scholarly journals Quantitative analysis of vascular network of oculogyric nerve nuclei

2011 ◽  
Vol 64 (3-4) ◽  
pp. 143-147
Author(s):  
Igor Sladojevic ◽  
Zdenka Krivokuca ◽  
Tatjana Bucma ◽  
Vesna Gajanin
Keyword(s):  
Blood Vessels ◽  
Digital Camera ◽  
Vascular Network ◽  
Precentral Gyrus ◽  
Vascular Networks ◽  
Oculomotor Nucleus ◽  
Abducens Nucleus ◽  
Significant Difference ◽  
Quantitative Characteristics ◽  
Trochlear Nucleus

Introduction. Nuclei of oculogyric nerves (principal oculomotor nucleus, trochlear nucleus and abducens nucleus) are densely vascularized brain?stem structures. The aim of this study was to determine quantitative characteristics of the vascular network of these nuclei. Material and methods. The study was done on 30 adult brainstems, both male and female, without diagnosed neurological disturbances. Three-millimetrethick stratums were taken in transversal plane and cut in 0.3 micrometer semi-serial sections stained with Mallory method. The images of studied nuclei were taken with ?Leica? DM 1000 microscope and ?Leica? EC3 digital camera under 400x magnification, and analyzed by ImageJ software with A 100 grid. The statistical analysis was performed by Statistical Package for the Social Sciences software with 5% level of significance. Results. A statistically significant difference was found in the volume and surface density between principal oculomotor nucleus and trochlear nucleus, and between trochlear nucleus and abducens nucleus. No difference was found in the length density. Discussion. The results of this research match the results of studies on characteristics of vascular network of oculogyric nerve nuclei, while the comparison of vascular networks of these nuclei, substantia nigra, vestibulocochlear nuclei and precentral gyrus illustrates differences in quantitative characteristics of blood vessels in these structures. Conclusion. Blood vessels of principal oculomotor nucleus and abducens nucleus have similar dimensions and approximately the same arborization pattern, while vessels of trochlear nucleus have significantly smaller dimensions and density.

Collective methods of propulsion and steering for untethered microscale nanorobots navigating in the human vascular network

2010 ◽  
Vol 224 (7) ◽  
pp. 1505-1513 ◽  
Author(s):  
S Martel
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Human Body ◽  
Interventional Procedures ◽  
Vascular Network ◽  
Single Type ◽  
Tumour Targeting ◽  
Miniature Robots ◽  
Medical Diagnostic ◽  
Blood Flow Velocities

In the field of medical nanorobotics, nanometre-scale components and phenomena are exploited within the context of robotics to provide new medical diagnostic and interventional procedures, or at least to enhance the existing ones. The best route for such miniature robots to access various regions inside the human body is certainly the vascular network. Such a network is made of nearly 100 000 km of blood vessels varying in diameters from a few millimetres in the arteries down to ∼ 4 μm in the capillaries with respective important variations in blood flow velocities. When injected in the blood circulatory network using existing modern techniques such as catheterization, such robots must travel from larger-diameter vessels before reaching much tinier capillaries. As such, the use of a single type of microscale robots capable of travelling in various environments and conditions related to such different blood vessels while being trackable by an external system seems, at the present time, inconceivable. Therefore, as explained in this article, an approach based on the use of several types of microscale robots with complementary methods of propulsion and steering capable of operating in a collective manner is more likely to achieve better results. This is especially true for interventions such as direct tumour targeting where the tiniest blood vessels such as the ones found in the angiogenesis network must be travelled.

Abstract 304: The Role of Calcitonin Gene Related Peptide (CGRP) in Cardiovascular Regulation and Blood Vessel Structure

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Tu Mai ◽  
Andre' Diedrich ◽  
Pandu Gangula ◽  
Emily Garland ◽  
David Robertson
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Baroreflex Sensitivity ◽  
Cardiovascular Regulation ◽  
Calcitonin Gene Related Peptide ◽  
Activity Level ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Significant Difference ◽  
Vessel Structure

Calcitonin gene related peptide (CGRP) is known to be a potent microvascular dilator and hypotensive agent. This peptide and its receptors are distributed widely in both central and peripheral nervous systems. CGRP-containing neural fibers are closely associated with blood vessels in the arterial circulation where its release leads to vascular dilation. However, its role in cardiovascular regulation remains controversial. We studied the hemodynamic and autonomic function, as well as blood vessel structure in CGRP knockout (KO) mice. Blood pressure (BP), heart rate (HR) and activity level were assessed at least one week after mice were implanted with telemeters. Ten CGRP KO and ten wild type (WT) mice (4-5 month old) were used in this study. After the recording period, 24-hr urine and blood were collected for assessment of catecholamines and their metabolites. To study the baroreflex sensitivity, phenylephrine and sodium nitroprusside were administered in an acute study with seven mice from each group. We found no significant difference in 24-hr mean arterial pressure (MAP) (105.0 ± 1.8mmHg, vs. 112.1 ± 3.1mmHg, p= 0.05) between the two groups. There was also no difference in HR (KO: 566.4 ± 12.1; WT: 581.9 ± 8.5, p = 0.31). Norepinephrine was greatly elevated in both plasma and 24-hr urine in KO mice (in urine: KO: 956 ± 91 pg/ml, WT: 618 ± 46pg/ml, p = 0.004; in plasma: KO: 2505 ± 596pg/ml, n=6, WT: 1168 ± 98 pg/ml, p = 0.04). Paradoxically, cardiovagal baroreflex sensitivity was higher in the KO mice (KO: 3.2 ± 0.7 ms/mmHg, n=7, WT: 1.4 ± 0.3 ms/mmHg, n=7, p=0.03). Thoracic aortas were collected from both groups to measure vessel stiffness. The diameter at 125 mmHg of the aorta was significantly smaller in CGRP KO mice than in WT (321±30μm, vs. 422±82μm, p<0.01). Therefore, we hypothesize that although CGRP may have a limited contribution to physiological cardiovascular regulation, it may play a significant role in modulating the vagal tone and the structure properties of blood vessels.

RESEARCH OF AEROSOL COMPOSITION IN THE AIR OF THE WORKING AREA AT DIFFERENT STAGES OF COPPER PROCESSING

2021 ◽  
Author(s):  
V.O. Ruzakov ◽  
Keyword(s):  
Raw Materials ◽  
Common Factor ◽  
Quantitative Composition ◽  
Production Environment ◽  
Aerosol Composition ◽  
Qualitative And Quantitative ◽  
Significant Difference ◽  
Quantitative Characteristics ◽  
Number Of Particles ◽  
Qualitative And Quantitative Characteristics

Abstract: Nanoparticles are a common factor in the production environment of existing technologies. In pyrometallurgical processes, the formation of nanoparticles occurs, which are released in the form of an aerosol into the air of the working area. The purpose of this work was to study the qualitative and quantitative characteristics of aerosols in the air of the working area arising from various technological processes of copper processing and to determine the most acceptable methods for practical application of sampling and instrumental research. In this work, using electron microscopy, the qualitative and quantitative composition of aerosols was studied at three technological stages of copper processing. A significant difference in the dispersed composition of aerosols was revealed depending on the technological process of the used raw materials and materials. It was found that the largest number of particles in the volume of condensation aerosol of the pyrometallurgical limit of copper is represented by particles of the nanometer range.

Characteristics of antidromically identified oculomotor internuclear neurons during vergence and versional eye movements

1994 ◽  
Vol 71 (3) ◽  
pp. 1111-1127 ◽  
Author(s):  
R. A. Clendaniel ◽  
L. E. Mays
Keyword(s):  
Eye Movements ◽  
Medial Rectus ◽  
Oculomotor Nucleus ◽  
Abducens Nucleus ◽  
Unit Recording ◽  
Antidromic Activation ◽  
Reversible Inactivation ◽  
Lidocaine Injection ◽  
Lidocaine Hcl ◽  
Tonic Pattern

1. Previous studies have shown that midbrain near response cells that increase their activity during convergent eye movements project to medial rectus motoneurons, which also increase their activity during convergence. Most neurons in the abducens nucleus decrease their firing rate during convergence, and the source of this vergence signal is unknown. Oculomotor internuclear neurons (OINs) in monkeys project primarily from the medial rectus subdivisions of the oculomotor nucleus to the contralateral abducens nucleus, although there is a smaller ipsilateral projection as well. Because of these anatomic connections, it has been suggested that the OIN input may be responsible for the vergence signal seen on abducens neurons. The behavior of the OINs during eye movements and their synaptic drive are not known. Thus the goal of this study is to determine the behavior of these neurons during conjugate and disjunctive eye movements and to determine if these neurons have an excitatory or inhibitory drive on the abducens neurons. 2. Single-unit recording studies in alert rhesus monkeys were used to characterize the behavior of OINs. Eighteen OINs were identified by antidromic activation and collision testing. The recorded OINs displayed a burst-tonic pattern of activity during adducting saccades, and the majority of these cells displayed an increase in tonic activity with convergent eye movements. 3. Identified OINs were compared with a large sample of non-activated and untested horizontal burst-tonic cells in the medial rectus subdivisions of the oculomotor nucleus. The results indicate that the OINs behave similarly to medial rectus motoneurons during vergence and versional eye movements. None of the OINs displayed vertical eye position sensitivity. 4. Microstimulation of the oculomotor nucleus where both the OINs and medial rectus motoneurons were located resulted in a large adducting twitch of the ipsilateral eye and a smaller abducting twitch of the contralateral eye. The latter effect was presumed to be the result of OIN innervation of the contralateral abducens nucleus. This result suggests that the crossed OIN pathway is predominately, if not entirely, excitatory. 5. Injection of 10% lidocaine HCl into the medial rectus subdivision of the oculomotor nucleus caused a reversible inactivation of the medial rectus motoneurons and OINs. As expected, the inactivation of medial rectus motoneurons resulted in an exophoria and weakness of adduction for the eye ipsilateral to the lidocaine injection. In addition, the lidocaine injection resulted in hypometric and slowed abducting saccades in the eye contralateral to the injection site. This result also suggest that the crossed OIN pathway is excitatory.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Perception and Characterization of Posed Smile: A Photographic Study

2020 ◽  
pp. 030157422096341
Author(s):  
Sukhpal Kaur ◽  
Sanjeev Soni ◽  
Anil Prashar ◽  
and Rajdeep Kaur
Keyword(s):  
Visual Analog Scale ◽  
Digital Camera ◽  
Analog Scale ◽  
Male And Female ◽  
Maxillary Tooth ◽  
Significant Difference ◽  
Smile Esthetics ◽  
Relationship Of ◽  
Buccal Corridor

Aims of the Study: The aims of the study are: (a) to compare the perceptions of dental specialists and laypeople regarding smile esthetics; (b) to compare male and female smile parameters; (c) to find influence of smile parameters on esthetics of smile. Materials and Methods: The study was conducted on 60 subjects (30 males and 30 females) of age 18 to 25 years. Frontal posed photographs of all subjects were taken using a digital camera and rated on a visual analog scale by 10 dental specialists and 10 laypersons. Measurements made on photographs were used to analyze various parameters of smile, such as buccal corridor space, smile arc, modified smile index, anterior height of smile, most posterior maxillary tooth visible, and midline relationship of central incisors to philtrum. Results: Visual analog scale values showed that 6 photographs were rated as very good (3 males, 3 females), 29 as good (11 males, 18 females), 21 as average (13 males, 8 females), and 4 photographs were rated as bad (3 males, 1 female). A high correlation was observed between ratings of dental specialists and layperson’s ratings for both male and female smiles. Most of the subjects had non-consonant smile arc, and a high correlation was found between buccal corridor space on right and left sides in both males and females. Most of the male and female smiles had an average anterior height of smile; permanent maxillary first molar was the last tooth visible during smile (73.3% females, 66.7 males); and 55% subjects had coincident midline relationship of central incisors to philtrum. Conclusion: There was no significant difference in perception of dental specialists and laypersons regarding esthetics of smile. Smile arc and anterior height of smile influenced the esthetics of smile. No significant difference was found between male and female smile parameters except modified smile index.

Multimodal imaging of amelanotic choroidal melanoma

2020 ◽  
pp. 112067212093618
Author(s):  
Luisa Pierro ◽  
Alessandro Arrigo ◽  
Emanuela Aragona ◽  
Francesco Bandello
Keyword(s):  
Optical Coherence Tomography ◽  
Blood Vessels ◽  
Malignant Tumor ◽  
Multimodal Imaging ◽  
Optical Coherence Tomography Angiography ◽  
Complex Structure ◽  
Choroidal Melanoma ◽  
Relevant Information ◽  
Vascular Network ◽  
Imaging Features

Amelanotic choroidal melanoma (ACM) is an extremely rare malignant tumor affecting the uvea. Because of the complex structure characterizing this kind of lesions, its morphologic features are partially understood, especially if looking to its vascular network. In this paper, we described in details the multimodal imaging features of ACM. Moreover, we disclosed new insights about different orders of blood vessels characterizing this tumor. Despite the entire vascular network is partially detectable by conventional dye-based angiography, it was reconstructed in its entirety by means of optical coherence tomography angiography. In conclusion, multimodal imaging represents a feasible and useful set of tools, able to describe in deep ACM features and its vascular network organization, and to provide clinically relevant information for ACM management.

Discharge patterns and recruitment order of identified motoneurons and internuclear neurons in the monkey abducens nucleus

1988 ◽  
Vol 60 (6) ◽  
pp. 1874-1895 ◽  
Author(s):  
A. F. Fuchs ◽  
C. A. Scudder ◽  
C. R. Kaneko
Keyword(s):  
Firing Rate ◽  
Smooth Pursuit ◽  
Action Potentials ◽  
Medial Rectus ◽  
Eye Position ◽  
Oculomotor Nucleus ◽  
Abducens Nucleus ◽  
Position Sensitivity ◽  
Discharge Patterns ◽  
Eye Velocity

1. Single neurons in the abducens nucleus were recorded extracellularly in alert rhesus macaques trained to make a variety of eye movements. An abducens neurons was identified as a motoneuron (MN) if its action potentials triggered an averaged EMG potential in the lateral rectus muscle. Abducens internuclear neurons (INNs) that project to the oculomotor nucleus were identified by collision block of spontaneous with antidromic action potentials evoked with a stimulating electrode placed in the medial rectus subdivision of the contralateral oculomotor nucleus. 2. All abducens MNs and INNs had qualitatively similar discharge patterns consisting of a burst of spikes for lateral saccades and a steady firing whose rate increased with lateral eye position in excess of a certain threshold. 3. For both MNs and INNs the firing rates associated with different, constant eye positions could be described accurately by a straight line with slope, K (the eye position sensitivity in spikes.s-1.deg-1), and intercept, T (the eye position threshold for steady firing). For different MNs, K increased as T varied from more medial to more lateral values. In contrast, the majority of INNs already were active for values of T more medial than 20 degrees and showed little evidence of recruitment according to K. 4. During horizontal sinusoidal smooth-pursuit eye movements, both MNs and INNs exhibited a sinusoidal modulation in firing rate whose peak preceded eye position. From these firing rate patterns, the component of firing rate related to eye velocity, R (the eye velocity sensitivity in spikes.s-1.deg-1.s-1), was determined. The R for INNs was, on average, 78% larger than that for MNs. Furthermore, R increased with T for MNs, whereas INNs showed no evidence of recruitment according to R. If, as in the cat, the INNs of monkeys provide the major input to medial rectus MNs and if simian medial rectus MNs behave like our abducens MNs, then recruitment order, which is absent in INNs, must be established at the MN pool itself. 5. Unexpectedly, the R of MNs decreased with the frequency of the smooth-pursuit movement. Furthermore, the eye position sensitivity, K, obtained during steady fixations was usually less than that determined during smooth pursuit. Therefore, conclusions about the roles of MNs and premotor neurons based on how their R and K values differ must be viewed with caution if the data have been obtained under different tracking conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Measuring Vegetation Phenology with Near-Surface Remote Sensing in a Temperate Deciduous Forest: Effects of Sensor Type and Deployment

2019 ◽  
Vol 11 (9) ◽  
pp. 1063 ◽  
Author(s):  
Fan Liu ◽  
Xingchang Wang ◽  
Chuankuan Wang
Keyword(s):  
Remote Sensing ◽  
Inclination Angle ◽  
Deciduous Forest ◽  
Digital Camera ◽  
In Situ Monitoring ◽  
Temperate Deciduous Forest ◽  
Near Surface ◽  
The North ◽  
Significant Difference ◽  
Temperate Deciduous

Near-surface remote sensing is an effective tool for in situ monitoring of canopy phenology, but the uncertainties involved in sensor-types and their deployments are rarely explored. We comprehensively compared three types of sensor (i.e., digital camera, spectroradiometer, and routine radiometer) at different inclination- and azimuth-angles in monitoring canopy phenology of a temperate deciduous forest in Northeast China for three years. The results showed that the greater contribution of understory advanced the middle of spring (MOS) for large inclination-angle of camera and spectroradiometer. The length of growing season estimated by camera from the east direction extended 11 d than that from the north direction in 2015 due to the spatial heterogeneity, but there was no significant difference in 2016 and 2018.The difference infield of view of sensors caused the MOS and the middle of fall, estimated by camera, to lag a week behind those by spectroradiometer and routine radiometer. Overall, the effect of azimuth-angle was greater than that of inclination-angle or sensor-type. Our assessments of the sensor types and their deployments are critical for the long-term accurate monitoring of phenology at the site scale and the regional/global-integration of canopy phenology data.

scholarly journals Interaction of Anabolic Androgenic Steroids and Induced Tooth Movement in Rats

2017 ◽  
Vol 28 (4) ◽  
pp. 504-510
Author(s):  
Lilian Mary Karakida ◽  
Cristiano Miranda de Araujo ◽  
Aline Cristina Batista Rodrigues Johann ◽  
Elisa Souza Camargo ◽  
Orlando Motohiro Tanaka ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Periodontal Ligament ◽  
Tooth Movement ◽  
Biological Effects ◽  
Anabolic Androgenic Steroids ◽  
Control Group ◽  
Tartrate Resistant Acid Phosphatase ◽  
Significant Difference ◽  
Androgenic Steroids ◽  
Orthodontic Devices

Abstract This study evaluated the interaction between tooth movement and two anabolic androgenic steroids (AAS), Deposteron® and Nebido®. One hundred Wistar rats were divided into 3 groups: control (C) n=30, Nebido experimental (N) n=35 and Deposteron experimental (D) n=35. The control group was subdivided into 6 subgroups: 1, 2, 3, 5, 7 and 14. The experimental groups were subdivided into 7 subgroups: 0, 1, 2, 3, 5, 7 and 14, which corresponded to the day of animal’s euthanasia after applying orthodontic force. Orthodontic devices were used to induce tooth movement using 50 cN of reciprocal force between the maxillary right first molar and the maxillary incisors. After euthanasia, the tissues were processed and stained with hematoxylin and eosin (HE) and tartrate-resistant acid phosphatase (TRAP). Osteoclasts, Howship’s lacunae and blood vessels were quantified. Groups N and D showed acceleration in the reorganization of the periodontal ligament compared to group C. The peak of the histological events occurred in group C on day 5 and in groups N and D on day 3 after installation of the orthodontic device. There was a statistically significant difference in the number of osteoclasts (p<0.05) between groups N3 and C3, and between groups N3 and D3. Supra-physiological doses of the AAS Nebido® and Deposteron® altered the number of osteoclasts, Howship’s lacunae and blood vessels, accelerating the reorganization of the periodontal ligament, resulting in accelerated biological effects from the induced tooth movement in rats.

Vertical eye movement-related secondary vestibular neurons ascending in medial longitudinal fasciculus in cat. II. Direct connections with extraocular motoneurons

1990 ◽  
Vol 63 (4) ◽  
pp. 918-935 ◽  
Author(s):  
Y. Iwamoto ◽  
T. Kitama ◽  
K. Yoshida
Keyword(s):  
Rectus Muscle ◽  
Medial Longitudinal Fasciculus ◽  
Field Potentials ◽  
Oculomotor Nucleus ◽  
Inferior Rectus ◽  
Interstitial Nucleus Of Cajal ◽  
Excitatory Connection ◽  
Superior Rectus ◽  
Spike Triggered Averaging ◽  
Trochlear Nucleus

1. The preceding study in the alert cat has shown that many secondary vestibular axons that ascend in the medial longitudinal fasciculus (MLF) increase their firing rate in proportion to downward eye position. In the present study, projection and termination of these downward-position-vestibular (DPV) neurons within extraocular motoneuron pools were studied electrophysiologically by spike-triggered averaging techniques and morphologically be reconstructing their axonal trajectory after intra-axonal injection of horseradish peroxidase (HRP). 2. Extracellular field potentials recorded within the trochlear nucleus and/or the inferior rectus subdivision of the oculomotor nucleus were averaged by the use of spike potentials of single DPV neurons as triggers. All the crossed-DPV axons tested induced negative unitary field potentials in the trochlear nucleus (n = 9) and in the inferior rectus subdivision of the oculomotor nucleus (n = 5), suggesting that they made monosynaptic excitatory connection with motoneurons in these nuclei. The four crossed-DPV axons tested in the two motoneuron pools induced unitary field potentials in both. The majority of crossed-DPV axons terminated in these nuclei were directly activated from the caudal MLF, indicating that they had descending collaterals projecting to the spinal cord as well. The uncrossed-DPV axons did not induce such unitary field potentials either in the trochlear nucleus (n = 4) or in the inferior rectus subdivision (n = 3). 3. All the uncrossed-DPV axons examined (n = 14) induced positive unitary field potentials in the superior rectus subdivision of the oculomotor nucleus, suggesting that they made monosynaptic inhibitory connections with motoneurons innervating the superior rectus muscle. These uncrossed-DPV axons displayed regular firing patterns and were not activated from the caudal MLF. None of the crossed-DPV axons tested (n = 4) induced unitary field potentials in the superior rectus subdivision. 4. Five crossed-DPV axons were injected with HRP. All these axons ascended in the MLF contralateral to their soma, gave off many collaterals to the trochlear nucleus, and projected more rostrally. For three well-stained axons, numerous terminal branches were also found in the rostroventral part of the contralateral oculomotor nucleus, the area corresponding to the inferior rectus subdivision. Some collaterals in the oculomotor nucleus recrossed the midline to terminate in the medial part of the ipsilateral oculomotor nucleus. Other terminations were observed in the interstitial nucleus of Cajal and in the periaqueductal gray adjacent to the oculomotor nucleus. The crossed axons injected included both regular and irregular types, and three of the four examined were activated from the caudal MLF.(ABSTRACT TRUNCATED AT 400 WORDS)

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