scholarly journals Initial pulp changes during orthodontic movement: histomorphological evaluation

2007 ◽  
Vol 18 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Milton Santamaria Jr. ◽  
Débora Milagres ◽  
Mamie Mizusaki Iyomasa ◽  
Maria Bernadete Sasso Stuani ◽  
Antonio Carlos de Oliveira Ruellas
Keyword(s):  
Tooth Movement ◽  
Central Area ◽  
Study Groups ◽  
Control Group ◽  
Coil Spring ◽  
Force Application ◽  
Male Wistar Rats ◽  
Physiological Limit ◽  
The Right ◽  
Tissue Alterations

This study evaluated pulp changes in molars of rats submitted to tooth movement by application of a 0.4 N force. Twenty-five adult male Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 5 groups (n=5), being one control group not submitted to force application, and four study groups of 6, 12, 24 and 72 h of force application. The study groups received a 5-mm long nickel-titanium closed coil spring, placed from the right maxillary first molar to the maxillary incisors of each animal. The coil spring was used for mesial inclination of the first molar. After the specific period of tooth movement of each study group, the animals were sacrificed and specimens containing the teeth submitted to movement were processed and stained with hematoxylin and eosin for histological analysis under light microscopy. The results demonstrated alteration of the odontoblastic layer, with hypertrophy of odontoblasts especially at the mesial area of the coronal pulp, edema of the pulp connective tissue in the central area of the pulp, and vascular alteration with accumulation of erythrocytes and leukocytes inside the vessels, especially at the mesial root of the moved teeth. These changes were less remarkable for the 72-h period. Thus, it may be concluded that tooth movement yielded pulpal tissue alterations compatible with an inflammatory process, which are reversible if the aggression is not more intense than the physiological limit of tissue tolerance.

Chronic immobilization stress induces anxiety-related behaviors and affects brain essential minerals in male rats

2020 ◽  
pp. 1-8
Author(s):  
Zafer Sahin ◽  
Alpaslan Ozkurkculer ◽  
Omer Faruk Kalkan ◽  
Ahmet Ozkaya ◽  
Aynur Koc ◽  
...  
Keyword(s):  
Immobilization Stress ◽  
Central Area ◽  
Essential Elements ◽  
Male Rats ◽  
Control Group ◽  
Male Wistar Rats ◽  
Swimming Test ◽  
The Brain ◽  
Center Area ◽  
Chronic Immobilization Stress

Abstract. Alterations of essential elements in the brain are associated with the pathophysiology of many neuropsychiatric disorders. It is known that chronic/overwhelming stress may cause some anxiety and/or depression. We aimed to investigate the effects of two different chronic immobilization stress protocols on anxiety-related behaviors and brain minerals. Adult male Wistar rats were divided into 3 groups as follows ( n = 10/group): control, immobilization stress-1 (45 minutes daily for 7-day) and immobilization stress-2 (45 minutes twice a day for 7-day). Stress-related behaviors were evaluated by open field test and forced swimming test. In the immobilization stress-1 and immobilization stress-2 groups, percentage of time spent in the central area (6.38 ± 0.41% and 6.28 ± 1.03% respectively, p < 0.05) and rearing frequency (2.75 ± 0.41 and 3.85 ± 0.46, p < 0.01 and p < 0.05, respectively) were lower, latency to center area (49.11 ± 5.87 s and 44.92 ± 8.04 s, p < 0.01 and p < 0.01, respectively), were higher than the control group (8.65 ± 0.49%, 5.37 ± 0.44 and 15.3 ± 3.32 s, respectively). In the immobilization stress-1 group, zinc (12.65 ± 0.1 ppm, p < 0.001), magnesium (170.4 ± 1.7 ppm, p < 0.005) and phosphate (2.76 ± 0.1 ppm, p < 0.05) levels were lower than the control group (13.87 ± 0.16 ppm, 179.31 ± 1.87 ppm and 3.11 ± 0.06 ppm, respectively). In the immobilization stress-2 group, magnesium (171.56 ± 1.87 ppm, p < 0.05), phosphate (2.44 ± 0.07 ppm, p < 0.001) levels were lower, and manganese (373.68 ± 5.76 ppb, p < 0.001) and copper (2.79 ± 0.15 ppm, p < 0.05) levels were higher than the control group (179.31 ± 1.87 ppm, 3.11 ± 0.06 ppm, 327.25 ± 8.35 ppb and 2.45 ± 0.05 ppm, respectively). Our results indicated that 7-day chronic immobilization stress increased anxiety-related behaviors in both stress groups. Zinc, magnesium, phosphate, copper and manganese levels were affected in the brain.

Different selective dry cow therapy concepts compared to blanket antibiotic dry cow treatment

2017 ◽  
Vol 45 (06) ◽  
pp. 343-349 ◽  
Author(s):  
Nicole Wente ◽  
Jan-Hendrik Paduch ◽  
Doris Klocke ◽  
Elisabeth Mansion-de Vries ◽  
Martina Hoedemaker ◽  
...  
Keyword(s):  
Rapid Test ◽  
Study Groups ◽  
Test Methods ◽  
Farm Animals ◽  
Control Group ◽  
Dry Period ◽  
Udder Health ◽  
Significant Difference ◽  
Group A ◽  
The Right

SummaryObjective: The aim of the study was to investigate the use of somatic cell count (SCC) and aerobic bacterial counts as possible tools to choose animals for selective dry cow treatment (DCT) on cow level. Blanket antibiotic DCT is an approved and common method in Germany aimed at increasing the cure rate of existing intramammary infections (IMI) at the time of drying off and decreasing the risk of new infections during the dry period. However, not all animals benefit equally from an antibiotic DCT. Moreover, dairies, consumers and politicians demand a reduction in the use of antibiotics in farm animals. Several criteria for identifying animals which would benefit from antibiotic DCT have been described in the literature. Material and methods: Animals chosen for this investigation were divided into three study groups: Aerobic Count Petrifilm® group A (153 cows), SCC group S (160 cows) and control group C (169 cows). All quarters were treated with an internal teat sealant (ITS) no matter which group the cows belonged to. Results: Group C, in which all cows received an antibiotic DCT, achieved the best results referred to udder health, particularly regarding bacteriological dry period cure. However, the results of the two study groups A and S, in which the animals were dried off selectively, were only marginally worse. A significant difference regarding bacterial dry period cure was revealed between group S and group C (p = 0.039), whereas no significant difference concerning new IMI risk could be detected between the three study groups. Compared to a blanket antibiotic DCT of all cows in the corresponding study group, a reduction of the usage of antibiotics of 23.5 % (A) and 55 % (S) was noticed, respectively. Furthermore, it could be shown that the lactation number as well as the microorganisms present at the time of drying off influence udder health. Conclusion: Selective DCT is an alternative method to the widespread blanket antibiotic DCT. However, it has to be mentioned that selective DCT involves the described marginal decline in udder health and the additional amount of time, which might arise from the procedure of choosing the right animals and performing the applied rapid test methods.

scholarly journals Histopathological analysis of gangliosides use in peripheral nerve regeneration after axonotmesis in rats

2008 ◽  
Vol 23 (4) ◽  
pp. 364-371 ◽  
Author(s):  
Camila Maria Beder Ribeiro ◽  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Joaquim Celestino da Silva Neto ◽  
Valdemiro Amaro da Silva Júnior ◽  
Nancy Gurgel Figueiredo
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Schwann Cells ◽  
Peripheral Nerve Regeneration ◽  
Cell Activity ◽  
Control Group ◽  
Histopathological Analysis ◽  
Male Wistar Rats ◽  
The Right

PURPOSE: To analyze the action of gangliosides in peripheral nerve regeneration in the sciatic nerve of the rat. METHODS: The sample was composed of 96 male Wistar rats. The animals were anaesthetized and, after identification of the anaesthesic plane, an incision was made in the posterior region of the thigh, followed by skin and muscle divulsion. The right sciatic nerve was isolated and compressed for 2 minutes. Continuous suture of the skin was performed. The animals were randomly divided into two groups: the experimental group (EG), which received subcutaneous injection of gangliosides, and the control group (CG), which received saline solution (0.9%) to mimic the effects of drug administration. RESULTS: No differences were observed between the experimental and control groups evaluated on the eighth day of observation. At 15 and 30 days the EG showed an decrease in Schwann cell activity and an apparent improvement in fibre organization; at 60 days, there was a slight presence of Schwann cells in the endoneural space and the fibres were organized, indicating nerve regeneration. At 15 and 30 days, the level of cell reaction in the CG had diminished, but there were many cells with cytoplasm in activity and in mitosis; at 60 days, hyperplastic Schwann cells and mitotic activity were again observed, as well as nerve regeneration, but to a lesser extent than in the EG. CONCLUSION: The administration of exogenous gangliosides seems to improve nerve regeneration.

scholarly journals Human Dental Pulp Tissue during Orthodontic Tooth Movement: An Immunofluorescence Study

2020 ◽  
Vol 5 (3) ◽  
pp. 65 ◽  
Author(s):  
Giovanna Vermiglio ◽  
Antonio Centofanti ◽  
Giovanni Matarese ◽  
Angela Militi ◽  
Marco Matarese ◽  
...  
Keyword(s):  
Protein Expression ◽  
Dental Pulp ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Control Group ◽  
Pulp Tissue ◽  
Force Application ◽  
Dental Pulp Tissue ◽  
Human Dental Pulp

The orthodontic tooth movement is the last step of several biological processes that take place after the application of external forces. During this process, dental pulp tissue is subjected to structural and protein expression modifications in order to maintain their integrity and functional morphology. The purpose of the present work was to perform an in vivo study, evaluating protein expression modifications in the human dental pulp of patients that have undergone orthodontic tooth movement due to pre-calibrated light force application for 30 days. Dental pulp samples were extracted from molars and premolars of the control group and after 7 and 30 days of treatment; the samples were then processed for immunofluorescence reactions using antibodies against fibronectin, collagen I and vascular endothelial growth factor (VEGF). Our results show that, after 7 days of treatment, all tested proteins change their pattern expression and will reset after 30 days. These data demonstrate that the dental pulp does not involve any irreversible iatrogenic alterations, supporting the efficacy and safety of using pre-calibrated force application to induce orthodontic tooth movement in clinical practice.

scholarly journals Skeletal Muscle Response to Deflazacort, Dexamethasone and Methylprednisolone

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 406 ◽  
Author(s):  
Alan Fappi ◽  
Juliana de Carvalho Neves ◽  
Leandro Nunes Sanches ◽  
Pedro Victor Massaroto e Silva ◽  
Guilherme Yuiti Sikusawa ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Saline Solution ◽  
Fiber Type ◽  
Neuromuscular Diseases ◽  
Study Groups ◽  
Control Group ◽  
Cross Sectional ◽  
Genes Expression ◽  
Male Wistar Rats ◽  
Synthetic Glucocorticoids

Glucocorticoids represent some of the most prescribed drugs that are widely used in the treatment of neuromuscular diseases, but their usage leads to side effects such as muscle atrophy. However, different synthetic glucocorticoids can lead to different muscle effects, depending upon its chemical formulation. Here, we intended to demonstrate the muscle histologic and molecular effects of administering different glucocorticoids in equivalency and different dosages. Methods: Seventy male Wistar rats distributed into seven groups received different glucocorticoids in equivalency for ten days or saline solution. The study groups were: Control group (CT) saline solution; dexamethasone (DX) 1.25 or 2.5 mg/kg/day; methylprednisolone (MP) 6.7 or 13.3mg/kg/day; and deflazacort (DC) 10 or 20 mg/kg/day. At the end of the study, the animals were euthanized, and the tibialis anterior and gastrocnemius muscles were collected for metachromatic ATPase (Cross-sectional area (CSA) measurement), Western blotting (protein expression of IGF-1 and Ras/Raf/MEK/ERK pathways) and RT-PCR (MYOSTATIN, MuRF-1, Atrogin-1, REDD-1, REDD-2, MYOD, MYOG and IRS1/2 genes expression) experiments. Results: Muscle atrophy occurred preferentially in type 2B fibers in all glucocorticoid treated groups. DC on 10 mg/kg/day was less harmful to type 2B fibers CSA than other doses and types of synthetic glucocorticoids. In type 1 fibers CSA, lower doses of DC and DX were more harmful than high doses. DX had a greater effect on the IGF-1 pathway than other glucocorticoids. MP more significantly affected P-ERK1/2 expression, muscle fiber switching (fast-to-slow), and expression of REDD1 and MyoD genes than other glucocorticoids. Compared to DX and MP, DC had less of an effect on the expression of atrogenes (MURF-1 and Atrogin-1) despite increased MYOSTATIN and decreased IRS-2 genes expression. Conclusions: Different glucocorticoids appears to cause muscle atrophy affecting secondarily different signaling mechanisms. MP is more likely to affect body/muscles mass, MEK/ERK pathway and fiber type transition, DX the IGF-1 pathway and IRS1/2 expression. DC had the smallest effect on muscle atrophic response possibly due a delayed timing on atrogenes response.

scholarly journals Occlusal Hypofunction Induces Atrophic Changes in Rat Gingiva

2008 ◽  
Vol 78 (6) ◽  
pp. 1015-1022 ◽  
Author(s):  
Yuji Ishida ◽  
Zuisei Kanno ◽  
Kunimichi Soma
Keyword(s):  
Connective Tissue ◽  
Structural Integrity ◽  
Lysyl Oxidase ◽  
Tissue Growth ◽  
Gingival Tissue ◽  
Control Group ◽  
Maxillary Molars ◽  
Male Wistar Rats ◽  
Hematoxylin And Eosin ◽  
The Right

Abstract Objective: To clarify the influence of occlusal hypofunction on the integrity of gingival tissue and gingival extracellular matrix biosynthesis. Materials and Methods: Thirteen-week-old male Wistar rats were divided into two groups. To eliminate occlusal forces, all the right maxillary molars were extracted in the hypofunctional group. The control group was anesthetized but not subjected to surgery. The rats were killed at 2 and 4 weeks after the procedure, and the lower right second molars were prepared for histological analysis. To investigate the effect of occlusal hypofunction on collagen biosynthesis, the expression of connective tissue growth factor (CTGF) and lysyl oxidase (LOX) was determined by immunohistochemistry as well as histological examination by hematoxylin and eosin staining. Results: Disorientation of the collagen fibers, proliferation of the connective tissue fibroblasts, and enlargement of epithelial intercellular gaps were observed in gingival tissue of rat molars with experimental occlusal hypofunction. Immunohistochemically, the expression of CTGF and LOX was increased significantly (P &lt; .05) in the hypofunctional group. Conclusion: These results suggest that occlusal hypofunction can affect the structural integrity and the expression of CTGF and LOX in gingival tissue.

scholarly journals Effect of supplementary zinc on orthodontic tooth movement in a rat model

2016 ◽  
Vol 21 (2) ◽  
pp. 45-50 ◽  
Author(s):  
Mohammad Sadegh Ahmad Akhoundi ◽  
Rezvaneh Ghazanfari ◽  
Shahroo Etemad-Moghadam ◽  
Mojgan Alaeddini ◽  
Azam Khorshidian ◽  
...  
Keyword(s):  
Rat Model ◽  
Tooth Movement ◽  
Root Resorption ◽  
Orthodontic Tooth Movement ◽  
Cumulative Effect ◽  
Study Groups ◽  
Model Material ◽  
Bone Homeostasis ◽  
Male Wistar Rats ◽  
Hematoxylin Eosin

ABSTRACT Introduction: Osteoclasts and osteoblasts are responsible for regulating bone homeostasis during which the trace element zinc has been shown to exert a cumulative effect on bone mass by stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption. Objective: The aim of the present study was to investigate the effects of zinc (Zn) on orthodontic tooth movement (OTM) in a rat model. Material and Methods: A total of 44 male Wistar rats were divided into four groups of 11 animals each and received 0, 1.5, 20 and 50 ppm Zn in distilled water for 60 days. In the last 21 days of the study, nickel-titanium closed coil springs were ligated between maxillary right incisors and first molars of all rats, and tooth movement was measured at the end of this period. Histological analysis of hematoxylin/eosin slides was performed to assess root resorption lacunae, osteoclast number and periodontal ligament (PDL) width. Results: Mean OTM was calculated as 51.8, 49.1, 35.5 and 45 µm in the 0, 1.5, 20 and 50 ppm zinc-receiving groups, respectively. There were no significant differences in neither OTM nor histological parameters among the study groups (p > 0.05). Conclusion: According to the results obtained in the current investigation, increase in supplementary zinc up to 50 ppm does not affect the rate of OTM neither bone and root resorption in rats.

scholarly journals The Effect of Intravitreal Azithromycin on the Albino Newborn Rabbit Retina

2016 ◽  
Vol 10 (1) ◽  
pp. 12-16
Author(s):  
Duygu Cam ◽  
Ali Osman Saatci ◽  
Serap Cilaker Micili ◽  
Bekir Ugur Ergur ◽  
Revan Yildirim Karabag ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Caspase 3 ◽  
Rabbit Model ◽  
Study Groups ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Control Group ◽  
Tunel Staining ◽  
Rabbit Retina ◽  
Newborn Rabbit ◽  
The Right

Purpose: To evaluate the effect of intravitreal azithromycin on the retina in a newborn rabbit model. Methods: Twelve, two-week old New Zealand albino rabbits were divided into two groups (six in each). The right eyes of six rabbits received 0.75 mg (0.05 mL) azithromycin and the right eyes of the remaining six rabbits 1.5 mg (0.1 mL) azithromycin intravitreally. Left eyes were served as the control and received the same volume of saline. All eyes were enucleated at the third postinjection week. Retinal histology was examined by light microscopy. Apoptosis of the retinal cells was further evaluated by immunohistochemical staining for caspase-3 and in situ terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) of DNA fragments. Results: Light microscopy demonstrated no retinal abnormalities in all eyes. However, retinal nuclear DNA fragmentation was evident in both study groups (33.6% with 1.5 mg and 21.4% with 0.75 mg azithromycin) with the TUNEL method. TUNEL staining ratio was statistically higher only in the second group treated with 1.5 mg azithromycin when compared to the control group (p=0.01 Mann Whitney U test). The ratio of caspase-3 positive cells in the two study groups was 21.5% and 20.2%, respectively. Caspase-3 staining ratio was statistically higher in both study groups when compared to the control eyes (p=0.00, p=0.00 respectively). The difference of TUNEL staining ratio between the two study groups was statistically significant (p=0.028), but there were no statistically significant differences in the two study groups by caspase-3 staining (p=0.247). Conclusion: In newborn rabbits, intravitreal azithromycin injection resulted in an apoptotic activity in the photoreceptor, bipolar and ganglion cells. Immunohistochemical analysis suggested that doses of 0.75 mg and 1.5 mg azithromycin, administered intravitreally might be toxic to the newborn rabbit retina.

scholarly journals A Comparison of Force Decay between Coil Spring, Elastomeric Chain and Tie-backs in Various Alcohol Concentrations found in Mouth Rinse: An In-vitro Study

2021 ◽  
pp. 155-162
Author(s):  
Asma Fatima ◽  
Prasad Konda ◽  
Asiya Fatima ◽  
Hidayathulla Shaikh ◽  
Butool Zohra ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tooth Movement ◽  
Artificial Saliva ◽  
Alcohol Exposure ◽  
Control Group ◽  
P Value ◽  
Coil Spring ◽  
Mouth Rinses ◽  
Force Decay

Background: The ability to close space efficiently in Orthodontics is of major clinical importance. Elastomeric power chain, coil spring, and tiebacks are commonly used in Orthodontics to achieve tooth movement during the closure of spaces. Many mouth rinses which are used by the patients to achieve good oral hygiene affect the properties of the material used during treatment resulting in force decay if they contain alcohol. Aim: To know the effect of mouth rinses containing different alcohol Concentrations on the force decay of retraction materials. Materials and Methods: A study was carried out to test the effect of alcohol exposure found in mouth rinses on orthodontic NiTi closing coils, elastomeric chains, and tie-back. A total of 135 specimens were divided into one control group and two test groups submerged in artificial saliva at 37⁰ C. Two test groups each of them exposed to different alcohol-containing mouthwashes (Listerine and Povidone-iodine) for 60 seconds twice a day and the control group were exposed only to deionized (DI) water for 28 days. Force measurements were taken at six-time points (initial, 7 days, 14 days, 21 days, and 28 days) using a digital force gauge. Results: The comparison between the tensile strength was made by digital force gauge and the p-value (≤ 0.05) for tensile strength was derived by ANOVA test, multiple comparisons, and Tukey’s correction. Significant force decay was seen in test groups when compared to the control group. Conclusion: Force degradation of retraction products used during orthodontic treatment was effected by mouth rinses containing alcohol.

scholarly journals Effects of salbutamol, montelukast and prednisone on orthodontic tooth movement in rats

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Victor Chumpitaz-Cerrate ◽  
Lesly Chávez-Rimache ◽  
César Franco-Quino ◽  
Eliberto Ruiz-Ramirez ◽  
Elías Aguirre-Siancas ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Study Groups ◽  
Preclinical Study ◽  
Control Group ◽  
Histopathological Analysis ◽  
Significant Difference ◽  
Interincisal Distance

Objective: To evaluate the effect of salbutamol, montelukast, and prednisone on orthodontic tooth movement in rats. Material and Methods: In vivo experimental preclinical study. The sample consisted of 48 rats randomly distributed in four study groups. Group A was given saline solution; to group B, salbutamol 4 mg/Kg; to group C, montelukast 2.5 mg/Kg and to group D, prednisone 2.5 mg/Kg. All were fitted with orthodontic devices and the medications were administered intraperitoneally every 12 hours for 5 days. The clinical evaluation (variation in the interincisal distance) was performed at one, three, five, and seven days and the histopathological analysis (cell count) at five and seven days. Results: In the clinical evaluation of the variation in the interincisal distance, a significant difference was found in all the evaluations (p <0.05). It was found that the salbutamol group presented higher variation values in the interincisal distance on all the days evaluated. In the histopathological analysis at five and seven days, it was found that the osteoblast and osteocyte count was significantly higher in the salbutamol group compared to the other groups (p ><0.05). However, in the subgroup analysis, it was found that there was no significant difference in the osteoblast and osteocyte count between the prednisone, montelukast, and control group (p>0.05). Conclusion: The administration of salbutamol increased the magnitude of orthodontic tooth movement; nonetheless, the administration of montelukast and prednisone did not modify the magnitude of orthodontic tooth movement in rats.   Keywords Albuterol; Montelukast; Prednisone; Rats; Tooth movement.

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