scholarly journals Effect of 10% urea solution on epithelialization of thermally wounded gingiva

2013 ◽  
Vol 60 (3) ◽  
pp. 147-154
Author(s):  
Stevanka Djordjevic ◽  
Dragan Ivanovic ◽  
Tanja Ivanovic

Introduction. Urea is the final product of protein degradation secreted in saliva. It has low molecular weight and neutral molecule that can freely diffuse through bacterial wall, mature plaque and extracellular polysaccharides exerting a buffering effect. In the presence of urease, urea is broken down into one molecule of ammonia and two molecules of weak carbonic acid, causing alkalization of the substrate and pH increase. Hydrolysis of urea begins at pH 4-6. In mature plaque with low pH, urea hydrolysis is a compensatory mechanism that opposes pH decrease trying to keep an optimal acidbase balance. This mechanism explains the role of urea in controlling plaque, caries and gingivitis. The aim of this study was to investigate the effect of urea on the quality and speed of epithelialisation of thermally wounded gingiva in rats. Material and Methods. The study included 36 Wistar albino rats, 3-4 months old, divided in three groups (12 in each group). According to the protocol thermal wounding of gingiva was performed in all animals. Wounded gingival epithelial tissue was treated with: 10% urea solution (experimental group), 3% hydrogen peroxide and saline (control groups). The extent and quality of epithelialisation was verified histologically after 3, 5, 8, 11 and 14 days. Results. There was a strong cellular infiltration and stromal edema with no significant morphological differences between groups in the samples analyzed after 3 days. The acceleration of epithelialisation in the experimental group observed in samples obtained after 5 days was evidenced by rapid mitotic division of epithelium and initial covering of defects in both directions. In samples obtained after 8 days, in the experimental group, epithelial defect was covered and in some areas cells were differentiated in vertical direction. After 11 days horizontal coverage of defects as well as accelerated cell differentiation in the vertical direction were noted. Restitutio ad integrum in the experimental group and significant delay in wound healing in the control groups was demonstrated in 14-day samples. Conclusion. Complete epithelialisation of gingiva occurred significantly faster in the group treated with 10% urea solution, than in the control groups treated with 3% hydrogen peroxide solution and saline.

1969 ◽  
Vol 24 (1) ◽  
pp. 331-337
Author(s):  
Albert M. Swanson ◽  
Glenn D. Richmond

Albino rats were adapted to a distinctive conditioning environment over a 4-day period and were then divided into experimental and control groups. The experimental group experienced 23 hr. of water privation in the conditioning environment on each of 14 successive days. The control group experienced only the first ½ hr. of privation in the conditioning environment and spent the rest of each privation period in a control environment. During subsequent tests in the conditioning environment, with Ss satiated, the experimental Ss consumed significantly more water than the control Ss. A replication produced similar results and indicated that the effect could be mediated by general, as well as specific, characteristics of the conditioning environment. The relation of the results to the conditioned drive hypothesis is discussed, and the direction of continuing research is indicated.


2000 ◽  
Vol 20 (6) ◽  
pp. 656-661 ◽  
Author(s):  
Ella Zeltzer ◽  
Osnat Klein ◽  
Gloria Rashid ◽  
Dov Katz ◽  
Ze'ev Korzets ◽  
...  

Objective Glucose-based dialysate induces non enzymatic glycation within the peritoneal cavity. To evaluate the relationship between the formation of advanced glycation end-products (AGEs) and peritoneal transfer for small solutes and macromolecules, we developed a model of simulated peritoneal dialysis (PD) in normal rats. Methods Male albino rats of the Charles River strain were divided into two sets of 3 groups (15 – 25 rats in each group). In the experimental (E) group, the rats were intra-peritoneally (IP) injected daily with a commercially available 4.25% dextrose solution. In the control puncture (CP) group, the peritoneum was punctured daily, but no PD solution infused. In an age-matched control (CC) group, no intervention was given. Two study protocols were used. Protocol A (duration 20 weeks) consisted of a daily IP injection of 10 mL PD solution per 100 g body weight. In protocol B, a double volume of PD solution was introduced (20 mL per 100 g body weight). At 9, 16, and 20 weeks in protocol A, and at 9 weeks in protocol B, urea, creatinine, microalbumin [(MAL) measured using specific anti-rat albumin monoclonal antibody], and AGEs (measured by fluorescent assay with excitation at 370 nm and emission at 440 nm) were measured in peritoneal effluent and serum. Results At no time during the study were AGEs detected in serum from any group in either protocol. In both protocols, no differences were found between the control groups (CP, CC) with respect to all parameters. In protocol A, the dialysate-to-plasma ratio (D/P) of urea was significantly higher in the experimental group as compared with the control groups at 9, 16, and 20 weeks [9 weeks: 0.59 ± 0.03 (E) vs 0.39 ± 0.02 (CP) vs 0.46 ± 0.02 (CC), p < 0.0004 and p < 0.002, respectively; 16 weeks: 0.71 ± 0.08 (E) vs 0.42 ± 0.01 (CP) vs 0.46 ± 0.01 (CC), p < 0.0001 and p < 0.02, respectively; 20 weeks: 0.57 ± 0.03 (E) vs 0.39 ± 0.01 (CP) vs 0.41 ± 0.02 (CC), p < 0.002 and p < 0.004, respectively]. At 16 and 20 weeks, dialysate MAL levels were significantly increased in group E [16 weeks: 354.00 ± 80.35 μg/mL (E) vs 134.75 ± 14.36 μg/mL (CP) vs 110.69 ± 7.83 μg/mL (CC), p < 0.04 and p < 0.03, respectively; 20 weeks: 283.17 ± 14.71 μg/mL (E) vs 105.14 ± 12.11 μg/mL (CP) vs 135.50 ± 19.03 μg/mL (CC), p < 0.00001 and p < 0.0001, respectively]. In protocol B, at completion of the study (week 9), D/P urea, effluent MAL, and AGEs were significantly higher in the experimental group as compared with the control groups [D/P: 0.67 ± 0.04 (E) vs 0.46 ± 0.07 (CP) vs 0.41 ± 0.02 (CC), p < 0.0002 and p < 00001, respectively; MAL: 336.8 ± 63.30 μg/mL (E) vs 125.71 ± 16.77 μg/mL (CP) vs 119.00 ± 39.75 μg/mL (CC), p < 0.008 and p < 0.007, respectively; AGEs: 265.77 ± 33.49 U/mg creatinine (E) vs 163.10 ± 21.99 U/mg creatinine (CP) vs 83.17 ± 22.66 U/mg creatinine (CC), p < 0.02 and p < 0.001, respectively]. Peritoneal effluent AGEs were found to be significantly correlated with D/P urea and dialysate MAL ( r = 0.42, p < 0.04, and r = 0.7, p = 0.00001, respectively). Conclusions In situ generation of AGEs constitutes the chief origin of peritoneal AGEs. Advanced glycation end-products affect peritoneal permselectivity for both small and large solutes. The rat model of simulated peritoneal dialysis developed in this experiment provides a reliable method for studying peritoneal AGE formation and effect on peritoneal transfer of small solutes and macro-molecules.


Author(s):  
Hasanul Arifin Zul And Masitowarni Siregar

This thesis is focused on the investigation of the effect of applying animal cartoon pictures on students’ achievement in writing narrative text. This study aims to find whether applying animal cartoon pictures significantly affect the students’ writing achievement or not. The data in this study were obtained by administering a written test. The population was the 2015/2016 first year (grade XI) of SMA Swasta Nusantara Lubuk Pakam and 66 students were taken as the sample by using random sampling. The sample was divided into two groups, experimental and control groups. The experimental group was taught by applying animal cartoon pictures while the control group without animal cartoon pictures (x = lecturing). The data were taken the scores from the pre-test and post-test to both experimental and control groups. These data were analyzed by using t-test. The result of computing the t-test obviously showed that t-observed is higher than t-table (5.21 >1,67) with the degree of freedom 64 (df =N-2) at the level significance 0,05 one tail test. It showed that the application of animal cartoon pictures significantly affected the students of SMA Swasta Nusantara Lubuk Pakam achievement in writing narrative text.


Author(s):  
Meryanti Napitupulu And Anni Holila Pulungan

This study was conducted as an attempt to discover the effect of applying Demonstration Method on students’ achievement in speaking skill. It was an experimental research. The subject was students of Grade XII, Vocational High School (Sekolah Menengah Kejuruan: SMK), which consisted of 79 students. The research was divided into two groups: experimental and control groups. The instrument used to collect the data was speaking test. To obtain the reliability of the test, the writer applied Kuder Richardson 21 formula. The result of the reliability was 0.7, and it was found that the test was reliable. The data were analyzed by using t-test formula. The analysis showed that the scores of the students in the experimental group were significantly higher than the scores of the students in the control group at the level of significant m = 0.05 with the degree of freedom (df) 77, t-observed value 8.9 > t-table value 1.99. The findings indicate that using Demonstration Method significantly affected the students’ achievement in speaking skill. So, English teachers are suggested to use Demonstration Method in order to improve students’ achievement in speaking skill.


2020 ◽  
Vol 14 (4) ◽  
pp. 99-103
Author(s):  
V. I. Kolesnikov

The purpose of the research is studying the efficacy of Eprimek (Eprinomectin) against gastrointestinal nematodes in sheep.Materials and methods. A commercial experiment to study the antiparasitic efficacy of Eprimek was carried out in June 2020 on 300 lambs of the North Caucasian breed in a private flock of Filimonovskaya Village, Izobilnensky District, the Stavropol Territory, which were divided into two groups. The experimental group of lambs (290 animals) was injected Eprimek subcutaneously at the earset at a dose of 1 ml/50 kg of live weight (10 mg of Eprinomectin in 1 ml), and 10 lambs were not treated; they were used as control. We collected feces from the lambs of the experimental and control groups before administration of the drugs and after 15 and 30 days. Fecal samples were examined by the flotation technique with a saturated solution of ammonium nitrate with counting nematode eggs in 1 g of feces. The results were processed statistically.Results and discussion. Eprimek showed a decrease in the number of excreted helminth eggs from 225.1±28.2 to 4.1±2.3 in production environment at a dose of 1 ml/50 kg of live weight, according to coprological studies on the 15th day after treatment in the experimental group of lambs. The efficacy was 98.2%, and 70% of the animals were free from the infection. The intensity of infection of the control lambs by gastrointestinal nematodes was 131–151 eggs per 1 g of feces at 100% prevalence.


2021 ◽  
pp. 104973152110014
Author(s):  
Siu-ming To ◽  
Xiaoyu Liu

Purpose: Using a nonrandomized control group pretest–posttest assessment, this study aimed to examine the outcomes of community-based youth empowerment initiatives that were informed by design thinking. Method: A total of 553 youth living in Hong Kong were recruited to participate in this study. Among them, 213 youth self-selected to join the experimental group, and 340 youth joined the two control groups. Multivariate analysis of covariance and post hoc group comparisons were used to examine the differences among the three groups at the posttest assessment. Results: The results indicate a positive improvement in creative self-efficacy among participants of the experimental group compared to the two control groups. Significant differences were also found between the experimental group and the second control group in terms of youth–adult partnerships and youth empowerment in the community. Conclusion: Youth empowerment programs informed by design thinking may reinforce self-efficacy beliefs by encouraging youth to bring about innovations in their community.


2015 ◽  
Vol 118 (9) ◽  
pp. 1128-1135 ◽  
Author(s):  
Karin Harumi Uchima Koecklin ◽  
Chiho Kato ◽  
Yukiha Funaki ◽  
Maya Hiranuma ◽  
Takayoshi Ishida ◽  
...  

Mouth breathing caused by nasal obstruction affects the normal growth and development of craniofacial structures, including changes in the orofacial muscles. Tongue muscles play an important role in patency of the pharyngeal airway, and changes in the breathing pattern may influence tongue function. The purpose of this study was to evaluate the effect of unilateral nasal obstruction during growth on contractile properties of the tongue-protruding muscles. Sixty 6-day-old male Wistar albino rats were divided randomly into control ( n = 30) and experimental ( n = 30) groups. Rats in the experimental group underwent a unilateral nasal obstruction after cauterization of the external nostril at the age of 8 days, and muscle contractile characteristics were measured at 5, 7, and 9 wk of age. The specific parameters measured were twitch force, contraction time, half-decay time, tetanic force, and fatigue index. Repeated-measures multivariate analysis of variance was used for intergroup and intragroup statistical comparisons. Twitch contraction force and half-decay time were significantly increased in the experimental group at all ages. Tetanic forces at 60 and 80 Hz were significantly higher in the experimental group at all ages. The fatigue index was decreased significantly in the experimental group at the age of 5 wk. These results suggest that early unilateral nasal obstruction may increase the contraction force of the tongue-protruding muscles and prolong the duration of muscle contraction, which may influence the shape and development of the craniofacial complex.


Author(s):  
Barbara Carretti ◽  
Erika Borella ◽  
Rossana De Beni

Abstract. The paper examines the effect of strategic training on the performance of younger and older adults in an immediate list-recall and a working memory task. The experimental groups of younger and older adults received three sessions of memory training, teaching the use of mental images to improve the memorization of word lists. In contrast, the control groups were not instructed to use any particular strategy, but they were requested to carry out the memory exercises. The results showed that strategic training improved performance of both the younger and older experimental groups in the immediate list recall and in the working memory task. Of particular interest, the improvement in working memory performance of the older experimental group was comparable to that of the younger experimental group.


2015 ◽  
Vol 118 (1) ◽  
pp. 71-79 ◽  
Author(s):  
R. T. Mahon ◽  
W. A. Cronin ◽  
M. Bodo ◽  
S. Tirumala ◽  
D. P. Regis ◽  
...  

Intravenous perfluorocarbons (PFC) have reduced the effects of decompression sickness (DCS) and improved mortality rates in animal models. However, concerns for the physiological effects of DCS combined with PFC therapy have not been examined in a balanced mixed-sex population. Thirty-two (16 male, 16 female) instrumented and sedated juvenile Yorkshire swine were exposed to 200 feet of seawater (fsw) for 31 min of hyperbaric air. Pulmonary artery pressure (PAP), cardiac output (CO), and systemic arterial pressure (SAP) were monitored before (control) and after exposure. Animals were randomized to treatment with Oxycyte (5 ml/kg; Oxygen Biotherapeutics, Inc., Morrisville, NC) vs. saline (control) with 100% oxygen administered upon DCS onset; animals were observed for 90 min. Parameters recorded and analyzed included PAP, CO, and SAP. In all animals PAP began to rise prior to cutis marmorata (CM) onset, the first sign of clinical DCS, generally peaking after CM onset. Female swine, compared with castrated males, had a more rapid onset of CM (7.30 vs. 11.46 min postsurfacing) and earlier onset to maximal PAP (6.41 vs. 9.69 min post-CM onset). Oxycyte therapy was associated with a sustained PAP elevation above controls in both sexes (33.41 vs. 25.78 mmHg). Significant pattern differences in PAP, CO, and SAP were noted between sexes and between therapeutic groups. There were no statistically significant differences in survival or paralysis between the PFC and control groups during the 48-h observation period. In conclusion, Oxycyte therapy for DCS is associated with a prolonged PAP increase in swine. These species and sex differences warrant further exploration.


1970 ◽  
Vol 7 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Md Sharif Hossain ◽  
Fatema Begum

In Bangladesh some researchers have done several studies to find the correlation of simple diffuse goiter with arsenic level but no one conducted any study to find the differences of urinary iodine, urinary arsenic, radioiodine uptake, the thyroid stimulating hormone (TSH) and free thyroxin (FT4) levels between goitrous and non goitrous. That is why, in this research an attempt has been made to compare the urinary iodine, urinary arsenic, radioiodine uptake, TSH and FT4 levels between experimental group with simple diffuse goiter and healthy control group. In this study another purpose has also been made to find the associations between different pairs of variables for both experimental and control group. In this study we have tried to find the impacts of arsenic level on simple diffuse goiter. This is a case-control analytical study. The study is carried out in the Institute of Nuclear Medicine and Ultrasound, in collaboration with the thyroid out patient department of Bangabandhu Sheikh Mujib Medical University. A total of eighty five (85) subjects are included in the study. Among the 85 subjects, a sample of forty five is considered for experimental group with simple diffuse goiter and another sample of forty is considered for healthy control group without any thyroid disease. From the experimental results it has been found that, the arsenic levels, FT4 and radioiodine uptake levels at 2 hours between the experimental and control groups are significantly different but the urinary iodine levels, TSH levels and radioiodine uptake levels at 24 hours between the experimental and control groups are not statistically different. From the experimental results it has also been found that there is significant differentiation between experimental and controls groups in respect of association between different pairs of variables. In this study, another significant finding is that iodine deficiency is not only the factor of causing simple diffuse goiter, but arsenic level is also one of the most important factor of causing simple diffuse goiter. Key words: Iodine deficiency, Simple diffuse goiter, Urinary arsenic, Statistical analysis, Association, Experimental and Control groups  DOI = 10.3329/dujps.v7i1.1224 Dhaka Univ. J. Pharm. Sci. 7(1): 89-98, 2008 (June)


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