Trends in Breast MRI Use Among Women with BRCA Mutations: A National Claims Analysis 2006–2016

Women with BRCA mutations are recommended to receive breast MRI as an adjunct to annual mammography for breast cancer screening however adoption of these guidelines is unclear. We estimated breast MRI use from 2006–2016 among insured US women to understand use over time. Methods: Using medical care claims, we conducted a cohort study of breast MRI use in commercially-insured women aged 20–64 years continuously enrolled for ≥1 year in a large national insurer between 2006–2016. Women were identified as BCRA mutation carriers without a personal history of breast cancer using ICD9/10 diagnosis codes. We used CPT codes to identify breast MRIs and developed claims-based algorithms to categorized MRI indication as: screening, diagnostic or other. We calculated annual age-specific and age-adjusted rates of use overall and by indication among BCRA mutation carrier women. We used autoregressive time series models to estimate the yearly trend. Results: We identified 12,457 women with BRCA mutations during the study period. Breast MRI use overall among BRCA+ women aged 20–64 was 47/1000 women in 2006 and increased on average by 11 MRIs per year to a rate of 174/1000 in 2016 (P < 0.001). Across this time period, use for screening accounted for over 80% of breast MRIs and rates mirrored the overall trend with a 4.8-fold increase from 31/1000 in 2006 to 146/1000 women by 2016. Over the same time period, use of breast MRI for diagnostic workup or other indications remained stable. Use of screening breast MRI was highest among older women aged 50–64 compared with women <40 and 40–49 years (in 2016, 189, 95, and 177/1000, respectively) Discussion: Breast MRI screening increased dramatically over the past decade in women with BRCA mutations concordant with clinical guidelines. Additional research is needed to understand use of breast imaging relative to health outcomes for this high-risk population.

Resolution optimization of an off-axis lensless digital holographic microscope

Microscopes aimed at detecting cellular life in extreme environments such as ocean-bearing solar system moons must provide high resolution in a compact, robust instrument. Here, we consider the resolution optimization of a compact off-axis lensless digital holographic microscope (DHM) that consists of a sample placed between an input point-source pair and a detector array. Two optimal high-resolution regimes are identified at opposite extremes-a low-magnification regime with the sample located near a small-pixel detector array, and a high-magnification regime with the sample near the input plane. In the former, resolution improves with smaller pixels, while in the latter, the effect of the finite pixel size is obviated, and the spatial resolution improves with detector array size. Using an off-axis lensless DHM with a 2 k×2 k array of 5.5 μm-pixels in the high-magnification regime, and standard aberration correction software, a resolution of ∼0.95  μm has been demonstrated, a factor of 5.8 smaller than the pixel size. Our analysis further suggests that with yet larger detector arrays, a lensless DHM should be capable of near wavelength-scale resolution.

Deep nulling of visible laser light

Nulling interferometry, a proposed technique for dimming a star relative to its surroundings by destructively interfering the light collected by two individual telescopes [Bracewell, Nature 274, 780-781 (1978); Shao and Colavita, Ann. Rev. Astron. Astrophys. 30, 457-498 (1992)], has the potential to permit the direct detection of nearby extrasolar planets. However, because of the extremely high degree of symmetry required for useful levels of starlight nulling, the technique remains in its infancy. We present results of laboratory experiments with a rotational shearing interferometer that are aimed at demonstrating the feasibility of deep nulling at the levels needed for direct planet detection. Our first results include the successful nulling of red laser light to a part in 10(5) and the stabilization of the null leakage to a part in 10(4).

Doppler ultrasonographic examination of the leg veins of patients with Parkinson disease

OBJECTIVE

To determine the incidence of deep venous thrombosis (DVT) in patients with Parkinson disease.

DESIGN

Prospective study.

SETTING

Outpatient neurology clinic.

PATIENTS

Eighty-one patients with Parkinson disease.

OUTCOME MEASURES

Duplex ultrasonographic scans consisting of M mode images and compression images, Doppler flow assessment and augmentation of flow assessment.

RESULTS

Four patients had leg DVT; in 3 of the patients the thrombi were in calf veins, whereas in 1 patient the thrombosis was in the superficial femoral vein. Of the patients with DVT, 1 (1.23%) had stage 2 Parkinson disease, 1 (1.23%) had stage 2.5, and the other 2 (2.46%) had stage 4.

CONCLUSIONS

There was no statistically significant difference in the incidence of DVT among patients who were more severely disabled by Parkinson disease. However, an overall incidence of DVT of 4.9% in a group of asymptomatic patients is clinically meaningful, suggesting that patients with Parkinson disease are at risk for asymptomatic leg DVT.

Characteristics of the vitamin K-dependent carboxylating system in human placenta

Gamma-carboxyglutamic acid, formed during the post-translational vitamin K-dependent carboxylation of glutamic acid residues in polypeptides has been identified not only in coagulation factors II (prothrombin),, VII, IX and X [1--4], but also in several other plasma proteins [3,5,6] and in protein of bone [7,8] and kidney [9]. In rat liver, carboxylation is mediated through an enzyme system located in the microsomal membrane [10]. The enzyme system requires CO2, O2 and the reduced (hydroquinone) form of the vitamin, as well as a suitable substrate [10,11]. Rat liver microsomes also convert vitamin K1 (phylloquinone) to its stable 2,3-epoxide [12]. Several studies suggest a link between carboxylation and the formation of the epoxide [12--14]. In one of these [14], a survey of rat tissues for vitamin K1 epoxidation revealed that, in addition to liver, this activity was also possessed by kidney, bone, spleen and placenta. In preliminary experiments, vitamin K-dependent carboxylating systems have been found in rat and chick kidney [9], in chick bone [15] and in rat spleen and placenta (unpublished observations). In this communication, we describe some of the basic characteristics of the vitamin K-dependent carboxylating system as found in human placental microsomes.

A saturable high affinity binding site for transcobalamin II-vitamin B12 complexes in human placental membrane preparations

Studies were designed to evaluate the binding of binding of vitamin B12 to cell membrane preparations from human placenta. The transcobalamin II-vitamin B12 complex (TCII-B12), which has a much greater affinity for the membranes than vitamin B12 alone, binds to a single saturable binding site with an approximate Ka = 7.2 mM-1. The binding requires a divalent cation and is temperature-dependent. Free TCII can compete with TCII-B12 for the binding site but has somewhat less affinity than does TCII-B12. Rat TCII-B12 has an affinity constant that is less than one-fifth that of human TCII-B12; human TCI-B12, bovine TCII-B12, hog intrinsic factor-B12 (IF-B12), and human IF-B12 do not bind to the membranes. Pretreating the membranes with trypsin causes a marked decrease in subsequent binding; this suggests the binding site includes a relatively exposed membrane protein. These data suggest that a specific cell surface receptor for the TCII-B12 complex exists in placenta. This TCII-B12 receptor can be solubilized with Triton X-100.