Experimental Effects of Bone Plating in Infancy on Craniomaxillofacial Skeletal Growth

1993 ◽  
Vol 30 (2) ◽  
pp. 164-169 ◽  
Author(s):  
Barry L. Eppley ◽  
James M. Platis ◽  
A. Michael Sadove
Keyword(s):  
Animal Model ◽  
Bone Growth ◽  
Craniofacial Development ◽  
Experimental Results ◽  
Skeletal Growth ◽  
Coronal Suture ◽  
Local Growth ◽  
The Right ◽  
Bone Deposition ◽  
Group 1

The potential effects of mini- and microfixation on craniofacial development was investigated in an animal model. Twenty-four rabbits had amalgam markers placed bilaterally at the lambdoid, coronal, and frontonasal sutures at 28 days of age. In group 1, plating was not done and served as controls. In groups 2 to 4, single 2- and 4-hole microplates and 4-hole miniplates were fixed across the left coronal suture. The right suture was not plated. After 6 months, intermarker distances and craniofacial angles were measured radiographically. Coronal sutures underneath the plates were also histologically evaluated. Plating across the coronal suture resulted in local anteroposterior constriction of marker distances that did not differ with the type of fixation used. More distant markers, however, were increased in all specimens as a compensation and, as a result, the cranionasal length of all groups were similar. No change in craniofacial angles was observed from that of the controls. Sutural morphology on the side of fixation was altered with decreased widths, cellular numbers, and bone deposition. These experimental results demonstrate that early plate application in a normal calvarium results in local growth restriction that can be overcome by regional bone growth compensation.

18F-sodium fluoride bone deposition quantitation with PET in Mice: Variation with age, sex, and circadian rhythm

2020 ◽  
Vol 59 (06) ◽  
pp. 428-437
Author(s):  
Viktoria Dorau-Rutke ◽  
Kai Huang ◽  
Mathias Lukas ◽  
Marc O. Schulze ◽  
Christian Rosner ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Sodium Fluoride ◽  
Bone Growth ◽  
Bone Volume ◽  
Sleep Phase ◽  
Median Percentage ◽  
Bone Uptake ◽  
Pooled Data ◽  
Uptake Studies ◽  
Bone Deposition

Abstract Aim The aim of this study was to establish a data base for normal 18F-sodium fluoride (18F-NaF) bone uptake as a function of age, sex and circadian rhythm in mice. Methods In 12 female (F) and 12 male (M) C57BL/6N mice PET images were acquired 90 min after intravenous injection of 20 MBq 18F-NaF for 30 minutes. Each mouse was imaged in follow-up studies at 1, 3, 6, 13 and 21 months of age. In order to assess for physiologic changes related to circadian rhythm, animals were imaged during light (sleep phase) as well as during night conditions (awake phase). Bone uptake is described as the median percentage of the injected activity (%IA) and in relation to bone volume (%IA/ml). Results A significant smaller bone volume was found in F (1.79 ml) compared to M (1.99 ml; p < 0.001). In sex-pooled data, highest bone uptake occurred at an age of 1 month (61.1 %IA, 44.5 %IA/ml) with a significant reduction (p < 0.001) at age 3 months (43.6 %IA, 23.6 %IA/ml), followed by an increase between 13 (47.3 %IA, 24.5 %IA/ml) and 21 months (52.2 %IA, 28.1 %IA/ml). F had a significantly higher total uptake (F 48.2 %IA, M 43.8 %IA; p = 0.026) as well as a higher uptake per ml bone tissue (F 27.0 %IA/ml; M 22.4 %IA/ml; p < 0.001). A significant impact of circadian rhythm was only found for F at ages of 3 and 6 months with a higher uptake during the sleep phase. Conclusion Circadian rhythm had a significant impact on uptake only in F of 3 and 6 months. Regarding sex, F showed generally higher uptake rates than M. The highest uptake values were observed during bone growth at age 1 month in both sexes, a second uptake peak occurred in elderly F. Designing future bone uptake studies with M, attention must be paid to age only, while in F circadian rhythm and age must be taken into account.

scholarly journals A tissue-engineered urinary conduit in a porcine urinary diversion model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arkadiusz Jundziłł ◽  
Piotr Kwieciński ◽  
Daria Balcerczyk ◽  
Tomasz Kloskowski ◽  
Dariusz Grzanka ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Urinary Diversion ◽  
Porcine Model ◽  
Histological Evaluation ◽  
Metabolic Complications ◽  
Group 3 ◽  
Group 2 ◽  
The Right ◽  
Group 1

AbstractThe use of an ileal segment is a standard method for urinary diversion after radical cystectomy. Unfortunately, utilization of this method can lead to numerous surgical and metabolic complications. This study aimed to assess the tissue-engineered artificial conduit for urinary diversion in a porcine model. Tissue-engineered tubular polypropylene mesh scaffolds were used for the right ureter incontinent urostomy model. Eighteen male pigs were divided into three equal groups: Group 1 (control ureterocutaneostomy), Group 2 (the right ureter-artificial conduit-skin anastomoses), and Group 3 (4 weeks before urostomy reconstruction, the artificial conduit was implanted between abdomen muscles). Follow-up was 6 months. Computed tomography, ultrasound examination, and pyelogram were used to confirm the patency of created diversions. Morphological and histological analyses were used to evaluate the tissue-engineered urinary diversion. All animals survived the experimental procedures and follow-up. The longest average patency was observed in the 3rd Group (15.8 weeks) compared to the 2nd Group (10 weeks) and the 1st Group (5.8 weeks). The implant’s remnants created a retroperitoneal post-inflammation tunnel confirmed by computed tomography and histological evaluation, which constitutes urostomy. The simultaneous urinary diversion using a tissue-engineered scaffold connected directly with the skin is inappropriate for clinical application.

A new rat model of chronic cerebral hypoperfusion associated with arteriovenous malformations

2002 ◽  
Vol 97 (5) ◽  
pp. 1198-1202 ◽  
Author(s):  
Jian Hai ◽  
Meixiu Ding ◽  
Zhilin Guo ◽  
Bingyu Wang
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Arteriovenous Malformations ◽  
Perfusion Pressure ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Model Group ◽  
Content Type ◽  
The Right ◽  
Fine Print

Object. A new experimental model of chronic cerebral hypoperfusion was developed to study the effects of systemic arterial shunting and obstruction of the primary vessel that drains intracranial venous blood on cerebral perfusion pressure (CPP), as well as cerebral pathological changes during restoration of normal perfusion pressure. Methods. Twenty-four Sprague—Dawley rats were randomly assigned to either a sham-operated group, an arteriovenous fistula (AVF) group, or a model group (eight rats each). The animal model was readied by creating a fistula through an end-to-side anastomosis between the right distal external jugular vein (EJV) and the ispilateral common carotid artery (CCA), followed by ligation of the left vein draining the transverse sinus and bilateral external carotid arteries. Systemic mean arterial pressure (MAP), draining vein pressure (DVP), and CPP were monitored and compared among the three groups preoperatively, immediately postoperatively, and again 90 days later. Following occlusion of the fistula after a 90-day interval, blood—brain barrier (BBB) disruption and water content in the right cortical tissues of the middle cerebral artery territory were confirmed and also quantified with transmission electron microscopy. Formation of a fistula resulted in significant decreases in MAP and CPP, and a significant increase in DVP in the AVF and model groups. Ninety days later, there were still significant increases in DVP and decreases in CPP in the model group compared with the other groups (p < 0.05). Damage to the BBB and brain edema were noted in animals in the model group during restoration of normal perfusion pressure by occlusion of the fistula. Electron microscopy studies revealed cerebral vasogenic edema and/or hemorrhage in various amounts, which correlated with absent astrocytic foot processes surrounding some cerebral capillaries. Conclusions. The results demonstrated that an end-to-side anastomosis between the distal EJV and CCA can induce a decrease in CPP, whereas a further chronic state of cerebral hypoperfusion may be caused by venous outflow restriction, which is associated with perfusion pressure breakthrough. This animal model conforms to the basic hemodynamic characteristics of human cerebral arteriovenous malformations.

Nanotechnology Enabled In Situ Orthopaedic Sensors for Personalized Medicine

2012 ◽  
Vol 86 ◽  
pp. 40-50
Author(s):  
Sirinrath Sirivisoot ◽  
Thomas J. Webster
Keyword(s):  
Bone Growth ◽  
Electrochemical Sensors ◽  
Electrochemical Analysis ◽  
Matrix Proteins ◽  
Implant Design ◽  
Implant Surface ◽  
Cellular Events ◽  
Bone Deposition ◽  
Made In

Although improvements have been made in implant design to increase bone formation and promote successful osseointegration using nanotechnology, the clinical diagnosis of early bone growth surrounding implants remains problematic. The development of a device allowing doctors to monitor the healing cascade and to diagnose potential infection or inflammation is necessary. Biological detection can be examined by the electrochemical analysis of electron transfer (or redox) reactions of extracellular matrix proteins involved in bone deposition and resorption. The use of nanomaterials as signal amplifiers in electrochemical sensors has greatly improved the sensitivity of detection. Nanotechnology-enabled electrochemical sensors that can be placed on the implant surface itself show promise as self-diagnosing devices in situ, possibly to detect new bone growth surrounding the implant and other cellular events to ensure implant success.

Onlay Silicone and Hydroxyapatite-Tricalciumphosphate Composite (HAP-TCP) Blocks Interfere with Nasal Bone Growth in Rabbits

1995 ◽  
Vol 32 (4) ◽  
pp. 282-289
Author(s):  
Minoru Arakaki ◽  
Shunichi Yamashita ◽  
Mehmet Mutaf ◽  
Shinji Naito ◽  
Tohru Fujii
Keyword(s):  
Bone Tissue ◽  
Bone Growth ◽  
Nasal Bone ◽  
Growth Period ◽  
Blood Biochemistry ◽  
Hydroxyapatite Ceramic ◽  
Cross Sectional ◽  
Porous Hydroxyapatite ◽  
New Type ◽  
The Right

We investigated how a new type of synthetic porous hydroxyapatite ceramic (HAP-TCP) acts when it is implanted in growing membranous bone. Seventy-six New Zealand White infant male rabbits (4-week-olds) were used. Rabbits received HAP-TCP block or silicone block implantation in their right nasal bone. The left nasal bone was used for a sham. Serial or cross-sectional examinations by morphometry, radiology, blood biochemistry, and histology were carried out. Both the HAP-TCP and silicone groups exhibited no systemic growth disturbance in terms of morphometry and blood biochemistry. Dual energy x-ray absorptiometry (DEXA) revealed, however, a decrease in the bone mineral content (BMC) of the right nasal bone in the silicone group. Histology revealed a superior affinity of HAP-TCP to bone tissue than that of silicone. When a HAP-TCP block was implanted under the periosteum it bonded directly to bone tissue. However, sinking of the implants into the bone tissue were noted both in the HAP-TCP and the silicone groups in longitudinal observation. These results suggest that although HAP-TCP has superior affinity to bone tissue, this by itself is not enough sufficient reason to believe that HAP-TCP can be effectively applied during the growth period.

Fuzzy Clustering with Repulsive Prototypes

2010 ◽  
pp. 332-346
Author(s):  
Frank Rehm ◽  
Roland Winkler ◽  
Rudolf Kruse
Keyword(s):  
Data Analysis ◽  
Fuzzy Clustering ◽  
Experimental Results ◽  
Number Of Clusters ◽  
Fuzzy C Means ◽  
Analysis Process ◽  
Fuzzy C Means Clustering ◽  
The Right

A well known issue with prototype-based clustering is the user’s obligation to know the right number of clusters in a dataset in advance or to determine it as a part of the data analysis process. There are different approaches to cope with this non-trivial problem. This chapter follows the approach to address this problem as an integrated part of the clustering process. An extension to repulsive fuzzy c-means clustering is proposed equipping non-Euclidean prototypes with repulsive properties. Experimental results are presented that demonstrate the feasibility of the authors’ technique.

scholarly journals Cardiotoxic effects of pavetamine extracted from Pavetta harborii in the rat

2008 ◽  
Vol 75 (3) ◽  
Author(s):  
L. Hay ◽  
R.A. Schultz ◽  
P.J. Schutte
Keyword(s):  
Heart Failure ◽  
Animal Model ◽  
Carotid Artery ◽  
Plant Material ◽  
Active Component ◽  
Systolic Function ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
The Right ◽  
Induce Heart Failure

Previous studies have shown that crude extracts from Pavetta harborii as well as dried plant material have cardiotoxic effects on rats and sheep that can lead to heart failure. The active component has since been isolated and identified. This substance has been named pavetamine. The aim of this study was to determine whether pavetamine has cardiotoxic effects similar to those seen in previous reports, when administered to rats intraperitoneally. Sprague Dawley rats received two doses, initially 4 mg / kg and then 3 mg / kg pavetamine respectively and were monitored for 35 days before cardiodynamic parameters were measured by inserting a fluid-filled catheter into the left ventricle via the right carotid artery. These values were compared to those of control rats that had received only saline. Pavetamine significantly reduced systolic function and body mass in the treated rats, which indicates that it has the potential to induce heart failure in this animal model.

scholarly journals The optical analysis of the abdominal wall using the biospeckle after implants of polypropylene mesh in rats

2009 ◽  
Vol 24 (6) ◽  
pp. 442-448
Author(s):  
Tâmara Maria Nieri ◽  
Marco Antonio de Oliveira Peres ◽  
Emerson Rodrigo da Silva ◽  
Inácio Maria Dal Fabbro ◽  
Mikiya Muramatsu ◽  
...  
Keyword(s):  
Animal Model ◽  
Abdominal Wall ◽  
Polypropylene Mesh ◽  
Male Rats ◽  
Mesh Placement ◽  
Group 4 ◽  
Mesh Prosthesis ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

PURPOSE: To evaluate an experimental animal model to study the abdominal tissue activity considering its interaction with a polypropylene mesh, through the use of one of the optical phenomena of light Laser, the biospeckle. METHODS: Fifty Wistar male rats were divided into four groups: Group 1: ten animals not submitted to surgery; Group 2: ten animals submitted to surgery without polypropylene mesh; Group 3: 20 animals submitted to surgery followed by the mesh placement; Group 4: (sham) with ten animals. None of the animals presented post surgical complications being submitted to the optical tests at the 20th postoperative day. RESULTS: The analysis from the biospeckle tests, comparing the medians and standard deviations with T Student test, indicated that no significative difference was observed on the abdominal wall tissue activity in the four groups considered, with and without polypropylene mesh prosthesis implantation. CONCLUSION: The animal model is viable and the biospeckle open ways for a great number of experiments to be developed in evaluating tissue activity.

Dexmedetomidine elevates the lethal dose threshold of bupivacaine in rats: A dosing study

2019 ◽  
Vol 39 (3) ◽  
pp. 365-373
Author(s):  
L Pan ◽  
Y Zhang ◽  
Y He ◽  
Z Chen ◽  
S Wang ◽  
...  
Keyword(s):  
Femoral Vein ◽  
Lethal Dose ◽  
Control Group ◽  
Sprague Dawley ◽  
Dose Threshold ◽  
Sd Rats ◽  
Group 12 ◽  
Group 3 ◽  
The Right ◽  
Group 1

Dexmedetomidine (DMED), an alpha-2 adrenoreceptor agonist, has been widely used in regional anesthesia procedures. However, the effect of DMED on local anesthetic cardiotoxicity has not been well delineated. This study consisted of two experiments. In experiment A, 42 Sprague–Dawley (SD) rats were randomly divided into 6 groups ( n = 7), each group was pretreated with DMED 0 μg kg−1 (D0 group), 1 μg kg−1 (D1 group), 3 μg kg−1 (D3 group), 6 μg kg−1 (D6 group), 12 μg kg−1 (D12 group), and 24 μg kg−1 (D24 group), administered through the right femoral vein. In experiment B, 20 SD rats were randomly divided into 4 groups ( n = 5), such as control group, DMED group, yohimbine (YOH) group, and DMED + YOH group. Each subgroup in experiment B was also pretreated similarly as in experiment A. After pretreatment of rats as described above (in experiments A and B), bupivacaine 2.5 mg kg−1 min−1 was infused to induce cardiac arrest. In experiment A, the lethal dose threshold of bupivacaine and plasma bupivacaine concentration in D3 and D6 group were higher than the other groups. In experiment B, there was no interaction between DMED and YOH in lethal dose threshold, arrhythmia time, plasma concentration of bupivacaine, and myocardial content of bupivacaine. DMED doses of 3–6 μg kg−1 elevated the lethal dose threshold of bupivacaine without involvement of the alpha-2 adrenoceptors.

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