scholarly journals 78 ESTABLISHMENT OF PREGNANCIES IN LARGE WHITE SOW RECIPIENTS AFTER TRANSFER OF CLONED EMBRYOS OF DIFFERENT PIG BREEDS

2010 ◽  
Vol 22 (1) ◽  
pp. 197 ◽  
Author(s):  
M. Schmidt ◽  
P. M. Kragh ◽  
J. Li ◽  
L. Lin ◽  
Y. Liu ◽  
...  
Keyword(s):  
Technical Assistance ◽  
Abortion Rate ◽  
Fetal Mortality ◽  
Large White ◽  
Abdominal Incision ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Significant Difference

Production of cloned piglets, using normal or transgenic donor cells, has been of limited efficiency. One reason could be breed differences between recipient and embryos. The aim of this study was to compare pregnancies after transfer to Large White (LW) sow recipients of cloned LW embryos or cloned, transgenic minipig embryos. Large White donor cells were from LYxD, and minipig cells were transgenic with 1 of 5 genes related to different human diseases and from either Göttingen or Yucatan. The cells were used on Day 0 for handmade cloning (Du et al. 2005 Cloning Stem Cells 7, 199-205). The reconstructed embryos were cultured in vitro until transfer on Day 5 to 6. As recipients, 70 LW sows were weaned and anesthetized 4 days after natural heat. Through an abdominal incision the ovaries were controlled (CL formation, absence of cysts) and the embryos slowly introduced into the uterus via a catheter inserted 5 to 6 cm into the tip of the upper horn. To each of 33 recipients, 40 to 60 LW embryos were transferred, and 37 recipients each received 50 to 100 transgenic minipig embryos. Pregnancies were examined by ultrasound scanning every second week. Abortions were defined as absence of earlier confirmed scanning or delivery of aborted fetuses. Caesarean sections were performed on Day 114 (minipig) or Day 116 (LW) 24 h after injection of a prostaglandin analogue. At delivery, placental gross morphology was recorded with samples taken for later histology. The piglets were fed every 3 h with colostrum for the first 24 h and then by the recipient LW sow. Data were analyzed by Fisher’s Exact test with a significance level of P < 0.05. The overall pregnancy rate was 49% (34/70) with an abortion rate of 29% (8 aborted + 2 resorbed/34) from Day 30 to 45 giving 24/70 deliveries (34% of the transfers). There was no significant difference between minipig (54%, 20/37) and LW pregnancy results (42%, 14/33), although there tended to be more abortions with minipig pregnancies (8/20 v. 2/14; P = 0.14) resulting in 12 minipig and 12 LW litters of which 4 and 9, respectively, have grown up to adulthood. In almost every recipient the placenta and fetal membranes showed abnormal thick and edematous morphology. The total litter sizes ranged from 1 to 10 piglets (mean 4.4 ± 0.6), and in 13 of 24 litters there were 1 to 5 stillborn piglets. Except for one litter of 9 transgenic Yucatan piglets that all died within their first 2 weeks, the postnatal mortality of both LW- and mini-piglets seemed similar to that of farm piglets of the same age, and the piglets appeared normal with respect to weight gain, gross morphology, and behavior. These results demonstrate that, in spite of a rather high abortion rate and some fetal mortality, an acceptable birth rate can be achieved after transfer to LW recipients of cloned LW embryos (36%) as well as cloned, transgenic minipig embryos (32%). Therefore, a breed difference between the embryos and their recipient seems not to influence the pregnancy results. The authors thank B. Synnestvedt, H. Kristiansen, S. Starsig, A. Pedersen, J. Adamsen, R. Kristiansen, and K. Villemoes for invaluable technical assistance.

30 POSTMORTEM FINDINGS IN CLONED AND TRANSGENIC PIGLETS DEAD BEFORE WEANING

2015 ◽  
Vol 27 (1) ◽  
pp. 107 ◽  
Author(s):  
M. Schmidt ◽  
K. D. Winther ◽  
H. Callesen
Keyword(s):  
Human Diseases ◽  
Large White ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Cloning Technique ◽  
Limb Malformations ◽  
Transgenic Cells ◽  
Transgenic Technologies

Around 50% of cloned and transgenic piglets are lost during the first month after birth (Reprod. Fertil. Develop. 26, 124), and one reason is malformations of vital organs. The aim of the present study was to describe the distribution of malformations in piglets (until weaning, i.e. age <Day 28) born after transfer to Large White (LW) recipients of cloned embryos. Donor cells were fibroblasts either from LW (non-transgenic) or from Yucatan or Göttingen (made transgenic with 1 of 7 genes related to different human diseases). Handmade cloning was used to produce embryos that, after 5–6 days in vitro culture, were transferred to 202 LW sows 4 days after natural heat. Abortion occurred in 29 sows, and 6.5 ± 0.4 piglets per litter (from 1 to 22) were delivered from 116 sows (46 litters with LW piglets, 40 with Göttingen, 30 with Yucatan). In 78 of these litters (67%), autopsies were performed on 55 ± 4% of piglets stillborn or dead before weaning. Data were analysed by Fisher's Exact test with P < 0.05 as significance level. Malformations were found in 1 to 12 piglets per litter, with a higher malformation rate in transgenic Göttingen and Yucatan piglets (35% and 46% of all born, respectively) than in non-transgenic LW (17%). Many piglets showed 2 (24%) or more (6%) malformations. Some malformations seemed to be related to breed and/or transgene (see Table 1 for most frequent malformations); for example, heart malformations were most frequent in Yucatan litters independent of the transgene, whereas gall bladder and limb malformations were more frequent in Göttingen and in various litters with the same transgene. These results show that pig cloning results in a considerable loss of piglets, and that a majority of these can be related to various malformations. Use of transgenic cells for cloning only adds to this problem. Some malformations are related to the specific breed in use, but the general finding is that the problem is related to the cloning technique as such. However, because approximately half of the cloned piglets still survive, perhaps with unknown minor malformations, use of pigs as a model for human diseases is still realistic. But choice of breed and possible improvements of the transgenic technologies for this kind of work should be considered carefully. Table 1.Malformations in transgenic and nontransgenic cloned piglets dead before weaning

22 MALFORMATIONS FOUND BY AUTOPSY OF CLONED AND TRANSGENIC PIGLETS OF DIFFERENT BREEDS

2012 ◽  
Vol 24 (1) ◽  
pp. 123 ◽  
Author(s):  
M. Schmidt ◽  
K. D. Winter ◽  
J. Li ◽  
P. M. Kragh ◽  
Y. Du ◽  
...  
Keyword(s):  
Human Diseases ◽  
Weaned Piglets ◽  
Large White ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Transgenic Embryos ◽  
Considerable Loss ◽  
Overall Mortality

Viability of cloned and transgenic piglets is seriously compromised and one obvious reason could be malformations. The aim of the present study was therefore to describe gross pathological conditions in dead pre-weaned piglets born after transfer to Large White (LW) recipients of cloned (LW donor cells) or transgenic (Yucatan or Göttingen donor cells) embryos. Donor cells were fibroblasts and the Göttingen and Yucatan cells were made transgenic with 1 of 5 genes known to dispose for different human diseases. Handmade cloning was used to produce embryos that after 5 to 6 days of in vitro culture were transferred surgically to 108 LW sows 4 days after their natural heat. Of these, 21 sows delivered cloned LW piglets, whereas 17 and 16 sows, respectively, delivered transgenic Göttingen and Yucatan piglets. Stillborn and dead pre-weaned piglets were necropsied and malformations registered. Data were analysed by Fisher's exact test with a significance level of P < 0.05. In the 54 litters, total litter size ranged from 1 to 22 piglets (mean 5.4 ± 0.5) and the overall mortality rate until weaning on day 28 was 59%. Malformations were found in piglets from 38 litters where an average of 35% of the piglets showed malformations (between 8 and 100%). In those litters, 1 to 7 piglets had 1, 2, or several malformations (Table 1). The malformation rate in the autopsied transgenic Göttingen was 58% and in Yucatan 46%; these were significantly higher than in the autopsied cloned LW piglets with 18%. Some of the malformations seemed to be related to breed and/or transgene; for instance, heart malformations were most frequent in Yucatan litters (70%) independent of the transgene, whereas gallbladder and gonad malformations were more frequent in various litters with the same transgene. These results show that the use of cloning in pigs results in a considerable loss of piglets due to malformations and transgenic transformation of the cells used for cloning superimpose on this problem. In combination, these elements could seriously compromise the use of pigs as a model for human diseases and the choice of breeds and also transgenes for this kind of work should be considered carefully. However, further improvements in production of cloned/transgenic embryos may ultimately reduce the incidence of malformations. Table 1.Number of malformations in 54 litters of cloned or transgenic piglets

19 LIFETIME MORTALITY OF CLONED PIGLETS

2014 ◽  
Vol 26 (1) ◽  
pp. 124
Author(s):  
M. Schmidt ◽  
K. D. Winther ◽  
H. Callesen
Keyword(s):  
Perinatal Mortality ◽  
Donor Cell ◽  
Well Being ◽  
Perinatal Period ◽  
Large White ◽  
Significance Level ◽  
Exact Test ◽  
Donor Cells ◽  
Birth Data ◽  
Piglet Mortality

Perinatal mortality of cloned animals is a well-recognised problem, but it is not clear if and how the problems continue throughout the life of cloned animals. Here we report occurrence and causes of lifetime mortality of cloned piglets from their perinatal period and onwards. From 2006 until 2013, 178 Large White (LW) sows received Day 5–6 handmade cloned morulae or blastocysts where donor cells were from LW, Yucatan, or Göttingen, and were either transgenic or not. Pregnancy rate on Day 30 was 73%, but 19% terminated before term, resulting in 104/178 deliveries. For each litter, each piglet was characterised as either alive or stillborn (i.e. dead without signs of autolysis or dying during the first minutes after birth). Data were analysed by Fisher's Exact test with a significance level of P < 0.05. In the 104 litters, stillborn piglets were found in 54 (from 1 to 7 stillborn piglets in a litter), and the highest number of stillborns was found in Göttingen piglets (P < 0.05; see Table 1). Alive piglets were followed and their mortality registered, and they either died spontaneously (arthritis, pericarditis, enteritis, septicemia, lethal malformations) or were killed if they had other malformations, no weight gain, anorexia, bristly hair coat or signs of compromised well-being. Piglet mortality was highest in the perinatal period but remained high until weaning at Day 28 (see Table 1), so almost half of the alive piglets died during the first month; this preweaning mortality was highest in Yucatan piglets (P < 0.05), which also had the highest cumulative mortality. Further analyses are needed to describe differences observed between donor cell breeds. After weaning, where the pigs were kept under standard conditions, the mortality was at the normal level for the farm. Few died of infections with no breed differences, so most were killed over the subsequent months and years for various experimental purposes. The oldest pig lived until 6 years of age. During their life, no differences compared with noncloned pigs were observed in behaviour, growth, occurrence of diseases, or viability. This study confirms the well-known high perinatal mortality of cloned piglets and shows also high mortality until weaning. However, after weaning, mortality was not different from that of noncloned piglets. Table 1.Lifetime mortality rates in cloned piglets of different breeds and at different time periods after birth

scholarly journals The Antibacterial Efficacy of Biopure MTAD in Root Canal Contaminated with Enterococcus faecalis

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Blerim Kamberi ◽  
Donika Bajrami ◽  
Miranda Stavileci ◽  
Shuhreta Omeragiq ◽  
Fatmir Dragidella ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Sodium Hypochlorite Solution ◽  
Antibacterial Efficacy ◽  
Human Teeth ◽  
Exact Test ◽  
Hypochlorite Solution ◽  
Root Canals ◽  
Significant Difference ◽  
Level Of Significance

Aim. The purpose of this in vitro study was to assess the antimicrobial efficacy of Biopure MTAD against E. faecalis in contaminated root canals. Materials and Methods. Forty-two single rooted extracted human teeth were inoculated with E. faecalis and incubated for four weeks. The samples were divided in two control and five experimental groups irrigated with 1.5% sodium hypochlorite solution (NaOCl); 3% NaOCl; BioPure MTAD; 1.5% NaOCl/17% EDTA; or 3% NaOCl/17% EDTA. After a one-week incubation, complete disinfection was confirmed by the absence of turbidity in the incubation media. Dentin shavings were taken from samples with no turbidity to verify whether E. faecalis was present in dentin tubules. Results were analyzed statistically using Fisher's exact test, with the level of significance set at . Results. Statistical analysis of the data obtained at Day 7 and after dentin shaving analysis showed that BioPure MTAD had significantly greater antibacterial activity than 1.5% NaOCl, 1.5% NaOCl/17% EDTA and 3% NaOCl/17% EDTA. No significant difference was detected between MTAD and 3% NaOCl. Conclusions. These findings suggest that BioPure MTAD possesses superior bactericidal activity compared with NaOCl and EDTA against E. faecalis.

Materials Sealing Preventing Biofilm Formation in Implant/Abutment Joints: Which Is the Most Effective? A Systematic Review and Meta-Analysis

2020 ◽  
Vol 46 (2) ◽  
pp. 163-171
Author(s):  
Cecília Alves de Sousa ◽  
Maria Beatriz Bello Taborda ◽  
Gustavo Antônio Correa Momesso ◽  
Eduardo Passos Rocha ◽  
Paulo Henrique dos Santos ◽  
...  
Keyword(s):  
Systematic Review ◽  
Biofilm Formation ◽  
Meta Analysis ◽  
Significance Level ◽  
Gutta Percha ◽  
Significant Difference ◽  
Physical Barriers ◽  
External Connection

The purpose of this systematic review was to evaluate the literature available for materials exhibiting the best efficacy in preventing biofilm formation in the interior of implants. We searched PubMed/MEDLINE, Scopus, and Cochrane databases. This review is registered with the PROSPERO database and followed the suitability of the PRISMA protocol. The initial search resulted in 326 articles from the databases. After they were read, 8 articles remained, and the inclusion and exclusion criteria were applied. Six of these 8 articles were classified as in vitro and 2 were classified as in situ. The regions of the implants evaluated ranged from the interface of the pieces to the occlusal upper access of the abutment. The implant connections evaluated the Morse taper, external connection, and internal connection. Meta-analysis of the quantitative data was performed at a significance level of .05. Cotton exhibited poor control of infiltration, even in combination with other materials. Isolated gutta-percha (GP) and polytetrafluoroethylene (PTFE) tape with composite resin (CR) or GP performed better as physical barriers. The best results for chemical barriers were observed by the application of 1% chlorhexidine gluconate (CG) gel, thymol varnish, and the deposition of Ag films onto the surface. The applied meta-analysis did not show a significant difference in comparison between the different types of implant connections (P &gt; .05). The application of CG and thymol varnish antimicrobials was effective in preventing biofilm formation and easy clinical execution; these could be used in combination with CR, GP, and PTFE.

52 INITIATION OF PREGNANCIES IN SOUTH AFRICAN RIVERINE RABBIT (BUNOLAGUS MONTICULARES) BY INTERSPECIES NUCLEAR TRANSFER USING ADIPOSE-DERIVED SOMATIC CELLS

2008 ◽  
Vol 20 (1) ◽  
pp. 106
Author(s):  
M. J. Sansinena ◽  
D. Owiny ◽  
R. S. Denniston ◽  
D. Salamone ◽  
D. Barry
Keyword(s):  
In Vitro Culture ◽  
Nuclear Transfer ◽  
Uv Light ◽  
Uv Exposure ◽  
Domestic Rabbit ◽  
Donor Cells ◽  
Significant Difference ◽  
Preliminary Study ◽  
Interspecies Nuclear Transfer

The riverine rabbit (Bunolagus monticulares), one of South Africa's most threatened mammals, with an estimated population size under 250, was upgraded from endangered to critically endangered in 2002. The low number of riverine rabbits precludes any attempts of nuclear transfer (NT) using intraspecific oocytes; therefore, the overall aim of this study was to assess the ability of the domestic rabbit (Oryctolagus cuniculus) oocyte to reprogram the somatic cell of the endangered riverine rabbit by interspecies NT. A preliminary study evaluated the effect of timing of enucleation after induction of ovulation (h post-hCG). A second study assessed the effects of two activation protocols. In addition, since the unique characteristics of the rabbit zona pellucida affect the speed of micromanipulation, different exposure periods to UV light at enucleation were evaluated. Adult domestic Californian rabbits were treated with eCG for 72 h, and ovulation was induced by hCG administration. Oocytes were collected by retrograde flushing at 12–14 h or 16–18 h post-hCG administration and stripped of cumulus investments with 0.5% hyaluronidase in Ca-Mg-free PBS. Metaphase-II oocytes were selected by visualizing the first polar body. Oocytes were stained with 2 mg mL–1 Hoechst 33342 for 5 min, and metaphase plates were removed with a 25–30 μm (O.D.) borosilicate beveled, spiked pipette after exposure to <5 or 30–40 s of UV light. Adult adipose-derived riverine rabbit fibroblasts grown to confluency in DMEM with 10% FCS were used as donor cells and fused with 2 consecutive DC pulses (3.2 kV cm–1, 45 μs). After reconstruction, couplets were randomly assigned for activation by either a second set of electrical pulses or incubation with ionomycin, followed by 1 h of incubation in 2 mm 6-DMAP. Embryos were co-cultured with a bovine oviductal cell monolayer in DMEM with 10% FCS and assessed for cleavage after 36 h of in vitro culture. There was a significant difference in the number of cleaved embryos from oocytes collected at 12–14 h post-hCG (n = 50) or 16–18 h post-hCG (n = 51) administration (57% v. 0% cleaved; P < 0.05). No significant difference was detected in embryos developing after electrofusion v. ionomycin activation treatments. However, a significantly greater number (P < 0.05) of embryos cleaved from oocytes exposed to <5 s UV than from oocytes exposed to 30–40 s UV (Table 1). A total of 20 embryos (4-cell to 16-cell stages) were surgically transferred to the oviducts of 4 adult New Zealand white synchronized recipients after 48 h of in vitro culture. Two recipients (<5 s UV exposure treatment group) were diagnosed pregnant by abdominal palpation at 15 days post-transfer; pregnancies were subsequently lost by Day 30, with placental tissues recovered. This preliminary study indicates the domestic rabbit oocyte is capable of reprogramming riverine rabbit donor cells. In addition, the time of oocyte collection after ovulation induction and the UV exposure period during enucleation have an effect on the efficiency of interspecies NT and embryo development in this species. Table 1. Effect of UV exposure during enucleation on the in vitro development of interspecies nuclear transfer riverine rabbit embryos

Effects of Load Cycling on the Microleakage of Beveled and Nonbeveled Margins in Class V Resin-Based Composite Restorations

2010 ◽  
Vol 11 (5) ◽  
pp. 25-32 ◽  
Author(s):  
Hamideh Ameri ◽  
Marjaneh Ghavamnasiri ◽  
Ehsan Abdoli
Keyword(s):  
High Speed ◽  
Class V ◽  
Significance Level ◽  
Gingival Margin ◽  
Composite Restorations ◽  
Nail Polish ◽  
Significant Difference ◽  
Load Cycling ◽  
Composite Restoration

Abstract Aim This study evaluated the influence of mechanical loading and thermocycling on microleakage of class V resin-based composite restorations with and without enamel bevel. Methods and Materials Sixty class V cavity preparations measuring 3.0 mm wide (mesiogingivally) x 2.0 mm high (occluso-gingivally) x 1.5 mm deep with the occlusal margin in enamel and the gingival margin in cementum were prepared on the buccal surfaces of human premolars using a #12 diamond round bur (Drendel & Zweiling Diamant GmbH, Lemgo, Germany) in a high-speed, water-cooled handpiece. The specimens were then divided into two groups of 30 specimens each, based on the type of enamel cavosurface margin configuration as beveled or nonbeveled (butt joint). After restoring the preparations with a flowable resin-based composite (Tetric Flow, Ivoclar Vivadent-AG, Schaan, Liechtenstein) and finishing and polishing with sequential discs (Sof-Lex Pop-on, 3M-ESPE, St. Paul, MN, USA), the teeth were stored at 37°C and 100 percent humidity. Twenty-four hours later, half of the specimens in each group (nonbeveled “N” or beveled “B”) were exposed to a cycling loading for 250,000 cycles to simulate occlusal loading and assigned to two subgroups (NL+ or BL+), while the remainder of the specimens in each group were only maintained in a 100-percent-humidity environment, without any cyclical loading, until tested (NL– or BL–). The specimens were sealed with sticky wax (Kemdent, Associated Dental Products, Swindon, UK) and nail polish. The apical foramen of each tooth was sealed with sticky wax and the rest of the tooth was covered with nail varnish, except for an area within 1.0 mm around the composite restoration. To detect marginal leakage, all of the samples were stored in a 0.5 percent basic fuchsine solution for 24 hours. The specimens were then sectioned longitudinally using a low-speed diamond blade (IsoMet, Buehler Ltd., Lake Bluff, IL, USA), machined, and evaluated under 25X magnification using a stereomicroscope (M9, Wild Heerbrugg, Switzerland). The specimens were scored on a scale from 1 to 4 on the degree of dye penetration. The qualitative data were analyzed by the Mann- Whitney U test at a 5 percent significance level (p<0.05). The null hypothesis of this study was that there is no difference in microleakage between beveled and nonbeveled class V buccal preparations in premolar teeth restored with resinbased composite and subjected to simulated occlusal loading and thermocycling. Results In each group the gingival margin showed significantly more microleakage than the enamel margin (p<0.05). Load cycling did not result in an increase in microleakage in nonbeveled (p=0.259) or in beveled (p=0.053) occlusal margins. However, the gingival margins showed a statistically significant difference in microleakage after load cycling whether in cavities with enamel occlusal bevel (p=0.004) or in groups without a bevel. This means the enamel margin configuration of the enamel occlusal margin had no effect on decreasing microleakage in the gingival aspect of class V composite restorations. In general, the nonbeveled preparations in this study had significantly less microleakage than the bevel specimens whether they were loaded occlusally or not (p=0.001). Clinical Significance Within the limitations of this in vitro study, no benefit was derived from placing an enamel cavosurface bevel on the occlusal margin of a standardized class V composite restoration located at the cementoenamel junction. The most important consideration is to prevent microleakage along the gingival margin regardless of whether the occlusal enamel margin is beveled. Citation Ameri H, Ghavamnasiri M, Abdoli E. Effects of load cycling on the microleakage of beveled and nonbeveled occlusal margins in class V resin-based composite restorations. J Contemp Dent Pract [Internet]. 2010 October; 11(5):025- 032. Available from: http://www.thejcdp.com/ journal/view/volume11-issue5-ghavamnasiri

A phase II, randomized, double blind comparison of calcium aluminosilicate clay (CASAD) versus placebo (dibasic calcium carbonate) for the prevention of diarrhea in patients (pts) with metastatic colorectal cancer (mCRC) treated with irinotecan (I).

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3600-3600
Author(s):  
Bryan K. Kee ◽  
Rebecca Slack ◽  
Todd S. Crocenzi ◽  
Lucas Wong ◽  
Benjamin Esparaz ◽  
...  
Keyword(s):  
Phase Ii ◽  
Performance Status ◽  
Symptom Burden ◽  
Active Metabolites ◽  
Serious Adverse Events ◽  
Double Blind ◽  
Significance Level ◽  
Significant Difference ◽  
Grade 3

3600 Background: CASAD is a naturally occurring calcium montmorrilonite clay that serves as a cation exchange absorbent. One of the active metabolites of Irinotecan is SN-38, which is adsorbed by CASAD in vitro. The study hypothesis was that oral CASAD would reduce the rate of grade 3/4 diarrhea in mCRC patients treated with irinotecan. Methods: The study is a multicenter, prospective, randomized, double blinded placebo-controlled phase II trial. One hundred patients receiving I-based chemotherapy were randomized equally between CASAD (1000 mg po 4x daily) and placebo in order to have 75% power to detect a difference in the proportions of patients with grade 3/4 diarrhea within 6 weeks at a 1-sided 5% significance level. We also compared symptom burden using the MDASI questionnaire summed over the 13 symptom items for weeks 0, 3, 5, and 6. Results: Between 5/2009 and 5/2012, 100 patients were randomized in a 1:1 ratio between study arms. Median age 57 yrs, 54% male, 74% Non-Hispanic White, 93% performance status 0 or 1. Serious diarrhea was less frequent than expected based upon prior studies with Irinotecan. In evaluable patients, no significant difference in the rate of G3/4 diarrhea was seen (the primary endpoint): CASAD arm: 7/43 pts (16%), Placebo arm: 3/32 pts (9%), p=0.70. The rate of any diarrhea among all pts was also similar: CASAD arm 64% vs. Placebo arm 70%. The rate of study dropout was 14% in CASAD and 38% for placebo (p=0.01; 2-sided). No differences were found in symptom burden or individual symptom items or serious adverse events. Conclusions: Compared with placebo, CASAD use was safe but ineffective in preventing diarrhea in mCRC patients treated with irinotecan-containing chemotherapy regimens. There were no favorable or unfavorable signals in terms of the patient experience related to symptoms, but there were significantly more dropouts in the placebo arm. Future CASAD trials are focused on active treatment of diarrhea. Clinical trial information: NCT00748215.

Marginal Gap Formation in Approximal “Bulk Fill” Resin Composite Restorations After Artificial Ageing

2018 ◽  
Vol 43 (2) ◽  
pp. 180-189 ◽  
Author(s):  
A Peutzfeldt ◽  
S Mühlebach ◽  
A Lussi ◽  
S Flury
Keyword(s):  
Tap Water ◽  
Resin Composite ◽  
Class Ii ◽  
Artificial Ageing ◽  
Resin Composites ◽  
Gap Formation ◽  
Marginal Gap ◽  
Significance Level ◽  
Significant Difference

SUMMARY The aim of this in vitro study was to investigate the marginal gap formation of a packable “regular” resin composite (Filtek Supreme XTE [3M ESPE]) and two flowable “bulk fill” resin composites (Filtek Bulk Fill [3M ESPE] and SDR [DENTSPLY DeTrey]) along the approximal margins of Class II restorations. In each of 39 extracted human molars (n=13 per resin composite), mesial and distal Class II cavities were prepared, placing the gingival margins below the cemento-enamel junction. The cavities were restored with the adhesive system OptiBond FL (Kerr) and one of the three resin composites. After restoration, each molar was cut in half in the oro-vestibular direction between the two restorations, resulting in two specimens per molar. Polyvinylsiloxane impressions were taken and “baseline” replicas were produced. The specimens were then divided into two groups: At the beginning of each month over the course of six months' tap water storage (37°C), one specimen per molar was subjected to mechanical toothbrushing, whereas the other was subjected to thermocycling. After artificial ageing, “final” replicas were produced. Baseline and final replicas were examined under the scanning electron microscope (SEM), and the SEM micrographs were used to determine the percentage of marginal gap formation in enamel or dentin. Paramarginal gaps were registered. The percentages of marginal gap formation were statistically analyzed with a nonparametric analysis of variance followed by Wilcoxon-Mann-Whitney tests and Wilcoxon signed rank tests, and all p-values were corrected with the Bonferroni-Holm adjustment for multiple testing (significance level: α=0.05). Paramarginal gaps were analyzed descriptively. In enamel, significantly lower marginal gap formation was found for Filtek Supreme XTE compared to Filtek Bulk Fill (p=0.0052) and SDR (p=0.0289), with no significant difference between Filtek Bulk Fill and SDR (p=0.4072). In dentin, significantly lower marginal gap formation was found for SDR compared to Filtek Supreme XTE (p&lt;0.0001) and Filtek Bulk Fill (p=0.0015), with no significant difference between Filtek Supreme XTE and Filtek Bulk Fill (p=0.4919). Marginal gap formation in dentin was significantly lower than in enamel (p&lt;0.0001). The percentage of restorations with paramarginal gaps varied between 0% and 85%, and for all three resin composites the percentages were markedly higher after artificial ageing. The results from this study suggest that in terms of marginal gap formation in enamel, packable resin composites may be superior to flowable “bulk fill” resin composites, while in dentin some flowable “bulk fill” resin composites may be superior to packable ones.

scholarly journals INFLUÊNCIA DA MODIFICAÇÃO DA BASE DE COLAGEM E DA CONTAMINAÇÃO SALIVAR NA RESISTÊNCIA DE UNIÃO DE TUBOS ORTODÔNTICOS COLADOS AO ESMALTE HUMANO

2021 ◽  
Vol 58 (1) ◽  
pp. eUJ3657
Author(s):  
Germano Brandão ◽  
◽  
Liliana Ávila Maltagliati ◽  
Ana Carla Raphaelli Nahás-Scocate ◽  
Murilo Matias ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Statistical Significance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Metal Mesh ◽  
Human Teeth ◽  
Significance Level ◽  
Significant Difference

The objective of this in vitro study was to assess and compare the shear bond strength of conventional and modified orthodontic tubes bonded to the surface of dry and saliva-contaminated enamel. The sample consisted of 40 human teeth, which were randomly divided into four groups according to attachment base and presence or absence of saliva contamination as follows: Group CB, conventional orthodontic tubes without salivary contamination; Group CB-S, conventional orthodontic tubes with salivary contamination; Groups BM, orthodontic tubes modified by welding a metal mesh to their base without salivary contamination; and Group BM-S, modified orthodontic tubes with salivary contamination. Shear bond strength test was performed in a universal testing machine and analysis of the adhesive remnant index (ARI) by optical microscopy. Two-way ANOVA was used, followed by Tukey’s test at a statistical significance level of 5%. The ARI results were analysed descriptively. There was statistically significant difference between the groups regarding the shear bond strength values, with conventional tubes presenting significantly higher values (P < 0.05). In addition, the presence of salivary contamination interfered negatively with the behaviour of conventional tubes only (P < 0.05). Shear bond strength was not improved by increasing the area of the orthodontic tubes. Moreover, salivary contamination influenced negatively the SBS values, but only when conventional tubes were used.

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