scholarly journals Influence on Bone-to-Implant Contact of Non-Thermal Low-Pressure Argon Plasma: An Experimental Study in Rats

2020 ◽  
Vol 10 (9) ◽  
pp. 3069
Author(s):  
Arturo Sanchez-Perez ◽  
Ana I. Nicolas-Silvente ◽  
Carmen Sanchez-Matas ◽  
Fernando Muñoz-Guzon ◽  
Carlos Navarro-Cuellar ◽  
...  
Keyword(s):  
Essential Role ◽  
Histological Analysis ◽  
Bacterial Colonization ◽  
Argon Plasma ◽  
Low Pressure ◽  
Sprague Dawley ◽  
New Techniques ◽  
Implant Placement ◽  
Sprague Dawley Rats ◽  
Bone To Implant Contact

Roughness characteristics play an essential role in osseointegration. However, there is a concern about the susceptibility of those surfaces to bacterial colonization. New techniques for cleaning and surface treatment have appeared that could favor osseointegration without the need to create surfaces as rough. Such is the case of non-thermal low-pressure argon plasma (NTLP-ArP). One hundred and forty-four implants were placed in the tibiae of 36 Sprague Dawley rats, distributed in four experimental groups: I: mechanized surface; II: mechanized surface treated with NTLP-ArP, III: resorbable blast media (RBM) surface; and IV: RBM surface treated with (NTLP-ArP). Bone-to-implant contact (BIC) percentages were calculated by microtomographic evaluation and histological analysis at one, two, and four weeks after implant placement. ANOVA and Mann–Whitney tests were used for statistical analysis, establishing p < 0.05. No significant differences were found at one-week comparisons. The groups treated with NTLP-ArP obtained higher BIC% than those not treated at two and four weeks. Mechanized surfaces treated with NTLP-ArP obtained BIC values similar to RBM surfaces.

Effect in a Rat Model of Heparinized Peritoneal Dialysis Catheters on Bacterial Colonization and the Healing of the Exit Site

2001 ◽  
Vol 21 (3_suppl) ◽  
pp. 357-358 ◽  
Author(s):  
Yong-Lim Kim ◽  
Seong Cho ◽  
Jun-Chul Kim ◽  
Dong-Kyu Cho ◽  
Yong-Jin Kim ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Bacterial Colonization ◽  
Randomized Study ◽  
Sprague Dawley ◽  
Exit Site ◽  
Double Blind ◽  
Polymeric Surfaces ◽  
Sprague Dawley Rats ◽  
Multipoint Method ◽  
Catheter Tip

We performed a prospective, double-blind, randomized study to evaluate whether stable surface heparinization of silicone peritoneal dialysis (PD) catheters prevents bacterial colonization or biofilm formation and improves healing of the exit site. Heparinized catheters were implanted in 20 Sprague–Dawley rats (group H) and non heparinized catheters in another 20 (group C). The PD catheters, constructed of silicon tubing with two polyester cuffs, were patterned after the standard Tenckhoff catheter. A covalent multipoint method of attachment onto polymeric surfaces was used for stable, permanent chemical immobilization of heparin on the PD catheter. Dialysis exchanges (25-mL instillation volume) were performed twice daily for 4 weeks through the permanent catheter. Prophylactic antibiotics were not used. The exit sites were evaluated at 2-week intervals. The extent of biofilm coverage on the intraperitoneal portion of the catheter (obtained at the end of the experiment) was assessed, and sonicated fluid from the catheter tip was cultured for evaluating bacterial colonization of the catheter. Exit-site scores in group H were lower than in group C ( p = 0.052) at the end of week 4. Bacterial colonization tended to be less common in group H [2 of 12 catheters (17%)] than in group C [8 of 15 catheters (53%); p = 0.058], but the extent of biofilm, the peritonitis rate, and the inflammation score of tissue adjacent to the cuff were not different between the groups. Those data suggest that heparinized PD catheters can be a practical approach to the prevention of bacterial colonization and can improve healing of the exit site.

Persistent functional and structural retinal anomalies in newborn rats exposed to hyperoxia

1999 ◽  
Vol 77 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Pierre Lachapelle ◽  
Olga Dembinska ◽  
Luz Marina Rojas ◽  
Julie Benoit ◽  
Guillermina Almazan ◽  
...  
Keyword(s):  
Structural Modification ◽  
Histological Analysis ◽  
Plexiform Layer ◽  
Oscillatory Potentials ◽  
Newborn Rats ◽  
Sprague Dawley ◽  
Structural Modifications ◽  
Retina Development ◽  
Sprague Dawley Rats ◽  
Retinal Disorder

Previous studies have shown that newborn rats exposed postnatally to hyperoxia will develop a permanent impairment of the retinal function as determined with the electroretinogram (ERG). The purpose of our study was to examine whether postnatal hyperoxia equally alters the light- and dark-adapted ERGs and oscillatory potentials (OPs) as well as leads to permanent structural modification of the retina. During the first 14 days of life, cohorts of Sprague-Dawley rats were exposed to a hyperoxic environment, and ERGs were recorded at mean ages of approximately 25 and 55 days. Our results indicate that both light- and dark-adapted ERGs and OPs are already significantly altered within a few days following exposure to hyperoxia. None of the ERG and (or) OP parameters, with the exception of the a-wave, returned to normal values by 55 days of age. In fact some dark-adapted OPs were completely abolished following postnatal O2 exposure. Histological analysis revealed that the retina of rats exposed to hyperoxia failed to develop an outer plexiform layer and had a reduced count of horizontal cells, consistent with the permanent postreceptoral anomalies seen in the ERG responses. Our results suggest that postnatal hyperoxia causes a generalized retinal disorder leading to permanent structural modifications of the retinal cytoarchitecture and lasting anomalies of the rod and cone functions.Key words: rods, cones, electroretinography, oscillatory potentials, hyperoxia, retina, development.

scholarly journals Experimental Study of the Effects of Hypoxia Simulator on Osteointegration of Titanium Prosthesis in Osteoporotic Rats

2021 ◽  
Author(s):  
Jiangfeng Liu ◽  
Huijun Kang ◽  
Jiangfeng Lu ◽  
Yike Dai ◽  
Fei Wang
Keyword(s):  
Control Group ◽  
Osteoporotic Bone ◽  
Mrna Levels ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Pull Out ◽  
Sprague Dawley Rats ◽  
Bone To Implant Contact ◽  
Polymerase Chain ◽  
And Control

Abstract Purpose: Poor osseointegration is the key reason for implant failure after arthroplasty, whether in osteoporotic or normal bone conditions. To date, osseointegration remains a major challenge. Recent studies have shown that deferoxamine(DFO) can accelerate osteogenesis by activation of the hypoxia signal pathway. The purpose of this study is to test the following hypothesis: after knee replacement, intra-articular injection of DFO will promote osteogenesis and osseointegration with titanium prosthesis in the bones of osteoporotic rats.Materials and Methods: 90 female sprague-dawley rats were used for the experiment. Ovariectomy and knee arthroplasty were performed. Then, the rats were randomly divided into DFO and control group(n=40 per group). The two groups were treated by intraarticular injection of DFO and saline respectively. After 2 weeks, polymerase chain reaction(PCR) and immunohistochemistry were used to evaluate the levels of HIF-1a, VEGF and CD31. After 12 weeks, the specimens were examined by micro CT, biomechanics and histopathology to evaluate osteogenesis and osseointegration.Results: The results of PCR showed mRNA levels of VEGF and CD31 in DFO group were significantly higher than those in control group. The immunohistochemistry results indicated positive cell expressions of HIF-1a, VEGF and CD31 in DFO group were also higher. Compared to control group, the microCT parameters of BMD, BV/TV, TB.N, TB.Th were significantly higher. The maximal pull-out force and the bone-to-implant contact (BIC) value were also higher . Conclusions: The local administration of DFO which is used to activate HIF-1a signaling pathway can promote osteogenesis and osseointegration with the prosthesis in osteoporotic bone.

Histological analysis of different local haemostatic agents used for periapical surgery: An experimental study with Sprague‐Dawley rats

2019 ◽  
Vol 45 (3) ◽  
pp. 357-364
Author(s):  
Jesús Mena‐Álvarez ◽  
Norberto Quispe‐López ◽  
Álvaro Zubizarreta‐Macho ◽  
Cristina Rico‐Romano ◽  
Rosa Rodero‐Villanueva ◽  
...  
Keyword(s):  
Experimental Study ◽  
Histological Analysis ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Haemostatic Agents

scholarly journals Diabetes increases brain damage caused by severe hypoglycemia

2009 ◽  
Vol 297 (1) ◽  
pp. E194-E201 ◽  
Author(s):  
Adam J. Bree ◽  
Erwin C. Puente ◽  
Dorit Daphna-Iken ◽  
Simon J. Fisher
Keyword(s):  
Brain Damage ◽  
Histological Analysis ◽  
Neuronal Damage ◽  
Severe Hypoglycemia ◽  
Hippocampal Damage ◽  
Sprague Dawley ◽  
Brain Areas ◽  
Sprague Dawley Rats ◽  
Brain Tissue Damage ◽  
Extent Of Damage

Insulin-induced severe hypoglycemia causes brain damage. The hypothesis to be tested was that diabetes portends to more extensive brain tissue damage following an episode of severe hypoglycemia. Nine-week-old male streptozotocin-diabetic (DIAB; n = 10) or vehicle-injected control (CONT; n = 7) Sprague-Dawley rats were subjected to hyperinsulinemic (0.2 U·kg−1·min−1) severe hypoglycemic (10–15 mg/dl) clamps while awake and unrestrained. Groups were precisely matched for depth and duration (1 h) of severe hypoglycemia (CONT 11 ± 0.5 and DIAB 12 ± 0.2 mg/dl, P = not significant). During severe hypoglycemia, an equal number of episodes of seizure-like activity were noted in both groups. One week later, histological analysis demonstrated extensive neuronal damage in regions of the hippocampus, especially in the dentate gyrus and CA1 regions and less so in the CA3 region ( P < 0.05), although total hippocampal damage was not different between groups. However, in the cortex, DIAB rats had significantly (2.3-fold) more dead neurons than CONT rats ( P < 0.05). There was a strong correlation between neuronal damage and the occurrence of seizure-like activity ( r2 > 0.9). Separate studies conducted in groups of diabetic ( n = 5) and nondiabetic ( n = 5) rats not exposed to severe hypoglycemia showed no brain damage. In summary, under the conditions studied, severe hypoglycemia causes brain damage in the cortex and regions within the hippocampus, and the extent of damage is closely correlated to the presence of seizure-like activity in nonanesthetized rats. It is concluded that, in response to insulin-induced severe hypoglycemia, diabetes uniquely increases the vulnerability of specific brain areas to neuronal damage.

scholarly journals Optimization of Complete Rat Heart Decellularization Using Artificial Neural Networks

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 79
Author(s):  
Greta Ionela Barbulescu ◽  
Taddeus Paul Buica ◽  
Iacob Daniel Goje ◽  
Florina Maria Bojin ◽  
Valentin Laurentiu Ordodi ◽  
...  
Keyword(s):  
Neural Networks ◽  
Histological Analysis ◽  
Sodium Dodecyl ◽  
Sprague Dawley ◽  
Deep Convolutional Neural Networks ◽  
Software Application ◽  
Sprague Dawley Rats ◽  
Machine Learning Approach ◽  
Image Set ◽  
Exact Moment

Whole organ decellularization techniques have facilitated the fabrication of extracellular matrices (ECMs) for engineering new organs. Unfortunately, there is no objective gold standard evaluation of the scaffold without applying a destructive method such as histological analysis or DNA removal quantification of the dry tissue. Our proposal is a software application using deep convolutional neural networks (DCNN) to distinguish between different stages of decellularization, determining the exact moment of completion. Hearts from male Sprague Dawley rats (n = 10) were decellularized using 1% sodium dodecyl sulfate (SDS) in a modified Langendorff device in the presence of an alternating rectangular electric field. Spectrophotometric measurements of deoxyribonucleic acid (DNA) and total proteins concentration from the decellularization solution were taken every 30 min. A monitoring system supervised the sessions, collecting a large number of photos saved in corresponding folders. This system aimed to prove a strong correlation between the data gathered by spectrophotometry and the state of the heart that could be visualized with an OpenCV-based spectrometer. A decellularization completion metric was built using a DCNN based classifier model trained using an image set comprising thousands of photos. Optimizing the decellularization process using a machine learning approach launches exponential progress in tissue bioengineering research.

scholarly journals Quantification of Osseointegration of Plasma-Polymer Coated Titanium Alloyed Implants by means of Microcomputed Tomography versus Histomorphometry

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Carolin Gabler ◽  
Carmen Zietz ◽  
Richard Bieck ◽  
Rebecca Göhler ◽  
Tobias Lindner ◽  
...  
Keyword(s):  
3D Imaging ◽  
Reconstruction Algorithm ◽  
Imaging Method ◽  
Sprague Dawley ◽  
Bone Implant ◽  
Qualitative And Quantitative ◽  
Sprague Dawley Rats ◽  
Custom Made ◽  
Ct Analysis ◽  
Bone To Implant Contact

A common method to derive both qualitative and quantitative data to evaluate osseointegration of implants is histomorphometry. The present study describes a new image reconstruction algorithm comparing the results of bone-to-implant contact (BIC) evaluated by means ofµCT with histomorphometry data. Custom-made conical titanium alloyed (Ti6Al4V) implants were inserted in the distal tibial bone of female Sprague-Dawley rats. Different surface configurations were examined: Ti6Al4V implants with plasma-polymerized allylamine (PPAAm) coating and plasma-polymerized ethylenediamine (PPEDA) coating as well as implants without surface coating. After six weeks postoperatively, tibiae were explanted and BIC was determined byµCT (3D) and afterwards by histomorphometry (2D). In comparison to uncoated Ti6Al4V implants demonstrating low BIC of 32.4% (histomorphometry) and 51.3% (µCT), PPAAm and PPEDA coated implants showed a nonsignificant increase in BIC (histomorphometry: 45.7% and 53.5% andµCT: 51.8% and 62.0%, resp.). Mean BIC calculated byµCT was higher for all surface configurations compared to BIC detected by histomorphometry. Overall, a high correlation coefficient of 0.70 (p<0.002) was found between 3D and 2D quantification of BIC. TheμCT analysis seems to be suitable as a nondestructive and accurate 3D imaging method for the evaluation of the bone-implant interface.

Abstract 262: A Rat Model of Heart Failure With Preserved Ejection Fraction Induced by Pressure Overload

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Shu-Yu Sun ◽  
Barry Campbell ◽  
Valdeci Da Cunha ◽  
Xuening Hong ◽  
Chin-hu Huang ◽  
...  
Keyword(s):  
Histological Analysis ◽  
Potential Model ◽  
Pressure Overload ◽  
Preserved Ejection Fraction ◽  
Sprague Dawley ◽  
Aortic Banding ◽  
Clinical Phenotypes ◽  
Novel Treatments ◽  
Sprague Dawley Rats ◽  
Invasive Hemodynamics

The absence of animal models displaying clinical phenotypes of HFpEF represents a challenge to the pharmaceutical industry in the hope of identifying novel treatments that would benefit patients with this syndrome. We, at Merck, examined the supracoronary aortic banding (SAB) in rats as a potential model and set out to characterize its phenotypes. Juvenile Sprague-Dawley rats were used; a hemostatic clip with an opening of 0.7 mm was placed around the ascending aorta to elicit a pressure overload to the LV. Echocardiography was performed every 3 weeks and invasive hemodynamics was measured at week 9 to evaluate cardiac structural and functional effects; heart and lungs were harvested at the end for morphological and histological analysis. Nine weeks after SAB, LV hypertrophy and dysfunction were apparent, as manifested by increases in LVEDP, left atrial pressure, plasma BNP, LV and lung weights; LV relaxation time constant (Tau) and mitral early to late inflow ratio (E/A) were also increased; while EF and FS were preserved (see table, mean ± SEM). In addition, SAB rats had elevated mean pulmonary pressure (sham 14 ± 1.7 vs. SAB 37 ± 4.4 mm Hg, p<0.05) with an abnormal transpulmonary gradient (sham 12 ± 2.5 vs. SAB 23 ± 0.1 mm Hg, p<0.05), indicating comorbidity of pulmonary hypertension. Finally, piloerection, dyspnea and loss of muscle mass were evident and exercise tolerance measured by treadmill test was decreased in SAB rats. In summary, rats undergoing SAB exhibit many of the clinical phenotypes of HFpEF. Further work includes examining the effects of novel therapies in SAB rats on improving these clinical phenotypes of HFpEF and expanding the model to study morbidity and mortality.

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