Absolute marine gravimetry with matter-wave interferometry.

Measuring gravity from an aircraft or a ship is essential in geodesy, geophysics, mineral and hydrocarbon exploration, and navigation. Today, only relative sensors are available for onboard gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints. Atom interferometry is a promising technology to obtain onboard absolute gravimeter. But, despite high performances obtained in static condition, no precise measurements were reported in dynamic. Here, we present absolute gravity measurements from a ship with a sensor based on atom interferometry. Despite rough sea conditions, we obtained precision below 10-5 m s-2. The atom gravimeter was also compared with a commercial spring gravimeter and showed better performances. This demonstration opens the way to the next generation of inertial sensors (accelerometer, gyroscope) based on atom interferometry which should provide high-precision absolute measurements from a moving platform.

A case of recurrent vulvar carcinoma treated with erlotinib, an EGFR inhibitor.

BACKGROUND: There is no effective therapy for patients with regional and/or distant recurrence of vulvar carcinoma. Recently two case reports about the use of erlotinib, an EGFR (epithelial growth factor receptor) inhibitor, in the context of recurrent vulvar cancer were published with a good clinical response reported. CASE: We report a case where erlotinib was used in a 67-year-old patient with recurrent and multi-treated vulvar carcinoma. Utilization of erlotinib was started with rapid clinical improvement. The treatment was well tolerated with palliation of symptoms. A CT scan also showed cutoff "net" improvement, with regression of size and number of hilar and pulmonary metastases. After one month of improvement, despite continuous treatment with erlotinib, dyspnea returned. A new CT scan showed an increased number of hilar nodes, a new hepatic lesion and increase in the size of the known pelvic lesion. CONCLUSION: EGFR inhibitors appear to be promising agents for this devastating and fatal disease. As with other studies with these agents, our patient showed a rapid response with important palliation of symptoms, however of short duration.

Evaluation of multiple-sphere head models for MEG source localization.

Magnetoencephalography (MEG) source analysis has largely relied on spherical conductor models of the head to simplify forward calculations of the brain's magnetic field. Multiple- (or overlapping, local) sphere models, where an optimal sphere is selected for each sensor, are considered an improvement over single-sphere models and are computationally simpler than realistic models. However, there is limited information available regarding the different methods used to generate these models and their relative accuracy. We describe a variety of single- and multiple-sphere fitting approaches, including a novel method that attempts to minimize the field error. An accurate boundary element method simulation was used to evaluate the relative field measurement error (12% on average) and dipole fit localization bias (3.5 mm) of each model over the entire brain. All spherical models can contribute in the order of 1 cm to the localization bias in regions of the head that depart significantly from a sphere (inferior frontal and temporal). These spherical approximation errors can give rise to larger localization differences when all modeling effects are taken into account and with more complex source configurations or other inverse techniques, as shown with a beamformer example. Results differed noticeably depending on the source location, making it difficult to recommend a fitting method that performs best in general. Given these limitations, it may be advisable to expand the use of realistic head models.

Resistance of ICAM-1-deficient mice to metastasis overcome by increased aggressiveness of lymphoma cells.

Our recent finding that resistance to lymphoma cell metastasis in intercellular adhesion molecule-1-(ICAM-1)-deficient mice was manifested after homing suggested that the mechanism could involve the capacity of ICAM-1 to induce, via leukocyte function-associated antigen-1 (LFA-1) signaling, the expression of new genes necessary for migration and survival of lymphoma cells after homing. This hypothesis would imply that lymphoma cells, on repeated metastatic cycles, would acquire such a highly aggressive phenotype that they no longer require contact with ICAM-1 at later stages of metastasis. We addressed this question by generating highly aggressive lymphoma variants to determine if increased tumorigenicity would allow lymphoma cells to grow into tumors in ICAM-1-deficient mice. We found that on repeated in vivo passages, a selective pressure favored the lymphoma cells that constitutively express high levels of matrix metalloproteainse-9 (MMP-9), a gene associated with a poor clinical outcome in non-Hodgkins's lymphoma. We further found that although the parent lymphoma cells could not grow tumors in ICAM-1-deficient mice, the aggressive lymphoma variants could. This indicates that, at late stages of the disease, tumor cells with a high metastatic efficiency, encoded by the repertoire of selected genes, no longer require some of the signals normally delivered by cell adhesion molecules. In light of these findings, the possibility of inhibiting dissemination of lymphoma cells at the late stage of the disease by acting against cell adhesion molecules must be reconsidered. (Blood. 2000;95:314-319)

Dissemination of T cell lymphoma to target organs: a post-homing event implicating ICAM-1 and matrix metalloproteinases.

There is increasing evidence that metastasis of a tumor cell (its ability to induce the "development of a tumor" at distant sites following intravasation) is manifested only after homing to distant site(s). All tumor cells, however, do not necessarily undergo uncontrolled cellular division to form secondary tumors once they have "homed" to a target site. One of the major rate-limiting steps in metastasis is in fact related to the ability of the extravasated tumor cells to find an appropriate "nest", where favorable growth conditions will allow them to form a secondary tumor upon massive cell division (1). But to establish such a favorable nest (referred herein as the "nidification" process), tumor cells must penetrate deep into the stroma of the target tissue. This process is facilitated when tumor cells produce of specific proteases, which degrade structural proteins of the extracellular matrix (2,3). The production of proteases by stromal cells can also occur; these enzymes will degrade stroma surrounding the tumor cells, resulting in a massive remodeling of the local parenchyma that may interfere with the vital functions of a target organ as well as help nidification (4). In this review, we focus our attention on post-extravasation events involving adhesion molecules and MMP in the metastatic process of lymphoma cells. We propose that during dissemination of LFA-1-positive lymphoma cells to peripheral organs, the interaction between lymphoma cells and vascular endothelial cells upregulates the local expression of MMP and TIMPs. Since control of lymphoma metastasis appears to occur at the post-extravasation level, we hypothesize that in addition to extravasation, adhesion molecules are implicated in the control of post-extravasation events.

Farmer's lung. Long-term outcome and lack of predictive value of bronchoalveolar lavage fibrosing factors.

This study evaluates the long-term outcome of farmer's lung (FL), adding high-resolution computed tomograms (HRCT) to previously reported procedures and verifying whether bronchoalveolar lavage (BAL) fluid markers or substrates of fibrosis (hyaluronic acid, Type III procollagen, fibronectin, and fibroblast growth factors) (FF) predict outcome. A total of 33 subjects with a history of FL dating back at least 6 yr were evaluated with pulmonary function tests, chest x-ray (CXR), and HRCT. All subjects had an initial evaluation, which included a BAL, 6 yr before the current study. Subjects were then either in acute FL (n = 19) or in clinical remission despite continued contact (n = 14). In the current study, pulmonary function tests revealed an obstructive profile in 13 subjects, restrictive changes in 1, an isolated decrease in lung diffusion capacity in 3, and normal values in 16. Chest radiographs (CXR) were normal in 22 subjects, abnormal with interstitial or reticulonodular changes in 6, and suggestive of emphysema in 5. HRCT revealed emphysema in 9 subjects; 3 had localized fibrotic changes, 2 a ground-glass pattern, and 19 were normal. There was a good correlation between the findings on pulmonary function tests and HRCT; however, CXR alone did not suggest the existence of emphysema in 4 subjects who had such findings on HRCT. No correlations were found between most outcome parameters and the level of the BAL FF measured 6 yr previously. We conclude that airflow obstruction with or without emphysema is an important long-term sequela of FL and that BAL FF do not predict outcome in this disease.