Prospective development of an individualised predictive model for treatment coverage using offline cone beam computed tomography surrogate measures in post‐prostatectomy radiotherapy

The aim of this study is to prospectively evaluate and model surrogate explanatory variables (SEVs) of target coverage and rectal dose pertaining to soft tissue anatomy visualised on cone beam computed tomography (CBCT) for incorporation into post‐prostatectomy treatment coverage verification protocols. Twenty post‐prostatectomy patients treated with conformal prostate bed radiotherapy (64–74 Gy) underwent CBCT daily at fractions 1 to 5, and then weekly. Treatment coverage was defined on each CBCT using ‘PTV95’, percentage of the CBCT PTV covered by original treatment fields, and ‘RECTD50’, dose delivered to 50% of CBCT rectal volume by original treatment fields. Three candidate SEVs for treatment coverage were defined for each scan: anterior rectal wall movement, change in bladder length and bladder base movement. Both anterior rectal wall movement and increase in bladder length predicted for the decreased PTV95 (P < 0.001 for each). Anterior movement of the anterior rectal wall predicted for increased RECTD50 (P < 0.001). Predictive models for the PTV95 and RECTD50 that accept the significant SEVs as inputs were developed. We developed simple CBCT‐acquired soft tissue anatomic surrogate measures that signal changes in target coverage and rectal dose during post‐prostatectomy radiotherapy. Conventional bony anatomy patient position verification protocols were inadequate in accounting for soft tissue target and organ variation seen with CBCT.     

Truncated NF2 proteins are not detected in meningiomas and schwannomas

Neurofibromatosis type 2 is caused by mutations in the NF2 tumor suppressor gene. The NF2 gene encodes a 595‐aminoacid protein, presumably functioning as a membrane‐organizing element. Theoretically, the majority of mutations found in the NF2 gene should lead to a truncated protein product. Using immunoprecipitation with an antibody raised to N‐terminal sequences of the NF2 protein, the authors sought to demonstrate the presence of truncated NF2 proteins in tumors. From 17 of 19 tumors (14 meningiomas and five schwannomas), 12 of which have previously been shown to harbor truncating NF2 mutations, wild‐type NF2 protein was immunopreci‐pitated. From two tumors no protein was precipitated. Truncated NF2 proteins were not observed. The authors conclude that mutant NF2 proteins are unstable and undergo accelerated degradation.     

Accuracy of three cone-beam CT devices and two software systems in the detection of vertical root fractures

Objectives :The aim of this study was to compare the accuracy of vertical root fracture (VRF) detection using three tomography devices and two software systems in teeth with different endodontic fillings.Methods:The sample consisted of 45 premolars divided into 3 groups: No filling (NF, n=15); Gutta percha (GP, n=15) and Metallic Post (MP, n=15). Cone-beam computed tomography (CBCT) images were acquired in Kodak 9000 3D, Orthopantomography 300 (OP300) and PreXion 3D devices, before and after induced root fractures. Two oral radiologists analyzed all images using InVivoDental and e-Vol DX software systems. The analysis was repeated after 15 days in 30% of the sample. Data analysis compared receiver operating characteristic (ROC) curves, as well the areas under the ROC curves. Accuracy, sensitivity, specificity, positive and negative predictive value were calculated according to each tomographic device and software. Intra- and interexaminer reliability were tested using the Kappa coefficient.Results:The highest accuracy was seen in the image set from the PreXion 3D, using InVivo (0.96) or e-Vol DX (0.92) in image analysis. The OP300 device presented a similar performance of the PreXion 3D in teeth with different endodontic fillings. When using e-Vol DX, the accuracy of Kodak 9000 3D improved from 0.62 to 0.74.Conclusions:The PreXion 3D device is the most accurate when detecting VRF, with a performance similar to the OP300 in endodontic filled teeth. Kodak 9000 3D is indicated for teeth without fillings, with better accuracy using e-Vol DX software.     

Platelet aggregation in allergic reactions

The platelet aggregation in the presence of 4 aggregation inducers was studied in 63 allergic patients, consisting of atopic and non-atopic asthmatics and aspirin-sensitive subjects, before and after inhalation tests or in vitro incubation with allergen. Basal platelet aggregation was decreased in 43% of the atopic patients for adrenaline and also in a smaller percentage for other agonists. A decreased aggregation was also observed in 3 out of 6 nonatopic patients and in aspirin-sensitive patients. In vivo or in vitro provocation tests decreased aggregation in some additional patients. These results point out to a compromise of platelets in allergic mechanisms.     

A clinicopathological study of loop recession in strabismus

This communication reports the histological structure of loop recessions of extraocular muscles from seven patients. In all cases the loops formed pseudotendons in which the typical histological structure was well established by four months. Subsequently, moulding of these pseudotendons occurred with improved alignment of collagen and decrease in vascularity. By three and a half years after the operation the pseudotendon had acquired a very close resemblance to true tendon.     

Predicting hemolytic disease of the newborn: a comparison of the monocyte monolayer assay and the chemiluminescence test

The ability of the monocyte monolayer assay (MMA) and the chemiluminescence test (CLT) to predict the clinical significance of alloantibodies associated with hemolytic disease of the newborn (HDN) was assessed by the use of 22 well-characterized antisera– predominantly anti-D–from alloimmunized pregnant women. Seventeen sera were obtained before delivery from women whose infants were antigen positive for the antibody specificities identified in the maternal serum. With testing of these 17 sera by MMA, 10 results were in agreement with the presence or absence of HDN, but there were 5 false- positive and 2 false-negative results. With the CLT, 16 results were in agreement with the presence or absence of HDN, and there was 1 false- negative result. Five sera were obtained from women whose infants were antigen negative for the antibody specificities identified in the maternal serum. The CLT and the MMA were both subject to false-positive results with these sera. These results suggest that the CLT may be more valuable than the MMA as a noninvasive test for predicting the clinical significance of alloantibodies in HDN.