Studies in Functional and analytical craniology. 14. Experiments with the decalcified skull of the Leaf Monkey.

1956 ◽  
Vol 4 (1) ◽  
pp. 60 ◽  
Author(s):  
R Tucker
Keyword(s):  
Lateral Wall ◽  
Leaf Monkey ◽  
Base Of The Skull ◽  
The Brain ◽  
Palatine Bone

The skull of the monkey was analysed experimentally. The strains around the supraorbital node differ from those in the calf (Tucker 1956c). The lateral wall of the brain case shows depressions related to the forces applied in the glenoidal cavity. The palatine bone in the monkey is replaced functionally by the lateral pterygoid lamina in the squamoso-maxillary tract. Three functional1y different areas at the base of the skull are described and illustrated.

scholarly journals Mesenchymal Chondrosarcoma of the Brain with Metastasis: A Case Report with Literature Review

2020 ◽  
Vol 11 (02) ◽  
pp. 344-348
Author(s):  
Sandeep Bhardwaj ◽  
Ashish Sharma ◽  
Akangsha Sharma
Keyword(s):  
Left Lung ◽  
Lumbar Vertebrae ◽  
Lateral Wall ◽  
Mesenchymal Chondrosarcoma ◽  
Radical Excision ◽  
Temporal Region ◽  
Ct Guided ◽  
Dismal Prognosis ◽  
Extraskeletal Mesenchymal Chondrosarcoma ◽  
The Brain

AbstractMesenchymal chondrosarcoma of the brain is one of the rarest tumors with dismal prognosis. A 26-year-old man presented with headache, vomiting, and diplopia. On evaluation, a moderately enhancing extra-axial lesion was seen in right temporal region involving right greater wing of sphenoid, adjacent right maxillary sinus, and lateral wall of right orbit. Patient underwent magnetic resonance imaging of the spine and computed tomography (CT) of the chest for possible metastasis which showed lesion in lumbar vertebrae and left lung. Patient was planned for CT-guided lung biopsy which proved inconclusive. The patient was further planned for craniotomy and underwent craniotomy with microscopic excision of the mass. Histoimmunochemistry was suggestive of extraskeletal mesenchymal chondrosarcoma. Mesenchymal chondrosarcoma of the brain is highly aggressive tumors which are difficult to differentiate radiologically. Radical excision followed by chemoradiotherapy is optimal treatment of choice.

Kanamycin Inhibits Cochlear-Renal ODC in Neonatal Rats

1992 ◽  
Vol 107 (4) ◽  
pp. 501-510 ◽  
Author(s):  
Andrew T. Lyos ◽  
William E. Winter ◽  
Charles M. Henley
Keyword(s):  
Organ Of Corti ◽  
Lateral Wall ◽  
Inhibitory Effect ◽  
Polyamine Biosynthesis ◽  
Key Enzyme ◽  
Old Rats ◽  
In Vivo Effects ◽  
The Brain

Ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, is important in development and regeneration. We hypothesize that aminoglycoside inhibition of ODC mediates developmental hypersensitivity to aminoglycoside ototoxicity. Kanamycin effects on ODC activity (decarboxylation of ornithine) in vitro were determined in the postmitochondriai fraction of cochlear and renal homogenates from 11-day-old rats. Kanamycin inhibited cochlear and renal ODC by an uncompetitive mechanism. For the cochlear enzyme, the inhibitor constant (Ki) for kanamycin was 99 ± 25 (μmol/L; for the renal enzyme, the Ki = 1.5 ± 0.1 mmol/L. In vivo effects of kanamycin on cochlear, renal, brain ODC activity were determined in rats treated with kanamycin (400 mg/kg/day, intramuscularly) or saline during postnatal days 11 through 20, the hypersensitive period for ototoxicity. Rats were killed on postnatal days 12,14,16, and 20 and ODC was assayed. Kanamycin significantly inhibited ODC in the lateral wall-organ of Corti and kidney (ANOVA α = 0.05), but had no effect on cochlear nerve and no consistent inhibitory effect in the brain. These results suggest that ODC is a potential target of kanamycin in susceptible tissues and may be a contributing factor in developmental sensitivity to the drug by inhibiting repair and developmental processes mediated by ODC.

The early development of the frog retinotectal projection

Development ◽  
1991 ◽  
Vol 113 (Supplement_2) ◽  
pp. 95-104
Author(s):  
Jeremy S. H. Taylor
Keyword(s):  
Ganglion Cell ◽  
Early Development ◽  
Short Distance ◽  
Lateral Wall ◽  
Retinal Ganglion ◽  
Initial Development ◽  
Retinal Axons ◽  
A Chain ◽  
The Brain ◽  
Rostral Part

The guidance of retinal ganglion cell axons has been investigated in embryos of the frog Xenopus. During the initial development of the brain a series of axon tracts are laid down forming a basic ‘scaffold’ or framework. Retinal axons grow through one of these tracts, the tract of the post-optic commissure (tPOC). This is the only tract that extends through the rostral part of the brain at these early stages of development. The origin and development of the tPOC has been studied using antibodies which label neurons at their earliest stages of differentiation. The first sign of the tPOC is a chain of neurons which differentiate simultaneously in the caudolateral part of the diencephalon. Axons from these neurons grow the short distance between adjacent cells interlinking the chain to form a descending tract. A series of other axon projections are then added to the tPOC, each of which is segregated into a particular subregion of the tract. Retinal axons are added to the tract approximately 18 h after its formation. They grow in the sub-pial part of the tract and always occupy the rostralmost edge. Retinal axons follow the tract to the region of the developing tectum where they leave, turn dorsally, and terminate. The reliance of retinal axons on this pre-existing pathway has been demonstrated by experimentally altering the course of the tPOC during its early development. The caudo-lateral wall of the diencephalon has been rotated through 90° at a stage just before the tPOC neurons differentiate. Confirmation of the predicted alteration in the course of the tPOC has been made using immunocytochemistry. In such manipulated brains, retinal axons maintain their strong affinity for the rostral edge of the tPOC, following its altered course through the diencephalon.

scholarly journals Evaluation of a spring-powered captive bolt gun for killing kangaroo pouch young

2014 ◽  
Vol 41 (7) ◽  
pp. 623 ◽  
Author(s):  
T. M. Sharp ◽  
S. R. McLeod ◽  
K. E. A. Leggett ◽  
T. J. Gibson
Keyword(s):  
Current Method ◽  
Domestic Animal ◽  
The Public ◽  
Blunt Head Trauma ◽  
Captive Bolt Gun ◽  
Base Of The Skull ◽  
Bolt Diameter ◽  
The Brain ◽  
Skull Thickness ◽  
Commercial Harvesting

Context During commercial harvesting or non-commercial kangaroo culling programs, dependent young of shot females are required to be euthanased to prevent suffering and because they would be unlikely to survive. However, the current method for killing pouch young, namely a single, forceful blow to the base of the skull, is applied inconsistently by operators and perceived by the public to be inhumane. Aims To determine whether an alternative method for killing pouch young, namely a spring-operated captive bolt gun, is effective at causing insensibility in kangaroo pouch young. Methods Trials of spring-operated captive bolt guns were conducted first on the heads of 15 dead kangaroo young and then on 21 live pouch young during commercial harvesting. We assessed the effectiveness at causing insensibility in live animals and damage caused to specific brain areas. We also measured depth of bolt penetration and skull thickness. Performance characteristics (e.g. bolt velocity) of two types of spring-operated guns were also measured and compared with cartridge-powered devices. Key results When tested on the heads of dead animals, the spring-operated captive bolt gun consistently produced a large entrance cavity and a well defined wound tract, which extended into the cerebrum, almost extending the full thickness of the brain, including the brainstem. When tested on live pouch young, the captive bolt gun caused immediate insensibility in only 13 of 21 animals. This 62% success rate is significantly below the 95% minimum acceptable threshold for captive bolt devices in domestic animal abattoirs. Failure to stun was related to bolt placement, but other factors such as bolt velocity, bolt diameter and skull properties such as thickness and hardness might have also contributed. Spring-operated captive bolt guns delivered 20 times less kinetic energy than did cartridge-powered devices. Conclusions Spring-operated captive bolt guns cannot be recommended as an acceptable or humane method for stunning or killing kangaroo pouch young. Implications Captive bolt guns have potential as a practical alternative to blunt head trauma for effective euthanasia and reducing animal (and observer) distress. However, operators must continue to use the existing prescribed killing methods until cartridge-powered captive bolt guns have been trialled as an alternative bolt propelling method.

Latencies of Climbing Fiber Inputs to Turtle Cerebellar Cortex

2005 ◽  
Vol 93 (2) ◽  
pp. 1042-1054 ◽  
Author(s):  
Michael Ariel
Keyword(s):  
Brain Stem ◽  
Cerebellar Cortex ◽  
Molecular Layer ◽  
Field Potential ◽  
Lateral Wall ◽  
Climbing Fiber ◽  
The Brain ◽  
Complex Spikes ◽  
Negative Field

Responses of separate regions of rat cerebellar cortex (Cb) to inferior olive (IO) stimulation occur with the same latency despite large differences in climbing fiber (CF) lengths. Here, the olivocerebellar path of turtle was studied because its Cb is an unfoliated sheet on which measurements of latency and CF length can be made directly across its entire surface in vitro. During extracellular DC recordings at a given Cb position below the molecular layer, IO stimulation evoked a large negative field potential with a half-width duration of ∼6.5 ms. On this response were smaller oscillations similar to complex spikes. The stimulating electrode was moved to map the IO and the CF path from the brain stem to the Cb. The contralateral brain stem region that evoked these responses was tightly circumscribed within the medulla, lateral and deep to the obex. This response remained when the brain stem was bathed in solutions that blocked synaptic transmission. The Cb response to IO stimulation had a peak latency of ∼10 ms that was not dependent on the position of the recording electrode across the entire 8-mm rostrocaudal length of the Cb. However, for a constant Cb recording position, moving the stimulation across the midline to the ipsilateral brain stem and along the lateral wall of the fourth ventricle toward the peduncle did shorten the response latency. Therefore a synchronous Cb response to CF stimulation seems to be caused by changes in its conduction velocity within the entire cerebellar cortex but not within the brain stem.

FGF8 induces formation of an ectopic isthmic organizer and isthmocerebellar development via a repressive effect on Otx2 expression

Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1189-1200 ◽  
Author(s):  
S. Martinez ◽  
P.H. Crossley ◽  
I. Cobos ◽  
J.L. Rubenstein ◽  
G.R. Martin
Keyword(s):  
Neural Tube ◽  
Lateral Wall ◽  
Mirror Image ◽  
Repressive Effect ◽  
Isthmic Nuclei ◽  
Signaling Center ◽  
The One ◽  
The Brain ◽  
Morphogenetic Effects ◽  
Wnt1 Expression

Beads containing recombinant FGF8 (FGF8-beads) were implanted in the prospective caudal diencephalon or midbrain of chick embryos at stages 9–12. This induced the neuroepithelium rostral and caudal to the FGF8-bead to form two ectopic, mirror-image midbrains. Furthermore, cells in direct contact with the bead formed an outgrowth that protruded laterally from the neural tube. Tissue within such lateral outgrowths developed proximally into isthmic nuclei and distally into a cerebellum-like structure. These morphogenetic effects were apparently due to FGF8-mediated changes in gene expression in the vicinity of the bead, including a repressive effect on Otx2 and an inductive effect on En1, Fgf8 and Wnt1 expression. The ectopic Fgf8 and Wnt1 expression domains formed nearly complete concentric rings around the FGF8-bead, with the Wnt1 ring outermost. These observations suggest that FGF8 induces the formation of a ring-like ectopic signaling center (organizer) in the lateral wall of the brain, similar to the one that normally encircles the neural tube at the isthmic constriction, which is located at the boundary between the prospective midbrain and hindbrain. This ectopic isthmic organizer apparently sends long-range patterning signals both rostrally and caudally, resulting in the development of the two ectopic midbrains. Interestingly, our data suggest that these inductive signals spread readily in a caudal direction, but are inhibited from spreading rostrally across diencephalic neuromere boundaries. These results provide insights into the mechanism by which FGF8 induces an ectopic organizer and suggest that a negative feedback loop between Fgf8 and Otx2 plays a key role in patterning the midbrain and anterior hindbrain.

The Role of Mouthguards in Preventing and Reducing Sports-Related Trauma

2017 ◽  
Vol 6 (2) ◽  
pp. 27-34 ◽  
Author(s):  
James Ij Green
Keyword(s):  
Ethylene Vinyl Acetate ◽  
Hot Water ◽  
Surrounding Tissue ◽  
Gingival Tissue ◽  
Surrounding Soft Tissue ◽  
Impact Forces ◽  
Custom Made ◽  
Base Of The Skull ◽  
The Brain

A mouthguard, also known as a gumshield, mouth protector or sports guard is an appliance that covers the teeth and surrounding mucosa with the aim of preventing or reducing trauma to the teeth, gingival tissue, lips and jaws. The device is usually worn on the maxillary arch and works by separating the maxillary and mandibular dentition, protecting the teeth from the surrounding soft tissue, absorbing or redistributing shock and/or stabilising the mandible during traumatic jaw closure. They may also play a role in preventing and reducing concussion by absorbing impact forces that would otherwise be transmitted through the base of the skull to the brain, although the evidence for this is less conclusive. A mouthguard will usually fall into one of three categories: stock mouthguards (which are made ready to use and are believed to give the least protection), the mouth-formed or 'boil and bite’ type (which are heated in hot water, placed in the mouth and moulded to the teeth) and custom-made mouthguards (which are usually made on a stone model of the maxillary teeth and surrounding tissue and are thought to give the most protection). These devices can be made from various materials but ethylene-vinyl acetate is by far the most popular material, probably because of the ease with which it can be used for the production of custom-made mouthguards. This paper gives a review of the role of mouthguards in preventing and reducing sports-related trauma and examines the materials that are used to fabricate them.

Telecanthal Approach for Meningiomas in the Ethmoid and Sphenoid Sinuses

Neurosurgery ◽  
1991 ◽  
Vol 28 (5) ◽  
pp. 714-720 ◽  
Author(s):  
Kazuhiko Fujitsu ◽  
Masakuni Saijoh ◽  
Fumihiko Aoki ◽  
Katsumi Sakata ◽  
Satoshi Fujii ◽  
...  
Keyword(s):  
Skull Base ◽  
Nasal Bone ◽  
Lateral Wall ◽  
Clinicopathological Features ◽  
Review Of The Literature ◽  
Tumor Removal ◽  
En Bloc ◽  
Working Space ◽  
The Brain ◽  
Sphenoid Sinuses

Abstract In three cases involving meningiomas in the ethmoid and sphenoid sinuses, transbasal spreading of the interocular distance (telecanthal approach) was used for tumor removal and reconstruction of the skull base. This telecanthal approach involves 1) bilateral en bloc removal of the superior lateral rim of the orbit, the nasal bone, and the posterior lateral wall of the orbit; 2) detachment of the medial canthal ligaments; and 3) spreading of the interocular distance. This approach provides a wide working space beneath the anterior half of the midline skull base, and needs neither a facial incision nor significant retraction of the brain. The surgical technique and its modification are described. The discussion focuses not only on comparisons with other techniques, but on the indications for this approach. Meningiomas originating in the paranasal sinuses are rare; a brief review of the literature concerning the clinicopathological features and pathogenesis is also given.

Sign in / Sign up

Export Citation Format

Share Document