scholarly journals The Evaluation of Osseointegration of Dental Implant Surface with Different Size of TiO2Nanotube in Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Young-Ah Yi ◽  
Young-Bum Park ◽  
Hyunmin Choi ◽  
Keun-Woo Lee ◽  
Sun-Jai Kim ◽  
...  

With the development of nanotechnology, many researches have shown that nanometer-scaled materials especially TiO2nanotube have a positive effect on cellular behavior and surface characteristics of implant, which are considered to be crucial factors in osseointegration. However, it has not yet been verified which nanotube size is effective in osseointegrationin vivo. The aim of this study was to evaluate the effect of implant surface-treated with different size of TiO2nanotubes on osseointegration in rat femur. The customized implants (threaded and nonthreaded type), surface-treated with different diameter of TiO2nanotubes (30 nm, 50 nm, 70 nm, and 100 nm nanotube), were placed on both sides of the femur of 50 male Sprague-Dawley rats (6 weeks old). Rats were sacrificed at 2 and 6 weeks following surgery; then the specimens were collected by perfusion fixation and the osseointegration of implants was evaluated by radiographic and histologic analyses and removal torque value test. The mean of bone area (%) and the mean of removal torque were different in each group, indicating that the difference in TiO2nanotube size may influence new bone formation and osseointegration in rats.

1998 ◽  
Vol 88 (4) ◽  
pp. 1071-1075 ◽  
Author(s):  
Guy L. Weinberg ◽  
Timothy VadeBoncouer ◽  
Gopal A. Ramaraju ◽  
Marcelo F. Garcia-Amaro ◽  
Michael J. Cwik

Background The authors sought to confirm a chance observation that intravenous lipid treatment increases the dose of bupivacaine required to produce asystole in rats. The authors also measured the partitioning of bupivacaine between the lipid and aqueous phases of a plasma-lipid emulsion mixture. Methods Anesthetized Sprague-Dawley rats were used in pretreatment (protocol 1) and resuscitation (protocol 2) experiments. In protocol 1, animals were pretreated with saline or 10%, 20%, or 30% Intralipid (n = 6 for all groups), then received 0.75% bupivacaine hydrochloride at a rate of 10 ml x kg x min(-1) to asystole. In protocol 2, mortality was compared over a range of bolus doses of bupivacaine after resuscitation with either saline or 30% Intralipid (n = 6 for all groups). The lipid:aqueous partitioning of bupivacaine in a mixture of plasma and Intralipid was measured using radiolabeled bupivacaine. Results Median doses of bupivacaine (in milligrams per kilogram) producing asystole in protocol 1 were for 17.7 for saline, 27.6 for 10% Intralipid, 49.7 for 20% Intralipid, and 82.0 for 30% Intralipid (P < 0.001 for differences between all groups). Differences in mean +/- SE concentrations of bupivacaine in plasma (in micrograms per milliliter) were significant (P < 0.05) for the difference between saline (93.3 +/- 7.6) and 30% Intralipid (212 +/- 45). In protocol 2, lipid infusion increased the dose of bupivacaine required to cause death in 50% of animals by 48%, from 12.5 to 18.5 mg/kg. The mean lipid:aqueous ratio of concentrations of bupivacaine in a plasma-Intralipid mixture was 11.9 +/- 1.77 (n = 3). Conclusions Lipid infusion shifts the dose-response to bupivacaine-induced asystole in rats. Partitioning of bupivacaine into the newly created lipid phase may partially explain this effect. These results suggest a potential application for lipid infusion in treating cardiotoxicity resulting from bupivacaine.


1988 ◽  
Vol 255 (6) ◽  
pp. E850-E856 ◽  
Author(s):  
R. R. Almon ◽  
D. C. Dubois

This report describes changes in muscle mass of innervated and denervated pairs of muscles taken from intact and adrenalectomized 250-g male Sprague-Dawley rats provided with different diets. Diets ranged from a nutritionally complete liquid diet to starvation (water only). In the intact animals, muscles with a more tonic character (soleus) are less sensitive to starvation than are muscles with a more phasic character (extensor digitorum longus), whereas the opposite is true of denervation. In the intact animals, starvation greatly increased the amount of atrophy following denervation. In the adrenalectomized animals, starvation had no effect on the amounts of atrophy following denervation. Furthermore, adrenalectomy virtually eliminated the fiber-type differences in the amount of atrophy following denervation. In addition, a comparison between denervated muscles from intact animals and adrenalectomized animals subjected to starvation demonstrates that all denervated muscles from the adrenalectomized animals atrophy less. Finally, it was observed that although an adrenalectomized animal can tolerate 6 days of starvation, an adrenalectomized-castrated animal cannot tolerate even short periods of starvation. The difference appears to be due to low amounts of corticosterone of testicular origin.


Author(s):  
Shu-Chieh Hu ◽  
Matthew S Bryant ◽  
Estatira Sepehr ◽  
Hyun-Ki Kang ◽  
Raul Trbojevich ◽  
...  

Abstract The tobacco-specific nitrosamine NNK [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone] is found in tobacco products and tobacco smoke. NNK is a potent genotoxin and human lung carcinogen; however, there are limited inhalation data for the toxicokinetics (TK) and genotoxicity of NNK in vivo. In the present study, a single dose of 5x10−5, 5x10−3, 0.1, or 50 mg/kg body weight (BW) of NNK, 75% propylene glycol (vehicle control), or air (sham control) was administered to male Sprague-Dawley (SD) rats (9-10 weeks age) via nose-only inhalation (INH) exposure for 1 hour. For comparison, the same doses of NNK were administered to male SD rats via intraperitoneal (IP) injection and oral gavage (PO). Plasma, urine, and tissue specimens were collected at designated timepoints and analyzed for levels of NNK and its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and tissue levels of DNA adduct O6-methylguanine by LC/MS/MS. TK data analysis was performed using a non-linear regression program. For the genotoxicity subgroup, tissues were collected at 3 hours post-dosing for comet assay analysis. Overall, the TK data indicated that NNK was rapidly absorbed and metabolized extensively to NNAL after NNK administration via the three routes. The IP route had the greatest systemic exposure to NNK. NNK metabolism to NNAL appeared to be more efficient via INH than IP or PO. NNK induced significant increases in DNA damage in multiple tissues via the three routes. The results of this study provide new information and understanding of the toxicokinetics and genotoxicity of NNK.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Giuseppina Laganà ◽  
Arianna Malara ◽  
Roberta Lione ◽  
Carlotta Danesi ◽  
Simonetta Meuli ◽  
...  

Abstract Background The aim of the study was to compare the amount of interproximal enamel reduction (IPR) provided on ClinCheck software with the amount of IPR carried out by the orthodontist during treatment with clear aligners. Methods 30 subjects (14 males, 16 females; mean age of 24.53 ± 13.41 years) randomly recruited from the Invisalign account of the Department of Orthodontics at the University of Rome “Tor Vergata” from November 2018 to October 2019, were collected according to the following inclusion criteria: mild to moderate dento-alveolar discrepancy (1.5–6.5 mm); Class I canine and molar relationship; full permanent dentition (excluding third molars); both arches treated only using Comprehensive Package by Invisalign system; treatment plan including IPR. Pre- (T0) and post-treatment (T1) digital models (.stl files), created from an iTero scan, were collected from all selected patients. The OrthoCAD digital software was used to measure tooth mesiodistal width in upper and lower arches before (T0) and at the end of treatment (T1) before any refinement. The widest mesio-distal diameter was measured for each tooth excluding molars by “Diagnostic” OrthoCAD tool. The total amount of IPR performed during treatment was obtained comparing the sum of mesio-distal widths of all measured teeth at T0 and T1. Significant T1–T0 differences were tested with dependent sample t-test (P < 0.05). Results In the upper arch, IPR was digitally planned on average for 0.62 mm while in the lower arch was on average for 1.92 mm. As for the amount of enamel actually removed after IPR performing, it was on average 0.62 mm in the maxillary arch. In the mandibular arch, the mean of IPR carried out was 1.93 mm. The difference between planned IPR and performed IPR is described: this difference was on average 0.00 mm in the upper arch and 0.01 in the lower arch. Conclusions The amount of enamel removed in vivo corresponded with the amount of IPR planned by the Orthodontist using ClinCheck software.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Himanshu Kushwah ◽  
Nidhi Sandal ◽  
Meenakshi Chauhan ◽  
Gaurav Mittal

Abstract Background Uncontrolled bleeding is one of the primary reasons for preventable death in both civilian trauma and military battle field. This study evaluates in vitro and in vivo hemostatic potential of four biopolymeric natural gums, namely, gum tragacanth, guar gum, xanthan gum, and gum acacia. In vitro evaluation of whole blood clotting time and erythrocyte agglutination assay were carried out. In vitro cytotoxicity studies with respect to each gum were done in human lymphocytes to ascertain percent cell viability. In vivo hemostatic potential of each gum (as sponge dressing and powder form) was evaluated in Sprague Dawley rats using tail bleeding assay and compared with commercially available hemostatic sponge. Other important parameters like (a) time taken for complete hemostasis, (b) amount of blood absorbed, (c) adherence strength of developed hemostatic dressing(s), (d) incidence of re-bleeding, and (e) survival of animals were also studied. Results Of the four test gums studied, xanthan gum (@3mg/ml of blood) and gum tragacanth (@35mg/ml of blood) were able to clot blood in least time (58.75±6.408 s and 59.00±2.082 s, respectively) and exhibited very good hemostatic potential in vitro. Except for xanthan gum, all other test gums did not exhibit any significant cytotoxicity at different time points till 24 h. In rat tail bleeding experiments, gum tragacanth sponge dressing and powder achieved hemostasis in least time (156.2±12.86 s and 76±12.55 s, respectively) and much earlier than commercially available product (333.3±38.84 s; p˂0.01). Conclusion Results indicate potential of gum tragacanth to be developed into a suitable hemostatic product.


1991 ◽  
Vol 7 (3) ◽  
pp. 125-139 ◽  
Author(s):  
David R. Bevan ◽  
David M. Ruggio

To evaluate health risks associated with exposure to particulates in the environment, it is necessary to quantify the bioavailability of carcinogens associated with the particulates. Direct analysis of bioavailability in vivo is most readily accomplished by adsorbing a radiolabeled form of the carcinogen to the particulate. A sam ple of native diesel particulate collected from an Oldsmobile die sel engine that contained 1.03 μ g benzo[ a] pyrene ( BaP)/ g particulate was supplemented with exogenous [ 3 H]- BaP to pro duce a particulate containing 2.62 μ g BaP/g. To insure that elu tion of BaP from native and [3 H] -BaP-supplemented particulate was similar, in vitro analyses were performed. When using phos pholipid vesicles composed of dimyristoylphosphatidylcholine (DMPC), 1.52% of total BaP was eluted from native particulate into the vesicles in 18 hrs; from [ 3 H] -BaP supplemented particu late, 1.68% was eluted. Using toluene as eluent, 2.55% was eluted from native particulate, and 8.25% from supplemented particulate, in 6 hrs. Supplemented particulate was then instilled intratracheally into male Sprague-Dawley rats and distribution of radioactivity was analyzed at selected times over 3 days. About 50% of radioactivity remained in lungs at 3 days following instil lation, with 30% being excreted into feces and the remainder dis tributed throughout the organs of the rats. To estimate the amount of radioactivity that entered feces through swallowing of a portion of the instilled dose, [3 H] -BaP-supplemented particu late was instilled intratracheally into rats that had a cannula sur gically implanted in the bile duct. Rate of elimination of radio activity into bile was monitored; 10.6% of radioactivity was re covered in 6 hr, an amount slightly lower than the 12.8% ex creted in 6 hrs into feces of animals with intact bile ducts. Our studies provide a quantitative description of the distribution of BaP and its metabolites following intratracheal instillation of diesel particulate. Because rates of elution of BaP in vitro are similar for native diesel particulate and particulate with supple mental [ 3H] -BaP, our results provide a reasonable estimate of the bioavailability in vivo of BaP associated with diesel particu late.


2016 ◽  
Vol 3 (4) ◽  
pp. 167-175 ◽  
Author(s):  
Jiang Pu ◽  
Yuanyuan Deng ◽  
Xiaoyan Tan ◽  
Gaofeng Chen ◽  
Cong Zhu ◽  
...  

2012 ◽  
Vol 303 (8) ◽  
pp. R850-R860 ◽  
Author(s):  
Miriam Goebel-Stengel ◽  
Andreas Stengel ◽  
Lixin Wang ◽  
Gordon Ohning ◽  
Yvette Taché ◽  
...  

Various molecular forms of CCK reduce food intake in rats. Although CCK-8 is the most studied form, we reported that CCK-58 is the only detectable endocrine peptide form in rats. We investigated the dark-phase rat chow intake pattern following injection of CCK-8 and CCK-58. Ad libitum-fed male Sprague-Dawley rats were intraperitoneally injected with CCK-8, CCK-58 (0.6, 1.8, and 5.2 nmol/kg), or vehicle. Food intake pattern was assessed during the dark phase using an automated weighing system that allowed continuous undisturbed monitoring of physiological eating behavior. Both CCK-8 and CCK-58 dose dependently reduced 1-h, dark-phase food intake, with an equimolar dose of 1.8 nmol being similarly effective (−49% and −44%). CCK-58 increased the latency to the first meal, whereas CCK-8 did not. The intermeal interval was reduced after CCK-8 (1.8 nmol/kg, −41%) but not after CCK-58. At this dose, CCK-8 increased the satiety ratio by 80% and CCK-58 by 160%, respectively, compared with vehicle. When behavior was assessed manually, CCK-8 reduced locomotor activity (−31%), whereas grooming behavior was increased (+59%). CCK-58 affected neither grooming nor locomotor activity. In conclusion, reduction of food intake by CCK-8 and CCK-58 is achieved by differential modulation of food intake microstructure and behavior. These data highlight the importance of studying the molecular forms of peptides that exist in vivo in tissue and circulation of the animal being studied.


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