Development of experimental HEMA-free three-step adhesive system

Objective

To evaluate the influence of Bis-EMA 30 on the resin-to-dentin microtensile bond strength (μTBS) and structural reliability of the experimental three-step etch-and-rinse adhesive systems.

Methods

Five experimental primers containing different dimethacrylate monomer concentrations (0, 10, 20, 40, 60 wt% of the Bis-EMA 30, P0.P60) added to acid monomer and solvents (ethanol/water), and a resin bond (Bis-GMA/TEGDMA, 50/50 wt%) were formulated. The adhesive system Scotchbond™ MultiPurpose (SBMP, 3M ESPE) was tested as commercial reference. Sixty bovine incisors were randomly separated into six groups, and their superficial coronal dentin was exposed. After acid etching and rinsing, the excess water was removed from the surface with absorbent paper. Each experimental primer was actively applied (30 s), followed by a mild air stream (10 s). The experimental adhesive resin was applied and light activated for 20 s. Resin composite restorations were incrementally built up. The restored teeth were stored in distilled water at 37 °C for 24 h, and then sectioned to obtain sticks with a cross-sectional area of approximately 0.5 mm², after which 24 specimens per group were subjected to the μTBS test. Data (MPa) were analyzed by One-way ANOVA, Tukey test (α = 0.05) and Weibull analysis.

Results

The P40 group showed μTBS means similar to those of the control (SBMP), whereas both had statistically higher values when compared with the other groups (p < 0.001). Moreover, P40 showed higher structural reliability, represented by the high Weibull modulus and characteristic strength values. The lowest μTBS was observed in the P0, P10 and P20 groups, which also had low structural reliability.

Significance

Bis-EMA 30 is a promising monomer to be considered as a substitute for HEMA in adhesive system compositions.     

Brenner tumor of the ovary: a correlative histologic, histochemical, immunohistochemical, and ultrastructural investigation

The histologic, histochemical, immunohistochemical, and ultrastructural features of Brenner tumor (BT) were studied. BT was compared with transitional bladder cells, and close similarities between the two tissues were identified. Abundant glycogen in all cellular layers, an alcianophilic/sialomucinic surface mucous coat, and argyrophilic cells characterized both BT and bladder epithelium. Immunohistochemically, chromogranin and neuron-specific enolase reactivity was observed in all cases examined. An additional relevant finding was the presence of serotonin-storing cells in both BT and urothelium. Moreover, carcinoembryonic antigen, epithelial membrane antigen, and keratin reaction were found in BT and urothelium, indicating an additional antigenic similarity. Additionally, malignant Brenner tumor was ultrastructurally found to share many common features with the bladder tissue. The distinct histochemical, ultrastructural, and antigenic pattern of BT, primarily of the transitional type, is emphasized.     

Octanol-water partition coefficients of substituted alpha, N-diphenylnitrones and benzonitrile N-oxides

Experimental octanol-water partition coefficients are reported for substituted alpha, N-diphenylnitrones and benzonitrile N-oxides. The results of these measurements are used to calculate the aromatic fragment constants pi HC = N(O)C6H5, pi C = N----O, fHC = N(O), and fC = N----O for the group contribution methods of Hansch and Leo.     

Five questions for assessing psychological problems in pediatric patients cured of neoplastic disease

Pediatric patients who have been cured of cancer may have particular unexpressed needs and psychopathological consequences. The authors describe their experience with an apparently well-adjusted 20-year-old girl previously cured of rhabdomyosarcoma, who developed severe psychological distress with serious difficulty in controlling her emotions due to defense mechanisms and massive rationalization. The trauma of tumor and its treatment can be associated with psychopathological disorders that may significantly affect the future life of a person cured of cancer. Doctors must learn to notice telltale signs and take the time to investigate the patient's social life and identify any psychopathological disorders. Experience drawn from pediatric oncology might suggest an approach based on a physician-patient relationship that could provide the means for identifying patients' psychological needs and problems.     

Force estimation processing as a function of the input--output relationship of the corticospinal pathway in humans

Static changes of the shoulder joint from 30 degrees adduction (ANT) to 30 degrees abduction (POST) in the horizontal plane reduce the gain of the input--output relationship of the corticospinal pathway to the abductor digiti minimi (ADM) muscle [F. Ginanneschi et al. (2005)Exp. Brain Res., 161, 374--382]. The present study examined force estimation under conditions in which the input--output relationship of the corticospinal innervation to ADM was modified by changing shoulder position as above. The input--output relationship was studied using transcranial magnetic stimulation. Estimates of force were assessed using a matching procedure; subjects first matched a target level (10--40% of maximum) on a screen by applying a reference (Ref) isometric contraction of ADM and then they reproduced the same level of force without visual feedback by a test contraction (Test). When Ref and Test contractions were performed at either ANT or POST (i.e. the same input--output), the respective force levels were closely matched. In contrast, when the Test and Ref were performed in POST and ANT, respectively (i.e. different input--output), subjects exerted more force than required. Errors were in the opposite direction when the Test and Ref were in ANT and POST, respectively. The present results suggest that the process of force estimation is based on the effort : tension ratio which is a direct function of the corticomotoneuronal input--output relationship. This notion may contribute to explaining the pathophysiology of central fatigue.     

Chirurgie der parapharyngealen Adenome

Pleomorphic adenomas are the most common tumors of the parapharyngeal space (PPS) and often grow to an enormous size before becoming visible or symptomatic. CT and MRI scans are important in both diagnosis and surgical treatment. There are basically four different surgical approaches (transoral-transpalatal, transcervical-submandibular, transparotid und transmandibular) to the anterior PPS. Wide and direct exposure of the PPS is provided by a midline mandibulotomy with transection of the floor of the mouth. Owing to its morbidity this approach is reserved exclusively for extended tumors. The transcervical-submandibular route with blunt finger dissection generally offers adequate access for total tumor removal. For adenomas arising from the parotid gland a transparotid approach may be utilized. Adenomas located medially are better be resected transorally by splitting the soft palate.     

What is the current role of radiation therapy in the treatment of skin carcinomas?

AIMS AND BACKGROUND: In recent years several radiation therapy units have recorded a decline in the number of referrals for the treatment of skin carcinomas. This study aims to ascertain whether this decline has also affected the radiation therapy unit of Trieste and, if so, to consider the possible reasons. METHODS: We retrospectively reviewed all cases of non-melanoma skin cancer treated in our unit from January 1986 to December 1999. A database was created that would allow rapid and controlled data entry and a sufficiently simple query system. RESULTS: The total number of irradiated skin cancers was 2,219:1,863 basal cell carcinomas, 276 squamous cell carcinomas, and 80 basosquamous carcinomas. The distribution curves for the number of cases treated every year were similar: each of the three types showed a slow and gradual reduction in the number of patients referred for radiotherapy. CONCLUSIONS: For most authors surgery remains the treatment of choice for skin carcinomas. However, radiation therapy can also yield excellent results in terms of local control, cosmesis and functionality. In our view the indications for radiation therapy are poor general health, elderly age, the presence of diseases that are a contraindication for surgery, location of the tumor in the head region, and tumor size between 1 and 5 cm.