The effects of mechanical immobilization on sutural development in the growing rabbit

1980 ◽  
Vol 53 (6) ◽  
pp. 794-801 ◽  
Author(s):  
William J. Foley ◽  
Vincent G. Kokich
Keyword(s):  
New Zealand ◽  
Biological Response ◽  
Bone Union ◽  
Coronal Suture ◽  
Content Type ◽  
Bone Bridge ◽  
Age Related ◽  
New Zealand White Rabbits ◽  
The Brain ◽  
Fine Print

✓ Methyl-2-cyanoacrylate was used to mechanically immobilize the coronal suture unilaterally in a series of New Zealand white rabbits at varying ages. The animals were separated into groups; some were sacrificed at 30 days and some at 60 days postoperatively. Amalgam markers were placed in the parietal and frontal bones across the coronal suture, and were measured immediately after surgery and at the time of sacrifice to confirm mechanical immobility. The animals were studied radiographically and histologically in order to document the presence or absence of sutural bone union. Based on the results of this study, it appears that immobilization of the coronal suture results in the formation of an ectocranial periosteal bone bridge in rabbits less than 8 weeks of age. Bone union was not found in animals older than 8 weeks of age. This age-related difference in response is believed to be due to decreased periosteal depository activity on the ectocranial surface of the calvaria once the brain ceases to expand actively. Furthermore, bone union or synostosis was never seen within or across the internal portion of the sutural ligament. It is suggested, therefore, that sutural immobilization at young ages in the rabbit does not result in sutural synostosis and that the term “periosteal bone bridge” should be used when referring to this biological response.

The intracerebral distribution of BCNU delivered by surgically implanted biodegradable polymers

1992 ◽  
Vol 76 (4) ◽  
pp. 640-647 ◽  
Author(s):  
Stuart A. Grossman ◽  
Carla Reinhard ◽  
O. Michael Colvin ◽  
Mark Chasin ◽  
Robert Brundrett ◽  
...  
Keyword(s):  
New Zealand ◽  
Brain Tissue ◽  
Direct Injection ◽  
Normal Brain ◽  
Local Concentration ◽  
Content Type ◽  
Drug Concentrations ◽  
New Zealand White Rabbits ◽  
The Brain ◽  
Fine Print

✓ The local concentration and distribution of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) within normal brain tissue were studied following surgical implantation of biodegradable polymer containing BCNU in New Zealand White rabbits. Cylindrical discs of poly(bis(p-carboxyphenoxy)-propane:sebacic acid) copolymer in a 20:80 formulation were made containing [3H]-inulin or [3H]-BCNU labeled in the methylene hydrogens of the chloroethyl groups. These were implanted in the brains of 56 New Zealand White rabbits. The animals were sacrificed 3, 7, 14, or 21 days later and the brains were rapidly removed, frozen, and prepared for quantitative autoradiography. Autoradiographs from coronal sections bisecting the polymer were analyzed to determine both the proportion of the brain section exposed to the tracer and the local drug concentrations as a function of distance from the polymer. Tritiated BCNU was also injected directly into the brains of eight additional rabbits, and local brain concentrations were studied over time. The results of this study demonstrate that approximately 50% of the area of the brain sections was exposed to radiolabeled compound 3 days after BCNU-polymer implantation, 15% at 7 days, and less than 10% at 14 and 21 days. Polymer discs containing 600 µg BCNU generated 6 mM concentrations of BCNU in brain tissue 10 mm from the polymer at 3 and 7 days. Pharmacological studies demonstrated that approximately 25% of the tritium label was associated with intact BCNU 3 days following polymer implantation. Radiolabeled inulin delivered by polymer remained dispersed throughout the ipsilateral hemisphere for 14 days. Direct injection of [3H]-BCNU into brain parenchyma resulted in widely distributed tracer at 1 and 3 hours with rapid disappearance thereafter. It is concluded that local delivery of BCNU to brain tissue with this polymeric drug delivery system results in sustained high local concentrations of BCNU which may be of value in the treatment of patients with brain tumors.

Experimental craniosynostosis in growing rabbits

1983 ◽  
Vol 58 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Dennis L. Nappen ◽  
Vincent G. Kokich
Keyword(s):  
New Zealand ◽  
The Other ◽  
Coronal Suture ◽  
Content Type ◽  
Metallic Implants ◽  
New Zealand White Rabbits ◽  
Parietal Bones ◽  
Fine Print

✓ Reports on the role of the periosteum in premature sutural synostosis have been contradictory. The present study summarizes a series of six experiments designed to clarify these previously conflicting findings. Twenty-five male New Zealand White rabbits were divided into six experimental groups. In four of the groups, methyl-2-cyanoacrylate was used to glue the frontal and parietal bones together and temporarily immobilize the coronal suture. In the other two groups, the sutures were not immobilized. Polyethylene was used to separate the cyanoacrylate from the periosteum in two of the groups. The experiments were performed at 5 weeks of age, and the animals were killed at either 30, 45, or 180 days postoperatively. Metallic implants were placed in the frontal and parietal bones for monitoring growth and/or sutural immobilization. Sutural fusion was confirmed radiographically or histologically. Based upon the findings it seems that mechanical immobilization of a suture does not induce fusion of that suture in rabbits. Furthermore, it appears that the mere application of methyl-2-cyanoacrylate to the periosteum overlying a suture will consistently cause the formation of a bony bridge in growing rabbits but not in nongrowing animals. The adhesive does not consistently induce synostosis if the periosteum is excised.

The use of bone morphogenetic protein—6 gene therapy for percutaneous spinal fusion in rabbits

2004 ◽  
Vol 1 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Jeffrey J. Laurent ◽  
K. Michael Webb ◽  
Elisa J. Beres ◽  
Kevin McGee ◽  
Jinzhong Li ◽  
...  
Keyword(s):  
Gene Therapy ◽  
New Zealand ◽  
Spinal Fusion ◽  
Ct Scanning ◽  
Content Type ◽  
Morphogenetic Protein ◽  
New Zealand White Rabbits ◽  
Percutaneous Administration ◽  
Multiple Levels ◽  
Fine Print

Object. Fusion procedures in the lumbar spine have been performed in the US since 1911. Since that time, the indications and techniques for spinal fusion have evolved. Despite technical advancements, spinal fusion remains a major operation, and fusion nonunion rates of up to 35% are still reported. In this study, the authors were able to induce intertransverse process fusions in immune-competent New Zealand White rabbits by percutaneous administration of an adenoviral vector containing the bone morphogenetic protein (BMP-6) gene (Ad-BMP-6). The results represent an important step forward in finding new methods to increase the success and decrease the morbidity associated with spinal fusion. Methods. Five New Zealand White rabbits were used. Injection of the adenoviral construct was performed at multiple levels (bilaterally) in each animal while using fluoroscopic guidance. Injection consisted of either Ad-BMP-6 or Ad—β-galactosidase (β-gal) (control). Because multiple levels were injected, each animal served as an internal control. The animals underwent postinjection computerized tomography (CT) scanning at 7 and 14 weeks. After undergoing final CT scanning, the animals were killed and the spines were harvested. The fusion sites were analyzed by gross inspection, histopathological methods, and micro—CT studies. Conclusions. The results of this study show that an anatomically precise fusion can be accomplished by percutaneous administration of gene therapy. The next step in these studies will be extension of the technique to nonhuman primates and eventually to human clinical studies.

Roentgen stereophotogrammetric analysis of neurocranial suturectomy in rabbits

1984 ◽  
Vol 60 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Per Alberius ◽  
Göran Selvik ◽  
Leif Ekelund
Keyword(s):  
Bone Growth ◽  
Initial Rate ◽  
The Other ◽  
Cranial Vault ◽  
Coronal Suture ◽  
Content Type ◽  
Growth Disturbances ◽  
New Zealand White Rabbits ◽  
Control Volumes ◽  
Fine Print

✓ This investigation was conducted to further elucidate both the significance of a calvarial suture and the compensatory ability of the cranial vault. Four-week-old male New Zealand White rabbits were subjected to unilateral or bilateral extirpation of the coronal suture after insertion of metallic markers, and were then followed regularly by roentgen stereophotogrammetry until age 21 weeks. Bilateral extirpation of the normal coronal suture resulted in a dramatically increased initial rate of bone separation, which tended to remain supranormal for the rest of the investigation. Unilateral suturectomy showed differences in growth between the sides, the operated side initially separating significantly more than the other. Volumetric calvarial growth in rabbits with unilateral extirpation terminated similar to that in control animals, while volumes in rabbits with bilateral extirpations constantly exceeded control volumes, finally exceeding these by 65%. Responses at intact sutures confirmed the compensatory capacity of cranial vaults. The results indicate that the passive longitudinal and volumetric cranial vault bone growth responds quickly to growth disturbances, thereby demonstrating its plasticity, and that the neurocranial suture is a restraining and modulating component in cranial growth.

Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 247-254 ◽  
Author(s):  
Jason Sheehan ◽  
Douglas Kondziolka ◽  
John Flickinger ◽  
L. Dade Lunsford
Keyword(s):  
Lung Cancer ◽  
Brain Metastases ◽  
Lung Carcinoma ◽  
Small Cell Lung Carcinoma ◽  
Small Cell ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma ◽  
Content Type ◽  
The Brain ◽  
Fine Print

Object. Lung carcinoma is the leading cause of death from cancer. More than 50% of those with small cell lung cancer develop a brain metastasis. Corticosteroid agents, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, median survival for patients with small cell lung carcinoma metastasis is approximately 4 to 5 months after cranial irradiation. In this study the authors examine the efficacy of gamma knife surgery for treating recurrent small cell lung carcinoma metastases to the brain following tumor growth in patients who have previously undergone radiation therapy, and they evaluate factors affecting survival. Methods. A retrospective review of 27 patients (47 recurrent small cell lung cancer brain metastases) undergoing radiosurgery was performed. Clinical and radiographic data obtained during a 14-year treatment period were collected. Multivariate analysis was utilized to determine significant prognostic factors influencing survival. The overall median survival was 18 months after the diagnosis of brain metastases. In multivariate analysis, factors significantly affecting survival included: 1) tumor volume (p = 0.0042); 2) preoperative Karnofsky Performance Scale score (p = 0.0035); and 3) time between initial lung cancer diagnosis and development of brain metastasis (p = 0.0127). Postradiosurgical imaging of the brain metastases revealed that 62% decreased, 19% remained stable, and 19% eventually increased in size. One patient later underwent a craniotomy and tumor resection for a tumor refractory to radiosurgery and radiation therapy. In three patients new brain metastases were demonstrating on follow-up imaging. Conclusions. Stereotactic radiosurgery for recurrent small cell lung carcinoma metastases provided effective local tumor control in the majority of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can extend survival.

Relief of facial pain after combined removal of precentral and postcentral cortex

1971 ◽  
Vol 34 (4) ◽  
pp. 537-543 ◽  
Author(s):  
Richard A. Lende ◽  
Wolff M. Kirsch ◽  
Ralph Druckman
Keyword(s):  
Facial Pain ◽  
The Other ◽  
Precentral Gyrus ◽  
Nerve Section ◽  
Content Type ◽  
Burning Pain ◽  
Cortical Localization ◽  
The Brain ◽  
Fine Print ◽  
Frontal Lobotomy

✓ Cortical removals which included precentral and postcentral facial representations resulted in relief of facial pain in two patients. Because of known failures following only postcentral (SmI) ablations, these operations were designed to eliminate also the cutaneous afferent projection to the precentral gyrus (MsI) and the second somatic sensory area (SmII). In one case burning pain developed after a stroke involving the brain stem and was not improved by total fifth nerve section; prompt relief followed corticectomy and lasted until death from heart disease 20 months later. In the other case persistent steady pain that developed after fifth rhizotomy for trigeminal neuralgia proved refractory to frontal lobotomy; relief after corticectomy was immediate and has lasted 14 months. Cortical localization was established by stimulation under local anesthesia. Each removal extended up to the border of the arm representation and down to the upper border of the insula. Such a resection necessarily included SmII, and in one case responses presumably from SmII were obtained before removal. The suggestions of Biemond (1956) and Poggio and Mountcastle (1960) that SmII might be concerned with pain sensibility may be pertinent in these cases.

Thymidine kinase-mediated killing of rat brain tumors

1993 ◽  
Vol 79 (5) ◽  
pp. 729-735 ◽  
Author(s):  
David Barba ◽  
Joseph Hardin ◽  
Jasodhara Ray ◽  
Fred H. Gage
Keyword(s):  
Gene Therapy ◽  
Brain Tumors ◽  
Tumor Cells ◽  
Wild Type ◽  
Cns Disorders ◽  
Content Type ◽  
Potential Applications ◽  
Ganciclovir Treatment ◽  
The Brain ◽  
Fine Print

✓ Gene therapy has many potential applications in central nervous system (CNS) disorders, including the selective killing of tumor cells in the brain. A rat brain tumor model was used to test the herpes simplex virus (HSV)-thymidine kinase (TK) gene for its ability to selectively kill C6 and 9L tumor cells in the brain following systemic administration of the nucleoside analog ganciclovir. The HSV-TK gene was introduced in vitro into tumor cells (C6-TK and 9L-TK), then these modified tumor cells were evaluated for their sensitivity to cell killing by ganciclovir. In a dose-response assay, both C6-TK and 9L-TK cells were 100 times more sensitive to killing by ganciclovir (median lethal dose: C6-TK, 0.1 µg ganciclovir/ml; C6, 5.0 µg ganciclovir/ml) than unmodified wild-type tumor cells or cultured fibroblasts. In vivo studies confirmed the ability of intraperitoneal ganciclovir administration to kill established brain tumors in rats as quantified by both stereological assessment of brain tumor volumes and studies of animal survival over 90 days. Rats with brain tumors established by intracerebral injection of wild-type or HSV-TK modified tumor cells or by a combination of wild-type and HSV-TK-modified cells were studied with and without ganciclovir treatments. Stereological methods determined that ganciclovir treatment eliminated tumors composed of HSV-TK-modified cells while control tumors grew as expected (p < 0.001). In survival studies, all 10 rats with 9L-TK tumors treated with ganciclovir survived 90 days while all untreated rats died within 25 days. Curiously, tumors composed of combinations of 9L and 9L-TK cells could be eliminated by ganciclovir treatments even when only one-half of the tumor cells carried the HSV-TK gene. While not completely understood, this additional tumor cell killing appears to be both tumor selective and local in nature. It is concluded that HSV-TK gene therapy with ganciclovir treatment does selectively kill tumor cells in the brain and has many potential applications in CNS disorders, including the treatment of cancer.

Arteriovenous malformations in the posterior fossa

1977 ◽  
Vol 47 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Hiroshi Matsumura ◽  
Yasumasa Makita ◽  
Kuniyuki Someda ◽  
Akinori Kondo
Keyword(s):  
Arteriovenous Malformation ◽  
Brain Stem ◽  
Posterior Fossa ◽  
Arteriovenous Malformations ◽  
Cerebellopontine Angle ◽  
Anterior Part ◽  
Content Type ◽  
The Brain ◽  
Fine Print

✓ We have operated on 12 of 14 cases of arteriovenous malformation (AVM) in the posterior fossa since 1968, with one death. The lesions were in the cerebellum in 10 cases (three anteromedial, one central, three lateral, and three posteromedial), and in the cerebellopontine angle in two; in two cases the lesions were directly related to the brain stem. The AVM's in the anterior part of the cerebellum were operated on through a transtentorial occipital approach.

Craniocerebral missile injuries in the monkey: an experimental physiological model

1972 ◽  
Vol 36 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Arthur M. Gerber ◽  
Robert A. Moody
Keyword(s):  
Rhesus Monkeys ◽  
Common Factor ◽  
Blood Gases ◽  
Physiological Model ◽  
Content Type ◽  
Epidural Compression ◽  
The Brain ◽  
Strong Suspicion ◽  
Fine Print ◽  
Carotid Flow

✓ Experiments were carried out on rhesus monkeys to determine what physiological parameters were most closely correlated with death due to craniocerebral missile injuries. Observations of intracranial pressure, blood pressure, carotid flow, blood gases, respiratory rate, depth and volume, and electroencephalograms were made. These parameters were compared in survivors and nonsurvivors as were the pathological injuries. The most important single parameter that correlated with death was the drop in carotid flow. As this same correlation has been observed in epidural compression experiments in the monkey, there is a strong suspicion that reduced blood flow to the brain as measured by carotid flow is a common factor in craniocerebral missile injuries and epidural compression injuries.

Age-related changes in the proportion of intracranial cerebrospinal fluid space measured using volumetric computerized tomography scanning

2002 ◽  
Vol 97 (3) ◽  
pp. 607-610 ◽  
Author(s):  
Hiroshi Wanifuchi ◽  
Takashi Shimizu ◽  
Takashi Maruyama
Keyword(s):  
Cerebrospinal Fluid ◽  
Computerized Tomography ◽  
Ct Scanning ◽  
Volume Measurement ◽  
Intracranial Volume ◽  
Content Type ◽  
Standard Curve ◽  
Age Related ◽  
Fine Print ◽  
Age Related Changes

Object. The purpose of this study was to establish a standard curve to demonstrate normal age-related changes in the proportion of intracranial cerebrospinal fluid (CSF) space in intracranial volume (ICV) during each decade of life. Methods. Using volumetric computerized tomography (CT) scanning and computer-guided volume measurement software, ICV and cerebral parenchymal volume (CPV) for each decade of life were measured and the intracranial CSF ratio was calculated by the following formula: percentage of CSF = (ICV − CPV)/ICV × 100%. The standard curve for age-related changes in normal percentages of intracranial CSF was obtained. Conclusions. Based on this standard curve, the percentage of intracranial CSF rapidly increased after the sixth decade, seeming to reflect the brain atrophy that accompanies increased age.

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