Efficacy of Mammographic Evaluation of Breast Cancer in Women Less Than 40 Years of Age: Experience from a Single Medical Center in Taiwan

Background/PurposeMammography is the standard imaging modality for breast cancer diagnosis. However, the value of mammographic diagnosis in breast cancer patients aged less than 40 years old has not been well assessed. The goal of our study was to determine the diagnostic efficacy of mammography for the detection of breast cancer in women under 40 years of age in a single medical center in Taiwan.MethodsOf 1766 women diagnosed with breast cancer in one medical center between 1999 and 2005, 227 (12.9%) who were younger than 40 years of age were enrolled, and 105 of these 227 patients had pre-biopsy mammograms available for analysis. The sensitivities for mammography at first (prospective) and second (retrospective) readings and for corresponding ultrasound were calculated. The distribution of different breast composition between the mammographic true-positive (TP) and false-negative (FN) lesions at the first and second readings was analyzed.ResultsOf the 105 patients, 104 presented with a palpable mass and the other one was asymptomatic. There were 109 pathologically proven breast cancers from the 105 patients; 92 of 109 cancerous lesions were detected at the first mammographic reading (sensitivity 84.4%), and the most common mammographic sign was microcalcifications (40.2%). The second reading detected seven additional cancers (99 of 109 lesions; sensitivity 90.8%). There was no significant difference between mammographic TP and FN lesions for the different breast composition on first and second readings. Ninety patients also had ultrasound available for correlation with 94 cancers diagnosed from them. The diagnostic sensitivity of ultrasound was 94.7% (89 of 94 lesions).ConclusionMammography has an acceptable sensitivity for the detection of breast cancer in women aged less than 40 years, regardless of different breast composition. Breast ultrasound can offer a higher sensitivity for such a population

Transmission dynamics of the etiological agent of SARS in Hong Kong: impact of public health interventions.

We present an analysis of the first 10 weeks of the severe acute respiratory syndrome (SARS) epidemic in Hong Kong. The epidemic to date has been characterized by two large clusters-initiated by two separate "super-spread" events (SSEs)-and by ongoing community transmission. By fitting a stochastic model to data on 1512 cases, including these clusters, we show that the etiological agent of SARS is moderately transmissible. Excluding SSEs, we estimate that 2.7 secondary infections were generated per case on average at the start of the epidemic, with a substantial contribution from hospital transmission. Transmission rates fell during the epidemic, primarily as a result of reductions in population contact rates and improved hospital infection control, but also because of more rapid hospital attendance by symptomatic individuals. As a result, the epidemic is now in decline, although continued vigilance is necessary for this to be maintained. Restrictions on longer range population movement are shown to be a potentially useful additional control measure in some contexts. We estimate that most currently infected persons are now hospitalized, which highlights the importance of control of nosocomial transmission

Is 'oil pulling' a 'snake oil'? : a clinical trial

The traditional Ayurveda practice of ‘oil pulling’ has become a recent phenomenon and concerns about its efficacy have been raised. Objectives: (1) to determine awareness about the practice of ‘oil pulling’ among a group of young adults, and to determine variations in awareness with respect to socio-demographic factors, oral health behaviours (oral hygiene and dental attendance) and use of natural health products; (2) to determine the effectiveness of ‘oil pulling’ and conventional oral hygiene practice compared to the use of conventional oral hygiene practice alone in terms of oral hygiene and (3) to determine the effectiveness of ‘oil pulling’ and conventional oral hygiene practice compared to the use of conventional oral hygiene practice alone in terms of gingival health. Methods: Group members recruited seventy-four young adults to participate in a clinical trial over a two-month period comparing the effectiveness of (a) ‘oil pulling’ and conventional oral hygiene methods (toothbrush and toothpaste) versus (b) conventional oral hygiene methods alone. Oral hygiene was assessed using the Plaque Index - PI (Silness and Löe, 1964) and the proportion of sites with visible plaque (PVP). Gingival health was assessed using the Gingival Index – GI (Silness and Löe,1963) and the proportion of sites with gingival bleeding (PGB). Participants were block randomized in groups of four to a cross over clinical trial and assessments were conducted at one-month and two-months. Results: Approximately a quarter (28.4%, 21) of participants was aware of the practice of ‘oil pulling’. Awareness of the practice was associated with reported use of natural dental/oral health products (p0.05). There were observed significant differences in gingival health among both the test and control groups from baseline to one-month (p0.05). No significant differences were observed in oral health parameters from one-month to two-month among neither the test nor control groups (p>0.05). Conclusion: Awareness of the practice of ‘oil pulling’ is relatively common and is associated with use of natural dental/oral health products. Findings from the clinical trial failed to support the adjunct use of ‘oil pulling’ in addition to conventional oral hygiene practices.published_or_final_versio

Intrinsic galaxy shapes and alignments I: Measuring and modelling COSMOS intrinsic galaxy ellipticities

The statistical properties of the ellipticities of galaxy images depend on how galaxies form and evolve, and therefore constrain models of galaxy morphology, which are key to the removal of the intrinsic alignment contamination of cosmological weak lensing surveys, as well as to the calibration of weak lensing shape measurements. We construct such models based on the halo properties of the Millennium Simulation and confront them with a sample of 90,000 galaxies from the COSMOS Survey, covering three decades in luminosity and redshifts out to z=2. The ellipticity measurements are corrected for effects of point spread function smearing, spurious image distortions, and measurement noise. Dividing galaxies into early, late, and irregular types, we find that early-type galaxies have up to a factor of two lower intrinsic ellipticity dispersion than late-type galaxies. None of the samples shows evidence for redshift evolution, while the ellipticity dispersion for late-type galaxies scales strongly with absolute magnitude at the bright end. The simulation-based models reproduce the main characteristics of the intrinsic ellipticity distributions although which model fares best depends on the selection criteria of the galaxy sample. We observe fewer close-to-circular late-type galaxy images in COSMOS than expected for a sample of randomly oriented circular thick disks and discuss possible explanations for this deficit.Comment: 18 pages, 8 figures; updated simulations and galaxy sample definition, more galaxy samples analysed; matches version published in MNRA

Neutrino Masses and a Fourth Generation of Fermions

We study neutrino mass generation in models with four chiral families of leptons and quarks and four right handed neutrinos. Generically, in these models there are three different contributions to the light neutrino masses: the usual see-saw contribution, the tree-level contribution due to mixing of light neutrinos with neutrino of the fourth generation, and the two loop contribution due to the Majorana mass term of the fourth neutrino. We study properties of these contributions and their experimental bounds. The regions of the parameters (mixings of the fourth neutrino, masses of RH neutrino components, etc.) have been identified where various contributions dominate. New possibilities of a realization of the flavour symmetries in the four family context are explored. In particular, we consider applications of the smallest groups, e.g. SG(20,3), with irreducible representation 4.Comment: 33 pages, 4 figures; Eq. (18) corrected and thus corrections to Eqs. (21,26-28,41,42,44-46) and figures, the loop contribution reduced by 2 orders of magnitude; general conclusions unchanged; accepted by Nucl. Phys.

A Close Binary Star Resolved from Occultation by 87 Sylvia

The star BD+29 1748 was resolved to be a close binary from its occultation by the asteroid 87 Sylvia on 2006 December 18 UT. Four telescopes were used to observe this event at two sites separated by some 80 km apart. Two flux drops were observed at one site, whereas only one flux drop was detected at the other. From the long-term variation of Sylvia, we inferred the probable shape of the shadow during the occultation, and this in turn constrains the binary parameters: the two components of BD+29 1748 have a projected separation of 0.097" to 0.110" on the sky with a position angle 104 deg to 107 deg. The asteroid was clearly resolved with a size scale ranging from 130 to 290 km, as projected onto the occultation direction. No occultation was detected for either of the two known moonlets of 87 Sylvia.Comment: 12 pages, 4 figures, 2 tables; submitted to the PAS

Multiple Lineages of Human Breast Cancer Stem/Progenitor Cells Identified by Profiling with Stem Cell Markers

Heterogeneity of cancer stem/progenitor cells that give rise to different forms of cancer has been well demonstrated for leukemia. However, this fundamental concept has yet to be established for solid tumors including breast cancer. In this communication, we analyzed solid tumor cancer stem cell markers in human breast cancer cell lines and primary specimens using flow cytometry. The stem/progenitor cell properties of different marker expressing-cell populations were further assessed by in vitro soft agar colony formation assay and the ability to form tumors in NOD/SCID mice. We found that the expression of stem cell markers varied greatly among breast cancer cell lines. In MDA-MB-231 cells, PROCR and ESA, instead of the widely used breast cancer stem cell markers CD44+/CD24-/low and ALDH, could be used to highly enrich cancer stem/progenitor cell populations which exhibited the ability to self renew and divide asymmetrically. Furthermore, the PROCR+/ESA+ cells expressed epithelial-mesenchymal transition markers. PROCR could also be used to enrich cells with colony forming ability from MB-361 cells. Moreover, consistent with the marker profiling using cell lines, the expression of stem cell markers differed greatly among primary tumors. There was an association between metastasis status and a high prevalence of certain markers including CD44+/CD24−/low, ESA+, CD133+, CXCR4+ and PROCR+ in primary tumor cells. Taken together, these results suggest that similar to leukemia, several stem/progenitor cell-like subpopulations can exist in breast cancer

Neutrino dark matter candidate in fourth generation scenarios

We overview the constraints on the 4th-generation neutrino dark matter candidate and investigate a possible way to make it a viable dark matter candidate. Given the LEP constraints tell us that the 4th-generation neutrino has to be rather heavy (> M_Z/2), in sharp contrast to the other three neutrinos, the underlying nature of the 4th-generation neutrino is expected to be different. We suggest that an additional gauge symmetry B-4L_4 distinguishes it from the Standard Model's three lighter neutrinos and this also facilitates promotion of the 4th-generation predominantly right-handed neutrino to a good cold dark matter candidate. It provides distinguishable predictions for the dark matter direct detection and the Large Hadron Collider experiments.Comment: Version to appear in PL

Molecular simulations of venom peptide-membrane interactions: Progress and challenges

Because of their wide range of biological activities venom peptides are a valuable source of lead molecules for the development of pharmaceuticals, pharmacological tools and insecticides. Many venom peptides work by modulating the activity of ion channels and receptors or by irreversibly damaging cell membranes. In many cases, the mechanism of action is intrinsically linked to the ability of the peptide to bind to or partition into membranes. Thus, understanding the biological activity of these venom peptides requires characterizing their membrane binding properties. This review presents an overview of the recent developments and challenges in using biomolecular simulations to study venom peptide‐membrane interactions. The review is focused on (i) gating modifier peptides that target voltage‐gated ion channels, (ii) venom peptides that inhibit mechanosensitive ion channels, and (iii) pore‐forming venom peptides. The methods and approaches used to study venom peptide‐membrane interactions are discussed with a particular focus on the challenges specific to these systems and the type of questions that can (and cannot) be addressed using state‐of‐the‐art simulation techniques. The review concludes with an outlook on future aims and directions in the field