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.

Effect of diet and drugs on the qualitative and quantitative distribution of cytochromes P-450 in rat liver

1980 ◽  
Vol 58 (4) ◽  
pp. 331-335 ◽  
Author(s):  
Daniel S. Sitar ◽  
Ellen R. Gordon
Keyword(s):  
Ion Exchange ◽  
Control Diet ◽  
Caloric Intake ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Sprague Dawley ◽  
Quantitative Distribution ◽  
Qualitative And Quantitative ◽  
Purina Chow ◽  
Sprague Dawley Rats

Male Sprague–Dawley rats were fed either Purina chow or a nutritionally adequate liquid control diet containing either 4 or 38% of the total caloric intake as fat. The hepatic cytochromes P-450 were induced in these animals either by the administration of phenobarbital, β-naphthoflavone, or isocaloric replacement of the carbohydrate of the liquid diets by ethanol at a level of 36% of total calories for 4 or 6 weeks. Three distinct groups of cytochromes P-450 could be efficiently separated by ion-exchange chromatography of microsomal preparations from these rats. The concentration of each group of cytochromes P-450 was markedly affected by variations in lipid and carbohydrate content of the diet as well as by administration of drugs.

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.

scholarly journals Strain differences in purified rat hepatic 3 α-hydroxysteroid UDP-glucuronosyltransferase

1985 ◽  
Vol 230 (2) ◽  
pp. 403-409 ◽  
Author(s):  
M D Green ◽  
C N Falany ◽  
R B Kirkpatrick ◽  
T R Tephly
Keyword(s):  
Individual Differences ◽  
Chenodeoxycholic Acid ◽  
Wistar Rats ◽  
Glucuronic Acid ◽  
Strain Differences ◽  
Sprague Dawley ◽  
Qualitative And Quantitative ◽  
Sprague Dawley Rats ◽  
Different Populations ◽  
Udp Glucuronosyltransferase

Qualitative and quantitative differences of purified hepatic 3 α-hydroxysteroid UDP-glucuronosyltransferase were investigated in Wistar and Sprague-Dawley rats. Individual differences in the glucuronidation rate of androsterone and chenodeoxycholic acid were observed in hepatic microsomal fractions from Wistar but not Sprague-Dawley rats. No individual variation was observed in the glucuronidation of testosterone, p-nitrophenol or oestrone. The 3 α-hydroxysteroid UDP-glucuronosyltransferases from livers of Wistar and Sprague-Dawley rats were isolated and highly purified by using Chromatofocusing and affinity chromatography. The amount of 3 α-hydroxysteroid UDP-glucuronosyltransferase in the liver of Wistar rats exhibiting low rates for androsterone glucuronidation is about 10% or less than that found in hepatic microsomal fractions obtained from Wistar rats having high rates for androsterone glucuronidation. The apparent Km for androsterone with purified 3 α-hydroxysteroid UDP-glucuronosyltransferase from Wistar rats with high glucuronidation activity (6 microM) was not different from that observed for the enzyme purified from Sprague-Dawley animals, whereas that for the enzyme purified from Wistar rats with low glucuronidation activity was substantially higher (120 microM). Despite the differences in apparent Km values for androsterone, the apparent Km for UDP-glucuronic acid (0.3 mM) was not different in the different populations of rats.

scholarly journals Qualitative and Quantitative Neuropathology Approaches Using Magnetic Resonance Microscopy (Diffusion Tensor Imaging) and Stereology in a Hexachlorophene Model of Myelinopathy in Sprague-Dawley Rats

2020 ◽  
Vol 48 (8) ◽  
pp. 965-980
Author(s):  
Robert C. Sills ◽  
G. Allan Johnson ◽  
Robert J. Anderson ◽  
Crystal L. Johnson ◽  
Michael Staup ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Magnetic Resonance Microscopy ◽  
Sprague Dawley ◽  
Qualitative And Quantitative ◽  
Quantitative Measurements ◽  
Sprague Dawley Rats ◽  
Intramyelinic Edema

It is well established that hexachlorophene, which is used as an antibacterial agent, causes intramyelinic edema in humans and animal models. The hexachlorophene myelinopathy model, in which male Sprague-Dawley rats received 25 to 30 mg/kg hexachlorophene by gavage for up to 5 days, provided an opportunity to compare traditional neuropathology evaluations with magnetic resonance microscopy (MRM) findings. In addition, stereology assessments of 3 neuroanatomical sites were compared to quantitative measurements of similar structures by MRM. There were positive correlations between hematoxylin and eosin and luxol fast blue stains and MRM for identifying intramyelinic edema in the cingulum of corpus callosum, optic chiasm, anterior commissure (aca), lateral olfactory tracts, pyramidal tracts (py), and white matter tracts in the cerebellum. Stereology assessments were focused on the aca, longitudinal fasciculus of the pons, and py and demonstrated differences between control and treated rats, as was observed using MRM. The added value of MRM assessments was the ability to acquire qualitative 3-dimensional (3-D) images and obtain quantitative measurements of intramyelinic edema in 26 neuroanatomical sites in the intact brain. Also, diffusion tensor imaging (fractional anisotropy [FA]) indicated that there were changes in the cytoarchitecture of the white matter as detected by decreases in the FA in the treated compared to the control rats. This study demonstrates creative strategies that are possible using qualitative and quantitative assessments of potential white matter neurotoxicants in nonclinical toxicity studies. Our results lead us to the conclusion that volumetric analysis by MRM and stereology adds significant value to the standard 2-D microscopic evaluations.

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.

Magnetic Particle Imaging–Guided Stenting

2019 ◽  
Vol 26 (4) ◽  
pp. 512-519 ◽  
Author(s):  
Stefan Herz ◽  
Patrick Vogel ◽  
Thomas Kampf ◽  
Philipp Dietrich ◽  
Simon Veldhoen ◽  
...  
Keyword(s):  
Magnetic Particle ◽  
Superparamagnetic Iron Oxide ◽  
Reconstruction Algorithm ◽  
Imaging Method ◽  
Phantom Model ◽  
Balloon Catheters ◽  
Magnetic Particle Imaging ◽  
Custom Made ◽  
Stent Lumen ◽  
Particle Imaging

Purpose:To assess the feasibility of magnetic particle imaging (MPI) to guide stenting in a phantom model. Materials and Methods: MPI is a new tomographic imaging method based on the background-free magnetic field detection of a tracer agent composed of superparamagnetic iron oxide nanoparticles (SPIOs). All experiments were conducted on a custom-built MPI scanner (field of view: 29-mm diameter, 65-mm length; isotropic spatial resolution 1–1.5-mm). Stenosis phantoms (n=3) consisted of polyvinyl chloride (PVC) tubes (8-mm inner diameter) prepared with centrally aligned cable binders to form a ~50% stenosis. A dedicated image reconstruction algorithm allowed precise tracking of endovascular instruments at 8 frames/s with a latency time of ~115 ms. A custom-made MPI-visible lacquer was used to manually label conventional guidewires, balloon catheters, and stainless steel balloon-expandable stents. Vascular stenoses were visualized by injecting a diluted SPIO tracer (ferucarbotran, 10 mmol iron/L) into the vessel phantoms. Balloon angioplasty and stent placement were performed by inflating balloon catheters and stent delivery balloons with diluted ferucarbotran. Results: After deployment of the stent, the markers on its ends were clearly visible. The applied lacquer markers were thin enough to not relevantly alter gliding properties of the devices while withstanding friction during the experiments. Placing an optimized flexible lacquer formulation on the preexisting radiopaque stent markers provided enough stability to withstand stent expansion. Final MPA confirmed successful stenosis treatment, facilitated by the disappearance of the lacquer markers on the stent due to differences in SPIO concentration. Thus, the in-stent lumen could be visualized without interference by the signal from the markers. Conclusion: Near real-time visualization of MPI-guided stenting of stenoses in a phantom model is feasible. Optimized MPI-visible markers can withstand the expansion process of stents.

Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

1982 ◽  
Vol 40 ◽  
pp. 216-217
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Microscopic Study ◽  
Pituitary Adenomas ◽  
Wistar Rats ◽  
Microscopic Level ◽  
Sprague Dawley ◽  
Prolactin Cells ◽  
Light Microscopic Level ◽  
Ultrastructural Investigation ◽  
Sprague Dawley Rats ◽  
Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

Early Development of Drug-Induced Hepatic Necrosis

1971 ◽  
Vol 29 ◽  
pp. 576-577
Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser
Keyword(s):  
Early Development ◽  
Hepatic Necrosis ◽  
Screening Tests ◽  
Dense Matrix ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Hepatocellular Damage ◽  
Sprague Dawley Rats ◽  
Microscopic Studies

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

Freeze-etch studies of epiphyseal growth plate cartilage reveal matrix vesicles associated with calcification

1978 ◽  
Vol 36 (2) ◽  
pp. 670-671
Author(s):  
Russell N. A. Cecil ◽  
H. Clarke Anderson
Keyword(s):  
Chromic Acid ◽  
Light And Electron Microscopy ◽  
Matrix Vesicles ◽  
Matrix Vesicle ◽  
Glycerol Solution ◽  
Sprague Dawley ◽  
Epiphyseal Growth Plate ◽  
Growth Plates ◽  
Sprague Dawley Rats ◽  
Tibial Epiphyseal

Unfixed proximal tibial epiphyseal growth plates were studied by freeze-etch to confirm the presence of extracellular calcifying matrix vesicles and to determine the substructure of matrix vesicle membranes as compared to plasma and other membranes of intact chondrocytes. Growth plates from 6-10 week old Sprague-Dawley rats were cut into 1x3 mm blocks whose long dimension was oriented either perpendicular or parallel to the long axis of the tibia. Some blocks were fixed at pH 7. 0 in 0. 2M cacodylate - buffered 2. 5% glutaraldehyde for 1 hour at 4ÅC. The blocks were immersed in 30% glycerol solution at 4ÅC for 1 hour, frozen in liquid nitrogen, and then fractured, etched for 2 minutes, and coated with platinum, carbon and 0. 2% Formvar solution. The replicas were cleaned with chromic acid, floated onto Formvar coated grids, and examined with a Phillips EM 300 electron microscope.Fixed and unfixed specimens appeared similar in ultrastructure. Chondrocytes, matrix, and matrix vesicles were identified. In specimens fractured parallel to the long axis of the tibia, the reserve, proliferative, hypertrophic, and calcifying zones could be discerned as described by light and electron microscopy.

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