scholarly journals Dynamic elongation of the vertebral artery during an in vitro whiplash simulation

1997 ◽  
Vol 6 (4) ◽  
pp. 286-289 ◽  
Author(s):  
K. Nibu ◽  
J. Cholewicki ◽  
M. M. Panjabi ◽  
L. B. Babat ◽  
J. N. Grauer ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Dynamic Elongation

In Vivo Retrieval of a Trapped Merci Embolectomy Device: Technical Case Report

2010 ◽  
Vol 67 (3) ◽  
pp. onsE304-onsE304 ◽  
Author(s):  
Ajeet Gordhan ◽  
John Soliman
Keyword(s):  
Vertebral Artery ◽  
Conformational Changes ◽  
Basilar Artery ◽  
Technical Note ◽  
Vessel Injury ◽  
Artery Segment ◽  
In Vitro Assessment ◽  
Artery Flow

Abstract BACKGROUND AND IMPORTANCE: This technical note describes a complication related to the use of the Merci embolectomy device not previously reported. The device can induce critical flow limitation within an accessed vessel because of a combination of vasospasm and anatomic conformational changes. Furthermore, this can limit the safe removal of the device from intracranial vasculature. We present a novel rescue technique that can be used to safely retrieve the entrapped Merci device without inciting localized vessel injury. CLINICAL PRESENTATION: A 51-year-old male with embolic occlusion of the distal basilar artery and dissection-related occlusion of the left cervical vertebral underwent mechanical thrombolysis. Flow-limiting vasospasm and/or anatomic conformational changes/ telescoping of the intracranial right vertebral artery segment was induced during deployment with subsequent entrapment of the device. Reclamation of the entrapped device was performed by initially removing the Merci microcatheter. The entrapped and fixated device was then resheathed into a 4F slip catheter within the intracranial vertebral artery. The Merci device and the slip catheter were then removed. Right vertebral and proximal basilar artery flow was reestablished after removal of the Merci device. Successful clot extraction was thereafter performed using a microsnare. CONCLUSION: In vitro assessment of the device has demonstrated its propensity to induce vasospasm. In vivo entrapment of the device has not been previously reported. Successful retrieval can be achieved if the Merci device becomes entrapped and fixated. This may be an important consideration as increased utilization of the device occurs.

scholarly journals Early reappearance of disappeared ruptured small aneurysm with concomitant vertebral artery dissection

2018 ◽  
Vol 24 (6) ◽  
pp. 639-642 ◽  
Author(s):  
Eugen Enesi ◽  
Arben Rroji ◽  
Fatmir Bilaj ◽  
Eni Reka ◽  
Adrian Ndroqi ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Posterior Inferior Cerebellar Artery ◽  
Vertebral Artery Dissection ◽  
Artery Aneurysm ◽  
Artery Dissection ◽  
Vitro Fertilization ◽  
Ruptured Intracranial Aneurysm ◽  
Frequent Event

Thrombosis of a previously ruptured intracranial aneurysm is a frequent event and it most commonly occurs in large or giant aneurysms. We present a dynamic short-term follow-up and management of thrombosis in a ruptured small posterior inferior cerebellar artery aneurysm with concomitant vertebral artery dissection (VAD). Clinical and radiological follow-up findings and reviewed literature on thrombosis of small ruptured aneurysms are the focus of this presentation. Early reappearance of a disappeared ruptured small cerebral aneurysm with a concomitant VAD may be attributed to the controlled ovarian hyperstimulation phase of in vitro fertilization and prolonged use of oral contraceptive pills.

scholarly journals Optimization technique for stenting of ostial vertebral artery stenosis

2020 ◽  
Vol 34 (4) ◽  
pp. 34-44
Author(s):  
Yu.V. Cherednychenko ◽  
A.Yu. Miroshnychenko ◽  
M.O. Zorin ◽  
L.A. Dzyak ◽  
O.S. Tsurkalenko
Keyword(s):  
Vertebral Artery ◽  
Postoperative Period ◽  
Optimization Technique ◽  
Carotid Stenting ◽  
Early Postoperative Period ◽  
Long Term Results ◽  
In Vitro Tests ◽  
Complex Method ◽  
Vertebral Arteries

Objective ‒ to develop a technique for endovascular treatment of symptomatic ostial stenosis of the vertebral arteries, which allows to minimize risks of delayed stent breakage and restenosis. Materials and methods. This is analysis of prospectively collected data from patients presenting from 2016 to 2019 in the endovascular center of the Dnepropetrovsk Regional Clinical Hospital named after I.I. Mechnikov. One hundred four stents were placed in 99 patients using the author’s complex method, which is based on our modification of Szabo technique. The principles of the method were developed based on a literature review and in vitro tests using 7 silicone models of the initial segments of the subclavian and vertebral arteries with different angles of divergence of the vertebral arteries (30, 45, 60, 90, 120, 135, 150°) and 9 balloon mounted drug-eluting stents with open-cell design Resolute (Medtronic).Results. There were no cases of displacement of the stent proximally or distally during implantation. In all cases, stents were implanted in the affected segment exactly and did not prolapse more than 1 mm beyond the ostium of the vertebral artery into the subclavian artery. There were no «clinical» ischemic complications in the early postoperative period. In 5 cases, isolated subclinical ischemic lessions in the carotid circulation were revealed during one-session stenting of ostial stenosis of the vertebral arteries and carotid stenting. In the posterior circulation, ischemic lessions on MRI in the early postoperative period were not detected in any observations.Conclusions. Developed complex stenting method based on our modification of Szabo technique allows us to achieve optimal long-term results of stenting of symptomatic ostial stenosis of the vertebral arteries.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Immunoenzymatic demonstration of the simultaneous presence of transferrin, hemopexin and albumin in a same hepatocyte and their ultrastructural localization

1978 ◽  
Vol 36 (2) ◽  
pp. 88-89
Author(s):  
M. Kraemer ◽  
J. Foucrier ◽  
J. Vassy ◽  
M.T. Chalumeau
Keyword(s):  
Plasma Proteins ◽  
Rat Hepatocytes ◽  
Ultrastructural Localization ◽  
Carrier Proteins ◽  
Normal Cells ◽  
Adult Rat ◽  
Adult Rat Hepatocytes ◽  
Monospecific Antisera ◽  
Different Levels

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

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