scholarly journals Comparative characteristics of the hemostasis system state during hypothermic and early reactive periods of general freeze injury in rats

2017 ◽  
Vol 98 (6) ◽  
pp. 989-993
Author(s):  
N A Lycheva ◽  
I I Shakhmatov ◽  
S V Moskalenko
Keyword(s):  
Cold Exposure ◽  
Control Group ◽  
System State ◽  
Delayed Effect ◽  
Profound Hypothermia ◽  
Hemostasis System ◽  
Hemostatic System ◽  
Male Wistar Rats ◽  
Aggregation Activity ◽  
Experimental Group

Aim. To study the hemostasis system state in rats during hypothermic and post-hypothermic periods. Methods. Male Wistar rats (53 individuals) were used in the study. The animals from the experimental group underwent single immersion cooling in water at a temperature of 5 °C until profound hypothermia was reached, the control group of the animals was placed in water at a temperature of 30 °C. From the animals of the first group, blood was taken immediately after reaching profound hypothermia and from the second group - 24 hours after cooling was stopped. Results. Comparative analysis of the results showed that immediately after the end of a single cold exposure, significant increase in platelet aggregation activity occured, as well as appearance of thrombinemia markers in the bloodstream and inhibition of fibrinolytic system activity. 24 hours after the experimental exposure, these parameters returned to the initial values. When assessing the activity of external and internal ways of coagulation immediately after the termination of cooling, development of hypocoagulation was established, both with routine tests and from thromboelastography. After 24-hour period, hypocoagulation, recorded immediately after reaching the sought rectal temperature, persisted. Thus, after the end of a 24-hour period after cold exposure termination, most of the parameters of hemostatic system that had deviated immediately after the end of the experiment, returned to the normal level. The delayed effect of hypothermia in such cold exposure regimen manifested only by hypocoagulative shift at the initial stages of coagulation. Conclusion. Signs of abnormal hemostasiological blood properties, recorded immediately after the cooling termination, disappear within 24 hours, and only hypocoagulation persists in the blood.

scholarly journals The use of Portland cement in the repair of mandibular fractures in rats

2011 ◽  
Vol 26 (6) ◽  
pp. 426-432
Author(s):  
Reginaldo Inojosa Carneiro Campello ◽  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Gerhilde Callou Sampaio ◽  
Antonio Rolim ◽  
Gabriela Granja Porto
Keyword(s):  
Portland Cement ◽  
Bone Healing ◽  
Soft Tissues ◽  
Lethal Dose ◽  
Mandibular Fracture ◽  
Point Of View ◽  
Control Group ◽  
Mandibular Fractures ◽  
Male Wistar Rats ◽  
Experimental Group

PURPOSE: To evaluate the bone healing of mandibular fractures following the use of Portland cement. METHODS: Thirty-two male Wistar rats were divided into control and experimental groups. In the control group the rats were submitted to a mandibular fracture, which was reduced, and the soft tissues were sutured. In the experimental group the rats had the mandibular fracture reduced and maintained with the Portland cement. The animals were euthanized 7 and 21 days after surgery by injecting a lethal dose of anesthetic. The following variables were studied: weight of the animals, radiographic images, histopathological features and time of surgery. RESULTS: A weight loss was observed in the specimens of both groups at the different times of evaluation, a greater difference in weight before and after surgery being found in the experimental group, which was statistically significant (p <0.05, p = 0.041). From the histological point of view, with a margin of error (5.0%) the only two significant differences (p <0.05) recorded in the variables were "Material deployed" and "Bone resorption" during the evaluations at 7 and 21 days, respectively. CONCLUSION: The Portland cement served to promote bone healing.

scholarly journals A Subpressor Dose of Angiotensin II Elevates Blood Pressure in a Normotensive Rat Model by Oxidative Stress

2015 ◽  
pp. 153-159 ◽  
Author(s):  
M. M. GOVENDER ◽  
A. NADAR
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Angiotensin Ii ◽  
Mrna Expression ◽  
Rat Model ◽  
Wistar Rat ◽  
Control Group ◽  
Sod Activity ◽  
Male Wistar Rats ◽  
Experimental Group

Oxidative stress is an imbalance between free radicals and antioxidants, and is an important etiological factor in the development of hypertension. Recent experimental evidence suggests that subpressor doses of angiotensin II elevate oxidative stress and blood pressure. We aimed to investigate the oxidative stress related mechanism by which a subpressor dose of angiotensin II induces hypertension in a normotensive rat model. Normotensive male Wistar rats were infused with a subpressor dose of angiotensin II for 28 days. The control group was sham operated and infused with saline only. Plasma angiotensin II and H2O2 levels, whole-blood glutathione peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA expression in the aorta was assessed. Systolic and diastolic blood pressures were elevated in the experimental group. There was no change in angiotensin II levels, but a significant increase in AT-1a mRNA expression was found in the experimental group. mRNA expression of p22phox was increased significantly and Cu/Zn SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels. Angiotensin II manipulates the free radical-antioxidant balance in the vasculature by selectively increasing O2− production and decreasing SOD activity and causes an oxidative stress induced elevation in blood pressure in the Wistar rat.

scholarly journals Morphometric evaluation of condylar cartilage of growing rats in response to mandibular retractive forces

2013 ◽  
Vol 18 (4) ◽  
pp. 113-119 ◽  
Author(s):  
Milena Peixoto Nogueira de Sá ◽  
Jacqueline Nelisis Zanoni ◽  
Carlos Luiz Fernandes de Salles ◽  
Fabrício Dias de Souza ◽  
Uhana Seifert Guimarães Suga ◽  
...  
Keyword(s):  
Functional Class ◽  
Control Group ◽  
Class Iii ◽  
Condylar Cartilage ◽  
Time Intervals ◽  
Undifferentiated Cells ◽  
Male Wistar Rats ◽  
Mandibular Retrusion ◽  
Experimental Group ◽  
Morphometric Evaluation

INTRODUCTION: The mandibular condylar surface is made up of four layers, i.e., an external layer composed of dense connective tissue, followed by a layer of undifferentiated cells, hyaline cartilage and bone. Few studies have demonstrated the behavior of the condylar cartilage when the mandible is positioned posteriorly, as in treatments for correcting functional Class III malocclusion. OBJECTIVE: The aim of this study was to assess the morphologic and histological aspects of rat condyles in response to posterior positioning of the mandible. METHODS: Thirty five-week-old male Wistar rats were selected and randomly divided into two groups: A control group (C) and an experimental group (E) which received devices for inducing mandibular retrusion. The animals were euthanized at time intervals of 7, 21 and 30 days after the experiment had began. For histological analysis, total condylar thickness was measured, including the proliferative, hyaline and hypertrophic layers, as well as each layer separately, totaling 30 measurements for each parameter of each animal. RESULTS: The greatest difference in cartilage thickness was observed in 21 days, although different levels were observed in the other periods. Group E showed an increase of 39.46% in the total layer, reflected by increases in the thickness of the hypertrophic (42.24%), hyaline (46.92%) and proliferative (17.70%) layers. CONCLUSIONS: Posteriorly repositioning the mandible produced a series of histological and morphological responses in the condyle, suggesting condylar and mandibular adaptation in rats.

scholarly journals Functional Changes of Temporomandibular Joint Mechanoreceptors Induced by Reduced Masseter Muscle Activity in Growing Rats

2009 ◽  
Vol 79 (5) ◽  
pp. 978-983 ◽  
Author(s):  
Takayoshi Ishida ◽  
Tadachika Yabushita ◽  
Kunimichi Soma
Keyword(s):  
Temporomandibular Joint ◽  
Muscle Activity ◽  
Masseter Muscle ◽  
Growth Period ◽  
Control Group ◽  
Functional Changes ◽  
Male Wistar Rats ◽  
Masseter Muscles ◽  
Experimental Group ◽  
Indirect Stimulation

Abstract Objective: To determine the influence of masseter muscle activity during growth on the functional characteristics of temporomandibular joint (TMJ) mechanoreceptors. Materials and Methods: Sixty-six 3-week-old male Wistar rats were divided into an experimental group, in which the masseter muscles were bilaterally resected at 3 weeks of age, and a control group. Single-unit activities of the TMJ mechanoreceptors were evoked by indirect stimulation of passive jaw movement. Electrophysiologic recordings of TMJ units were made at 5, 7, and 9 weeks of age. Results: During this period, the firing threshold of the TMJ units was significantly lower and the maximum instantaneous frequency of the TMJ units was significantly higher in the experimental group than in the control group. Conclusion: Reduced masseter activity during the growth period alters the response properties of TMJ mechanoreceptors.

scholarly journals Forced internal desynchrony induces cardiometabolic alterations in adult rats

2019 ◽  
Vol 242 (2) ◽  
pp. 25-36
Author(s):  
Isis Gabrielli Barbieri de Oliveira ◽  
Marcos Divino Ferreira Junior ◽  
Paulo Ricardo Lopes ◽  
Dhiogenes Balsanufo Taveira Campos ◽  
Marcos Luiz Ferreira-Neto ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Metabolic Response ◽  
Hepatic Metabolism ◽  
Control Group ◽  
Dark Cycle ◽  
Adult Rats ◽  
Internal Desynchronization ◽  
Male Wistar Rats ◽  
Experimental Group

Disruptions in circadian rhythms have been associated with several diseases, including cardiovascular and metabolic disorders. Forced internal desynchronization induced by a period of T-cycles of 22 h (T22 protocol) reaches the lower limit of entrainment and dissociates the circadian rhythmicity of the locomotor activity into two components, driven by different outputs from the suprachiasmatic nucleus (SCN). The main goal of this study was to evaluate the cardiovascular and metabolic response in rats submitted to internal desynchronization by T22 protocol. Male Wistar rats were assigned to either a control group subjected to a usual T-cycles of 24 h (12 h–12 h) or an experimental group subjected to the T22 protocol involving a 22-h symmetric light–dark cycle (11 h–11 h). After 8 weeks, rats subjected to the T22 exhibited desynchrony in their locomotor activity. Although plasma glucose and insulin levels were similar in both groups, desynchronized rats demonstrated dyslipidemia, significant hypertrophy of the fasciculate zone of the adrenal gland, low IRB, IRS2, PI3K, AKT, SOD and CAT protein expression and an increased expression of phosphoenolpyruvate carboxykinase in the liver. Furthermore, though they maintained normal baseline heart rates and mean arterial pressure levels, they also presented reduced baroreflex sensitivity. The findings indicate that circadian timing desynchrony following the T22 protocol can induce cardiometabolic disruptions. Early hepatic metabolism dysfunction can trigger other disorders, though additional studies are needed to clarify the causes.

Critical Hematocrit in Intestinal Tissue Oxygenation during Severe Normovolemic Hemodilution

2001 ◽  
Vol 94 (1) ◽  
pp. 152-160 ◽  
Author(s):  
Jasper van Bommel ◽  
Martin Siegemund ◽  
C. Pieter Henny ◽  
Adrianus Trouwborst ◽  
Can Ince
Keyword(s):  
Venous Pressure ◽  
Control Group ◽  
Mesenteric Blood Flow ◽  
Systemic Hemodynamic ◽  
Male Wistar Rats ◽  
Normovolemic Hemodilution ◽  
Baseline Values ◽  
And Control ◽  
Experimental Group ◽  
Microvascular Oxygenation

Background A critical point in oxygen supply for microvascular oxygenation during normovolemic hemodilution has not been identified. The relation between organ microvascular oxygen partial pressure (microPO2) and organ oxygen consumption (VO2) during a decreasing oxygen delivery (DO2) is not well understood. The present study was designed to determine the systemic hematocrit and organ DO2 values below which organ microPO2 and VO2 cannot be preserved by regulatory mechanisms during normovolemic hemodilution. Methods Eighteen male Wistar rats were randomized between an experimental group (n = 12), in which normovolemic hemodilution was performed with pasteurized protein solution (PPS), and a control group (n = 6). Systemic hemodynamic and intestinal oxygenation parameters were monitored. Intestinal microPO2 was measured using the oxygen-dependent quenching of palladium-porphyrin phosphorescence. Results Baseline values in hemodilution and control group were similar. Hemodilution decreased hematocrit to 6.2 +/- 0.8% (mean +/- SD). Constant central venous pressure measurements suggested maintenance of isovolemia. Despite an increasing mesenteric blood flow, intestinal DO2 decreased immediately. Initially, microPO2 was preserved, whereas mesenteric venous PO2 (P(mv)O2) decreased; below a hematocrit of 15%, microPO2 decreased significantly below P(mv)O2. Critical DO2 was 1.5 +/- 0.5 ml x kg(-1) x min(-1) for VO2, and 1.6 +/- 0.5 ml x kg(-1) x min(-1) for microPO2. Critical hematocrit values for VO2 and microPO2 were 15.8 +/- 4.6% and 16.0 +/- 3.5%, respectively. Conclusions Intestinal microPO2 and VO2 were limited by a critical decrease in DO2 and hematocrit at the same time. Beyond these critical points not only shunting of oxygen from the microcirculation could be demonstrated, but also a significant correlation between intestinal microPO2 and VO2.

scholarly journals Tartrazine induces structural and functional aberrations and genotoxic effectsin vivo

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3041 ◽  
Author(s):  
Latifa Khayyat ◽  
Amina Essawy ◽  
Jehan Sorour ◽  
Ahmed Soffar
Keyword(s):  
Comet Assay ◽  
Blood Cells ◽  
White Blood Cells ◽  
Pharmaceutical Products ◽  
Food Additive ◽  
Control Group ◽  
Adverse Health Effects ◽  
Male Wistar Rats ◽  
Liver And Kidney ◽  
Experimental Group

Tartrazine is a synthetic organic azo dye widely used in food and pharmaceutical products. The current study aimed to evaluate the possible adverse effect of this coloring food additive on renal and hepatic structures and functions. Also, the genotoxic potential of tartrazine on white blood cells was investigated using comet assay. Twenty adult male Wistar rats were grouped into two groups of 10 each, control- and tartrazine-treated groups. The control group was administered orally with water alone. The experimental group was administered orally with tartrazine (7.5 mg/kg, b.wt.). Our results showed a marked increase in the levels of ALT, AST, ALP, urea, uric acid, creatinine, MDA and NO, and a decreased level of total antioxidants in the serum of rats dosed with tartrazine compared to controls. On the other hand, administration of tartrazine was associated with severe histopathological and cellular alterations of rat liver and kidney tissues and induced DNA damage in leucocytes as detected by comet assay. Taken together, the results showed that tartrazine intake may lead to adverse health effects.

scholarly journals Morphological and radiological characteristics of experimental bone tissue regeneration

2021 ◽  
pp. 94-104
Author(s):  
E. A. Nadyrov ◽  
V. I. Nikolaev ◽  
S. I. Kirilenko ◽  
V. V. Rozhin ◽  
N. G. Maltseva ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Tissue Regeneration ◽  
Bone Tissue Regeneration ◽  
Control Group ◽  
Experimental Animals ◽  
Male Wistar Rats ◽  
Group A ◽  
Bone Trabeculae ◽  
The Right ◽  
Experimental Group

Objective. To study the dynamics of reparative bone tissue regeneration in experimental animals using a native transplantation autosmix (NTA).Materials and methods. Male Wistar rats weighing 180–200 g and aged 6–7 months were used. Bone tissue defects were modelled using a cutter with a diameter of 2 mm (experimental group). A similar defect of the middle third of the right tibia was formed in the control group animals without flling the defects with bone tissue. The animals were removed from the experiment on days 3, 7, 14, 30 and 60 of the experiment (per 6 animals for each observation period). The indicators of defect occupancy, necrosis, the area of bone trabeculae, the area of granulation tissue were determined in the histological sections. All the indicators were presented as percentage of the tested area. Osteoblasts, osteocytes, and osteoclasts were calculated in absolute values on the tested area.Results. The study has showed a higher rate of bone tissue formation in the bone defects in the experimental animals after autotransplantation of the bone mixture. Bone recovery in the experimental group had a higher rate, which was manifested by faster flling of the bone tissue defect, a low percentage of the necrosis area, a higher area of bone trabeculae, its rapid transformation into lamellar bone tissue.Conclusion. Osteogenesis had practically completed by day 30 of the experiment. At the same time, in the control group it had completed by day 60. The results obtained are a theoretical precondition for further research in the feld of bone autoplasty. Advanced development of surgical and minimally invasive technologies of bone mixture application will increase the effciency of modern reconstructive surgery of bones and joints.

scholarly journals Apoptosis of rats’ cardiomyocytes after chronic energy drinks consumption

2018 ◽  
Vol 31 (1) ◽  
pp. 25-28
Author(s):  
Miroslaw Aleksander Slawinski ◽  
Ewelina Wawryk-Gawda ◽  
Michal Konrad Zarobkiewicz ◽  
Pawel Halczuk ◽  
Barbara Jodlowska-Jedrych
Keyword(s):  
Cell Biology ◽  
Caspase 3 ◽  
P53 Protein ◽  
Energy Drinks ◽  
Control Group ◽  
Rat Cardiomyocytes ◽  
Male Wistar Rats ◽  
Staining Protocol ◽  
The Impact ◽  
Experimental Group

AbstractEnergy drinks (ED) are beverages containing caffeine, taurine, vitamins, herbal extracts, and sugar or sweeteners. They are marketed as capable of improving stamina, athletic performance and concentration, moreover, as serving as a source of energy. Still, there are very few papers describing the impact of ED on cell biology – including cell apoptosis within tissues. Therefore, in our study, we assessed the symptoms of rat cardiomyocytes apoptosis after 8 weeks consumption of ED.For the research, we used male Wistar rats divided into 2 groups (experimental and control). The experimental animals received ED at a dose average of 0.190 ml per g of body weight per day for a period of 8 weeks. The animals of the control group received just water and food without limitation. After 8 weeks, the rats were decapitated; hearts and other organs were collected. After embedding in paraffin blocks, 5μm thick tissue slides were prepared and stained according to standard hematoxylin and eosine (H&E) staining protocol. Additional slides were stained by immunohistochemistry with antibodies directed against either caspaze-3 or p53 protein.Our results showed that the expression of caspase 3 and p53 protein varied depending on the group of rats. The expression of caspase 3 observed in cardiomyocytes was much more intense in the experimental group compared to the control group. Furthermore, the immunoprecipitation of p53 protein was observed more frequently in the cardiomyocytes nuclei of the experimental group than in the control group.Obtained results suggest that chronic use of ED induces intracellular disorders and apoptosis in consumer cardiomyocytes.

scholarly journals Using Ki-67 Mitotic Activity Markers as a Predictor of the Progression of Adhesions in the Abdominal Cavity

2020 ◽  
Vol 10 (4) ◽  
pp. 412-415
Author(s):  
Irina Shurygina ◽  
Michael Shurygin ◽  
Elena Chepurnykh ◽  
Nataliya Ayushinova
Keyword(s):  
Mitotic Activity ◽  
Proliferative Activity ◽  
Abdominal Cavity ◽  
Control Group ◽  
Proliferative Potential ◽  
Proliferating Cells ◽  
Maximum Increase ◽  
Ki 67 ◽  
Male Wistar Rats ◽  
Experimental Group

Background: Ki-67 is a nuclear protein expressed in all proliferating cells of vertebrates during mitotic cycle phases S, G1, G2, and M, except for G0. Studying this marker is widely used to diagnose the proliferative activity of tumors. However, studying Ki-67 in non-neoplastic diseases attracts much less attention among the researchers. The aim of this study was to assess the possibility of using staining for Ki-67 to identify the proliferative potential of fibroblasts during the formation of adhesions in the abdominal cavity (AC). Methods and Results: Experiments were carried out on male Wistar rats. The adhesion process in AC was simulated in the control group (n=25), and in the experimental group (n=25) with the administration of Seroguard®. Animals were sacrificed on Days 1–30, and the severity of the adhesive process in AC was assessed. Histological sections were prepared and stained for Ki-67. It was found that the animals of the control group had increased severity of the adhesive process in AC during the observation. Maximum increase in severity was registered on Day 30 – 12[9-13] points in the control group and 4[4-4] points in the experimental group (P=0.0079). High proliferative activity of fibroblasts in the control group was detected on Days 3, 7, 14 and 30, which may indicate an active division of fibroblasts and the formation of adhesions in the damaged area. In the experimental group, single Ki-67 positive cells were noted during the entire observation period, which may point to a reduced potential for the formation of adhesions. Conclusion: Our study showed the prospects of using Ki-67 staining to determine the severity of the developing adhesive process in AC, and also revealed one of the possible mechanisms that inhibit the formation of the adhesive process when using Seroguard® – a decrease in the mitotic activity of fibroblasts in the area of peritoneal injury.

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