Study of the Variability in Upper and Lower Airway Morphology in Sprague-Dawley Rats Using Modern Micro-CT Scan-Based Segmentation Techniques

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.

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Radiomorphometric Quantitative Analysis of Vasculature Utilizing Micro–Computed Tomography and Vessel Perfusion in the Murine Mandible

Craniomaxillofacial Trauma & Reconstruction ◽

10.1055/s-0032-1329540 ◽

2012 ◽

Vol 5 (4) ◽

pp. 223-229 ◽

Cited By ~ 6

Author(s):

Xi Lin Jing ◽

Aaron S. Farberg ◽

Laura A. Monson ◽

Alexis Donneys ◽

Catherine N. Tchanque-Fossuo ◽

...

Keyword(s):

Computed Tomography ◽

Quantitative Measure ◽

Micro Ct ◽

Vascular Networks ◽

Sprague Dawley ◽

Micro Computed Tomography ◽

Craniofacial Skeleton ◽

Sprague Dawley Rats ◽

Quantitative Data Analysis

Purpose Biomechanical, densitometric, and histological analyses have been the mainstay for reproducible outcome measures for investigation of new bone formation and osseous healing. Here we report the addition of radiomorphometric vascular analysis as a quantitative measure of vascularity in the murine mandible. To our knowledge this is the first description of using micro–computed tomography (micro-CT) to evaluate the temporal and spatial pattern of angiogenesis in the craniofacial skeleton. Methods The vessel perfusion technique was performed on 10 Sprague-Dawley rats using Microfil (MV-122, Flow Tech; Carver, MA). After decalcification, hemimandibles were imaged using high-resolution micro-CT. Six separate radiomorphometric vascular metrics were calculated. Results Radiomorphometric values were analyzed using three different thresholds on micro-CT. Experimentally, 1000 Hounsfield units was found to be the optimal threshold for analysis to capture the maximal vascular content of the bone. Data from seven hemimandibles were analyzed. Minimal statistical variance in each of the quantitative measures of vascularity resulted in reproducible metrics for each of the radiomorphometric parameters. Conclusions We have demonstrated that micro-CT vascular imaging provides a robust methodology for evaluation of vascular networks in the craniofacial skeleton. This technique provides 3D quantitative data analysis that differs significantly from laser Doppler and microsphere methods, which simply measure flow. This technique is advantageous over labor-intensive 2D conventional analyses using histology and X-ray microangiography. Our data establish the appropriate thresholding for optimal vascular analyses and provide baseline measurements that can be used to analyze the role of angiogenesis in bone regeneration and repair in the craniofacial skeleton.

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Rat Animal Model of Pectus Excavatum

Life ◽

10.3390/life10060096 ◽

2020 ◽

Vol 10 (6) ◽

pp. 96

Author(s):

Vlad-Laurentiu David ◽

Bogdan Ciornei ◽

Florin-George Horhat ◽

Elena Amaricai ◽

Ioana-Delia Horhat ◽

...

Keyword(s):

Animal Model ◽

Ct Scan ◽

Pectus Excavatum ◽

Surrounding Tissue ◽

Thoracic Wall ◽

Congenital Deformity ◽

Control Group ◽

Sprague Dawley ◽

Invasive Treatment ◽

Sprague Dawley Rats

Background: pectus excavatum (PE) is the most common congenital deformity of the thoracic wall. Lately, significant achievements have been made in finding new, less invasive treatment methods for PE. However, most of the experimental work was carried out without the help of an animal model. In this report we describe a method to create an animal model for PE in Sprague-Dawley rats. Methods: We selected 15 Sprague-Dawley rat pups and divided them into two groups: 10 for the experimental group (EG) and 5 for the control group (CG). We surgically resected the last four pairs of costal cartilages in rats from the EG. The animals were assessed by CT-scan prior to surgery and weekly for four consecutive weeks. After four weeks, the animals were euthanized and the thoracic cage was dissected from the surrounding tissue. Results: On the first postoperative CT, seven days after surgery, we observed a marked depression of the lower sternum in all animals from the EG. This deformity was present at every CT-scan after surgery and at the post-euthanasia assessment. Conclusions: By decreasing the structural strength of the lower costal cartilages, we produced a PE animal model in Sprague-Dawley rats.

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Reconstructive Effects of Percutaneous Electrical Stimulation Combined with GGT Composite on Large Bone Defect in Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/607201 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Bo-Yin Yang ◽

Tzung-Chi Huang ◽

Yueh-Sheng Chen ◽

Chun-Hsu Yao

Keyword(s):

Electrical Stimulation ◽

Bone Repair ◽

Bone Growth ◽

Micro Ct ◽

Sprague Dawley ◽

Control Groups ◽

Inhalation Anesthesia ◽

Electromagnetic Stimulation ◽

Sprague Dawley Rats ◽

Large Bone

Previous studies have shown the electromagnetic stimulation improves bone remodeling and bone healing. However, the effect of percutaneous electrical stimulation (ES) was not directly explored. The purpose of this study was to evaluate effect of ES on improvement of bone repair. Twenty-four adult maleSprague-Dawley ratswere used for cranial implantation. We used a composite comprising genipin cross-linked gelatin mixed with tricalcium phosphate (GGT). Bone defects of all rats were filled with the GGT composites, and the rats were assigned into six groups after operation. The first three groups underwent 4, 8, and 12 weeks of ES, and the anode was connected to the backward of the defect on the neck; the cathode was connected to the front of the defect on the head. Rats were under inhalation anesthesia during the stimulation. The other three groups only received inhalation anesthesia without ES, as control groups. All the rats were examined afterward at 4, 8, and 12 weeks. Radiographic examinations including X-ray and micro-CT showed the progressive bone regeneration in the both ES and non-ES groups. The amount of the newly formed bone increased with the time between implantation and examination in the ES and non-ES groups and was higher in the ES groups. Besides, the new bone growth trended on bilateral sides in ES groups and accumulated in U-shape in non-ES groups. The results indicated that ES could improve bone repair, and the effect is higher around the cathode.

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An In Vivo Study in Rat Femurs of Bioactive Silicate Coatings on Titanium Dental Implants

Journal of Clinical Medicine ◽

10.3390/jcm9051290 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1290

Author(s):

Giulia Brunello ◽

Lisa Biasetto ◽

Hamada Elsayed ◽

Elia Sbettega ◽

Chiara Gardin ◽

...

Keyword(s):

Synovial Fluid ◽

Knee Joints ◽

Histological Evaluation ◽

Micro Ct ◽

Sprague Dawley ◽

Micro Computed Tomography ◽

Suitable Material ◽

Sprague Dawley Rats ◽

Ct Data

Silica-based ceramics have been proposed for coating purposes to enhance dental and orthopedic titanium (Ti) implant bioactivity. The aim of this study was to investigate the influence of sphene-based bioceramic (CaO.TiO2.SiO2) coatings on implant osseointegration in vivo. Sphene coatings were obtained from preceramic polymers and nano-sized active precursors and deposited by an automatic airbrush. Twenty customized Ti implants, ten sphene-coated and ten uncoated rough implants were implanted into the proximal femurs of ten Sprague-Dawley rats. Overall, cortical and cancellous bone-to-implant contact (BIC) were determined using micro-computed tomography (micro-CT) at 14 and 28 days. Moreover, peri-implant bone healing was histologically and histomorphometrically evaluated. The white blood cell count in the synovial fluid of the knee joints, if present, was also assessed. No difference in the BIC values was observed between the sphene-coated and uncoated implants, overall and in the two bone compartments (p > 0.05). Delamination of the coating occurred in three cases. Consistently with micro-CT data, the histological evaluation revealed no differences between the two groups. In addition, no synovial fluid could be collected on the test side, thus confirming sphene biocompatibility. In conclusion, sphene coating was found to be a suitable material for biomedical applications. Further studies are needed to improve coating adhesion to the implants.

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Mechanical ventilation affects the microecology of the rat respiratory tract

10.1101/2021.12.07.471701 ◽

2021 ◽

Author(s):

XueMeng Chen ◽

GaoWang Liu ◽

XiaoMei Ling ◽

FanFang Zeng ◽

JinFang Xiao

Keyword(s):

Mechanical Ventilation ◽

Tracheal Intubation ◽

Respiratory Tract ◽

Weight Ratio ◽

Dry Weight ◽

Lower Airway ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

Ventilator Therapy ◽

Spontaneously Breathing

Background: The most common 'second strike' in mechanically ventilated patients is a pulmonary infection caused by the ease with which bacteria can invade and colonize the lungs due to mechanical ventilation. At the same time, metastasis of lower airway microbiota may have significant implications in the development of intubation mechanical ventilation lung inflammation. Thus, we establish a rat model of tracheal intubation with mechanical ventilation and explore the effects of mechanical ventilation on lung injury and microbiological changes in rats. Methods: Sprague-Dawley rats were randomized into control, Spontaneously Breathing (1, 3, 6 hours), Mechanical ventilation(1, 3, 6 hours) groups. Lung wet to dry weight ratio (W/D weight ratio) and Lung histopathological injury score were evaluated.16SrDNA sequencing was performed to explore respiratory flora changes. Results: Bacterial diversity was comparable between healthy and intubation mechanical ventilation rats, with time relation. Ordination analyses revealed that samples clustered more dispersing by tracheal intubation and mechanical ventilation. Finally, predicted metagenomes suggested a substantial increase in biofilm formation phenotype during early tracheal intubation and mechanical ventilation. Conclusion: Collectively, these results establish a link between the duration of mechanical ventilation and alterations to the respiratory tract microecology. In future studies, we hope to discover the effectiveness of new immunomodulatory or probiotic bacteria to prevent airway diseases associated with ventilator therapy.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053747 ◽

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.

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Early Development of Drug-Induced Hepatic Necrosis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066942 ◽

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077086 ◽

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084223 ◽

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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