Human tooth germ stem cell response to calcium-silicate based endodontic cements

Objective

The aim of this study was to compare the cytotoxic effects of endodontic cements on human tooth germ stem cells (hTGSCs). MTA Fillapex, a mineral trioxide aggregate (MTA)-based, salicylate resin containing root canal sealer, was compared with iRoot SP, a bioceramic sealer, and AH Plus Jet, an epoxy resin-based root canal sealer.

Material and Methods

To evaluate cytotoxicity, all materials were packed into Teflon rings (4 mmµ3 mm) and co-cultured with hTGSCs with the aid of 24-well Transwell permeable supports, which had a pore size of 0.4 µm. Coverslips were coated with MTA Fillapex, iRoot SP and AH Plus Jet and each coverslip was placed onto the bottom of one well of a six-well plate for scanning electron microscopy (SEM) analysis. Before the cytotoxicity and SEM analysis, all samples were stored at 37ºC and at 95% humidity and 5% CO₂ for 24 hours to set. The cellular viability was analyzed using MTS test (3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H-tetrazolium). The cytotoxic effects and SEM visualization of the tested materials were analyzed at 24-hour, 72-hour, one-week and two-week periods.

Results

On the 1^st day, only MTA Fillapex caused cytotoxicity compared to negative control (NC) group (p<0.008). No significant difference was observed between the other tested materials at this period (p>0.05). After 14 days of incubation with the test materials, MTA Fillapex exhibited significantly higher cytotoxicity compared with iRoot SP, AH Plus Jet and the NC group (P<0.008). In the SEM analysis, the highest levels of cell attachment were observed for iRoot SP and the control group. After 24 hours, MTA Fillapex reduced the number of cells attached to the surface.

Conclusions

Within the limitations of this study, sealers exerted different cytotoxic effects on hTGSCs. Although all materials have exerted cellular toxicity, iRoot SP and AH Plus Jet may promote better attachment to hTGSCs.     

Urolithiasis in infants: evaluation of risk factors

Objective

Urolithiasis in infants is not a very rare situation in Turkey, and the incidence has been increasing in recent years. The purpose of this paper was to investigate the clinical characteristics, metabolic and anatomic risk factors for urolithiasis and microlithiasis in infants.

Methods

The cases of 178 infants (63 girls, 115 boys), who were referred to our department between 1999 and 2009 with urolithiasis, were evaluated.

Results

The mean age at diagnosis of stone disease was 11.5 months (range, 10 days–24 months). The mean follow-up duration was 33.6 months (1.2–110 months). The major clinical symptoms of our patients were restlessness in 24 children (13.5%) and vomiting in 23 (13%). Thirty-five infants (19.7%) had a urinary tract abnormality; vesico-ureteral reflux was the most common abnormality (12.9%). Hypercalciuria and hyperuricosuria were detected in 46 and 56%, respectively. Stone analysis was performed in 56 infants, and calcium oxalate was determined in 36 patients (64.3%). A family history of urolithiasis, presenting symptoms and underlying metabolic abnormalities were similar for patients with microlithiasis and those with larger stones. However, infants with microlithiasis had higher ratios for history of vitamin D administration and feeding with formula. Surgical treatment was performed in 42 infants and extracorporeal shock wave lithotripsy in 30 infants.

Conclusion

Our results showed that urolithiasis in infants may present nonspecific symptoms and may even be asymptomatic and that a positive family history for urolithiasis, urologic abnormalities, metabolic disorders, urinary tract infections, vitamin D administration and feeding with formula may increase the occurrence of urolithiasis in infants.     

The status of mineral trioxide aggregate in endodontics education in dental schools in Turkey

The aim of this study was to assess the current status of mineral trioxide aggregate (MTA) as an educational material in dental schools in Turkey. A survey was sent to senior members of the endodontic departments of seventeen dental schools; fourteen responded. All respondents reported that they used MTA in their clinical practice, with apexification, perforations, retrograde fillings, and root resorptions being the most frequently occurring treatment procedures. All reported that information was given to students regarding MTA mainly as part of the curriculum. The third and fourth years were the periods when MTA was introduced to students in most of the schools. Twelve schools reported that students had the opportunity to observe procedures in which MTA was used, but students had the chance to use the material in a very minor proportion of the schools, mainly under the supervision of clinical instructors. Ten schools agreed that MTA should be included in the regular endodontic curriculum. Financial constraints seemed to be the predominant reason for those who answered this question negatively, followed by difficult handling properties and low radiopacity of the material. Within the limitations of this study, it can be concluded that ways should be sought to prevent financial difficulties from depriving dental students of the opportunity to receive information about contemporary methodologies such as MTA utilization.     

Age-related characteristics of breast invasive ductal carcinoma

377 patients aged 30 to 79 years who had breast carcinoma were examined to study the age-related features of tumor anaplasia. The degree of tumor anaplasia was studied, in primary nodules, less and more than 2.5 cm in diameter in patients of different ages. This index decreased with age. This may explain more a malignant course of the disease in young patients.     

Alteration of thiol-disulfide homeostasis in workers occupationally exposed to arsenic

This study evaluates the redox state in occupationally arsenic-exposed workers (n = 71) by assessing the dynamic serum thiol-disulfide homeostasis. We determined the serum thiol-disulfide homeostasis parameters of exposed workers and controls (n = 43) using a novel automated colorimetric assay. Median urinary As and 8-isoprostane levels of exposed group were significantly higher than control group (16.40 μg/L vs 2μg/L, p < .001 and 2.28 ng/ml vs 0.54 ng/ml, p < .001, respectively). Disulfide level, disulfide/native thiol ratio, and disulfide/total thiol ratio were significantly higher in exposed group. The mean ceruloplasmine and myeloperoxidase activities of As-exposed group were significantly higher than control group (117.15 U/L vs 87.02 U/L, p = .035 and 148.53 U/L vs 97.75 U/L, p = .000, respectively). The median catalase activity did not differ in the two groups. Our findings revealed that As disrupts the thiol-disulfide homeostasis in favor of disulfide.     

Impact of total body weight on acute kidney injury in patients with gram-negative bacteremia

Background: The impact of total body weight (TBW) on the development of acute kidney injury (AKI) associated with gram-negative bacteremia has not been previously evaluated.

Methods: The cohort included 323 patients >/ = 18 years old with gram-negative bacteremia (1/1/2008–8/31/2011) who received >/ = 48 hours of antibiotics. We compared the incidence of AKI in patients with a TBW </ = 80kg vs. >80kg with a multivariable stepwise logistic regression adjusting for age >/ = 70 years, baseline serum creatinine of > 2.0 mg/dl, and receipt of a vasopressor. AKI was defined as an increase of 0.5 mg/dL or a > 50% increase from baseline for at least two consecutive days.

Results: The cohort was 62% TBW </ = 80kg and 38% TBW >80kg. TBW >80kg patients had higher risk of AKI (24% vs. 9%, p < 0.001), which was significant in the multivariable analysis (OR 3.41, 95% CI 1.73–6.73). A baseline serum creatinine of > 2.0 mg/dl and vasopressor use were also independently associated with AKI.

Conclusions: TBW >80kg was associated with the development of AKI. However, the mechanism for this association is not clear.     

Dosing strategies to optimize currently available anti-MRSA treatment options (Part 2: PO options)

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a problematic pathogen in both outpatient and inpatient settings. Research to optimize the dosing of these agents is needed to slow the development of antimicrobial resistance and to decrease the likelihood of clinical failure.

Areas covered: This review summarizes the available data for orally administered antimicrobials routinely used as monotherapy for MRSA infections. We make recommendations and highlight the current gaps in the literature. A PubMed (1966 – Present) search was performed to identify relevant literature for this review.

Expert commentary: There is a vast divide in the amount of pharmacokinetic/pharmacodynamic data to guide dosing decisions for older MRSA agents compared with the oxazolidenones.

Five-year view: Additional retrospective data will become available for the older MRSA agents in severe MRSA infections.     

Platelet function testing during 5-day storage of single and random donor plateletpheresis.

Platelet concentrates are routinely manufactured from whole blood by differential centrifugation (random donor platelets-RDP) or by plateletpheresis (single donor platelets-SDP). These platelet concentrates have a storage period of 5 days and many different approaches exist to measure the condition of platelets during their storage. In this study, platelet aggregation testing using adenosine diphosphate (ADP) and collagen and flow cytometric platelet activation analysis using CD41 FITC and CD62 PE before and after ADP was performed on days 1, 3 and 5 of storage of platelet preparations. Thirty three RDPs, stored in Baxter and Kansuk blood bags and 18 SDPs stored in Fresenius blood bags were evaluated. In RDPs and in SDPs; ADP and collagen induced PA responses were decreased significantly on the 3rd and 5th days compared to 1st day. CD62 positive platelet percentage after ADP were decreased significantly on the 3rd and 5th days compared to the 1st day in Kansuk((R)) bags. Flow cytometric analysis revealed minor changes in CD41 expression after ADP on the 3rd day compared to 1st day and on the 5th day compared to 3rd day. Differences in CD62 positive platelet percentage were not significant between the RDPs and SDPs. Our results suggest that: (1) ADP and collagen induced PA responses decrease both in RDPs and SDPs during storage. (2) Flow cytometric analysis does not show major significant changes in platelet activation after ADP during storage. (3) Continous shaking on the agitator does not cause a significant change in CD62 positive platelet percentage during storage. (4) Platelet aggregation responses in RDPs stored in Baxter((R)) and Kansuk((R)) blood bags do not differ during storage.