Which surface properties enhance bone response to implants? Comparison of oxidized magnesium, TiUnite, and Osseotite implant surfaces

PURPOSE: This study compared the speed and strength of osseointegration and osteoconductivity between an oxidized experimental magnesium (Mg) implant, an oxidized commercially available TiUnite implant, and a dual acid-etched surface Osseotite implant. The aim was to investigate which surface properties enhance bone response to implants, and thereby to test a biochemical bonding theory. MATERIALS AND METHODS: A total of 60 screw implants (20 of each design) were inserted through 1 cortex into the tibiae of 10 rabbits. Surface chemistry, oxide thickness, morphology, crystal structure, and surface roughness were evaluated. After healing times of 3 and 6 weeks, all bone implants were unscrewed with removal torque (RTQ) devices, and the bone specimens were subjected to histomorphometry. RESULTS: RTQ values for Mg, TiUnite, and Osseotite implants were 27.1, 21.3, and 15.4 Ncm, with new bone formation values of 29%, 18%, and 15%, respectively, at 3 weeks. At 6 weeks the RTQ values were 37.5, 36.4, and 21.5 Ncm, with new bone formation values of 39%, 31%, and 26%, respectively. Discussion: Mg implants demonstrated significantly greater RTQ values (P = .008 and P = .0001) and more new bone formation (P = .031 and P = .030) than Osseotite at 3 and 6 weeks, respectively. Mg implants also showed higher RTQ values at 3 weeks and new bone formation at 6 weeks than TiUnite, but neither were significant (P > .05). TiUnite showed significantly higher RTQ values than Osseotite at 6 weeks (P = .001), but was not significant at 3 weeks (P > .05). Osseointegration rate (deltaRTQ/deltaweeks) was significantly faster for Mg (P = .011) and TiUnite (P = .001) implants between 3 and 6 weeks of healing time, but was not significant for Osseotite. CONCLUSIONS: The results indicate that surface chemistry facilitated more rapid and stronger osseointegration of the Mg implants despite their minimal roughness compared to the moderately roughened TiUnite. This suggests potential advantages of Mg implants for reducing high implant failure rates in the early postimplantation stage and in compromised bone, making it possible to shorten bone healing time from surgery to functional loading, and enhancing the possibility of immediate/early loading.     

Relationship of whole-blood FK506 concentrations to rejection and toxicity in liver and kidney transplants

FK506 (tacrolimus) has been shown to be a safe and effective immunosuppressant for the prevention of organ rejection after liver and kidney transplantation. Like cyclosporine,

the use of FK506 has been associated with some adverse effects such as toxicity and organ rejection. Therapeutic monitoring of the whole-blood FK506 drug concentrations has been used in an effort to determine how the concentration of FK506 in the blood is related to the development of toxicity or the risk for organ rejection. Cox regression analysis of two recent clinical trials of FK506 in patients receiving kidney and liver transplants shows a significant correlation between the whole-blood FK506 concentrations and the incidence of both toxicity and organ rejection. Because of these relationships and the pharmacokinetics of FK506, therapeutic monitoring of the whole-blood FK506 levels is expected to be helpful for minimizing the risks of both toxicity and rejection in liver and kidney transplants.     

Nomograms for prediction of disease recurrence in patients with primary Ta, T1 transitional cell carcinoma of the bladder

We developed nomograms to predict disease recurrence in patients with Ta, T1 transitional cell carcinoma of the bladder. Thirty-eight training hospitals participated in this retrospective multicenter study. Between 1998 and 2002, a total of 1,587 patients with newly diagnosed non-muscle invasive bladder cancer were enrolled in this study. Patients with prior histories of bladder cancer, non-transitional cell carcinoma, or a follow-up duration of less than 12 months were excluded. With univariate and multivariate logistic regression analyses, we constructed nomograms to predict disease recurrence, and internal validation was performed using statistical techniques. Three-year and five-year recurrence-free rates were 64.3% and 55.3%, respectively. Multivariate analysis revealed that age (hazard ratio [HR]=1.437, p<0.001), tumor size (HR=1.328, p=0.001), multiplicity (HR=1.505, p<0.001), tumor grade (HR=1.347, p=0.007), concomitant carcinoma in situ (HR=1.611, p=0.007), and intravesical therapy (HR=0.681, p<0.001) were independent predictors for disease recurrence. Based on these prognostic factors, nomograms for the prediction of disease recurrence were developed. These nomograms can be used to predict the probability of disease recurrence in patients with newly diagnosed Ta, T1 transitional cell carcinoma of the bladder. They may be useful for patient counseling, clinical trial design, and patient follow-up planning.     

Effect of weather variables on the incidence of trauma: A retrospective study at a single tertiary hospital center for 4 years

The occurrence of trauma is associated with various factors, including weather. We aimed to elucidate the relationship between local weather factors and the incidence of trauma to effectively manage and treat patients in a community setting. A retrospective study was conducted at a single center from January 2016 to December 2019. The study participants were trauma patients in the Cheongju area where the regional trauma center is located. Weather data including average daily temperature (°C), rainfall duration (hours), amount of rainfall (mm), average relative humidity (%), wind speed (m/s), and total sunlight hours per day were collected. One-way analysis of variance, correlation analysis, and linear regression analysis were performed. The average age of the participants (n = 3352) was 52.69 years. As regards seasonal difference in the incidence of trauma, there were more patients in spring than in winter (2.42/day vs 2.06/day, P = .05). The highest number of average daily trauma incidents occurred from April to June, and the difference between this value and that from January to February was significant (F = 2.20, P = .01). According to the distributed lag nonlinear model (DLnM), the relative risk is greater than 1 when the mean temperature is high (>15°C) compared to when the temperature is low (<15°C). The trauma patient prevalence was the highest at high wind speed (4.5 m/s). When the total amount of sunlight was long (>Ref. 8 hours), the trauma patient prevalence was relatively higher than the median value (lag = 0). DLnM analysis results showed that the relative risk of trauma patients increased as the amount of precipitation increased, and the incidence of trauma increased when the relative humidity was 40% to 50%. Multiple linear regression analysis revealed that high average daily temperatures and long average daily total sunlight hours resulted in an increased incidence of trauma (F = 6.605, P < .001). An increase in temperature, an increase in the daily sunlight hours, an increase in rainfall, high wind speed, and relative humidity of 40% to 50% are associated with a relatively high risk of trauma.     

Cataract,Glaucoma, and Dry Eye Disease in Adults with Atopic Dermatitis: A Nationwide Cross-Sectional Study from the Republic of Korea

BackgroundAtopic dermatitis (AD) is an inflammatory skin disorder characterized by relapsing eczema with intractable itching. Ocular diseases in patients with AD, including cataract, retinal detachment, blepharitis, glaucoma, keratoconjunctivitis, and keratoconus, have frequently been reported worldwide. However, only a few studies using a large-sample, population-based study design have been reported so far.ObjectiveWe investigated the association between cataract, glaucoma, and dry eye disease and AD in an adult population in the Republic of Korea.MethodsA total of 14,900 adults who participated in the Korean National Health and Nutrition Examination Survey, a nationwide, population-based, cross-sectional survey, between 2010 and 2012 were included in the study. Multiple logistic regression analyses identified the possible association between cataract, glaucoma, and dry eye disease and AD relative to matched controls.ResultsAfter we adjusted for confounding factors in patients with AD, cataract and glaucoma were significantly associated with AD. Moreover, patients with AD had a higher prevalence of ophthalmic surgery compared to those without AD.ConclusionDermatologists should therefore be aware of possible ocular disorders in patients with AD and should recommend regular ophthalmic screening for early detection.     

Anti-Proliferative Effects of Methanol and Water Extracts of Pyrrosia piloselloides on the Hela Human Cervical Carcinoma Cell Line

Background: Cervical cancer is one of the most commonly diagnosed neoplasms and a leading cause of cancerdeath among females worldwide. Limitations with conventional medical treatments have driven researchers tosearch for alternative approaches using natural products. This study aimed to detemine potential anti-proliferativeeffects of methanol and water extracts of Pyrrosia piloselloides (P. piloselloides) on the HeLa cell line. Methods:3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to determine IC50concentrations and apoptosis analysis was by flow cytometry. To identify chemical compounds in the extracts, gaschromatography-mass spectrometry (GC-MS) was employed. Results: P. piloselloides methanol extracts (PPME) showedantiproliferative effects on HeL awith an IC50 of 16.25μg/mL while the P. piloselloides water extract (PPWE) was withoutinfluence. Neither extract showed any significant effects on apoptosis. GC-MS analysis, revealed 5-hydroxymethylfurfural(23.1%), allopurinol (8.66%) and 3, 5-dihydroxy-6-methyl-2,3-dihydropyran-4-one (7.41%) as major components inthe PPME, while sulfolan-3-ol (10.1%), linoleic acid (9.06%) and β-sitosterol acetate (7.98%) predominated in thePPWE case. Conclusion: This first study of P. piloselloides showed PPME to exert potent anti-proliferative effect onHeLa cell lines. Further research now needs to be performed to establish the mechanisms of inhibition.     

Effects of benzo(a)pyrene on the expression of heat shock proteins, pro-inflammatory cytokines and antioxidant enzymes in hepatic tumors induced by rat hepatoma N1-S1 cells

Benzo(a)pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) that is easily introduced to humans via consumption of grilled or smoked meat. BaP causes harmful oxidative effects on cell development, growth and survival through an increase in membrane lipid peroxidation, oxidative DNA damage and mutagenesis. Therefore, the present study was conducted to evaluate the synergistic effects of BaP on oxidative stress in hepatic tumors. In this study, we established a hepatic tumor model by injecting rat hepatoma N1-S1 cells into healthy rats. Changes in the abundance of heat shock proteins (HSPs), antioxidant enzymes and pro-inflammatory cytokines were then investigated by western blot analysis. In addition, we examined changes in oxidative stress levels. Injection of N1-S1 cells or concomitant injection of BaP and N1-S1 cells resulted in the formation of hepatic tumors at the injection site. Evaluation of rat plasma reveals that hepatic tumors induced by BaP and N1-S1 cells expresses higher levels of Hsp27, superoxide dismutase (SOD), and tumor necrosis factor-α (TNF-α) when compared to those induced by N1-S1 cells only. The collective results of this study suggest that BaP exerts synergistic effects on the expression of HSP, cytokines and antioxidant enzymes in hepatic tumors induced by rat hepatoma N1-S1 cells.     

Ultrastructural analysis of the synaptic connectivity of TRPV1-expressing primary afferent terminals in the rat trigeminal caudal nucleus

Trigeminal primary afferents that express the transient receptor potential vanilloid 1 (TRPV1) are important for the transmission of orofacial nociception. However, little is known about how the TRPV1-mediated nociceptive information is processed at the first relay nucleus in the central nervous system (CNS). To address this issue, we studied the synaptic connectivity of TRPV1-positive (+) terminals in the rat trigeminal caudal nucleus (Vc) by using electron microscopic immunohistochemistry and analysis of serial thin sections. Whereas the large majority of TRPV1+ terminals made synaptic contacts of an asymmetric type with one or two postsynaptic dendrites, a considerable fraction also participated in complex glomerular synaptic arrangements. A few TRPV1+ terminals received axoaxonic contacts from synaptic endings that contained pleomorphic synaptic vesicles and were immunolabeled for glutamic acid decarboxylase, the synthesizing enzyme for the inhibitory neurotransmitter γ-aminobutyric acid (GABA). We classified the TRPV1+ terminals into an S-type, containing less than five dense-core vesicles (DCVs), and a DCV-type, containing five or more DCVs. The number of postsynaptic dendrites was similar between the two types of terminals; however, whereas axoaxonic contacts were frequent on the S-type, the DCV-type did not receive axoaxonic contacts. In the sensory root of the trigeminal ganglion, TRPV1+ axons were mostly unmyelinated, and a small fraction was small myelinated. These results suggest that the TRPV1-mediated nociceptive information from the orofacial region is processed in a specific manner by two distinct types of synaptic arrangements in the Vc, and that the central input of a few TRPV1+ afferents is presynaptically modulated via a GABA-mediated mechanism.     

Simvastatin suppresses expression of angiogenic factors in the retinas of rats with streptozotocin-induced diabetes

Background  

Angiogenic factors such as vascular endothelial growth factor (VEGF), erythropoietin, and angiopoietin play important roles in the pathophysiology of diabetic retinopathy. Increased amounts of reactive oxygen species (ROS) are also known to associated with diabetic retinopathy and VEGF expression. This study evaluated the effect of a simvastatin on ROS generation and the changes in various angiogenic factors in the retinas of diabetic rats.