Porcelain surface treatment by laser for bracket-porcelain bonding.

INTRODUCTION: The purposes of this study were to investigate the effect of laser irradiation on the adhesion of brackets bonded to feldspathic porcelain and to compare it with brackets bonded with conventional techniques. METHODS: One hundred porcelain-fused-to-metal specimens were divided into 10 groups of 10. The treatment groups were sandblasted (SB), sandblasted with silane (SB+S), orthophosphoric acid (OFA), orthophosphoric acid with silane (OFA+S), hydrofluoric acid (HFA), hydrofluoric acid with silane (HFA+S), laser etched (L), laser etched with silane (L+S), glazed (Control 1/C1), and deglazed (Control 2/C2). Five other specimens were irradiated by 2-, 3-, 5-, 10-, and 15-watt superpulse carbon dioxide (CO2) laser for 20 seconds and examined by scanning electron microscopy. Metal brackets were bonded with a self-cure composite material and the specimens were stored in water at 37 degrees C for 24 hours and then thermocycled in water baths between 5 degrees C and 55 degrees C 500 times. Bond strength was determined in megapascals (MPa) by shear test at 1 mm/minute crosshead speed. Bond failure modes were observed under stereomicroscope. For the statistical analysis, 1-way ANOVA and Tamhane post hoc test were used. RESULTS: Statistical analysis showed significant differences between the groups at the .05 level. The HFA+S group yielded the highest mean strength (15.07 +/- 1.44). This was followed by SB+S (13.81 +/- 2.00), HFA (10.78 +/- 0.62), OFA+S (10.73 +/- 1.12), L+S (8.25 +/- 0.90), L (6.26 +/- 0.58), C2 (2.45 +/- 0.54), OFA (2.36 +/- 0.41), SB (2.04 +/- 0.41), and C1 (1.64 +/- 0.33). The bond failure modes of HFA and silane groups, except L+S, were cohesive in porcelain. Control groups and other test groups showed adhesive failure. Only irradiation by 2 watts for 20 seconds provided a porous surface texture without cracks. CONCLUSIONS: Two-watt/20 second superpulse CO2 laser irradiation might be an alternative conditioning method for pretreating ceramic surfaces. Increased bond strength can be achieved by silanation after CO2 laser irradiation.     

Michael J. Simmonds1, Herbert J. Meiselman2, Oguz K. Baskurt3

The flow properties of blood play significant roles in tissue perfusion by contributing to hydrodynamic resistance in blood vessels. These properties are influenced by pathophysiological processes, the...     

Tissue Oxygen Demand in Regulation of the Behavior of the Cells in the Vasculature

The control of arteriolar diameters in microvasculature has been in the focus of studies on mechanisms matching oxygen demand and supply at the tissue level. Functionally, important vascular elements include EC, VSMC, and RBC. Integration of these different cell types into functional units aimed at matching tissue oxygen supply with tissue oxygen demand is only achieved when all these cells can respond to the signals of tissue oxygen demand. Many vasoactive agents that serve as signals of tissue oxygen demand have their receptors on all these types of cells (VSMC, EC, and RBC) implying that there can be a coordinated regulation of their behavior by the tissue oxygen demand. Such functions of RBC as oxygen carrying by Hb, rheology, and release of vasoactive agents are considered. Several common extra‐ and intracellular signaling pathways that link tissue oxygen demand with control of VSMC contractility, EC permeability, and RBC functioning are discussed.     

Neutrophil gelatinase-associated lipocalin as a biomarker for acute kidney injury in patients undergoing coronary artery bypass grafting

BACKGROUND/OBJECTIVE:

The development of acute renal injury (ARI) is an important indicator of clinical outcomes after cardiac surgery. Neutrophil gelatinase-associated lipocalin (NGAL) has been certified as a predictive biomarker of hypoxic ARI. The present study aimed to determine the predictive role of NGAL in coronary bypass graft (CABG) surgery.

METHOD:

A total of 72 consecutive patients undergoing elective CABG were enrolled in the study. NGAL levels were determined preoperatively and postoperatively after 6 h, 24 h and 72 h for all participants. The participants were then divided into two groups according to their preoperative creatinine levels (group I, creatinine 111.38 μmol/L to 361.55 μmol/L; group II, creatinine <111.38 μmol/L).

RESULTS:

There was no statistically significant difference between the groups according to their NGAL values (P>0.05), except at 6 h (P=0.045). Three patients required continuous hemodialysis. Comparison of the NGAL levels of these three patients with those of the other participants did not reveal any correlation with serum creatinine levels. In contrast, the NGAL levels were significantly lower in the continuous hemodialysis patients (1.9±1 ng/mL) compared with those of the other participants (22.6±12.8 ng/mL; P=0.001).

CONCLUSION:

NGAL is one of the most frequently used biomarkers for ARI after cardiac operations, especially in younger patients. The participants in the present study were coronary artery disease patients and were, therefore, older than patients in previous reports. These results support the view that NGAL is not a relevant predictive factor for ARI in patients with CABG, including older patients.     

Retinal Toxicity of Intraocular Vancomycin and Ceftazidime in Vitrectomized Rabbit Eyes

The purpose of this study was to evaluate the retinal toxicity of vancomycin and ceftazidime combined into an infusion solution that was intraoculary given after or during vitrectomy. Forty albino rabbits were divided into 4 groups of 10 each. Vitrectomized right eyes of groups 1, 2, and 3 were given recommended doses of vancomycin and ceftazidime alone or combined, while right eyes in the fourth group were vitrectomized using an infusion solution to which was added ceftazidime and vancomycin combination. Toxicity was tested with electroretinography (ERG) and light microscopy. ERG and light microscopy did not show any toxicity signs associated with vancomycin or ceftazidime alone or with combined therapy. Vancomycin and/or ceftazidime can reliably and effectively be used combined in an infusion solution at recommended doses after and during vitrectomy. This treatment modality does not have any toxic effects to retinal structures and is an alternative method to separate injections of the two antimicrobial agents.     

Percutaneous treatment of hydatid liver cysts in children as a primary treatment: long-term results

PURPOSE: To evaluate the effectiveness and long-term results of percutaneous treatment for hydatid liver cysts in pediatric patients. MATERIALS AND METHODS: Thirty-four pediatric patients (15 male, 19 female; ages 4-17 years; mean age, 9.4 years) with 51 hydatid liver cysts underwent ultrasound (US)-guided percutaneous treatment with albendazole prophylaxis. There were 15 type II lesions with membrane detachment and 36 type I lesions resembling simple hepatic cysts with pure anechogenic content or small echogenic reflections and a regular well-delineated wall. The method of US-guided puncture, aspiration, injection of hypertonic saline solution, and reaspiration was preferred for 21 lesions. For the remaining 30 larger cysts, the intervention was performed with the same percutaneous technique but followed by catheterization, drainage, control cystography, and sclerotherapy with ethanol. During follow-up, US examinations were performed at 1, 3, 6, and 12 months for the first year and yearly thereafter. RESULTS: Percutaneous treatment of hepatic hydatid disease was successful in 33 patients (97.1%). During follow-up, US findings in the lesions changed significantly; at year 1, the inner content of the lesions became heterogeneous with a semisolid appearance, and the mean reduction in volume was 81.4%. At 2-year follow-up, most hydatid cysts had become solid in nature and the reduction in volume reached 65%-99% (mean, 85.1%). There were no recurrences or additional lesions after the follow-up of 1-6 years (mean, 3.1 years). Average hospital stay for the whole group in this study was 3.5 days. CONCLUSIONS: The long-term results of percutaneous liver hydatid cyst treatment in children are in accordance with the results in adults. Percutaneous treatment of uncomplicated type I and type II liver hydatid cysts in pediatric patients is an efficient and safe treatment with short hospitalization.     

Tc-99m pyrophosphate scintigraphy for cardiac amyloidosis: concordance between planar and SPECT/CT imaging

The International Journal of Cardiovascular Imaging - The imaging protocol and the optimal cut-off points for quantitative assessment of technetium-99m pyrophosphate (Tc-99m PYP) cardiac...     

Survival of Bifidobacterium longum and its effect on physicochemical properties and sensorial attributes of white brined cheese

Survival of the probiotic adjunct culture Bifidobacterium longum and cheese starters during ripening of white brined cheese, effect of the probiotic culture on physicochemical properties and sensorial attributes of cheeses were investigated throughout 90?d of ripening. Bifidobacterium longum were able to survive at higher levels (>10^7?cfu/g cheese) than the therapeutic minimum (10⁶–10^7?cfu/g cheese) after 90?d and did not have any negative effect on the survival of Streptococcus spp. (including common cheese starters). Incorporation of the probiotic adjunct into white brined cheese and high levels of their survival rates during ripening had an insignificant effect on the composition of cheeses. Results indicated that white brined cheese is a suitable food matrix for the delivery of B. longum used in this study, and white brined cheeses with B. longum may be considered as a probiotic dairy product.