Comparison of the translucency of shaded zirconia all-ceramic systems

PURPOSE

The purpose of this study was to evaluate and compare the translucency of shaded zirconia all-ceramic systems.

MATERIALS AND METHODS

Translucency of 3 different zirconia all-ceramic systems colored by different techniques was compared with a lithium disilicate glass-ceramic (IPS e.max Press). Square-shaped specimens with 0.5 mm thickness were fabricated from In-Ceram YZ, ICE Zirkon and Katana systems in A1, A2 and A3.5 shades according to Vitapan Classical shade tab (n=11). Specimens were then veneered and glazed with corresponding veneer ceramic recommended by each zirconia system manufacturer and the total thickness was set to 1.5 mm. Translucency measurements were performed with VITA Easyshade Compact spectrophotometer after each stage and translucency parameter was calculated. Data were statistically analyzed with repeated measures ANOVA and Tukey multiple comparison test.

RESULTS

The control group was significantly more translucent than the zirconia systems (P<.05). ICE Zirkon cores showed the least translucency; neither In-Ceram YZ nor Katana systems were superior to each other in terms of translucency. Translucency of all specimens was decreased after veneering, and the translucency rankings were changed.

CONCLUSION

Coloring technique did not have a significant effect on translucency of zirconia cores. Although zirconia systems were less translucent than lithium disilicate glass ceramic, they had partial translucency and there were translucency differences among the zirconia systems. Chroma affected the translucency of precolored zirconia cores.     

The effect of varicocele repair on testicular volume in children and adolescents with varicocele

PURPOSE: We investigated the effect of varicocele repair on testicular volume according to age in children and adolescents and review the long-term results of varicocele surgery. MATERIALS AND METHODS: The study included 39 boys 11 to 19 years old with clinical palpable varicocele who underwent varicocele surgery with at least 1 year of postoperative followup. Preoperative and postoperative testicular volumes were monitored and measured with an ellipsoid Prader orchidometer. Physical examination findings (testicular volumes and testicular consistency) in all boys, and serum hormone values and semen parameters in 16 adolescents were recorded and compared before and after surgery. RESULTS: Left unilateral varicocelectomy was done in 29 boys (74%) and bilateral varicocelectomy in 10 (26%). While no postoperative hematoma, infection or testicular atrophy was observed, 1 boy (2.5%) had varicocele recurrence and 2 boys (5.1%) had minimal hydroceles that required no intervention. Significant increases were observed in postoperative sperm concentration (p = 0.01), total motile sperm count (p = 0.009), testis volume (p = 0.000) and serum testosterone level (p = 0.014). All 15 boys with preoperative soft testis had normal testicular consistency postoperatively. Of the 19 boys with preoperative testicular atrophy 10 (53%) did regain normal testicular growth, while 9 (47%) retained testicular volume loss after surgery. When comparing preoperative to postoperative increase in testicular volume according to age in all boys, the mean was statistically significantly higher in boys younger than 14 years (left testis p = 0.037, right testis p = 0.000). CONCLUSIONS: Testicular consistency achieved normal firmness after varicocelectomy in all boys with preoperative soft testis. While there was catch-up growth in comparison to the contralateral testis, testicular consistency improved but testicular volumes may not increase significantly after varicocele repair at ages older than 14 years. However, in these adolescents postoperative semen parameters and serum hormone values may significantly improve regardless of testicular volume. Therefore, boys with varicocele and their families should be fully informed in light of these findings.     

Effects of caudal block on cortisol and prolactin responses to postoperative pain in children.

We have performed a randomized controlled study in 60 children (ASA 1.8 month to 10 yrs) undergoing lower abdominal and genitourinary surgery, to assess the effects of caudal anaesthesia on plasma cortisol and prolactin concentrations during early postoperative period. After induction of anaesthesia by inhalation or intravenously, thirty children received a standardized general anaesthetic (control group) while the remaining children received caudal anaesthetics with 0.25% bupivacaine in addition to a similar general anaesthetic (caudal group). Blood samples for cortisol and prolactin were taken after induction and 1 hour after surgery. Postoperative analgesia was assessed by modified pain objective scale and side effects were noted. Children in the caudal group had significantly smaller plasma cortisol and prolactin concentrations at 1 hr postoperatively, compared with those in the control group. Plasma cortisol concentration after induction was higher than after one hour of surgery in the caudal group. These results were correlated with pain scores. No serious side effects were recorded. In conclusion, caudal anaesthesia attenuated the postoperative cortisol and prolactin responses to surgery and pain in children.     

Protective effect of propolis on methotrexate-induced kidney injury in the rat

Objectives Propolis is a potent antioxidant and a free radical scavenger. Pharmacological induction of heat shock proteins (HSPs) has been investigated for restoring normal cellular function following an injury. In this study, effect of propolis on HSP-70 expression in methotrexate-induced nephrotoxicity and direct preventive effect of propolis in this toxicity were investigated. Material and methods A total of 40 male Wistar albino rats were divided into four groups: Group 1 was the untreated control. On the eighth day of the experiment, groups 2 and 3 received single intraperitoneal injections of methotrexate (MTX) at 20?mg/kg. Groups 3 and 4 received 100?mg/kg/day propolis (by oral gavage) for 15 d by the first day of the experimental protocol. Then the rats were decapitated under ketamine esthesia and their kidney tissues were removed. HSP-70 expression, apoptosis, and histopathological damage scores were then compared. Results MTX caused epithelial desquamation into the lumen of the tubules, dilatation, and congestion of the peritubular vessels and renal corpuscles with obscure Bowman’s space. The number of apoptotic cells (p?=?0.000) and HSP-70 (p?=?0.002) expression were increased in group 2. Propolis prevented the rise in number of apoptotic cells (p?=?0.017), HSP-70 (p?=?0.000) expression, and improved kidney morphology. Conclusions It was found that methotrexate gives rise to serious damage in the kidney and propolis is a potent antioxidant agent in preventing kidney injury.     

Time-dependent Variations in Ischemia-modified Albumin Levels in Mesenteric Ischemia

Objectives:  The objective was to determine the value of ischemia-modified albumin (IMA) in the diagnosis of mesenteric embolism. The authors investigated whether or not plasma IMA levels rose in the acute period in a rat model of mesenteric ischemia and the related time-dependent changes.
Methods:  In this randomized, controlled, nonblinded trial, 36 mature female Wistar rats were divided into six groups: three control (Groups I, III, and V) and three ischemia (Groups II, IV, and VI). In the control groups, blood was sampled at 30 minutes (Group I), 2 hours (Group III), and 6 hours (Group V) following a simple laparotomy. In the ischemia groups, following laparotomy, the superior mesenteric artery (SMA) was clamped using a bulldog clamp, and blood samples were taken at 30 minutes (Group II), 2 hours (Group IV), and 6 hours (Group VI).
Results:  Plasma IMA levels in the ischemia groups were significantly higher compared to those of the control groups (p < 0.004). In addition, levels were higher in the 6-hour blood samples of the ischemia group than in the 2-hour and 30-minute samples (p < 0.001). Serum IMA was also higher in the 2-hour blood samples of the ischemia group than in the 30-minute samples (p < 0.001).
Conclusions:  These preliminary findings suggest that serum IMA levels may represent a significant parameter in the early diagnosis of acute mesenteric ischemia and that further studies are necessary.     

Renal mass anatomic characteristics and perioperative outcomes of laparoscopic partial nephrectomy: a critical analysis

Abstract Background and Purpose: Anatomic parameters determining renal mass complexity have been used in a number of proposed scoring systems despite lack of a critical analysis of their independent contributions. We sought to assess the independent contribution of anatomic parameters on perioperative outcomes of laparoscopic partial nephrectomy (LPN). Patients and Methods: Preoperative imaging studies were reviewed for 147 consecutive patients undergoing LPN for a single renal mass. Renal mass anatomy was recorded: Size, growth pattern (endo-/meso-/exophytic), centrality (central/hilar/peripheral), anterior/posterior, lateral/medial, polar location. Multivariable models were used to determine associations of anatomic parameters with warm ischemia time (WIT), operative time (OT), estimated blood loss (EBL), intra- and postoperative complications, as well as renal function. All models were adjusted for the learning curve and relevant confounders. Results: Median (range) tumor size was 3.3?cm (1.5-11?cm); 52% were central and 14% hilar. While 44% were exophytic, 23% and 33% were mesophytic and endophytic, respectively. Anatomic parameters did not uniformly predict perioperative outcomes. WIT was associated with tumor size (P=0.068), centrality (central, P=0.016; hilar, P=0.073), and endophytic growth pattern (P=0.017). OT was only associated with tumor size (P<0.001). No anatomic parameter predicted EBL. Tumor centrality increased the odds of overall and intraoperative complications, without reaching statistical significance. Postoperative renal function was not associated with any of the anatomic parameters considered after adjustment for baseline function and WIT. Learning curve, considered as a confounder, was independently associated with reduced WIT and OT as well as reduced odds of intraoperative complications. Conclusion: This study provides a detailed analysis of the independent impact of renal mass anatomic parameters on perioperative outcomes. Our findings suggest diverse independent contributions of the anatomic parameters to the different measures of outcomes (WIT, OT, EBL, complications, and renal function) emphasizing the importance of the learning curve.     

Point mutations in the conserved box 1 region inactivate the human granulocyte colony-stimulating factor receptor for growth signal transduction and tyrosine phosphorylation of p75c-rel

The human granulocyte colony-stimulating factor receptor (hG-CSFR) belongs to the cytokine receptor superfamily. As with other members of this family, the cytoplasmic domain of hG-CSFR lacks intrinsic tyrosine kinase activity. To identify critical regions mediating growth signal transduction by hG-CSFR, deletions or site-directed amino acid substitutions were introduced into the cytoplasmic domain of hG-CSFR, and the mutant cDNAs were transfected into the murine interleukin-3 (IL- 3)-dependent Ba/F3 and FDCP cell lines. Truncation of the carboxy- terminal end of the receptor to the membrane-proximal 53 amino acids of the cytoplasmic domain, which retained the conserved Box 1 and Box 2 sequence motifs, decreased the ability of hG-CSFR to transduce G-CSF- mediated growth signals without an associated loss in receptor binding affinity. Substitution of proline by alanine at amino acid positions 639 and 641 within Box 1 completely abolished the G-CSF-mediated growth signal. Rapid induction of tyrosine phosphorylation of several cellular proteins, including a 75-kD protein (p75) identified as c-rel, was an early event associated with transduction of proliferative signals by hG- CSFR in Ba/F3 transfectants. Mutant receptors containing Pro-to-Ala substitutions that inactivated the receptor for mitogenic activity also inactivated the receptor for tyrosine-specific phosphorylation of p75. These results show that the conserved Box 1 sequence motif (amino acids 634 to 641) is critical for mitogenesis and activation of cellular tyrosine kinases by hG-CSFR.