An Evaluation of the Hydrolytic Stability of Selected Experimental Dental Matrices and Composites

Materials with potential use as dental restoration should be evaluated in an aggressive environment. Such accelerated aging is widely used in other industries and allows the assessment of service life. In the presented study, three neat resins (UDMA/Bis-GMA/TEGDMA 70/10/20 wt.%, UDMA/Bis-GMA/TEGDMA 40/40/20 wt.% and UDMA/Bis-EMA/TEGDMA 40/40/20 wt.%) and three composites based on these matrices were tested before and after aging protocols (I-7500 cycles, 5 °C and 55 °C, water and 7 days, 60 °C, 0.1 M NaOH; II-5 days, 55 °C, water and 7 days, 60 °C, 0.1 M NaOH). Flexural strength (FS), diametral tensile strength (DTS) and hardness (HV) were determined. Applied aging protocols resulted in a decrease in the value of the FS, DTS and HV. Larger changes were noticed for the neat resins. Materials in which the content of bis-GMA was lower or substituted by bis-EMA showed better resistance to degradation. The choice of mixtures with monomers characterized by lower sorption values may favorably affect hydrolytic stability. It was shown that for composites there was a drastic decrease in hardness, which suggests a more superficial effect of the used protocols. However, degradation of the surface layer can result in a growing problem over time given that the mastication processes are an inherent element in the oral environment.     

Vasospastic Angina with J‐Wave Pattern and Polymorphic Ventricular Tachycardia Effectively Treated with Quinidine

Background: Myocardial ischemia during coronary spasm may generate malignant ventricular arrhythmias. The J‐wave pattern was suggested to be a marker of a disorder associated with life‐threatening arrhythmias. Results: We report the case of a patient with vasospastic angina and J‐wave pattern in inferior and lateral leads associated with polymorphic ventricular tachycardia which was effectively treated only with quinidine—vasodilating drugs were not able to prevent the arrhythmia although they were effective in preventing ischemic events. Conclusion: The J‐wave pattern in inferolateral leads may be a sign of electrical vulnerability to lethal ventricular arrhythmia in patients suffering from vasospastic angina—quinidine can effectively prevent such arrhythmias in these patients.     

BCL11B,FLT3, NOTCH1 and FBXW7 mutation status in T-cell acute lymphoblastic leukemia patients

T‐cell acute lymphoblastic leukemia is a heterogeneous malignancy originating from developing lymphocyte precursors likely due to mutations in genes regulating thymocyte differentiation. Here, we characterized mutation status of BCL11B and FLT3 genes, presumably involved in T-ALL, together with FBXW7 and NOTCH1 as known players in T-ALL in 65 pediatric T-cell acute lymphoblastic leukemia patients. We also aimed at the assessment of prognostic value of NOTCH1 and FBXW7 mutations in ALL-IC BFM 2002 protocol.FLT3 and BCL11B mutations were detected in 3% and 2% of patients, respectively. FBXW7 mutations were observed in 8% of patients, while NOTCH1 was mutated in 40%. No correlation was found between NOTCH1 and FBXW7 mutations and traditionally used clinical factors or molecular features. In total we have detected nine mutations, which have not been previously described by others. Eight of them were found in NOTCH1 and one in BCL11B gene.Observed frequencies of NOTCH1 and FBXW7 are in line with previous reports, thus confirming postulated participation of these two genes in T-ALL pathomechanism. Moreover, we report on mutation frequency of FLT3 and BCL11B, not extensively studied in T-ALL so far. Finally, we suggest a putative role of BLC11B as an oncogene in T-ALL pathogenesis.     

Mild Elevation of Fasting Plasma Glucose is a Strong Risk Factor for Postoperative Complications in Gastric Bypass Patients

Background: Bariatric surgery may be associated with surgical complications. The aim of the study was to identify significant risk factors for postoperative complications in patients undergoing Roux-en-Y gastric bypass (RYGBP). Methods: The study consisted of 75 consecutive patients undergoing RYGBP. Full medical examination was performed, and the following parameters were assessed in the fasting state: plasma glucose, insulin, leptin, serum lipids, liver function tests, and lipoprotein Lp(a). All subjects had oral 75 g glucose tolerance test before the surgery. All complications occurring within 6 months after the RYGBP were recorded. The patients were divided into Group 1 - patients in whom complications occurred, and Group 2 - patients with no complications in the 6-month period. Results: Postoperative complications occurred in 16 patients (wound infection, hernia, splenic injury, gastro-jejunal obstruction, duodenal ulcer, lower limb deep vein thrombosis). 3 significant risk factors for postoperative complications within 6 months after gastric bypass were found: 1) fasting plasma glucose ≥ 6.0 mmol/l (OR 11.0; 95% confidence interval (CI) 2.1-77.3), 2) age ≥40 years (OR 5.89, 95% CI 1.35-29.4), and 3) BMI ≥45 kg/m² (OR 4.1, 95% CI 1.04-17.2). Conclusion: RYGBP is associated with increased risk of developing early postoperative complications in subjects with even slightly elevated fasting plasma glucose, age ≥40 and BMI ≥45 kg/m².     

Post-stenting intravascular brachytherapy trials on hypercholesterolemic rabbits using 32P liquid sources: implications for prevention of in-stent restenosis

PURPOSE: Liquid sources of radiation delivered in angioplasty balloons may be a convenient self-centering device used for prevention of in-stent restenosis. To test the effectiveness of this method an intravascular brachytherapy study was performed using 32P liquid sources in an animal model. METHODS: The radial dose distribution around angioplasty balloons filled with solutions of Na 2H 32PO 4 was calibrated by thermoluminescence dosimetry. The animal experiments were performed in rabbits with induced hypercholesterolemia. The balloons containing 32P were introduced into iliac arteries immediately after stent implantation. Estimated 7-49 Gy doses required 30-100 min irradiations. Radiation effects were evaluated by comparing the thickness of various components of the artery wall. RESULTS: Doses of 7, 12, 16 or 49 Gy on the internal artery surface required 30-100 min of irradiation. The dose of 49 Gy at "zero" distance corresponding to 16 Gy at 1.0 mm from the balloon surface reduced hypertrophy in every layer of the arterial wall: in the intima the cross-sectional areas were 0.13 versus 0.91 mm 2, in the media were 0.5 versus 0.46 mm 2 and in the adventitia were 0.04 versus 0.3 mm 2 (p <0.05). A dose of 7 Gy at the balloon surface produced adverse irradiation effects: the intimal area of the artery was 2.087 versus 0.857 mm 2, the medial area was 0.59 versus 0.282 mm 2 and the adventitial area was 0.033 versus 0.209 mm 2 in treated and control arteries, respectively. CONCLUSION: Application of a 49 Gy irradiation dose to the internal arterial surface effectively prevented in-stent restenosis.     

Using NGAL as an early diagnostic test of acute kidney injury

Neutrophil gelatinase-associated lipocalin (NGAL) has generated great interest as a novel biomarker for the timely detection of acute kidney injury (AKI). Despite the enthusiasm surrounding NGAL, the research so far details and attempts to minimize a host of limitations that substantially preclude its use as a valuable diagnostic biomarker to detect AKI and guide clinical treatment. In our review of the current research, obvious drawbacks such as variable sensitivity and specificity, even among similar patient populations were discovered. Furthermore, there are not well-defined cutoff values among various patient populations which would permit use of NGAL as a positive or negative diagnostic marker similar to troponin in cardiac injury. Moreover, due to the wide variation in baseline concentration of NGAL among patients, the added requirement of serial measurements, that may not even be accurate in at-risk or chronic kidney injury populations, further degrades the benefit of early detection.     

The characteristics of fractures in Polish adolescents aged 16–20 years

The aim of the study was to identify associations between fractures in childhood and family, anthropometric and lifestyle factors. Among 1,246 subjects aged 16.3–20.6 years (539 boys, 707 girls), based on a questionnaire, 869 were fracture-free while 377 (30.26%) had fractures. Of those reporting fractures, 146 reported multiple fractures (12% of studied population, 39% of all fractures). More boys had fractures than girls (35.6% vs 24.9%, p < 0.001). Fracture sites included: forearm (37%), fingers (23%) wrist (16%), ankle (14%), humerus (10%), tibia (8%) clavicle (7%) and femoral shaft / neck (3%). Among adolescents with multiple fractures, 52% also reported fractures in at least one family member, compared with 29% of those without a fracture history. Fractures in siblings and mothers (but not fathers) accounted for 44% of the liability in adolescents fractures. Subjects with multiple fractures reported more time at the computer than those without fractures and reported more time participating in team sports, and 18.6% avoided milk, whereas 12.4% of those without fractures reported milk-free diets. Using a logistic regression model, none of the lifestyle factors, except for computer use, were independently associated with fractures. Fractures, particularly multiple fractures, are common in childhood and adolescence. Familial clustering of fractures suggests shared genetic and environmental factors are responsible.     

Benign epithelioid peripheral nerve sheath tumors of the soft tissues: clinicopathologic spectrum of 33 cases

Benign epithelioid peripheral nerve sheath tumors (BEPNSTs) have not been fully characterized, and their relationship to conventional schwannoma and neurofibroma has not been satisfactorily established. Herein, we detail the clinicopathologic features of 33 examples of BEPNST. The study included 22 females and 11 males ranging in age from 2 to 68 years (median, 31.5 years). Only one patient probably has neurofibromatosis type 1. The tumors were predominantly dermal/subcutaneous in location (85%) and involved the lower limb (n=15), upper limb (n=11), trunk (n=4), and head/neck (n=3). The lesions ranged in size from 0.3 to 6.8 cm (median, 1.1 cm). Microscopically, the tumors were generally well-circumscribed, uninodular, or multinodular masses. Twenty-six lesions were encapsulated. Tumors consisted of trabeculae, loosely arranged nodules, and cohesive nests of epithelioid tumor cells immersed in collagenous, myxohyaline, or chiefly myxoid stroma. A bland spindled cell component comprising 5% to 40% of the tumor was noted in 15 cases. Mitotic activity ranged from 0 to 6 mitoses/50 high power fields (mean, 1.5 mitoses/50 high power fields) with no abnormal division figures identified. Five lesions were considered atypical based on presence of focal nuclear/nucleolar enlargement and hyperchromasia. Immunohistochemical reactivity for Schwann cell-related markers in tumor cells included S-100 protein (20 of 20 cases), collagen type IV (10 of 10), laminin (8 of 8), nerve growth factor receptor, p75(7 of 8), CD57 (6 of 9), and glial fibrillary acidic protein (8 of 15). CD34-positive fibroblast-like cells were identified in all 12 neoplasms tested. Anti-epithelial membrane antigen highlighted perineurial cells in 9 of the 11 encapsulated tumors. Anti-neurofilament protein did not identify intralesional neuraxons in the 10 tumors evaluated. Eighteen tumors were subtyped as epithelioid neurofibromas. The remaining 15 cases showed some histologic features suggestive of schwannoma, but their uniform cellularity, absence of nuclear palisading, and presence of a significant CD34-positive spindled cell population in 5 cases led to their classification as "BEPNST of indeterminate histogenesis." Evaluation for loss of heterozygosity in 2 cases demonstrated deletion of genetic material on chromosome 22q and 17q involving NF2 and NF1 loci. However, sequencing of NF2 coding sequences revealed no mutations. Follow-up for 18 patients (median interval, 13.5 years), including 4 patients with tumors exhibiting cytologic atypia, revealed a nondestructive recurrence or persistent disease in 3 patients whose tumors lacked atypia, but no evidence of metastatic spread or tumor-related death. BEPNSTs are usually small neoplasms located in superficial soft tissue and have an excellent prognosis after complete local excision. Accurate subclassification of some of these lesions is difficult based on currently available techniques.     

Atrial septal defect in adults: echocardiography and cardiopulmonary exercise capacity associated with hemodynamics before and after surgical closure

The study aimed to evaluate pre and postoperative echocardiographic data and exercise capacity in relation to age and hemodynamics in adults with atrial septal defect (ASD). Fifty-two subjects with ASD (mean age: 38.6+/-15 years) were enrolled. Echocardiography and cardiopulmonary exercise test were performed before and a year after surgery. Pre and postoperative data were analyzed for the entire group and then compared in terms of age: <40 and >or=40 years, right ventricular systolic pressure (RVSP): 30 mmHg and pulmonary to systemic flow ratio (Qp/Qs): <2.5 and >or=2.5. After surgery right ventricle dimension decreased in all patients, although it remained significantly larger in patients over 40 years. There was a negative correlation between peak oxygen uptake and preoperative RVSP (r=-0.69, P<0.001). Exercise capacity improved irrespective of the age at surgery, preoperative RVSP and Qp/Qs, although it failed to normalize in patients with RVSP >30 mmHg. Adults with ASD benefit from surgical closure irrespective of the actual age at surgery. Patient's age at surgery and pulmonary hypertension crucially impact the results of surgical intervention. Early defect correction is therefore highly recommendable, specifically with a view to preventing the hemodynamic consequences of ASD.     

Effect of organism environment upon bacteriostatic and mechanical properties of palacos R cement with antibiotic--second part]

The results of bacteriological tests of Palacos R cement with antibiotic 4 days, 7 days, 2 weeks, 3 weeks and 4 weeks after implantation in rabbit organism have been presented in this work. The results of tests of mechanical characteristics of cement with and without antibiotic samples after being kept in physiological saline for 3 to 6 weeks have also been discussed. Bacteriological tests prove that antibiotic (III generation cephalosporin) added to surgical cement retain its bacteriostatic properties. When tested on rabbits cement plus antibiotic retains its bacteriostatic properties after 4 weeks period. It has state, that by reason of prolonged time of activity antibiotic into surgical cement, it is necessary to investigate the mechanical characteristics of cement conditioned in physiological saline for 3 months at least.