Endoluminal surface registration for CT colonography using haustral fold matching

Computed Tomographic (CT) colonography is a technique used for the detection of bowel cancer or potentially precancerous polyps. The procedure is performed routinely with the patient both prone and supine to differentiate fixed colonic pathology from mobile faecal residue. Matching corresponding locations is difficult and time consuming for radiologists due to colonic deformations that occur during patient repositioning.We propose a novel method to establish correspondence between the two acquisitions automatically. The problem is first simplified by detecting haustral folds using a graph cut method applied to a curvature-based metric applied to a surface mesh generated from segmentation of the colonic lumen. A virtual camera is used to create a set of images that provide a metric for matching pairs of folds between the prone and supine acquisitions. Image patches are generated at the fold positions using depth map renderings of the endoluminal surface and optimised by performing a virtual camera registration over a restricted set of degrees of freedom. The intensity difference between image pairs, along with additional neighbourhood information to enforce geometric constraints over a 2D parameterisation of the 3D space, are used as unary and pair-wise costs respectively, and included in a Markov Random Field (MRF) model to estimate the maximum a posteriori fold labelling assignment.The method achieved fold matching accuracy of 96.0% and 96.1% in patient cases with and without local colonic collapse. Moreover, it improved upon an existing surface-based registration algorithm by providing an initialisation. The set of landmark correspondences is used to non-rigidly transform a 2D source image derived from a conformal mapping process on the 3D endoluminal surface mesh. This achieves full surface correspondence between prone and supine views and can be further refined with an intensity based registration showing a statistically significant improvement (p < 0.001), and decreasing mean error from 11.9 mm to 6.0 mm measured at 1743 reference points from 17 CTC datasets.     

Funding community-based participatory research: lessons learned

The California Breast Cancer Research Program (CBCRP) was created to fund innovative breast cancer research specifically addressing the needs of women in California. Beginning in 1997, the Program launched the Community Research Collaboration (CRC) Program, a Community-Based Participatory Research (CBPR) program intended to foster community-researcher collaboration on all aspects of the research process, essentially placing the community in the center of the research paradigm. The CBCRP conducted a process evaluation of the CRC Program to assess success and identify areas for improvement. The evaluation included community-researcher collaborations and the award process. The evaluation identified successes that speak to the effectiveness of the collaboration concept: empowering women to formulate and initiate research; involving underserved and hard-to-reach populations; addressing important and useful research questions; increasing communities' skills and expertise, and enabling lasting collaborations. The greatest weakness identified was the involvement of the broader community (beyond the group/organization involved) in these projects. The evaluation identified strengths in CBCRP's award process, including technical assistance and feedback, the emphasis on collaboration in the review process, and awarding funds directly to community groups. Barriers included: power imbalances due to the community's lack of experience in the dominant research funding culture; funding limits and award delays; and the increased service demand beyond the funding limits of the award that is created. The CBCRP has been able to incorporate many of the evaluation findings to improve the CRC Program.     

Myeloid,B and T lymphoid and mixed lineage thymic lymphomas in the irradiated mouse

Thymic lymphoma is a very common spontaneous and/or induced malignancy in both inbred mice and in transgenic mouse models of human cancer. Although a thymic lymphoma is defined as thymus-dependent T-cell malignancy, diagnostic criteria vary between studies and considerable heterogeneity has been reported. To define and classify the thymic lymphomas that arose in our study of X-irradiated (CBA/HxC57BL/6)F1, F1 backcross and F1 intercross mice, 66 thymic lymphomas were immunogenotyped for immunoglobulin heavy chain (IgH) and T-cell receptor beta (TCRbeta) gene rearrangements, and/or analysed for expression of lineage-specific markers and allelic loss on chromosome 4. The data indicate that 33% of the thymic lymphomas are very similar to mouse radiation-induced acute myeloid (AML) and mixed lineage (IgH(R), TCRbeta(G)) pre-B lympho-myeloid (L-MLs) leukaemias, 33% are mixed lineage (IgH(R), TCRbeta(R)) B/T lymphoid and <33% can be described as single lineage (IgH(G), TCRbeta(R)) T-cell malignancies. As the myeloid and L-ML leukaemias are not thymus-dependent this suggests that a malignant myeloid or pre-B lympho-myeloid cell can colonize the spleen to give an AML or L-ML leukaemia, or can colonize the thymus where TCRbeta gene rearrangement(s) may be induced to give the mixed lineage thymic lymphomas. Thus, assuming the single lineage T-cell thymic lymphomas fulfil the criteria of a thymus-dependent T-cell malignancy, thymic lymphomas are comprised of at least three distinct malignancies.     

Toremifene in the treatment of breast cancer

Although more widespread screening and routine adjuvant therapy has improved the outcome for breast cancer patients in recent years, there remains considerable scope for improving the efficacy, safety and tolerability of adjuvant therapy in the early stage disease and the treatment of advanced disease. Toremifene is a selective estrogen receptor modifier (SERM) that has been widely used for decades in hormone receptor positive breast cancer both in early and late stage disease. Its efficacy has been well established in nine prospective randomized phase III trials compared to tamoxifen involving more than 5500 patients, as well as in several large uncontrolled and non-randomized studies. Although most studies show therapeutic equivalence between the two SERMs, some show an advantage for toremifene. Several meta-analyses have also confirmed that the efficacy of toremifene is at least as good as that of tamoxifen. In terms of safety and tolerability toremifene is broadly similar to tamoxifen although there is some evidence that toremifene is less likely to cause uterine neoplasms, serious vascular events and it has a more positive effect on serum lipids than does tamoxifen. Toremifene is therefore effective and safe in the treatment of breast cancer. It provides not only a useful therapeutic alternative to tamoxifen, but may bring specific benefits.     

Antioxidant activities of extracts from five anti-viral medicinal plants

The antioxidant activities of five medicinal plants (Ampelopsis sinica, Ampelopsis humiliforlia var. heterophylla, Potentilla freyniana, Selaginella labordei and Chrysanthemum multiflorum), used in the Hubei province of China, have been investigated using both enzymatic and non-enzymatic in vitro antioxidant assays. Extracts from all five of the plants inhibited xanthine oxidase and lipoxygenase activities, and were scavengers of the ABTS*+ radical cation using the Trolox equivalent antioxidant capacity assay (TEAC). Extracts from Potentilla freyniana and Selaginella labordei down-regulated cyclooxygenase-2 gene expression, measured by real-time RT-PCR, in human colon adenocarcinoma CaCo-2 cells.     

Exposure to polychlorinated biphenyl (PCB) congeners measured shortly after giving birth and subsequent risk of maternal breast cancer before age 50

Mammographic density is a strong risk factor for breast cancer but its underlying biology in healthy women is not well-defined. Using a novel collection of core biopsies from mammographically dense versus non-dense regions of the breasts of healthy women, we examined histologic and molecular differences between these two tissue types. Eligible participants were 40 + years, had a screening mammogram and no prior breast cancer or current endocrine therapy. Mammograms were used to identify dense and non-dense regions and ultrasound-guided core biopsies were performed to obtain tissue from these regions. Quantitative assessment of epithelium, stroma, and fat was performed on dense and non-dense cores. Molecular markers including Ki-67, estrogen receptor (ER) and progesterone receptor (PR) were also assessed for participants who had >0% epithelial area in both dense and non-dense tissue. Signed rank test was used to assess within woman differences in epithelium, stroma and fat between dense and non-dense tissue. Differences in molecular markers (Ki-67, ER, and PR) were analyzed using generalized linear models, adjusting for total epithelial area. Fifty-nine women, mean age 51 years (range: 40-82), were eligible for analyses. Dense tissue was comprised of greater mean areas of epithelium and stroma (1.1 and 9.2 mm(2) more, respectively) but less fat (6.0 mm(2) less) than non-dense tissue. There were no statistically significant differences in relative expression of Ki-67 (P = 0.82), ER (P = 0.09), or PR (P = 0.96) between dense and non-dense tissue. Consistent with prior reports, we found that mammographically dense areas of the breast differ histologically from non-dense areas, reflected in greater proportions of epithelium and stroma and lesser proportions of fat in the dense compared to non-dense breast tissue. Studies of both epithelial and stromal components are important in understanding the association between mammographic density and breast cancer risk.     

How to effectively use and interpret the barium swallow: Current role in esophageal dysphagia

Background

The barium swallow is a commonly performed investigation, though recent decades have seen major advances in other esophageal diagnostic modalities.

Purpose

The purpose of this review is to clarify the rationale for components of the barium swallow protocol, provide guidance on interpretation of findings, and describe the current role of the barium swallow in the diagnostic paradigm for esophageal dysphagia in relation to other esophageal investigations. The barium swallow protocol, interpretation, and reporting terminology are subjective and non-standardized. Common reporting terminology and an approach to their interpretation are provided. A timed barium swallow (TBS) protocol provides more standardized assessment of esophageal emptying but does not evaluate peristalsis. Barium swallow may have higher sensitivity than endoscopy for detecting subtle strictures. Barium swallow has lower overall accuracy than high-resolution manometry for diagnosing achalasia but can help secure the diagnosis in cases of equivocal manometry. TBS has an established role in objective assessment of therapeutic response in achalasia and helps identify the cause of symptom relapse. Barium swallow has a role in the evaluating manometric esophagogastric junction outflow obstruction, in some cases helping to identify where it represents an achalasia-like syndrome. Barium swallow should be performed in dysphagia following bariatric or anti-reflux surgery, to assess for both structural and functional postsurgical abnormality. Barium swallow remains a useful investigation in esophageal dysphagia, though its role has evolved due to advancements in other diagnostics. Current evidence-based guidance regarding its strengths, weaknesses, and current role are described in this review.