Thermal and pH changes,and dimensional stability in irreversible hydrocolloid impression material during setting

Present study the relation between pH, thermal changes and dimensional stability during setting of irreversible hydrocolloid impression materials was investigated. Ten specimens of each product were prepared for different measurements: Thermal, pH changes and dimensional stability (mass and linear). Thermal and pH readings for 20 min and dimensional measurements for a 2 hr period were taken after mixing. It was observed that pH and thermal values changed in relation to different materials, while they did not change with the time according to variance analysis results. On the other hand, dimensional stability showed significant differences with time in all tested impression materials. A continuous pH change was observed with the time of gelation in all irreversible hydrocolloid impression materials tested. Dimensional stability also showed significant differences with time in all impression material and as a result hydrocolloids with a high pH showed better dimensional stability than those with a low pH.     

The Springer Model for Lifetime Prediction of Wind Turbine Blade Leading Edge Protection Systems: A Review and Sensitivity Study

The wind energy sector is growing rapidly. Wind turbines are increasing in size, leading to higher tip velocities. The leading edges of the blades interact with rain droplets, causing erosion damage over time. In order to mitigate the erosion, coating materials are required to protect the blades. To predict the fatigue lifetime of coated substrates, the Springer model is often used. The current work summarizes the research performed using this model in the wind energy sector and studies the sensitivity of the model to its input parameters. It is shown that the Springer model highly depends on the Poisson ratio, the strength values of the coating and the empirically fitted a2 constant. The assumptions made in the Springer model are not physically representative, and we reasoned that more modern methods are required to accurately predict coating lifetimes. The proposed framework is split into three parts—(1) a contact pressure model, (2) a coating stress model and (3) a fatigue strength model—which overall is sufficient to capture the underlying physics during rain erosion of wind turbine blades. Possible improvements to each of the individual aspects of the framework are proposed.     

Therapeutic plasma exchange for the treatment of thrombotic thrombocytopenic purpura: a retrospective multicenter study.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare disease that is fatal if it is not treated. Therapeutic plasma exchange (TPE) has resulted in excellent remission and survival rates in TTP patients. MATERIAL AND METHODS: We describe our experience with 52 TTP patients treated with TPE during the past eight years (65% of the patients were females; patient median age=34 years, range: 17-73). TPE was carried out 1-1.5 times plasma volume. Fresh frozen plasma (FFP) or cryosupernatant plasma (CSP) was used as the replacement fluid. TPE was performed daily until normalization of serum LDH and recovery of the platelet count to >150 x 10(9)/dL; TPE was then slowly tapered. Clinical, laboratory data, the number of TPE, other given therapy modalities, treatment outcomes and survival rate were evaluated retrospectively. RESULTS: Overall response (OR) and complete response (CR) rates were 77% and 60%, respectively. Response was excellent in 82.8% of the patients with primary TTP among whom 74.2% were CR. Additionally, there were statistical differences in terms of CR rate between patients with primary TTP and secondary TTP (74.2% vs. 29.4%; p=0.005). OR and CR rates were 79% and 57.9% in patients on TPE alone and 75.8% and 60.6% in patients on TPE+prednisolone, respectively (p=1 and p=0.8). Additionally, there were no statistical differences in terms of OR and CR rates between patients on TPE with FFP and CSP (p=0.25 and p=0.16, respectively). The presence of fever and the number of TPE were statistically important factors influencing the probability of response in multivariate logistic regression analysis (p<0.01 and p<0.01, respectively). Additionally, in multivariate Cox's regression analysis, the probability of survival was higher in patients who were responsive to treatment compared to patients who were unresponsive (p<0.001). CONCLUSION: TPE is an effective treatment for primary TTP; however, it may be used as adjunctive therapy for secondary TTP until it is under control. The addition of steroids to TPE had no advantage compared to TPE alone. CSP as replacement fluid is not superior compared to FFP. Fever appears to be a bad prognostic indicator. Therefore, prolonged treatment with TPE may be needed in patients with fever.     

The effect of resveratrol on the prevention of cisplatin ototoxicity

One of the most important adverse effects of cisplatin, a chemotherapeutic agent which is widely used in the treatment of cancer patients, is hearing loss. This has primarily been associated with the loss of inner ear hairy and spiral ganglion cells due to oxidative stress. Resveratrol is known to be an antioxidant agent, which has the theoretical potential of preventing cisplatin-related ototoxicity. This experimental study was approved by Animal Ethics Committee of Inonu University (2008–20) and supported by Inonu University Scientific Research Projects Support Fund (2009–17). Thirty-four 3-month-old Wistar albino female rats weighing 210–270?g were used in the study. The animals were allocated into four groups: in cisplatin group (Group A), a single dose of 12?mg/kg cisplatin was administered intraperitoneally to 10 rats; in cisplatin?+?resveratrol group (Group B), a single dose of 12?mg/kg cisplatin and 10?mg/kg resveratrol were administered intraperitoneally for 5?days to 10 rats; in resveratrol group (Group C), 10?mg/kg resveratrol was administered intraperitoneally for 5?days to seven rats and in control group (Group D), resveratrol solvent (5% alcohol–95% physiological saline) was administered intraperitoneally for 5?days to seven rats. Resveratrol administration has begun 1?day before cisplatin administration in the group treated with cisplatin and resveratrol combination. Distortion product otoacoustic emission (DPOAE) (Grason Stadler, Madison, USA) measurements were performed in the same ear of all rats (right ear) under general anesthesia at baseline, 1st and 5th days after drug administration. Statistically significant distortion product amplitude reductions were found in the cisplatin group at 1,418, 2,003, 3,363, 5,660, 8,003 and 9,515?Hz frequencies. Whereas in the cisplatin?+?resveratrol group, statistically significant difference was found between 1st and 5th day measurements only at 3,996?Hz frequency. No significant differences were noted between the measurements either in the resveratrol or in the control groups. According to these results, cisplatin-related ototoxicity has been greatly prevented by resveratrol use.     

Incidence of cochlear involvement in hyperbilirubinemic deafness

Neonatal hyperbilirubinemia remains an important cause of childhood deafness, especially in developing countries. After neonatal hyperbilirubinemia, the auditory neural pathways, cochlea, or both may be affected. In this study, we aimed to determine the incidence of cochlear impairment and the appropriate means of hearing screening in hyperbilirubinemic neonates. A retrospective review of 1,032 pediatric patients with hearing loss revealed 67 cases (6.5%) of severe hyperbilirubinemia in the neonatal period. Thirty of these patients had neonatal hyperbilirubinemia as the single identifiable risk factor for hearing loss. In 26 of 30 cases (87%), otoacoustic emissions (OAEs) were absent, whereas in the remaining 4 cases (13%), robust emissions were detected despite an absent auditory brain stem response (ABR). Auditory screening of newborns with jaundice by OAEs possesses a significant risk of undiagnosed deafness. On the other hand, if the ABR is used as the single means of screening, auditory neuropathic conditions will probably be underlooked. Therefore, we recommend dual screening of hearing by ABR and OAEs in hyperbilirubinemic newborns.     

Management of carotid artery invasion in advanced malignancies of head and neck comparison of techniques

The objective of this study was to retrospectively investigate a single institution's experience with carotid artery resection performed as part of an oncological procedure and to determine acute and convalescent complication and survival rates. We performed a record review of 28 patients with head and neck malignancy invading the carotid artery. Immediate carotid artery resection and ligation on an emergent basis was performed on 12 patients (group 1), elective resection and ligation was performed on 8 patients (group 2), and elective resection and revascularization was performed on 8 patients (group 3). In group 1, although 1 patient survived for 1 year and 1 patient survived for 2 years, 1 patient died of severe neurologic deficit, 2 patients experienced neurologic deficit with good recovery, and 1 patient was moderately disabled. In group 2, 2 patients survived without disease for 5 years, and 2 patients experienced neurologic deficit, 1 with good recovery and the other with complete recovery. In group 3, only 1 patient survived for 5 years, and within this group, 1 patient died of severe neurologic deficit, 1 patient had neurologic deficit with moderate recovery, and 1 patient had neurologic deficit with complete recovery. No significant difference in mortality and morbidity rate was observed between the "resection and ligation" group and the "resection and revascularization" group (p = .52, chi(2) = 0.79). We conclude that the surgical treatment of patients with an invaded carotid artery, including carotid resection, provides a small but real chance of 5-year survival. The methods of carotid resection and repair should be guided by clinical presentation and by preoperative and intraoperative investigations.     

The organochlorine pesticide residues and antioxidant enzyme activities in human breast tumors: is there any association?

The levels of some organochlorine pesticides (OCP)s (hexachlorobenzene, HCB, -hexachlorocyclohexane, -HCH, -HCH, -HCH, heptachlorepoxide, HE, bis (4-chlorophenyl)-1,1-dichloroethene, p.pDDE, bis (4-chlorophenyl)-1,1,1-trichloroethane, p.p DDT and total DDT (-DDT) and antioxidant enzyme activities namely Cu, Zn superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px), total glutathione peroxidase (T-GSH-Px), selenium independent glutathione peroxidase (GSH-Px II), glutathione reductase (GRd), level of reduced glutathione (GSH) and lipid peroxidation (LP), glutathione S-transferase (GST) activity toward several substrates including 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (ENPP) were measured in tumor and surrounding tumor free tissues of 24 female breast cancer patients and was evaluated whether there exist any association between the levels of OCPs and antioxidants. The mean levels of GSH, -BHC, -BHC and HE, and activities of SOD, Se-GSH-Px, T-GSH-Px, GSH-Px II,GRd, GST CDNB, and GST DCNB were significantly higher in tumors than in controls. In tumors, significant correlations were noted between: SOD and -BHC; Se-GSH-Px and -BHC; T-GSH-Px and -BHC; GSH-Px II and -BHC, -BHC; GSH and -BHC, -BHC, HE; GRd and -BHC; CDNB GST and -BHC, -BHC. These results show that free-radical mediated oxidative stress is, at least partly, associated with some of these OCP residues in human breast tumors.     

The role of Tc-99m RBC scintigraphy in the differential diagnosis of orbital cavernous hemangioma

The cavernous hemangioma is the most common benign orbital tumor in adults. Its presentation is during the forth to fifth decades with a slowly progressive unilateral proptosis. Intraconal cavernous hemangiomas may be difficult to differentiate from other intraconal lesions such as schwannomas, meningiomas and hemangiopericytomas. We report a case of orbital cavernous hemangioma diagnosed by Tc-99m RBC scintigraphy. Tc-99m RBC scintigraphy revealed a typical scintigraphic pattern in which there is intense focally increased uptake on the delayed image. We conclude that Tc-99m RBC scintigraphy can be a useful method in the differential diagnosis of orbital cavernous hemangioma as in hepatic hemangioma.     

Topical steroids in the management of Churg-Strauss syndrome involving the conjunctiva

PURPOSE: To discuss a case of Churg-Strauss syndrome that developed bilateral conjunctival involvement while recovering from miliary tuberculosis. METHODS: Case report and literature review. RESULTS: A 22-year-old man who was on oral prednisolone for Churg-Strauss syndrome since 2002 contracted miliary tuberculosis in June 2004. The diagnosis was confirmed by liver biopsy. Ophthalmologic examination was within reference limits except for bilateral multifocal choroiditis. A combined therapy of rifampicin, ethambutol, streptomycin, and morphazinamide was started on June 24, 2004. Complete recovery was achieved, and the antituberculosis therapy was terminated in June 2005. The patient noted redness and pain in both eyes a month later. He had bilateral irregular, pink-yellow, gravel-like infiltrations involving the bulbar conjunctiva. Biopsy revealed granulomas with central fibrinoid necrosis, histiocytes, and eosinophils, suggestive of conjunctival involvement of Churg-Strauss syndrome. Topical dexamethasone 0.1% drops were started 4 times per day and tapered gradually. Lesions totally regressed within 2 months. No recurrence was noted during a follow-up of 11 months. CONCLUSIONS: Churg-Strauss syndrome may rarely involve the conjunctiva, and conjunctival lesions respond favorably to topical steroids.