scholarly journals Distraction Osteogenesis in the Combined and Sequential Use of Transosseous and Intramedullary Osteosynthesis: Experimental Study

2021 ◽  
Vol 27 (1) ◽  
pp. 19-36
Author(s):  
E. A. Shchepkina ◽  
I. V. Lebedkov ◽  
G. I. Netylko ◽  
L. N. Solomin ◽  
L. O. Anisimova ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Bone Formation ◽  
External Fixation ◽  
Experimental Studies ◽  
Total Duration ◽  
Periosteal Bone Formation ◽  
Morphological Studies ◽  
Ilizarov Apparatus ◽  
Negative Effect ◽  
Density Values

Background. The methods of “lengthening over the nail” (LON) and the sequential use of the external fixation and nailing in the option “lengthening and then the nail” (LATN) are characterized by ignoring non-observance of the formulated by G.A. Ilizarov is the most important condition for optimizing the osteogenesis process, namely, the preservation of medullary blood supply and osteogenic bone marrow tissue. At the same time, in clinical practice, there was no negative effect of the intramedullary nail on the formation of the regenerate. In experimental studies, the activation of periosteal bone formation during LON is noted. But the active periosteal bone formation detected in clinical practice with a sequential technique has not been confirmed by experimental studies.The aim of the study was to compare the organotypical rebuilding of the distraction regenerate during tibial lengthening in rabbits according to Ilizarov, over the intramedullary fixator and with the sequential use of the external fixation and nailing.Materials and Methods. The study was carried out on 54 mature rabbits of the Soviet Chinchilla breed, which were divided into 3 groups of 18 animals. In Gr-1 (control), the tibia was lengthened by 1 cm in a mini-Ilizarov apparatus at a rate of 1 mm per day for 4 sessions step. In Gr-2, the LATN technique was modeled. After the end of lengthening, an intramedullary fixator was implanted installed, the apparatus with the presence of wires only in the base supports was kept as an imitation of blocking the intramedullary fixator. In Gr-3, lengthening was performed over the intramedullary fixator; at the end of lengthening, the wires were left only in the base supports. The fixation period was is 30 days. The total duration of the experiment is 45 days. On the 10th, 15th, 20th, 30th, 45th day X-ray, CT and morphological studies were performed during the experiment.Results. In the experimental groups, a more pronounced periosteal bone formation in the area of regenerates was noted, while in Gr-3 (LON) cortical plates were formed mainly from the periosteal component, and in Gr-2 (LATN) wide cortical plates were formed from the intermediate and periosteal areas. In this group, the maximum densitometric density values are noted. Endosteal bone formation was preserved in all groups.Conclusion. The LON and LATN techniques, when compared with the classical Ilizarov lengthening, do not demonstrate any deficiency in the organotypical rebuilding of the bone tissue of the regenerates. All zones of bone formation are present, including endosteal, with intense periosteal bone formation. The most powerful bone structures are formed with the sequential use of the external fixation and nailing (LATN) in the form of the formation of wide cortical plates due to the intermediate and periosteal zones of the regenerate.

METHODS FOR SIMULATION OF ACUTE BRAIN ISCHEMIA: PATHOPHYSIOLOGICAL SUBSTANTIATION OF SELECTION AND IMPORTANCE FOR CLINICAL PRACTICE

2019 ◽  
pp. 142-152
Author(s):  
Б.И. Гельцер ◽  
Э.В. Слабенко ◽  
Ю.В. Заяц ◽  
В.Н. Котельников
Keyword(s):  
Clinical Practice ◽  
Experimental Studies ◽  
Cerebrovascular Diseases ◽  
Experimental Models ◽  
Pathological Process ◽  
Ischemic Brain ◽  
Actual Clinical Practice ◽  
Acute Cerebral Ischemia ◽  
Different Types ◽  
Acute Brain Ischemia

Одним из основных требований к разработке экспериментальных моделей цереброваскулярных заболеваний является их максимальная приближенность к реальной клинической практике. В работе систематизированы данные по основным методам моделирования острой ишемии головного мозга (ОИГМ), представлена их классификация, анализируются данные о преимуществах и недостатках той или иной модели. Обсуждаются результаты экспериментальных исследований по изучению патогенеза ОИГМ с использованием различных моделей (полной и неполной глобальной, локальной и мультифокальной ишемии) и способов их реализации (перевязка артерий, клипирование, коагуляция, эмболизация и др.). Особое внимание уделяется «стабильности» последствий острого нарушения мозгового кровообращения: необратимых ишемических повреждений головного мозга или обратимых с реперфузией заданной продолжительности. Отмечается, что важное значение в этих исследованиях должно принадлежать современным методам прижизненной визуализации очагов острого ишемического повреждения, что позволяет оценивать динамику патологического процесса. Предлагаемый метод отвечает требованиям гуманного обращения с животными. Подчеркивается, что выбор релевантной модели ОИГМ определяется задачами предстоящего исследования и технологическими ресурсами научной лаборатории. Development of experimental models for acute forms of cerebrovascular diseases is essential for implementation of methods for their prevention and treatment. One of the principal requirements to such models is their maximum approximation to actual clinical practice. This review systematized major models of acute cerebral ischemia (ACI), their classification, and presented information about their advantages and shortcomings. Also, the review presented results of experimental studies on pathophysiological mechanisms of different types of modeled ACI (complete and incomplete global, local, and multifocal ischemia) and methods for creating these models (arterial ligation, clipping, coagulation, embolization, etc.). Particular attention was paid to “stability” of the consequences of acutely impaired cerebral circulation - an irreversible ischemic brain injury or a reversible injury with reperfusion of a given duration. The authors emphasized that in such studies, a special significance should be given to intravital imaging of acute ischemic damage foci using modern methods, which allow assessing the dynamics of the pathological process and meet the requirements to humane treatment of animals. The choice of a relevant ACI model is determined by objectives of the planned study and the technological resources available at the research laboratory.

scholarly journals Pharmacological inhibition of TAK1, with the selective inhibitor takinib, alleviates clinical manifestation of arthritis in CIA mice

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Scott A. Scarneo ◽  
Liesl S. Eibschutz ◽  
Phillip J. Bendele ◽  
Kelly W. Yang ◽  
Juliane Totzke ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Bone Resorption ◽  
Bone Formation ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Inflammatory Diseases ◽  
Cartilage Damage ◽  
Cytokine Signaling ◽  
Periosteal Bone Formation ◽  
Bone Width

Abstract Objectives To examine the ability of takinib, a selective transforming growth factor beta-activated kinase 1 (TAK1) inhibitor, to reduce the severity of murine type II collagen-induced arthritis (CIA), and to affect function of synovial cells. Methods Following the induction of CIA, mice were treated daily with takinib (50 mg/kg) and clinical scores assessed. Thirty-six days post-CIA induction, histology was performed on various joints of treated and vehicle-treated animals. Inflammation, pannus, cartilage damage, bone resorption, and periosteal bone formation were quantified. Furthermore, pharmacokinetics of takinib were evaluated by LC-MS in various tissues. Rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) cells were cultured with 10 μM takinib and cytokine secretion analyzed by cytokine/chemokine proteome array. Cytotoxicity of takinib for RA-FLS was measured with 24 to 48 h cultures in the presence or absence of tumor necrosis factor (TNF). Results Here, we show takinib’s ability to reduce the clinical score in the CIA mouse model of rheumatoid arthritis (RA) (p < 0.001). TAK1 inhibition reduced inflammation (p < 0.01), cartilage damage (p < 0.01), pannus, bone resorption, and periosteal bone formation and periosteal bone width in all joints of treated mice compared to vehicle treated. Significant reduction of inflammation (p < 0.004) and cartilage damage (p < 0.004) were observed in the knees of diseased treated animals, with moderate reduction seen in the forepaws and hind paws. Furthermore, the pharmacokinetics of takinib show rapid plasma clearance (t½ = 21 min). In stimulated RA-FLS cells, takinib reduced GROα, G-CSF, and ICAM-1 pro-inflammatory cytokine signaling. Conclusion Our findings support the hypothesis that TAK1 targeted therapy represents a novel therapeutic axis to treat RA and other inflammatory diseases.

scholarly journals Fracture fixation strategy and specific muscle tissue availability of neutrophilic granulocytes following mono- and polytrauma: intramedullary nailing vs. external fixation of femoral fractures

2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Johannes Greven ◽  
Klemens Horst ◽  
Zhi Qiao ◽  
Felix Marius Bläsius ◽  
Ümit Mert ◽  
...  
Keyword(s):  
Clinical Practice ◽  
External Fixation ◽  
Intramedullary Nailing ◽  
Muscle Tissue ◽  
Femur Fracture ◽  
Femoral Fractures ◽  
Pig Model ◽  
Minor Role ◽  
Neutrophil Granulocytes ◽  
Concomitant Injuries

Abstract Background In the stabilization of femoral fractures in mono- and polytrauma, clinical practice has shown better care through intramedullary nailing. However, the reason why this is the case is not fully understood. In addition to concomitant injuries, the immunological aspect is increasingly coming to the fore. Neutrophil granulocytes (PMNL), in particular next to other immunological cell types, seem to be associated with the fracture healing processes. For this reason, the early phase after fracture (up to 72 h after trauma) near the fracture zone in muscle tissue was investigated in a pig model. Material and methods A mono- and polytrauma pig model (sole femur fracture or blunt thoracic trauma, hemorrhagic shock, liver laceration, and femur fracture) was used to demonstrate the immunological situation through muscle biopsies and their analysis by histology and qRT-PCR during a 72 h follow-up phase. Two stabilization methods were used (intramedullary nail vs. external fixator) and compared with a nontraumatized sham group. Results Monotrauma shows higher PMNL numbers in muscle tissue compared with polytrauma (15.52 ± 5.39 mono vs. 8.23 ± 3.36 poly; p = 0.013), regardless of the treatment strategy. In contrast, polytrauma shows a longer lasting invasion of PMNL (24 h vs. 72 h). At 24 h in the case of monotrauma, the fracture treated with external fixation shows more PMNL than the fracture treated with intramedullary nailing (p = 0.026). This difference cannot be determined in polytrauma probably caused by a generalized immune response. Both monotrauma and polytrauma show a delayed PMNL increase in the muscle tissue of the uninjured side. The use of intramedullary nailing in monotrauma resulted in a significant increase in IL-6 (2 h after trauma) and IL-8 (24 and 48 h after trauma) transcription. Conclusion The reduction of PMNL invasion into the nearby muscle tissue of a monotrauma femur fracture stabilized by intramedullary nailing supports the advantages found in everyday clinical practice and therefore underlines the usage of nailing. For the polytrauma situation, the fixation seems to play a minor role, possibly due to a generalized immune reaction.

scholarly journals EXPERIMENTAL STUDIES ON HETEROPLASTIC BONE FORMATION

1920 ◽  
Vol 32 (6) ◽  
pp. 745-766 ◽  
Author(s):  
Goichi Asami ◽  
William Dock
Keyword(s):  
Connective Tissue ◽  
Bone Formation ◽  
Direct Contact ◽  
Endochondral Ossification ◽  
Experimental Studies ◽  
Rabbit Kidney ◽  
Transitional Epithelium ◽  
Ear Cartilage ◽  
Calcium Deposits ◽  
New Formation

1. Bone formation in the rabbit kidney with ligated vessels takes place (a) through the activity of young fibroblasts which accumulate to form a membrane-like structure; (b) subsequently by direct ossification of hyaline connective tissue in continuity with preformed bone; and (c) through erosion of lime placques by granulating tissue and laying down of lamellar bone by cells derived from fibroblasts. 2. Bone formation in the rabbit kidney begins not in direct contact with calcium deposits, but in the loose vascular connective tissue close under the transitional epithelium of the calices. 3. With autotransplanted ear cartilage of the rabbit there is an active new formation of cartilage in the connective tissue which surrounds the transplants, and the bone is formed by the fibroblasts from the perichondrium which erode and invade the calcified areas in this new cartilage. 4. The process of bone formation in the kidney is similar to that found in normal membranous ossification, while with the transplanted ear cartilage the process is identical with endochondral ossification.

Impact of the Limestone Powder on the Properties of Cement Paste and Mortar

2012 ◽  
Vol 174-177 ◽  
pp. 236-240
Author(s):  
Jing Zhang ◽  
Zhu Li
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Experimental Studies ◽  
Water Requirement ◽  
Limestone Powder ◽  
Inert Material ◽  
Normal Concrete ◽  
Significant Negative Effect ◽  
Negative Effect

Experimental studies on the properties of cement paste and mortar with the use of limestone powder were carried out. The results show that the replacement with 10% to 30% limestone powder in cement paste can reduce the water requirement for certain flowability. As an inert material, the use of the limestone powder has significant negative effect on the mechanical properties of mortar. However, strength requirement of normal concrete (mortar) can be reached by reducing the water to cementious material ratio, which makes the use of limestone powder as a replacement of cement possible.

Results of an experimental study of hydrogel drainage containing ranibizumab in antiglaucoma operations

2021 ◽  
pp. 63-67
Author(s):  
I.I. Khusnitdinov ◽  
Keyword(s):  
Experimental Study ◽  
Hyaluronic Acid ◽  
Key Words ◽  
Experimental Research ◽  
Experimental Studies ◽  
Glaucoma Surgery ◽  
Control Group ◽  
Morphological Studies

Purpose. Еxperimental substantiation of the effectiveness of biocompatible biodegradable hydrogels based on hyaluronic acid and chitosan succinate as a carrier of ranibizumab in antiglaucoma operations. Material and methods. Hydrogel drainage (HD) was obtained immediately before surgery. A solution of ranibizumab (0.23 ml) was mixed with a solution of hyaluronic acid dialdehyde (0.5 ml), then a solution of chitosan succinate (0.5 ml) was added. Experimental studies were performed in 12 (12 eyes) healthy rabbits. The first group consisted of 6 eyes – 0.187 ml of ranibizumab per 1 ml of gel. In the control group, HD was used intraoperatively without the addition of ranibizumab (6 eyes). Morphological studies were performed on 7th, 21st, and 42nd days. Results. In experimental studies in vitro and in vivo, it was proved that ranibizumab, administered as a part of 0.1 ml of hydrogel drainage in the antiglaucoma surgery area is released within 3 weeks and suppresses vascularization, scarring of the operating area, and preserves the intrascleral cavity. The optimal concentration of ranibizumab was selected-0.02 ml in 0.1 ml of gel. Conclusion. The safety and effectiveness of the use of hydrogel drainage with ranibizumab based on hyaluronic acid dialdehyde and chitosan succinate in anti-glaucoma operations has been proven. Key words: experimental research, hydrogel drainage, ranibizumab, glaucoma surgery.

EVALUATION OF TOXIOLOGICAL INDICATORS OF MONTHMORRILLONITE CLAY FOR THE PURPOSE OF USING THEM AS ALUMOSILICATE SOBENT AGAINST THE NEGATIVE EFFECT OF MYCOTOXINS ON THE BODY OF ANIMALS AND BIRDS

2021 ◽  
Vol 1 (1) ◽  
pp. 72-78
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Montmorillonite Clay ◽  
Test Substance ◽  
Negative Effects ◽  
Experimental Animals ◽  
Eyelid Edema ◽  
White Rats ◽  
Mucous Membranes ◽  
Negative Effect

The article presents the results of laboratory studies to assess the toxicological parameters of montmorillonite clay from the Pogadaevskoye deposit in the West Kazakhstan region in order to use them as an aluminosilicate sorbent in the composition of feeds that reduce the negative effects of mycotoxins on the body of animals and birds. The relevance of research is associated with the cultivation of healthy and highly productive animals and poultry in order to ensure the food security of the Republic of Kazakhstan.The studies carried out to assess the toxicological parameters of montmorillonite clay in order to use them as an aluminosilicate sorbent in experimental animals (rabbits and white rats) allowed the following results to be obtained: Visual study of the intensity of erythema when exposed to the test substance on the skin of rabbits showed their absence (0 points). The study of the intensity of edema (an increase in the thickness of the skin clutch of rabbits) when exposed to the test substance on the skin of rabbits showed no reaction (0 points). Studies evaluating the irritating effect of the test substances on the mucous membranes of the eyes of rabbits by symptoms of damage showed the absence of hyperemia (0 points). Weak eyelid edema (1 point), the minimum amount of discharge in the corner of the eye (1 point). The results of studies on the classification assessment of the test substance for the severity of the irritant effect on the eyes of rabbits showed that the average total score of the severity of the irritative effect corresponds to 1 point. A comprehensive analysis of the results obtained on the basis of scientific and experimental studies to assess the toxicological indicators of montmorillonite clay from the Pogadaevskoye deposit in relation to irritating effects on the skin and mucous membranes of experimental animals (rabbits) showed their harmlessness.

scholarly journals Mechanisms of Atrial Fibrillation – Reentry, Rotors and Reality

2014 ◽  
Vol 3 (2) ◽  
pp. 90 ◽  
Author(s):  
Jonathan W Waks ◽  
Mark E Josephson ◽  
◽  
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Practice ◽  
Catheter Ablation ◽  
20Th Century ◽  
Experimental Studies ◽  
Therapeutic Targets ◽  
Spiral Waves ◽  
Historical Understanding ◽  
New Strategies ◽  
Complex Fractionated Atrial Electrograms

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice, yet our understanding of the mechanisms that initiate and sustain this arrhythmia remains quite poor. Over the last 50 years, various mechanisms of AF have been proposed, yet none has been consistently observed in both experimental studies and in humans. Recently, there has been increasing interest in understanding how spiral waves or rotors – which are specific, organised forms of functional reentry – sustain human AF and how they might be therapeutic targets for catheter-based ablation. The following review describes the historical understanding of reentry and AF mechanisms from earlier in the 20th century, advances in our understanding of mechanisms that are able to sustain AF with a focus on rotors and complex fractionated atrial electrograms (CFAEs), and how the study of AF mechanisms has resulted in new strategies for treating AF with novel forms of catheter ablation.

A NEW GEARBOX FAULT DIAGNOSIS METHOD BASED ON LUCY–RICHARDSON DECONVOLUTION

2015 ◽  
Vol 39 (3) ◽  
pp. 593-603
Author(s):  
Xinghui Zhang ◽  
Jianshe Kang ◽  
Hongzhi Teng ◽  
Jianmin Zhao
Keyword(s):  
Fault Diagnosis ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Rolling Element Bearings ◽  
Envelope Analysis ◽  
Rolling Element ◽  
Negative Effect ◽  
Diagnosis Method ◽  
Good Identification ◽  
Incipient Fault Diagnosis

Gear and bearing faults are the main causes of gearbox failure. Till now, incipient fault diagnosis of these two components has been a problem and needs further research. In this context, it is found that Lucy–Richardson deconvolution (LRD) proved to be an excellent tool to enhance fault diagnosis in rolling element bearings and gears. LRD’s good identification capabilities of fault frequencies are presented which outperform envelope analysis. This is very critical for early fault diagnosis. The case studies were carried out to evaluate the effectiveness of the proposed method. The results of simulated and experimental studies show that LRD is efficient in alleviating the negative effect of noise and transmission path. The results of simulation and experimental tests demonstrated outperformance of LRD compared to classical envelope analysis for fault diagnosis in rolling element bearings and gears, especially when it is applied to the processing of signals with strong background noise.

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