis, and treatment: current understandings and approaches
Full text linkFracture healing is a carefully orchestrated process that closely resembles embryonic skeletal development. In 5-10% of all fractures however this process arrests or is impeded, creating a nonunion of bone across the fracture site that severely complicates patient recovery at great economic cost. The pathophysiology of this complication remains largely unknown, although the disruption of specific cytokine signaling pathways, lack of osteogenic cells, vascular disruption, and a suboptimal mechanical environment may all contribute. Smoking, diabetes, and the use of NSAIDs have also demonstrated associations with nonunion. Diagnosis of a nonunion has also proven difficult as radiographic and clinical assessments remain the gold standard but are largely subjective. Following a diagnosis, surgical intervention is typically pursued and augmented with pharmacologic agents and bone stimulators, although evidence for the effectiveness of both remains limited.
The future of nonunion understanding and diagnosis are coupled, as current research into the complication’s pathophysiology hopes to elucidate biologic markers of bone healing potentially disrupted in nonunion and detectable in the serum. The use of these markers in addition to the expanded use of validated radiographic scoring present the most promising future diagnostic tools. Advanced grafting techniques and compounds as well as stronger evidence-based pharmacologic augmentation seek to improve outcomes after treatment as well. Overall, this review seeks to provide a comprehensive report of current understandings, diagnostics, and treatments for fracture nonunion and the evidence that supports them, as well as present current and planned future research aimed at developing more efficacious diagnostic and therapeutic modalities
Shock attenuation at the knee during walking in people with knee osteoarthritis: association with disease severity and effects of exercise
No full textBACKGROUND: Knee osteoarthritis is a debilitating disease largely affecting the elderly population, impacting their quality of life through joint pain and decreased mobility. Shock attenuation at the knee has been one measure associated with increased pain due to the inability to properly absorb shock as one performs physical activities such as walking and running. Although there is currently no cure to knee osteoarthritis, there are many treatments ranging from exercise to surgical interventions that aim to minimize these negative symptoms and prevent further joint degradation and disease severity.
RESEARCH QUESTION/PURPOSE: This thesis aims to examine shock attenuation at the knee during walking and its association with muscle activation and disease severity in people with knee osteoarthritis. In addition, this study will investigate the effects of exercise intervention on shock attenuation at the knee in this population of individuals.
METHODS: 295 individuals with confirmed knee osteoarthritis were recruited from surrounding communities in this study. Of these 295 participants, 58 participants were included in a 12-week follow-up study to compare the effects of exercise therapy. All muscle activation and shock attenuation data were collected using a 13-camera motion capture system and muscle co-contraction was measured using electromyography (EMG) sensors. A multivariate regression model accounting for age, sex, and BMI was sued to analyze the association between shock attenuation at the knee and disease severity as well as with muscle activation. A linear mixed model was also used to the difference between repeated measures in analyzing the effects of exercise intervention on shock attenuation.
RESULTS: Shock attenuation from shank to thigh and as calculated by coupled vector angle had a significant negative correlation with disease severity characterized by an increase in Kellgren-Lawrence grade as well as a positive correlation with Knee Injury and Osteoarthritis Outcome (KOOS) pain scores. An increase in vastus lateralis and left hamstring muscle co-contraction was also associated with a decrease in coupled vector angle. In analyzing the effects of exercise intervention on shock absorption, there was a significant decrease in shock attenuation from the shank to thigh after a 12-week follow-up study.
DISCUSSION: As the knee osteoarthritis disease severity progresses, patients will also experience lower shock attenuation and increased pain. In addition, increased muscular co-contraction between the vastus lateralis and left hamstring corresponded with a decrease in coupled vector angle. Our results also suggest that exercise may decrease a patient’s ability to absorb shock at the knee.2026-03-15T00:00:00
Characterizing heterotopic ossification development following muscle injury
Full text linkINTRODUCTION: Musculoskeletal trauma is a well-known cause of heterotopic ossification, also known as ectopic ossification, a pathological process in which bone forms within soft tissues. Previous studies in the lab have shown that muscle trauma increases the amount of bone formed in demineralized bone matrix-induced animal models. Moreover, recent studies have shown that ectopic ossification's underlying mechanism follows a specific gene expression progression similar to endochondral ossification. Because of the inherent complexity of the biological composition of DBM, the need to use immune deficient animals with human DBM, and the experimental objective to clarify the role of BMP2 in the inductive process on musculoskeletal trauma on ectopic bone formation a simpler and better defined model of inducing ectopic bone formation was examined. For the studies reported here, defined concentrations of BMP2 were added to gelatin sponges in combination with a defined muscle injury to induce ectopic bone formation on bone formation.
OBJECTIVE: Characterize the effects muscle trauma on ectopic bone formation using absorbable gelatin sponge/BMP2 – induction model for ectopic bone formation. Bone volume and structure were assessed by MicroCT. The quantitative expression of specific mRNAs was used to examine: the induction and recruitment of stem cells: skeletal cell development and differentiation; and BMP signaling.
METHODS: Tamoxifen inducible B6.Cg-Pax7^tm1(cre/ER2)Gaka/J transgenic mice were crossed with B6.Cg-Gt(ROSA)26Sor^tm14(CAG-tdTomato)Hze/J to create Pax7/Ai14 reporter. These animals were subsequently crossed with B6.129S7-Rag1^tm1Mom/J mice. This created an inducible reporter mouse capable of receiving the absorbable gelatin sponge loaded with recombinant human bone morphogenic protein 2 (BMP-2). Between 8-10 weeks of age, mice received two tamoxifen injections within 48 hours apart, followed by a washout period of 96 hours. Animals were implanted with 0.2 cm^3 of sterile absorbable gelatin sponged loaded with 0.3 µg of BMP-2 along the periosteal surface of the femur bilaterally. Muscle injury was induced in select animals following surgery. Animals were harvested at either postoperative day (POD) two, eight, or sixteen. Tissue samples were either prepared for plain film radiographs and micro-computed tomography (µCT) or mRNA extraction. Samples selected for imaging were radiographed using plain film and then proceeded for µCT. Micro-computed tomography allowed for analysis of the ectopic bone and the creation of 3D renderings. Implant samples selected for mRNA extraction were further prepared to analyze gene expression using real time quantitative polymerase chain reaction (qPCR).
RESULTS: Muscle trauma did not significantly change the characteristics of ectopic bone formed in the BMP-2 supplemented absorbable gelatin sponge implant. However, a batch effect had been observed between samples that received two different batches of BMP-2, which differed significantly in tissue volume and trabecular morphology. Gene expression showed a progressive pattern of expression. Sox2 expression peaked early in POD 2 samples. In comparison, Prx1 and α-SMA expression peaked later on at POD 8 and 16. Early markers of chondrogenesis, Sox9, and Acan, peaked at POD 8, while late makers of chondrogenesis, Col10a1, and osteogenesis markers, RUNX2, Sp7, and DMP-1, peaked at POD16. Expression of various members of the BMP gene family showed that BMPs were endogenously induced over the course of ectopic bone formation and suggests that BMP signaling is central to progressive development of ectopic bone formation.
CONCLUSION: Skeletal muscle injury does not appear to significantly impact the formation of ectopic bone in gelatin sponge implants supplemented with 0.3 µg of BMP-2. However, batch 2 samples showed some distinction between injured and noninjured samples, but the sample size was too small to make any firm conclusion. Further studies with the same protocol would help create a more definitive conclusion. RNA analysis reaffirmed a previous study's findings showing a progression of gene expression similar to endochondral ossification. However, this study produced evidence suggesting a delay in either osteogenesis or in the apoptosis and resorption of the hypertrophic cartilage within this model. Further studies could introduce later harvest times at 21 or 31 days postoperative, allowing a better understanding of when osteogenesis peaks during ectopic ossification
Validation of utilizing the pediatric Sequential Organ Failure Assessment scoring system in patients with congenital heart disease
Full text linkThe Sequential Organ Failure Assessment has been used to track a patient’s status for over two decades. It essentially provides a numeric value to quantify the severity of organ dysfunction, most commonly used in sepsis (1). This assessment system was primarily developed for adult patients. However, this threshold cannot be applied in pediatric patients as organ function matures over time. A team of researchers published a paper in 2017 describing the SOFA scale adjusted for pediatric populations (Pediatric Sequential Organ Failure Assessment; pSOFA). Furthermore, they conducted a retrospective study to validate the use of their pSOFA scoring system in pediatric patients admitted to the general Intensive Care Unit. This demonstrated a good correlation with the study for adult patients (2). Patients with congenital heart disease (CHD) often have abnormal circulatory patterns, which can significantly affect cardiovascular and respiratory systems at baseline. This thesis project aims to explore the utilization of pSOFA in assessing the severity of illness in critically ill pediatric patients with congenital heart disease (CHD). Retrospective data collection was carried out in a population of patients with CHD during their stay in the Cardiac ICU (CICU) at Boston Children’s Hospital. Two pSOFA scores, separated based on using indirect vs. direct bilirubin values, were assigned each day spent in the CICU for 101 patients. Of these 101 patients, 50 had a diagnosis of cyanotic CHD while 51 patients had acyanotic CHD. pSOFA scores were compared between cyanotic and acyanotic patients with CHD as well as with a cohort of patients without CHD. This was an exploratory study which provides a deeper understanding for future analysis in order to validate the utilization of pSOFA in a population of patients with CHD.2022-06-07T00:00:00
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