Preparation of epoxy-SiO2 hybrid sol-gel material for bone cement

An organic-inorganic hybrid material, epoxy-SiO(2), was prepared by incorporating epoxy structure units covalently into a SiO(2) glass network via the sol-gel approach. The precursor was obtained by the reaction of diglycidyl ether of bisphenol A (DGEBA) with 3-aminopropyl trimethoxysilane (APTS). The precursor was then hydrolyzed and co-condensated with tetraethyl orthosilicate (TEOS) in tetrahydrofuran (THF) at room temperature to yield epoxy-SiO(2) hybrid sol-gel material having a 50 wt % SiO(2) content. Thermal properties of the hybrid material were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The hybrid sol-gel material epoxy-SiO(2) was the solid, powder component of bone cement. The liquid component contains bis-phenol-A glycidyl methacrylate (Bis-GMA), triethyleneglycol dimethacrylate (TEGDMA), and methyl methacrylate (MMA) with 25, 55, and 20 vol %, respectively. We discuss the comparison between the new epoxy-SiO(2) bone cement and the commercial Simplex P bone cement. Mechanical properties such as Young's modulus, compressive strength, hardness, and impact strength of the new epoxy-SiO(2) bone cement exceeded those of Simplex P bone cement. The tensile and bending strengths of the new epoxy-SiO(2) bone cement were approximately the same as those of Simplex P bone cement. In order to evaluate the biocompatibility of the new bone cement, an MTT test and optical microscopy were conducted in cell culture. Results indicated that the new epoxy-SiO(2) bone cement exhibits very low cytotoxicity compared with Simplex P bone cement.     

Endoscopic banding ligation can effectively resect hyperplastic polyps of stomach

AIM: Bleeding and perforation are the major and serious complications associated with endoscopic polypectomy. To develop a safe and effective method to resect hyperplastic polyps of the stomach, we employed rubber bands to strangulate hyperplastic polyps and to determine the possibility of inducing avascular necrosis in these lesions. METHODS: Forty-seven patients with 72 hyperplastic polyps were treated with endoscopic banding ligation (EBL). On 14 days after endoscopic ligation, follow-up endoscopies were performed to assess the outcomes of the strangulated polyps. RESULTS: After being strangulated by the rubber bands, all of the polyps immediately became congested (100%), and then developed cyanotic changes (100%) approximately 4 minutes later. On follow-up endoscopy 2 weeks later, all the polyps except one had dropped off. The only one residual polyp shrank with a rubber band in its base, and it also dropped off spontaneously during subsequent follow-up. No complications occurred during or following the ligation procedures. CONCLUSION: Gastric polyps develop avascular necrosis following ligation by rubber bands. Employing suction equipment, EBL can easily capture sessile polyps. It is an easy, safe and effective method to eradicate hyperplastic polyps of the stomach.     

Familial aggregation of dyslexia phenotypes. II: paired correlated measures

Dyslexia is a common and complex behavioral disorder characterized by unexpected difficulty in learning to read. Psychometric measures used to assess dyslexia often evaluate overlapping processes or abilities. To identify subphenotypes amenable to model-based linkage analyses, we have used careful language phenotyping, familial aggregation analyses of single phenotype measures, and segregation analyses. In the current study, to identify covariates to use in future segregation analyses we examined six pairs of related measures selected from among the most promising candidates in the initial aggregation analyses whose aggregation patterns were most consistent with a genetic basis. For these reciprocal aggregation analyses each measure is evaluated with the paired measure as the covariate to obtain information about the interdependence of the paired measures on shared genetic factors. Six pairs of measures were evaluated: 1) accuracy and efficiency of phonological decoding; 2) phonological nonword memory and written spelling; 3) phonological decoding accuracy and written spelling; 4) inattention ratings and rapid automatized naming for switching letters and numerals (RAS); 5) inattention ratings and oral reading rate; and 6) RAS and oral reading rate. Results of these analyses provide evidence that there may be a genetic contribution to efficiency of phonological decoding in addition to the genetic contribution it shares with accuracy of phonological decoding, a genetic contribution to phonological nonword memory in addition to the genetic contribution it shares with written spelling, a genetic contribution to written spelling in addition to the genetic contribution it shares with accuracy of phonological decoding, and a genetic contribution to inattention ratings in addition to the genetic contribution it shares with either RAS or oral reading rate.     

Ultrastructural and biophysical studies on protein conformations of epithelium and stroma in benign prostatic hyperplasia before and after transurethral resection of the prostate

The alterations in protein conformation of epithelium and stroma in human benign prostatic hyperplasia (BPH) undergoing prostatic needle biopsy (PNB) and transurethral resection of the prostate (TURP) were isolated in vitro and investigated using attenuated total reflectance (ATR)/Fourier transform infrared (FT-IR) microspectroscopy. Second-derivative spectral analysis and a curve-fitting program were used to verify and obtain the protein secondary conformation and composition of the samples. TURP uses an electric cutting heat but PNB is a nonheating process. The results indicate a predominantly higher proportion of β-sheet conformation of the epithelium or stroma in BPH tissue at 1633 or 1630 cm -1 in the amide I band, but after treatment with TURP, both maximum peaks shifted to 1644 or 1646 cm -1 due to random coil structure, respectively. This conversion suggests that the heat generated by the cutting loop could increase the temperature in the tissue surrounding the prostate, thereby modifying the protein conformational structure of epithelium and stroma in BPH tissue.     

Interobserver reproducibility of Her-2/neu protein overexpression in invasive breast carcinoma using the DAKO HercepTest

Although there are criteria for interpretation of the staining results for Her-2/neu in the DAKO HercepTest, the determination of staining intensity and percentage of complete membrane staining is subjective. We studied 46 cases of invasive breast carcinoma to evaluate interobserver reproducibility among 5 pathologists. Complete agreement was achieved in 22 (48%) of46 cases. Generalized kappa values indicated substantial agreement (0.80). Discrepancies between negative (0, 1+) and positive (2+, 3+) results occurred in 2 cases (kappa = 0.96). One was because of a tangential cut of the basal part of the tumor that mimicked complete membranous staining, and the other was a borderline case that revealedfocal (5%-15%) complete membranous staining. Distinguishing weakly (2+) from strongly (3+) positive results showed agreement in only 13 (59%) of 22 positive cases (kappa = 0.38). If more than 50% of tumor cells revealing strong complete membrane staining were regarded as strongly positive, agreement would be improved (kappa = 0.78). While there was a high percentage (70%-80%) of negative cases during routine evaluation, the good interobserver agreement and high negative predictive value made immunohistochemical analysis an effective screening test to exclude negative cases.     

Chemoprevention of oral cancer by green tea

Green tea has been a popular beverage for many centuries. Only recently, however, has the anti-cancer power of green tea constituents been unveiled. Green tea polyphenols are found to induce apoptosis (programmed cell death) in many types of tumor cells, including oral cancer cells. However, mechanisms that enable normal cells to evade the apoptotic effect still are not understood. In this study, cell growth and invasion assays combined with apoptosis assays were used to examine the effects of green tea extracts, green tea polyphenols, and the most potent green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), on normal human keratinocytes and oral carcinoma cells. The results showed that green tea and its constituents selectively induce apoptosis only in oral carcinoma cells, while EGCG was able to inhibit the growth and invasion of oral carcinoma cells. These differential responses to green tea and its constituents between normal and malignant cells were correlated with the induction of p57, a cell cycle regulator. These data suggest that the chemopreventive effects of green tea polyphenols may involve a p57 mediated survival pathway in normal epithelial cells, while oral carcinoma cells undergo an apoptotic pathway. Therefore, regular consumption of green tea could be beneficial in the prevention of oral cancer.     

Autoimmune bullous dermatoses: a review

Bullous dermatoses can be debilitating and possibly fatal. A selection of autoimmune blistering diseases, including pemphigus vulgaris, paraneoplastic pemphigus, bullous pemphigoid, cicatricial pemphigoid, dermatitis herpetiformis and linear IgA dermatosis are reviewed. Pemphigus vulgaris usually starts in the oral mucosa followed by blistering of the skin, which is often painful. Paraneoplastic pemphigus is associated with neoplasms, most commonly of lymphoid tissue, but also Waldenstr?m's macroglobulinemia, sarcomas, thymomas and Castleman's disease. Bullous pemphigoid is characterized by large, tense bullae, but may begin as an urticarial eruption. Cicatricial (scarring) pemphigoid presents with severe, erosive lesions of the mucous membranes with skin involvement in one third of patients focused around the head and upper trunk. Dermatitis herpetiformis is intensely pruritic and chronic, characterized by papulovesicles and urticarial wheals on the extensor surfaces in a grouped or herpetiform, symmetric distribution. Linear IgA dermatosis is clinically similar to dermatitis herpetiformis, but it is not associated with gluten-sensitive enteropathy as is dermatitis herpetiformis.     

Characterization of tissue resistance during a dorsally directed translational mobilization of the glenohumeral joint

OBJECTIVES: To quantify forces applied by therapists during dorsal glide translational mobilization of the glenohumeral joint, to determine the relationship of tissue resistance to the load-displacement relation of the glenohumeral joint, and to determine the safety of the forces applied by the therapists during dorsal glide translational mobilization. DESIGN: A fresh cadaver shoulder specimen mounted on a 6-axis load cell was used to register forces applied by therapists during dorsal glide translational mobilization of the glenohumeral joint in a test-retest pattern. SETTING: Biomechanics laboratory. PARTICIPANTS: Twelve experienced orthopedic physical therapists. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Forces exerted by therapists during passive dorsal glide translational mobilization in the loose-packed position and in the end range of abduction, with different grades of movements. The movements did not include any manipulation or thrust-type procedures. Simulated dorsal glide procedures were performed by the material testing system to construct the load-displacement curve of the glenohumeral specimen. The corresponding locations of the forces applied by therapists were interpolated and plotted on the load-displacement curve. RESULTS: The peak force values measured during mobilization were characterized by large intertherapist variability: coefficients of variation ranged from 40.97% to 77.49%. Test-retest reliability for intrasession measures was high (ICC(2,1) range,.90-.94); intersession reliability was poor (ICC(2,1) range,.01-.54). The mean forces ranged from 18.36 to 38.76N. When interpolated to the load-displacement curve, the mean peak forces obtained fell mostly in the toe and the linear elastic regions of the load-displacement curve. CONCLUSION: Force parameters measured during dorsal glide mobilization were characterized by large intertherapist variability with high intrasession and poor intersession test-retest reliability. The mobilization forces applied by experienced orthopedic physical therapists fall safely in the toe and the linear elastic regions of the load-displacement curve.