Rudimentary pedal grasping in mice and implications for terminal branch arboreal quadrupedalism

2010 ◽  
Vol 272 (2) ◽  
pp. 230-240 ◽  
Author(s):  
Craig Byron ◽  
Hawley Kunz ◽  
Heather Matuszek ◽  
Stephanie Lewis ◽  
Daniel Van Valkinburgh
Keyword(s):  
Terminal Branch ◽  
Arboreal Quadrupedalism

Anatomy of the terminal branch of the posterior circumflex humeral artery

2016 ◽  
Vol 98-B (10) ◽  
pp. 1395-1398 ◽  
Author(s):  
C. D. Smith ◽  
S. J. Booker ◽  
H. S. Uppal ◽  
J. Kitson ◽  
T. D. Bunker
Keyword(s):  
Terminal Branch ◽  
Posterior Circumflex Humeral Artery

Development of neuromuscular synapses

1983 ◽  
Vol 63 (3) ◽  
pp. 915-1048 ◽  
Author(s):  
M. R. Bennett
Keyword(s):  
Motor Unit ◽  
Muscle Cells ◽  
Terminal Branch ◽  
Quantal Release ◽  
Synaptic Site ◽  
Neuromuscular Synapses ◽  
A Site ◽  
Threshold Amount ◽  
Neuron Soma ◽  
Secretory Capacity

Quantal secretion at nerve terminals in mature muscles depends on the number of terminal branches and the size of release sites (sect. VB4). The physical length of SBL determines the length of terminal branch that can be laid down in a reinnervation experiment (sect. IVA4). A limit is set on the total length of terminal branches formed by a motoneuron; this limit is determined by the amount of TF (sect. IVB) made available from the neuron soma to the peripheral branches of the neuron (sect. VC). As a result of this limit, not all SBL needs to be occupied at a site by terminal branches. The SBL eventually disappears if it is not occupied by terminal branches (sect. IVA2). If a muscle is relatively inactive, it synthesizes and releases at synaptic sites additional amounts of NGF, which stimulates the growth of additional terminal branches. These may secrete sufficient amounts of AF to induce the formation of new SRs with associated SBL. In these circumstances a new synaptic site is formed or an extension of an existing site is created. If the size of a motor unit is decreased, the enhanced release of TF at the remaining terminals ensures that each occupies all the SBL at the synaptic site. Furthermore the enhanced release of AF per terminal induces more SBL, allowing additional terminal branches on the muscle cells to be established. Neither of these changes occurs unless the threshold amount of NGF is available from the muscle to stabilize the terminals. If this condition is met, an increase in quantal release per terminal occurs after reducing the size of a motor unit (sect. VC). An increase in quantal release per terminal also occurs after inactivation of a muscle. Such inactivation leads to an enhanced release of NGF per synaptic site (sect. VA4). Extra terminals may then form if sufficient TF is available; these may innervate existing but empty synaptic sites. In rare circumstances the extra terminal may induce SBL and innervate these new sites if sufficient AF is available. In both cases the quantal release per terminal increases. During development the secretory capacity of the axon terminal depends on the muscle cells with which it synapses. This secretory capacity can be enhanced either by increasing the number of terminal branch pairs or by increasing the secretory capacity of individual release sites. If two terminals innervate a synaptic site, their individual secretory capacity is reduced--in these circumstances the terminal's secretory capacity depends on the amount of NGF available to the terminal; two terminals must share their NGF.

scholarly journals Combined surgical treatment of arteriovenous malformation of the lower jaw

2020 ◽  
Vol 34 (4) ◽  
pp. 95-104
Author(s):  
D.V. Shchehlov ◽  
V.M. Zahorodnii ◽  
I.V. Altman ◽  
N.V. Kiselyova ◽  
I.I. Kashkish
Keyword(s):  
Arteriovenous Malformation ◽  
Cerebral Angiography ◽  
Combined Treatment ◽  
The Body ◽  
Facial Artery ◽  
External Carotid ◽  
Maxillary Artery ◽  
Terminal Branch ◽  
Lower Jaw ◽  
The Right

The objective – to presents the observation of combined treatment of a patient with arteriovenous malformation of the lower jaw.A man, 21 years old, was hospitalized in the Scientific-Practical Center of Endovascular Neuroradiology NAMS of Ukraine with complaints of bleeding from a tooth socket after an attempt to remove the 6th tooth (first painter) of the lower jaw on the left. According to the performed survey radiography of the lower jaw, an aneurysmal bone cyst was revealed in the body of the lower jaw on the left, corresponding to the localization of bleeding. According to cerebral angiography, an arteriovenous malformation of the lower jaw was revealed on the left, the afferent arteries of which were: the right facial artery (a branch of the right external carotid artery (ECA)), the left facial artery (a branch of the left ECA), the lower alveolar artery, the superior-posterior alveolar artery (branches of the maxillary artery ‒ the terminal branch of the left ECA) with drainage into a vein, which was located in the body of the lower jaw. In order to exclude the malformation from the bloodstream and prevent bleeding, a controlled embolization of the malformation was performed using non-spherical emboli – polyvinyl alcohol (PVA) particles from Cook, USA. Using a transfemoral approach, a guide catheter was inserted into the orifice of the ECA, then a Headway 27 microcatheter (Microvention, USA) was passed through it along a Traxes 14 guide wire (Microvention, USA), the afferent arteries of the malformation were selectively cathete-rized in turn, and embolization was performed after superselective angiography. The patient was discharged in a satisfactory condition. Two weeks after the operation, the bleeding resumed. The performed control cerebral angiography revealed a relapse of the malformation with a change in its angioarchitectonics ‒ the filling of the malformation in the late arterial and venous phases of cerebral blood flow was noted. Re-embolization was performed using PVA emboli (Cook), which was supplemented by transcutaneous puncture of the drainage vein in the mandible and its embolization with histoacryl (B. Braun, Germany) and lipiodol (Guerbet, France) in a 1 : 1 ratio. Results. As a result of using this technique, it was possible to turn off the malformation completely. For 6 months from the moment of surgery, no bleeding was noted, and subsequently the patient had a tooth removed without complications.Conclusions. The proposed method for treating arteriovenous malformation of the lower jaw, proposed in this case, showed the effectiveness of a combination of endovascular embolization in combination with transcutaneous embolization of the draining vein and can be successfully used to treat this pathology.

scholarly journals Systematization of the Brain Base Arteries in Nutria (Myocastor coypus)

2018 ◽  
Vol 46 (1) ◽  
pp. 9
Author(s):  
Rodrigo Cavalcanti De Azambuja ◽  
Laura Ver Goltz ◽  
Rui Campos
Keyword(s):  
Carotid Artery ◽  
Cerebral Artery ◽  
Basilar Artery ◽  
Internal Carotid ◽  
Terminal Branch ◽  
Medial Branch ◽  
Myocastor Coypus ◽  
Collateral Branch ◽  
Cerebellar Artery ◽  
The Brain

Background: The nutria (Myocastor coypus) is a medium-size, semi-aquatic rodent, valued in skin and meat industry. The brain circulation has been well studied in rodents but not in nutria. To understand and compare the phylogenetic development of the arteries of the base of the brain in rodents, this paper aims to describe and systematize these arteries, establishing a standard model and its main variations in nutria.Materials, Methods & Results: Following approval by the Ethics Committee of Federal University of Rio Grande do Sul, thirty nutrias from a commercial establishment authorized by Brazilian Institute of Environment and Natural Resources (IBAMA) were studied. For euthanasia, was applied heparin (10000 U.I for animal), intraperitoneally, and after thirty minutes the animals ware sedated with acepromazine (0.5 mg/kg) and meperidine (20 mg/kg), intramuscularly. After sedation, they were euthanized with thiopental sodium (120 mg/kg) and lidocaine (10 mg/mL), intraperitoneally. The heart was accessed, the cardiac apex was sectioned, the aorta was cannulated via the left ventricle and clamped close to the diaphragm, and the arterial system was washed with saline solution and filled with latex. The animals were submerged in water for latex polymerization, the trunk was sectioned, the skin removed and a bony window was opened in the skull vault. The pieces were fixed in formaldehyde. The brains were removed, and schematic drawings of the arteries from the base of the brain were made for elaboration of the results. The nutria’s brain was vascularized by the vertebro-basilar system. The terminal branches of the right and left vertebral artery were anastomosed on the ventral surface of the medulla oblongata, forming the basilar artery, and caudally the ventral spinal artery. The basilar artery formed collateral branches, the caudal and middle cerebellar and trigeminal arteries, and at the height of the rostral pons groove, divided into its two terminal branches, the rostral cerebellar and cerebral caudal arteries. The terminal branches of the basilar artery projected rostrally, forming the hypophyseal and rostral choroid arteries. The basilar artery passed the optic tract and bifurcated in the middle cerebral artery, its last collateral branch, and in the rostral cerebral artery, its terminal branch. The rostral cerebral artery formed the medial branch, closing the cerebral arterial circle caudally in 40% of the cases.Discussion: In rodents, variability of the cerebral arterial circle was observed due to the degree of atrophy of the internal carotid artery. The basilar artery was a rectilinear vessel of great caliber in all described rodents, and in rodents with a vertebro-basilar system, it was divided into its terminal branches after crossing the pons, forming the rostral cerebellar, hypophyseal, rostral choroid, caudal, middle and rostral cerebral arteries. The caudal cerebellar artery had variation of origin and sometimes duplication. The median cerebellar artery, a collateral branch of the caudal cerebellar artery, was a branch of the basilar artery in capybara. The caudal cerebral artery had variations between rodents. In capybara, chinchilla and nutria the middle cerebral artery was the collateral branch of the terminal branches of the basilar artery, and distributed on the convex surface of the cerebral hemisphere. The rostral cerebral artery, a branch of the terminal branch of the basilar artery, was a branch of the internal carotid artery in other rodents, forming the medial branch, which was anastomosed with that of the opposite antimer, when present, forming the rostral communicating artery. In nutria, the cerebral arterial circle was closed caudally in all cases, as in other rodents, however, it was opened rostrally in 60% of cases, compared to 70% in chinchilla and 10% in capybara.

scholarly journals Tip rates, phylogenies, and diversification: what are we estimating, and how good are the estimates?

2018 ◽  
Author(s):  
Pascal O. Title ◽  
Daniel L. Rabosky
Keyword(s):  
Diversification Rate ◽  
Rate Variation ◽  
Terminal Branch ◽  
List Type ◽  
Large Set ◽  
Extinction Rate ◽  
Diversification Rates ◽  
Speciation Rate ◽  
Model Based ◽  
Model Free

AbstractSpecies-specific diversification rates, or “tip rates”, can be computed quickly from phylogenies and are widely used to study diversification rate variation in relation to geography, ecology, and phenotypes. These tip rates provide a number of theoretical and practical advantages, such as the relaxation of assumptions of rate homogeneity in trait-dependent diversification studies. However, there is substantial confusion in the literature regarding whether these metrics estimate speciation or net diversification rates. Additionally, no study has yet compared the relative performance and accuracy of tip rate metrics across simulated diversification scenarios.We compared the statistical performance of three model-free rate metrics (inverse terminal branch lengths; node density metric; DR statistic) and a model-based approach (BAMM). We applied each method to a large set of simulated phylogenies that had been generated under different diversification processes; scenarios included multi-regime time-constant and diversity-dependent trees, as well as trees where the rate of speciation evolves under a diffusion process. We summarized performance in relation to the type of rate variation, the magnitude of rate heterogeneity and rate regime size. We also compared the ability of the metrics to estimate both speciation and net diversification rates.We show decisively that model-free tip rate metrics provide a better estimate of the rate of speciation than of net diversification. Error in net diversification rate estimates increases as a function of the relative extinction rate. In contrast, error in speciation rate estimates is low and relatively insensitive to extinction. Overall, and in particular when relative extinction was high, BAMM inferred the most accurate tip rates and exhibited lower error than non-model-based approaches. DR was highly correlated with true speciation rates but exhibited high error variance, and was the best metric for very small rate regimes.We found that, of the metrics tested, DR and BAMM are the most useful metrics for studying speciation rate dynamics and trait-dependent diversification. Although BAMM was more accurate than DR overall, the two approaches have complementary strengths. Because tip rate metrics are more reliable estimators of speciation rate, we recommend that empirical studies using these metrics exercise caution when drawing biological interpretations in any situation where the distinction between speciation and net diversification is important.

scholarly journals The Extracellular Transport Signal of the Vibrio cholerae Endochitinase (ChiA) Is a Structural Motif Located between Amino Acids 75 and 555

2002 ◽  
Vol 184 (8) ◽  
pp. 2225-2234 ◽  
Author(s):  
Jason P. Folster ◽  
Terry D. Connell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Vibrio Cholerae ◽  
Structural Information ◽  
Amino Acid Sequences ◽  
Structural Motif ◽  
Terminal Branch ◽  
C Terminus ◽  
N Terminus ◽  
Extracellular Transport

ABSTRACT ChiA, an 88-kDa endochitinase encoded by the chiA gene of the gram-negative enteropathogen Vibrio cholerae, is secreted via the eps-encoded main terminal branch of the general secretory pathway (GSP), a mechanism which also transports cholera toxin. To localize the extracellular transport signal of ChiA that initiates transport of the protein through the GSP, a chimera comprised of ChiA fused at the N terminus with the maltose-binding protein (MalE) of Escherichia coli and fused at the C terminus with a 13-amino-acid epitope tag (E-tag) was expressed in strain 569B(chiA::Kanr), a chiA-deficient but secretion-competent mutant of V. cholerae. Fractionation studies revealed that blockage of the natural N terminus and C terminus of ChiA did not prevent secretion of the MalE-ChiA-E-tag chimera. To locate the amino acid sequences which encoded the transport signal, a series of truncations of ChiA were engineered. Secretion of the mutant polypeptides was curtailed only when ChiA was deleted from the N terminus beyond amino acid position 75 or from the C terminus beyond amino acid 555. A mutant ChiA comprised of only those amino acids was secreted by wild-type V. cholerae but not by an epsD mutant, establishing that amino acids 75 to 555 independently harbored sufficient structural information to promote secretion by the GSP of V. cholerae. Cys77 and Cys537, two cysteines located just within the termini of ChiA(75-555), were not required for secretion, indicating that those residues were not essential for maintaining the functional activity of the ChiA extracellular transport signal.

Automated Quantitative Analysis of Terminal Tree Branch Similarity by 3D Registration

2017 ◽  
Author(s):  
Joseph A. Brucculeri ◽  
Lance Evans ◽  
Zahra Shahbazi
Keyword(s):  
Sensitivity Analysis ◽  
Quantitative Analysis ◽  
Root Mean Square Error ◽  
Tree Species ◽  
Side Branch ◽  
Terminal Branch ◽  
Mean Square ◽  
3D Registration ◽  
Self Similarity ◽  
Tree Branch

A popular, but unsubstantiated view is that tree branch morphologies are similar (self-similarity) and are of an iterative nature. To date there are no studies that document plant branch self-similarities. The purpose of this research is to develop a program (3D Simquant) that estimated self-similarities among paired branch terminals quantitatively. After 3D Simquant was written, the program was verified and sensitivity analysis performed, eighty-five terminal branch pair-wise comparisons from five different tree species were analyzed. Only two branch geometries (Y and Y+1 terminals) were compared. Simple Y terminals are terminal main stems with one side branch while Y+1 terminals are main steams with two side branches. Similarities among paired branch terminals were quantified with Root-Mean-Square-Error (RMSE) after registration of images. For the five species tested, all Y terminals had RMSE values less than 1.5 which indicates they were similar. For most Y+1 terminals, RMSE values were twice that of Y terminals indicating the Y+1 samples were more dissimilar than Y terminals. Overall, the programs were accurate and rapid for an analysis of branch similarities.

Development of the Drosophila tracheal system occurs by a series of morphologically distinct but genetically coupled branching events

Development ◽  
1996 ◽  
Vol 122 (5) ◽  
pp. 1395-1407 ◽  
Author(s):  
C. Samakovlis ◽  
N. Hacohen ◽  
G. Manning ◽  
D.C. Sutherland ◽  
K. Guillemin ◽  
...  
Keyword(s):  
Tube Formation ◽  
The Body ◽  
Terminal Branch ◽  
Cellular Mechanisms ◽  
Morphological Marker ◽  
Tracheal System ◽  
Fgf Receptor ◽  
Restricted Domains ◽  
Gene Regulatory ◽  
Ets Domain

The tracheal (respiratory) system of Drosophila melanogaster is a branched network of epithelial tubes that ramifies throughout the body and transports oxygen to the tissues. It forms by a series of sequential branching events in each hemisegment from T2 to A8. Here we present a cellular and initial genetic analysis of the branching process. We show that although branching is sequential it is not iterative. The three levels of branching that we distinguish involve different cellular mechanisms of tube formation. Primary branches are multicellular tubes that arise by cell migration and intercalation; secondary branches are unicellular tubes formed by individual tracheal cells; terminal branches are subcellular tubes formed within long cytoplasmic extensions. Each level of branching is accompanied by expression of a different set of enhancer trap markers. These sets of markers are sequentially activated in progressively restricted domains and ultimately individual tracheal cells that are actively forming new branches. A clonal analysis demonstrates that branching fates are not assigned to tracheal cells until after cell division ceases and branching begins. We further show that the breathless FGF receptor, a tracheal gene required for primary branching, is also required to activate expression of markers involved in secondary branching and that the pointed ETS-domain transcription factor is required for secondary branching and also to activate expression of terminal branch markers. The combined morphological, marker expression and genetic data support a model in which successive branching events are mechanistically and genetically distinct but coupled through the action of a tracheal gene regulatory hierarchy.

A Cadaveric Study on the Variation in the Level of Division of Sciatic Nerve in Nepalese Population

2020 ◽  
Vol 9 (1) ◽  
pp. 12-16
Author(s):  
Diwakar Kumar Shah ◽  
Sanzida Khatun
Keyword(s):  
Sciatic Nerve ◽  
Ischial Tuberosity ◽  
Lower Limbs ◽  
Pelvic Cavity ◽  
Terminal Branch ◽  
Middle Region ◽  
Common Site ◽  
Greater Trochanter ◽  
Cross Sectional ◽  
Medical College

Background: Sciatic nerve, the thickest nerve of our body (around 2cm wide at its origin), leaves the pelvic cavity from the greater sciatic foramina below the piriformis muscle and between the greater trochanter of femur and ischial tuberosity. As variations have been reported in the level of division of sciatic nerve into its terminal branches, the current study aims to determine the most common site of division of sciatic nerve in Nepalese population. Materials and Methods: The current study is a cross-sectional and descriptive study which was carried out in the Department of Anatomy, Nobel Medical College, where twenty-three cadavers were used and both the lower limbs were examined. Depending upon the level of division of the sciatic nerve into its terminal branches, it was categorized into six different groups (A-F). Results: It was seen that the sciatic nerve had already divided into its terminal branches before its exit into the gluteal regionin 23.91% extremities. The second commonestsite for the termination of sciatic nerve into its terminal branch was found to be at the middle region of the back of the thigh in 19.57% followed by its division in the popliteal fossa in 17.39%. Conclusion: From the current study we conclude that the level of division of sciatic nerve was variable and it is wise to go for other means to find out the level of termination of sciatic nerve before performing any procedure in that area.

Hypoperfusion in lenticulostriate arteries territory related to unexplained early neurological deterioration after intravenous thrombolysis

2019 ◽  
Vol 14 (3) ◽  
pp. 306-309 ◽  
Author(s):  
Ying Zhou ◽  
Wansi Zhong ◽  
Anli Wang ◽  
Wanyun Huang ◽  
Shenqiang Yan ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Acute Ischemic Stroke ◽  
Cerebral Artery ◽  
Intravenous Thrombolysis ◽  
Neurological Deterioration ◽  
Terminal Branch ◽  
Stroke Patients ◽  
Lenticulostriate Arteries ◽  
Early Neurological Deterioration

Background Early neurological deterioration occurs in approximately 10% acute ischemic stroke patients after thrombolysis. Over half of the early neurological deterioration occurred without known causes and is called unexplained early neurological deterioration. Aims We aimed to explore the development of early neurological deterioration at 24 h after thrombolysis, and whether it could be predicted by the presence of baseline hypoperfusion in lenticulostriate arteries territory in acute ischemic stroke patients. Methods We retrospectively reviewed our prospectively collected database of acute ischemic stroke patients in the unilateral middle cerebral artery territory who had baseline perfusion image and received thrombolysis. Unexplained early neurological deterioration was defined as ≥ 2 points increase of National Institutes of Health Stroke Scale (NIHSS) from baseline to 24 h, without known causes. Hypoperfusion lesions in different territories were identified on perfusion maps. Results A total of 306 patients were included in analysis. Patients with pure lenticulostriate arteries hypoperfusion (defined as the presence of hypoperfusion in lenticulostriate artery territory, but not in middle cerebral artery terminal branch territory) were more likely to have unexplained early neurological deterioration than others (27.6% vs. 6.1%; OR, 5.974; p = 0.001), after adjusting for age, baseline NIHSS and onset to treatment time. Conclusions Patients presenting hypoperfusion in pure lenticulostriate arteries territory were easier to experience unexplained early neurological deterioration.

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