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STUDY DESIGN: Basic science. OBJECTIVE: To compare the effects of a neuropeptide Y1 receptor antagonist (NPY-1RA) to estrogen on maintaining vertebral bone microarchitecture and disc height in a rat model of menopause. METHODS: This study was an institutional animal care approved randomized control study with 104 ovariectomized rats and 32 intact control animals. Comparison of disc height, trabecular bone, body weights, circulating levels of NPY and estrogen, and distribution of Y1 receptors in the intervertebral disc in an established rodent osteoporotic model were made at baseline and after 2, 4, and 8 weeks after receiving either an implant containing estrogen or an antagonist to the neuropeptide Y1 receptor. Data was compared statistically using One-way analysis of variance. RESULTS: Circulating levels of estrogen increased and NPY decreased following estrogen replacement, with values comparable to ovary-intact animals. NPY-1RA-treated animals had low estrogen and high NPY circulating levels and were similar to ovariectomized control rats. Both NPY-1RA and estrogen administration were able reduce, menopause associated weight gain. NPY-1RA appeared to restore bone formation and maintain disc height, while estrogen replacement prevented further bone loss. CONCLUSION: NPY-1RA in osteoporotic rats activates osteoblast production of bone and decreased marrow and body fat more effectively than estrogen replacement when delivered in similar concentrations. Annulus cells had NPY receptors, which may play a role in disc nutrition, extracellular matrix production, and pain signaling cascades.
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The goals of this study are to evaluate the ability of the multicomponent collagen-elastin-like polypeptide (ELP)-Bioglass scaffolds to support osteogenesis of rat mesenchymal stem cells (rMSCs), demonstrate in vivo biocompatibility by subcutaneous implantation in Sprague-Dawley rats, monitor degradation noninvasively, and finally assess the scaffold's ability in healing critical-sized cranial bone defects. The collagen-ELP-Bioglass scaffold supports the in vitro osteogenic differentiation of rMSCs over a 3 week culture period. The cellular (rMSC-containing) or acellular scaffolds implanted in the subcutaneous pockets of rats do not cause any local or systemic toxic effects or tumors. The real-time monitoring of the fluorescently labeled scaffolds by IVIS reveals that the scaffolds remain at the site of implantation for up to three weeks, during which they degrade gradually. Micro-CT analysis shows that the bilateral cranial critical-sized defects created in rats lead to greater bone regeneration when filled with cellular scaffolds. Bone mineral density and bone microarchitectural parameters are comparable among different scaffold groups, but the histological analysis reveals increased formation of high-quality mature bone in the cellular group, while the acellular group has immature bone and organized connective tissue. These results suggest that the rMSC-seeded collagen-ELP-Bioglass composite scaffolds can aid in better bone healing process.
Asunto(s)
Elastina , Osteogénesis , Animales , Regeneración Ósea , Diferenciación Celular , Cerámica , Colágeno , Péptidos , Ratas , Ratas Sprague-Dawley , Ingeniería de Tejidos , Andamios del TejidoRESUMEN
The needs of dental patients are becoming ever complex. This is largely due to the increasing number of systemic conditions that patients present with during routine or emergency dental visits, such as hypertension and angina pectoris. Medications that patients are prescribed have potential to cause effects on the oral tissues. There is a need to understand the interactions between the oral tissues and materials used to restore teeth. The objective of this study was to assess the physiological function of human gingival fibroblasts upon exposure to dental adhesives; polymethyl methacryate, OptiBond®, and Prime & Bond®; Porphyromonas gingivalis lipopolysaccharide and Cortisol or Nifedipine. An increase in metabolic activity was noted with the experimental group exposed to the combination of Prime & Bond®, LPS-PG, and Nifedipine (P<0.001). Oxidative stress was observed in experimental groups exposed to the combinations of PMMA, LPS-PG, and Cortisol (P<0.001); also noted in all three dental adhesives in combinations with LPS-PG and Nifedipine (P<0.001). Cellular membrane damage was evident in experimental groups exposed to the combinations of PMMA, LPS-PG, and Cortisol; PMMA, LPS-PG, and Nifedipine; and Prime & Bond®, LPS-PG, and Nifedipine. In conclusion, it appears that the addition of Nifedipine in combination with LPS-PG negatively alters cellular function by causing membrane damage and inducing oxidative stress.
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Demineralized bone matrix protein (DBM) was considered highly effective in stimulating bone healing. The objective of the study was to explore the use of tricalcium phosphate (TCP) delivery system to continuously deliver DBM in an osteoporotic condition and to evaluate changes in bone density and preservation of the spine. Ovariectomized Sprague Dawley rats were divided into three equal groups (n=16 per group). Animals in group I served as control, animals in groups II and III were surgically implanted with either empty (SHAM) or DBM filled TCP implants adjacent to L4/L5. Eight animals from each group were euthanized at 2 and 8 weeks post implantation. Femurs were evaluated for changes in density, and the lumbar spine was evaluated for changes in the endplate. Results of this study revealed (1) TCP implants were capable of delivering DBM for long duration, (2) use of sustained delivery of DBM did not induce untoward effects in the vital organs or in the uterus, fallopian tubes, or vaginal tissues, (3) DBM had no effect on chondrocyte differentiation in the spine, and (4) DBM did not increase bone density in osteoporotic female rats.
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Dental adhesives are necessary for the retention of specific dental restorations utilized to repair the anatomy of the tooth after dental decay is removed. Adhesives come into contact with healthy and diseased periodontal tissues. Porphyromonas gingivalis is a gram negative bacterial pathogen, and lipopolysaccharide (LPS-PG) is an endotoxin found in gingival connective tissues of patients who suffer from periodontal disease. The presence of the endotoxin causes inflammation. This study aims to evaluate the effectiveness of potent dental adhesives when human gingival fibroblasts are challenged with LPS-PG. The fibroblasts were exposed to the dental adhesives polymethly methacrylate (PMMA), OptiBond®, and Prime & Bond® which were purchased from Patterson Dental, a national dental materials supplier. The human gingival fibroblasts (HGF-1, ATCC® CRL-2014) were purchased from American Type Culture Collection (ATCC). The porphyromonas gingival lipopolysaccharide (LPS-PG) was purchased from Fisher Scientific (Pittsburg, PA). No significant differences in metabolic behavior was detected among the groups (p<0.132). While the glutathione assay determined that there was not any significant increase in oxidative stress levels; the lactate dehydrogenase assay identified significant cellular damage in the group exposed to combinations of the Prime & Bond® adhesives and LPS-PG at 48 hour intervals (p<0.003). No significant changes were noted in cellular morphology at any phases, and all cells demonstrated typical fibroblast spindle shape.
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This study investigated the effects of dual delivery of statin and vancomycin on angiogenesis during the healing process of a femoral defect injury using tricalcium phosphate lysine (TCPL) delivery system in an animal model. The experimental design consisted of 14 rats divided into the following three groups: Group I animals (n=5) served as the intact control without treatment. Group II animals (n=5) were subjected to a surgically induced defect (2 mm, midshaft of the right femur) and implanted (IM) with TCPL capsules loaded with vancomycin (20mg) (TCPL-AB). Group III animals (n=4) were operated on in a similar fashion as Group II, and subsequently implanted with TCPL capsules loaded vancomycin (20 mg) plus statin (5 mg). The animals were euthanized at 30 days post-implantation using overdose of isoflourane. The right femurs were then harvested in addition to the vital organs, the reproductive organs, and sample of the adjacent skeletal muscles. The hard and soft tissues were evaluated histopathologically by following laboratory standard techniques. The results of this study indicated that statin plus vancomycin treated animals had increased angiogenetic activities with many blood vessels compared to the sham group and the animals also healed in a greater magnitude than the sham group (independent evaluators (p<0.001)). Histomorphometric analysis demonstrated that exposure to sustained delivery of statin resulted in increased blood vessels. It appeared there is a direct correlation of the increased angiogenesis and the increased bone formation in the statin group and this may be one of the mechanisms with which statin form bone. In conclusion, data obtained from this study demonstrated that sustained delivery of statin by TCPL resulted in a remarkable increase in angiogenic and osteogenic activities during the healing process of a femoral defect.
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The objective of this investigation was to evaluate the location and activity of cytokines in the fibrous tissue surrounding tricalcium phosphate (TCP) implants loaded with androgenic hormones. Sixteen animals in four experimental groups (n = 4/group) were implanted with one TCP implant each: Group I (control), Group II (testosterone), Group III (dihydrotestosterone), and Group IV (androstenedione). At 90 days post-implantation, the fibrous tissue surrounding the implants were evaluated following staining with antibodies to IL-1ß, IL-2, IL-6, and TNF?. Data were collected on the presence and distribution of cytokines within the fibrous tissue surrounding all four groups. IL-1ß was primarily found intercellular and associated with fibroblasts and macrophages of Groups I-III. IL-2 was present in the extracellular matrix and was sporadically found on the surface of macrophages in Groups I-III. IL-6 was found primarily concentrated in the fibroblast and collagen rich portions of the fibrous tissue matrix in Groups I-III. TNF-? was present in the extracellular matrix of the fibrous tissue of all four groups and was strongly associated with fibroblast and macrophage rich areas. The results of this study confirm activity of cytokines on target cells and indicate their actions may vary in their effect within the fibrous tissue surrounding TCP implants loaded with androgens.
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Alzheimers disease (AD) is the only cause of death among the top 10 diseases that cannot be prevented, cured, or slowed with the current treatments available. Amyloid beta is thought to be the main initiator of AD cognitive decline, activating internal pathways which lead to inflammation, oxidation, and cell death. The objective of this study was to determine if pretreatment of human SH-SY5Y neuroblastoma cells, a model for AD, with antioxidants thymoquinone (TQ), epigallocatechin-3-gallate (EGCG), or dilinoleoylphosphatidylcholine (DLPC) 30 minutes prior to a challenge with tumor necrosis factor a (TNFa), an inflammatory mediator, can prevent oxidation of amyloid beta (Aß). Following treatment, cells were incubated and groups evaluated at 24, 48, and 72 hours. Human amyloid precursor protein (APP) enzyme-linked immune-sorbent assay (ELISA) and nitric oxide assays were performed from supernatant whereas protein and glutathione assays were performed from cells. When TNFa was added to cells, Aß significantly increased 3-fold compared to untreated cells. The addition of antioxidants EGCG, TQ, and DLPC reduced Aß back toward control value at the initial time point. TNFa also caused a significant increase in nitric oxide without changes in glutathione. TQ administered to the cells prior to a challenge with TNFa resulted in a decrease in nitric oxide and an increase in glutathione which may be a possible mechanism to reduce inflammation and reduce oxidation. Additional studies are needed to determine the signaling pathways implemented in the SH-SY5Y cells following TNFa.
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The objective of this study was to investigate the synergistic effect of Thymoquinone (TQ) and Epigallocatechin-3-gallate (EGCG) using Caov-3 cell line as a model. A total of 144 wells were plated with 10^5 Caov-3 ovarian cancer cells. The wells were divided into groups of 72 wells for conventional and sustained delivery, respectively. Each group was subdivided into 4 groups of 6 wells. Group 1 served as control and groups 2, 3, and 4 were treated with TQ (16 µM), EGCG (3 µg/ml), and TQ plus EGCG, respectively. Biomarkers evaluations were performed following standard lab techniques. The results of the study revealed: conventional delivery of TQ, EGCG, and the combination did not induce intracellular oxidative stress (glutathione levels) at 24, 48, and 72 hours; however, sustained delivery of all agents showed significant difference from the control at 72 hours; and there was no significant difference at 24 and 48 hours. Overall conclusion: the route of potent agents to manipulate ovarian cancer cells is highly dependent on the route of administration.
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Osteoporosis and cardiovascular disease (CVD) are common age-related conditions, which are major public health problems leading to an increase in mortality, morbidity, and disability. There have been several connections found between CVD and osteoporosis such as common genetic factors, risk factors, and pathological mechanisms. There is a direct effect of estrogen on CVD and osteoporosis that is demonstrated by the manifestation of estrogen receptors on osteoblasts, osteoclasts, and vascular endothelial and smooth muscle cells. Loss of estrogen has been found to be involved in the pathogenesis of atherosclerosis and bone loss through modulation of other factors including cytokines and oxidized lipids. The goal of this proposed research was to determine if sustained delivery of estrogen is capable of regulating bone cell function while improving cardiovascular panels. Ovariectomized Sprague Dawley rats were administered estradiol at a rate of 5ng/day over an eight-week period. Body weights, estradiol levels, cholesterol levels, and bone strength were determined at 2, 4, and 8 weeks following sustained delivery of estradiol and compared with intact control and ovariectomized control animals. Estrogen replacement resulted in improved cholesterol panels without significant changes in bone flexural strength or improvements in bone porosity. Additional long term studies are needed to determine if the benefits of estrogen replacement outweigh the inherent risks associated with hormone replacement therapies.
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Ovarian cancer is the fifth most common cancer and the leading cause of mortality among the gynecologic cancers. Ovarian cancer is a very devastating disease it is rarely diagnosed in its early stages, and it is usually quite advanced by the time diagnosis is made leading to very poor outcomes. It is believed that in advanced stage ovarian cancer cells produce a protein that enables the tumor cells to proliferate and become resistance to conventional drug treatments. Development of new treatment options strongly relies on understanding the ovarian carcinoma ability to proliferate and to attack the cells using combination drug treatments that are synergistic. Recent studies in our laboratory have indicated that the exposure of Thymoquinone (TQ) and Epigallocatechin-3-gallate (EGCG) to adenocarcinoma of the prostate, colon, and pancreas. This study was executed to investigate the effectiveness of TQ and EGCG on reducing early stage ovarian cancer cells. A total of 72 wells were plated with (105) Caov-3 ovarian cancer cells according to standard lab protocols. Each group was subdivided into 4 groups. Group 1 served as control and groups 2, 3, and 4 were treated with TQ (16 µM), EGCG (3 µM), and TQ + EGCG, respectively. Biomarkers and morphological evaluations were performed following standard lab techniques. The results of the study revealed: (1) an increase in nitric oxide following administration of EGCG and the combination at 24 and 48 hours (p<0.05) and (2) no membrane or cellular damage to the cells at all phases. The results of this study suggest used in combination have shown to be more effective method for manipulating Caov-3 ovarian cancer cells than when used alone.
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ISSUE: In an effort to increase knowledge regarding infection prevention and compliance with isolation precautions among our staff in a 722 bed tertiary referral teaching hospital, we created a standardized color-coded isolation signs. PROJECT: Different versions of isolation precaution signs existed at our institution. Concerns in regards to these signs included being in a neutral color and easily overlooked, providing insufficient information regarding isolated pathogen, ignoring appropriate isolation garb, and technique required for performing hand hygiene. This led to the creation of a standardized signage throughout the institution. Signs were color-coded, with each color representing a common pathogen requiring isolation. Such a system allowed us to maintain patient confidentiality. Pocket references explaining the coding system, as well as cards that would adhere to personal identification badges were provided to care providers. the reason for isolation. Staff was no longer required to reference the patients chart to discern the reason for isolation, which saved time. Housekeeping could immediately discern appropriate needs in cleaning and disinfection. Our rate of compliance with isolation precautions was maintained in the ninetieth percentile. A Lesson Learned: Communication and cooperation amongst healthcare workers were essential keys in problem solving and served to increase both staff and patient safety and increase the knowledge and comfort level with the infection control practices and guidelines. The process was driven by frontline care providers and, as such, led to immediate uptake and likely improved adherence.
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The FaDu squamous cell carcinoma cell line was used to test combination treatments of natural (EgCg and TQ) drugs and a chemotherapeutic (5-FU) drug to determine if combining drugs with different cell cycle targets would be more effective at destroying cancer cells than one drug that only targets one phase of the cell cycle. There were a total of four different combinations. One combination consisted of all three treatments: EgCg, TQ, and 5-FU. The other three combinations were as follows: EgCg + TQ, EgCg + 5-FU, and TQ + 5-FU. The combination treatments were measured at 24, 48, and 72 hours. There were significant reductions in cell number at each time increment. The combination of any two drugs especially a natural drug plus a chemotherapeutic drug proved to be more effective than single individual drugs in eradicating cancer. The combination of EGCG + TQ + 5-FU proved to be most effective in cell reduction. Since a combination of drugs target more than one phase of the cell cycle, the cells were less likely to become resistant to two or more drugs.
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Patients with type 2 diabetes mellitus require adequate blood glucose control with insulin, metformin or other anti-hyperglycemic agents to prevent significant co-morbidities such as cardiovascular disease. Studies have determined that metformin increases the activity of AMP activated protein kinase and reduces hepatic glucose production and increases tissue sensitivity to insulin. Insulin has some vascular protective qualities; however insulin resistance of type 2 diabetes may be harmful to vascular endothelium. The objective of this study was to investigate the effects of metformin and insulin on H9c2 rat cardiomyocytes in high glucose culture media. Results of this study indicate that clinical doses both insulin and metformin are capable of reducing supernatant glucose levels in high glucose media. Metformin may offer some protection to cardiomyoctyes. Morphologically, cellular changes occurred after exposure to both insulin and metformin at both 24 and 48 hours although at 72 hours, both groups exhibit evidence of cellular damage.
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Approximately 7.9 million bone fractures occur every year in the United States, with an estimated cost of $70 billion. It is estimated that 5-10 percent of patients will develop infections or delayed healing following orthopedic surgery. The probability of osteomyelitis is related to the severity of trauma and infection is most frequent after high velocity, open injuries with skin loss. Complications with bone healing and antibiotic drug-resistance increases morbidity and costs associated with osteomyelitis are estimated at $15,000-$30,000 per incident. Traditional osteomyelitis treatment often requires additional surgery and systemic antibiotics that are harmful, burdensome, and costly. There is limited evidence in the literature examining the effects pharmacological agents tobramycin (TOB) and parathyroid hormone (PTH) have on the mesenchymal stem cells (MSCs) that differentiate into many cell types. The purpose of this investigation was to evaluate the in vitro dose-dependent effects of TOB and PTH on mesenchymal stem cells. MSCs were treated for periods of 24, 48 and 72 hours in the presence of TOB and PTH. Following incubation, MSCs were examined for cellular morphology, viability, proliferation, and damage. Our results show an increase in morphological changes following treatments with both PTH and TOB which are confirmed by decreases in cellular protein concentration. Are results also indicate PTH acts as an essential factor in mesenchymal development and may control differentiation into osteogenic or chondrogenic lineage. Development of targeted delivery of PTH and TOB to a fracture may be effective at treating both infection and bone loss.
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Acute Lymphoblastic Leukemia remains the most common cancer for children, and if left untreated is rapidly fatal. The gold standard for treatment of ALL in children is with a class of drugs known as the antracyclines. Long term outcomes following treatment of leukemia with antracylines can result in cardiac abnormalities including arrhythmias, congestive heart failure, myocardial infarction, hypertension and left ventricular failure. Thymoquinone is a natural product that has demonstrated anti-proliferative, anti-inflammatory, anti-cancer, and chemo-protective effects in control trials as well as a reduction in cardiotoxicity in antracyline treated rats. The aims of the study were to determine if thymoqunione could be used to reduce leukemia cell viability without injuring primary cardiomyocyte, and to determine its effects if used in conjunction with a known chemotherapeutic agent. Cellular viability and morphological changes were observed in the, RAW leukemia cells and cardiac myocytes following treatment with thymoquinone, antracyline (doxorubicin), alone and in combination for 24, 48 and 72 hours. The results suggest that thymoquinone treatment in RAW leukemia cells reduced the cell number without altering the morphology, while doxorubicin reduced cell number and induced spindle cell formation and increased cellular damage. Findings also suggest RAW cell apoptosis increased in combination therapy with thymoquinone and doxorubicin. Thymoquinone administered to cardiomyocytes showed similar morphological changes as control over time in culture; whereas doxorubicin treated cells showed evidence of loss of connectivity and disruption of cell membranes. Combination treatment with doxorubicin and thymoquinone demonstrated significant cardiac myocyte survival at concentrations when used alone were able to reduce the leukemia cells. Overall, the data is promising and may provide a treatment regime to protect the heart tissue. Additional work is warrant to understand the mechanisms involved to reduce cardio toxicity by combining thymoquinone with doxorubicin.
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The experimental impact of retinoic acid (All Trans Retinoic Acid; ATRA), citrals, ovalbumin and mold spores in the development of lung pathology and tissue remodeling are not well established in the literature. As well, the role of these agents in lung pathology was not ascertained under an in vivo setting. Therefore, it is hypothesized that citrals, ATRA, ovalbumin and mold-spore exposure will sensitize lung tissues and will lead to the development of lung tissue pathology in these animals. The study used an IACUC approved between-subject in vivo randomized split plot factorial design (F344 rat model; N=30). Mold spores were applied to animals by intra-tracheal route whereas vehicle, ovalbumin, C1, C2 and ATRA were administered by intra-peritoneal route. Rat weight data and blood were collected on Days 1 and 21. All animals were sacrificed on day 21 and lung tissues were processed for histopathology. Evidence from weights and blood (ANOVA and Duncan) as well as histopatholgical analysis supported the findings that exposure of these animals to C1, C2, ATRA, ovalbumin and mold spores showed different levels of lung tissue damage representing environmental exposure to these agents. This promising study showed variable lung tissue responses to the administration of ATRA, ovalbumin, citrals, and mold spores in the development of various levels of lung tissue pathologies.
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The impact of retinoic acid (All Trans Retinoic Acid; ATRA) in the development of lung pathology and tissue remodeling are not well established in the literature. As well, the role of citral (inhibitor of retinoid function) in the improvement of lung pathology was not ascertained under an in vivo setting. Therefore, it is hypothesized that ATRA and ovalbumin exposure will sensitize lung tissues leading to lung tissue pathology and that citrals (C1 and C2) will reverse or ameliorate the related pathological damage to lung tissues. The study used an IACUC approved between-subject in vivo randomized split plot factorial design (F344 rat model; N=40). Animals were exposed to 8 different treatments including vehicle, OVA, ATRA, citrals (C1 and C2) and their ovalbumin combinations (OVA+ ATRA, OVA+ C1, and OVA+ C2) by intra-peritoneal route. Rat weight data and blood were collected on Days 1 and 21, all animals were sacrificed on day 21 and lung tissues were processed for histopathology. Results from weights and blood (ANOVA and Duncan) as well as from the histopatholgical analysis supported the findings that exposure of F344 rats to OVA combinations with ATRA and citrals showed various levels of lung tissue damage that was improved or worsened by either C1 or C2. This promising study showed variable responses on the interaction of ovalbumin, citrals, and ATRA as related to their damage/improvement of related lung tissue pathologies.
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Surgically repaired tendons are plagued by complications related to the healing response. Adhesion formation between the tendon and its sheath or surrounding tissues inhibits free gliding and results in a loss of excursion. The random orientation of collagen deposition at the site of repair creates a focal area of weakness, rendering the tendon prone to rupture at this point. Even the strongest, most technically precise repair can be negated by either of these complications. Research in tendon injury and healing is primarily focused on the pathogenesis of fibrosis and how to prevent the formation of excessive scar tissue. However, no widely accepted therapy currently exists to promote healing and prevent fibrosis in surgically repaired tendons. The goal of this study was to determine the effects of varying concentrations of transforming growth factor ß1(TGF-ß1), the main constituent of a clinically used treatment, PRP, on fibroblast cells. Cells were treated with low, medium, and high concentrations of TGF-ß1 for periods of 24, 48, and 72 hours and cell proliferation, damage, and morphology were evaluated at each time point. The results show that low dose treatment resulted in significant increases in cell number and cell along with distinct cytological changes within 48 hours of treatment. This information is clinically important and may help to provide an explanation for the inconsistencies seen with use of PRP as an adjuvant for tendon and ligament healing.
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The need for bone graft substitutes is increasing. The understanding of how these potential treatments exert their effect is lacking. Currently, BMPs are used clinically for augmentation of fracture healing and the exact mechanism(s) how they contribute bone healing is not clear. The literature show that demineralized bone matrix protein, OP-1, and IGF-1 are all factors which contribute to increased bone growth. The goal of this study was to determine if these factor signal through similar pathways that can affect bone growth. Our findings show upregulated intracellular MAPK and JAK STAT signaling by OP-1 as well as novel upregulated intracellular SMAD signaling by IGF-1. As expected, OP-1 signaled through the SMAD pathway and IGF-1 signaled through the MAPK and JAK STAT pathways. DBM which contains both OP-1 and IGF-1 signaled through all three pathways as well. The exact role of each of these factors needs to be further investigated to determine which pathway is crucial for normal bone formation and which pathways will be important for bone remodeling.