[Breast cancer : individualized risk assessment for tailor-made screening]

Breast cancer is the leading cause of neoplastic death in women around the world. In the era of personalized medicine, legitimately awaited by our patients, the future of breast cancer screening will depend on an individual-based risk assessment, making it possible to better adapt the age of onset, frequency and the type of examinations useful for this screening. This article reviews the three broad categories of highest risk factors available to establish a risk score appropriate for each patient.

Better Sleep at Night: How Light Influences Sleep in Drosophila

Sleep-like states have been described in Drosophila and the mechanisms and factors that generate and define sleep-wake profiles in this model organism are being thoroughly investigated. Sleep is controlled by both circadian and homeostatic mechanisms, and environmental factors such as light, temperature, and social stimuli are fundamental in shaping and confining sleep episodes into the correct time of the day. Among environmental cues, light seems to have a prominent function in modulating the timing of sleep during the 24 h and, in this review, we will discuss the role of light inputs in modulating the distribution of the fly sleep-wake cycles. This phenomenon is of growing interest in the modern society, where artificial light exposure during the night is a common trait, opening the possibility to study Drosophila as a model organism for investigating shift-work disorders.

Peptidergic signaling from clock neurons regulates reproductive dormancy in Drosophila melanogaster

With the approach of winter, many insects switch to an alternative protective developmental program called diapause. Drosophila melanogaster females overwinter as adults by inducing a reproductive arrest that is characterized by inhibition of ovarian development at previtellogenic stages. The insulin producing cells (IPCs) are key regulators of this process, since they produce and release insulin-like peptides that act as diapause-antagonizing hormones. Here we show that in D. melanogaster two neuropeptides, Pigment Dispersing Factor (PDF) and short Neuropeptide F (sNPF) inhibit reproductive arrest, likely through modulation of the IPCs. In particular, genetic manipulations of the PDF-expressing neurons, which include the sNPF-producing small ventral Lateral Neurons (s-LNvs), modulated the levels of reproductive dormancy, suggesting the involvement of both neuropeptides. We expressed a genetically encoded cAMP sensor in the IPCs and challenged brain explants with synthetic PDF and sNPF. Bath applications of both neuropeptides increased cAMP levels in the IPCs, even more so when they were applied together, suggesting a synergistic effect. Bath application of sNPF additionally increased Ca2+ levels in the IPCs. Our results indicate that PDF and sNPF inhibit reproductive dormancy by maintaining the IPCs in an active state.

Inhibition of the deubiquitinase USP8 corrects a Drosophila PINK1 model of mitochondria dysfunction

Aberrant mitochondrial dynamics disrupts mitochondrial function and contributes to disease conditions. A targeted RNA interference screen for deubiquitinating enzymes (DUBs) affecting protein levels of multifunctional mitochondrial fusion protein Mitofusin (MFN) identified USP8 prominently influencing MFN levels. Genetic and pharmacological inhibition of USP8 normalized the elevated MFN protein levels observed in PINK1 and Parkin-deficient models. This correlated with improved mitochondrial function, locomotor performance and life span, and prevented dopaminergic neurons loss in Drosophila PINK1 KO flies. We identified a novel target antagonizing pathologically elevated MFN levels, mitochondrial dysfunction, and dopaminergic neuron loss of a Drosophila model of mitochondrial dysfunction.

The RNA Helicase BELLE Is Involved in Circadian Rhythmicity and in Transposons Regulation in Drosophila melanogaster

Circadian clocks control and synchronize biological rhythms of several behavioral and physiological phenomena in most, if not all, organisms. Rhythm generation relies on molecular auto-regulatory oscillations of interlocked transcriptional-translational feedback loops. Rhythmic clock-gene expression is at the base of rhythmic protein accumulation, though post-transcriptional and post-translational mechanisms have evolved to adjust and consolidate the proper pace of the clock. In Drosophila, BELLE, a conserved DEAD-box RNA helicase playing important roles in reproductive capacity, is involved in the small RNA-mediated regulation associated to the piRNA pathway. Here, we report that BELLE is implicated in the circadian rhythmicity and in the regulation of endogenous transposable elements (TEs) in both nervous system and gonads. We suggest that BELLE acts as important element in the piRNA-mediated regulation of the TEs and raise the hypothesis that this specific regulation could represent another level of post-transcriptional control adopted by the clock to ensure the proper rhythmicity.

Calmodulin Enhances Cryptochrome Binding to INAD in Drosophila Photoreceptors

Light is the main environmental stimulus that synchronizes the endogenous timekeeping systems in most terrestrial organisms. Drosophila cryptochrome (dCRY) is a light-responsive flavoprotein that detects changes in light intensity and wavelength around dawn and dusk. We have previously shown that dCRY acts through Inactivation No Afterpotential D (INAD) in a light-dependent manner on the Signalplex, a multiprotein complex that includes visual-signaling molecules, suggesting a role for dCRY in fly vision. Here, we predict and demonstrate a novel Ca²⁺-dependent interaction between dCRY and calmodulin (CaM). Through yeast two hybrid, coimmunoprecipitation (Co-IP), nuclear magnetic resonance (NMR) and calorimetric analyses we were able to identify and characterize a CaM binding motif in the dCRY C-terminus. Similarly, we also detailed the CaM binding site of the scaffold protein INAD and demonstrated that CaM bridges dCRY and INAD to form a ternary complex in vivo. Our results suggest a process whereby a rapid dCRY light response stimulates an interaction with INAD, which can be further consolidated by a novel mechanism regulated by CaM.

Cryptochrome Interacts With Actin and Enhances Eye-Mediated Light Sensitivity of the Circadian Clock in Drosophila melanogaster

Cryptochromes (CRYs) are a class of flavoproteins that sense blue light. In animals, CRYs are expressed in the eyes and in the clock neurons that control sleep/wake cycles and are implied in the generation and/or entrainment of circadian rhythmicity. Moreover, CRYs are sensing magnetic fields in insects as well as in humans. Here, we show that in the fruit fly Drosophila melanogaster CRY plays a light-independent role as "assembling" protein in the rhabdomeres of the compound eyes. CRY interacts with actin and appears to increase light sensitivity of the eyes by keeping the "signalplex" of the phototransduction cascade close to the membrane. By this way, CRY also enhances light-responses of the circadian clock.

Modulation of miR-210 alters phasing of circadian locomotor activity and impairs projections of PDF clock neurons in Drosophila melanogaster

Single microRNAs are usually associated with hundreds of putative target genes that can influence multiple phenotypic traits in Drosophila, ranging from development to behaviour. We investigated the function of Drosophila miR-210 in circadian behaviour by misexpressing it within circadian clock cells. Manipulation of miR-210 expression levels in the PDF (pigment dispersing factor) positive neurons affected the phase of locomotor activity, under both light-dark conditions and constant darkness. PER cyclical expression was not affected in clock neurons, however, when miR-210 was up-regulated, a dramatic alteration in the morphology of PDF ventral lateral neuron (LNv) arborisations was observed. The effect of miR-210 in shaping neuronal projections was confirmed in vitro, using a Drosophila neuronal cell line. A transcriptomic analysis revealed that miR-210 overexpression affects the expression of several genes belonging to pathways related to circadian processes, neuronal development, GTPases signal transduction and photoreception. Collectively, these data reveal the role of miR-210 in modulating circadian outputs in flies and guiding/remodelling PDF positive LNv arborisations and indicate that miR-210 may have pleiotropic effects on the clock, light perception and neuronal development.

In recent years, the role of microRNAs in regulating the endogenous circadian clock and its rhythmic outputs for behaviour/physiology has been recognized. We have observed that depletion or over-expression of miR-210 in Drosophila melanogaster modulates the phase of locomotor activity, without affecting the molecular oscillation of the pacemaker neurons. Moreover, miR-210 over-expression dramatically alters the pattern of projections from the PDF-positive Lateral Neurons (LNvs). Differentially expressed genes detected in miR-210 over-expressing flies implicated circadian processes, neuronal development, and photoreception. Taken together, our findings indicate the involvement of miR-210 in modulating circadian output and remodelling the projections of PDF clock neurons, and suggest that miR-210 may have pleiotropic effects on clock, light perception and neuronal development.

[Primary and secondary prevention for women at high risk for breast cancer]

Many factors determine a woman's risk of breast cancer; some genetic are related to family history, others are based on personal factors such reproductive and medical history. A high-risk woman must benefit of a specific screening regimen including breast examination, mammography, ultrasonography and contrast material-enhanced magnetic resonance. But she can also benefit of chemo prevention or/and risk-reducing surgery such bilateral prophylactic salpingo-oophorectomy and bilateral prophylactic mastectomy.

[Hormone therapy for breast cancer]

Following Beatson's publications in 1896, various modalities of endocrine therapy applied to breast cancer have been developed. Endocrine treatment has greatly contributed to the improvement of the disease's prognosis. Tamoxifen has established itself as a first choice adjuvant therapy for patients with tumors expressing hormone receptors. Over the last decade, third generation aromatase inhibitors have demonstrated their efficacy amongst menopausal patients, alone or in combination with tamoxifen. Efficacy of these medications is dependent on patient's compliance. This article proposes a synthesis of the main knowledges available in the field of breast cancer endocrine therapy.

[Bilateral prophylactic mastectomy for women at very high risk for breast cancer: beyond the technique]

Bilateral prophylactic mastectomy is the most efficient risk management strategy for women at very high risk for breast cancer. Different methods can be used. The implementation of such a strategy must respond to the request of a well informed patient.

[Sentinel lymph node biopsy and axillary reverse mapping: a tailoring axillary staging in breast cancer]

The status of the axillary lymph nodes is one of the most important prognostic factors in women with early stage breast cancer. Histologic examination of removed lymph nodes is the most accurate method for assessing spread of disease to these nodes. Axillary lymph node dissection (ALND) remains the standard approach for women who have clinically palpable axillary nodes. The benefits of ALND include its impact on disease control (axillary recurrence and survival), its prognostic value, and its role in treatment selection. However, the anatomic disruption caused by ALND may result in lymphedema, nerve injury, and shoulder dysfunction, which compromise functionality and quality of life. For patients who have clinically negative axillary lymph nodes, sentinel lymph node (SLN) biopsy offers a less morbid method to determine if there are positive nodes, in which case axillary node dissection would be necessary. Patients who are SLN-positive should undergo complete ALND. Axillary reverse mapping (ARM) is a recent improvement of ALND which, like the biopsy of the GS, would reduce morbidity.

[Microsurgical breast reconstruction: for whom and how?]

Breast reconstruction is now an integral part of breast cancer treatment. There are several different procedures that make use of flaps or prostheses, or a combination of the two. Which of these procedures is indicated depends on the sequelae of the initial treatment and the patient's wishes and morphology. However, the constraints caused by the prosthetic material and the now regular use of microsurgical techniques have greatly favoured the purely autologous options. The different surgical techniques and their respective advantages and disadvantages will be described, before considering the timing of the various stages of the procedure. We will also give a summary of our experience with free flaps.

[Management and follow-up of a consecutive series of 411 surgically treated breast cancer patients]

This study reports a consecutive serie of 427 breast neoplasms (411 patients) diagnosed and treated in our department between 1994 and 2004. Patients' records were prospectively collected including personnal medical history and the major elements of the diagnostic and the therapeutic protocol applied. 12 patients (3%) had to be excluded due to incomplete follow-up data. With a median follow-up of 8 years, a 4.5% loco-regional relapse rate is noted while 11% of patients recurred at distant sites and 9% died of their disease progression. These statistics are comparable to those published by prominant breast cancer centers. Amongst the 16% of deaths (67/411 Pts), 54% are due to breast cancer progression. The results are discussed with the aim to upgrade the diagnostic and the therapeutic protocols offered to our patients.

[Adherence to long-term medication: the particular case of the adjuvant endocrine therapy for breast cancer]

The aim of adjuvant hormone therapy for breast cancer is to reach, in daily practice, an efficacy similar to that obtained in clinical trials. In spite of the demonstrated efficacy of hormone therapy, compliance represents a major challenge and a multidimensional problem. A better understanding of the reasons underlying non-compliance would help identify the patients at higher risk and would permit the implementation of strategies to improve compliance to adjuvant hormone therapy. With this in mind, we undertook a review of the recent literature on the topic (Pub Med 2003-2009).

Prospective Evaluation of Pre and Postoperative Lymphoscintigraphy in Axillary Reverse Mapping (ARM) for Breast Cancer Patients

BackgroundThe sentinel lymph node (SLN) procedure, has been used successfully to detect lymphatic involvement. The expected reduction in morbidity and improvement in the quality of life of patients remains uncertain. In spite of this minimal invasive technique, 40 to 50 % of axilla are explored by classic axillary dissection. The aim of axillary reverse mapping (ARM) is to preserve the main lymphatic chain in relation to lymphatic arm drainage during an axillary dissection, reducing the rate of lymphedema.ObjectivesThe objective of this study is to describe a prospective comparison of pre and post axillary dissection (AD) lymphoscintigraphy, in 15 consecutive breast cancer patients.MethodsIsotope InjectionThe morning of surgery, all patients underwent isotope injection in the ipsilateral hand. Each patients received a single injection of 60 MBq (vol 0.2 ml) into the first interdigital space. The preoperative lymphoscintigraphy was performed 45 min after injection, in surgical position. An average of 2 nodes were visible in the axilla. The postoperative lymphoscintigraphy was planned before starting adjuvant treatment.Surgical TechniqueAfter having performed the lumpectomy or the mastectomy, the surgeon began the AD. The first important step was the identification of the second intercostals brachial nerve. While reserving the nerve, the dissection was carried out from medial to lateral, below the nerve. The gamma probe was then used in order to identify the first radioactive node draining the upper limb. This node was localized in the lateral pillar of the axilla. The ARM nodes were carefully preserved during the dissection with retractors placed over them to protect from inadvertent damage. After completion of AD, the axillary content was examined ex-vivo to identify at least ten nodes within the surgical specimen.ResultsThe mean age is 62.4 years (range 40-81). For all 15 patients, the mean number of axillary nodes removed by means of AD was 10.7 (range 7–14). Of all patients, 3 (87%) had metastatic involvement in the AD with an average of 1.3 (range 1– 2) nodes involved.A lymphoscintigraphic mapping concordance between pre and post, was found in 13 out 15 patients (87%).ConclusionsIsotopic ARM allows identification of radioactive nodes in the axilla in 91% of cases.The very good correlation between pre and postoperative mapping suggests a persistence of the normal LAD, and lets hope for a risk reduction of lymphodema after AD.A longterm follow up is needed to confirm these very promising preliminary results.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1025.

Current management of lobular in situ neoplasia

Although the term of lobular neoplasia was first proposed in 1978 and the term Lobular In situ Neoplasia (LIN) has been incorporated in the current World Health Organisation (WHO) classification to cover both atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), the clinical significance and the natural history of lobular neoplasia is far from being fully understood. Furthermore problems and confusion still remain surrounding (1) the most appropriate terminology and classification for these lesions, (2) the best course of long-term management after diagnosis.This article summarizes the opinions on LCIS management of a group of Belgian experts.

Light activates output from evening neurons and inhibits output from morning neurons in the Drosophila circadian clock

Animal circadian clocks are based on multiple oscillators whose interactions allow the daily control of complex behaviors. The Drosophila brain contains a circadian clock that controls rest–activity rhythms and relies upon different groups of PERIOD (PER)–expressing neurons. Two distinct oscillators have been functionally characterized under light-dark cycles. Lateral neurons (LNs) that express the pigment-dispersing factor (PDF) drive morning activity, whereas PDF-negative LNs are required for the evening activity. In constant darkness, several lines of evidence indicate that the LN morning oscillator (LN-MO) drives the activity rhythms, whereas the LN evening oscillator (LN-EO) does not. Since mutants devoid of functional CRYPTOCHROME (CRY), as opposed to wild-type flies, are rhythmic in constant light, we analyzed transgenic flies expressing PER or CRY in the LN-MO or LN-EO. We show that, under constant light conditions and reduced CRY function, the LN evening oscillator drives robust activity rhythms, whereas the LN morning oscillator does not. Remarkably, light acts by inhibiting the LN-MO behavioral output and activating the LN-EO behavioral output. Finally, we show that PDF signaling is not required for robust activity rhythms in constant light as opposed to its requirement in constant darkness, further supporting the minor contribution of the morning cells to the behavior in the presence of light. We therefore propose that day–night cycles alternatively activate behavioral outputs of the Drosophila evening and morning lateral neurons.

Living organisms have evolved circadian clocks that anticipate daily changes in their environment. Their clockwork is fully endogenous, but can be reset by external cues. (Light is the most efficient cue.) The circadian neuronal network of the fruit fly (Drosophila) brain perceives light through the visual system and a dedicated photoreceptor molecule, cryptochrome. Flies exhibit a bimodal locomotor activity pattern that peaks at dawn and dusk in light–dark conditions. These morning and evening activity bouts are controlled by two distinct neuronal clocks in the fly brain. By using flies with a deficient cryptochrome pathway, we have uncovered an unexpected role for light in the circadian system. In addition to synchronizing the two oscillators to solar time, light also controls their behavioral output. The morning oscillator can periodically rouse the fly when in constant darkness, but not in constant light, whereas the evening oscillator can do the same in constant light, but not in constant darkness. This suggests the existence of a light-dependent switch between oscillators that appears to require the visual system. Such a mechanism likely contributes to better separate the active periods of the fly at dawn and dusk, and may help the animal to adapt to seasonal changes in day length.

In fruit flies, light not only resets the circadian clock to solar time, but also enables the signaling from one oscillator while disabling the signaling from the other.

The lateral and dorsal neurons of Drosophila melanogaster: new insights about their morphology and function

This chapter summarizes our present knowledge about the master clock of the fruit fly at the neuronal level. The clock is organized in distinct groups of interconnected pacemaker neurons with different functions. All of these neurons appear to communicate with one another in order to produce the species-specific activity rhythm, which is organized in morning (M) and evening (E) activity bouts. These two activity components are differentially influenced by distinct groups of pacemaker neurons reminiscent of the Pittendrigh-Daan dual oscillator model. In the original work (Grima et al. 2004; Stoleru et al. 2004), the ventrolateral (LN(v)) and dorsolateral (LN(d)) plus some dorsal groups (DN) of clock neurons have been defined as M and E cells, respectively. We further specify that the clock neurons belong to the M and E oscillators and define a more complex picture of the Drosophila brain clock.

High-power diode-pumped AlGaAs surface-emitting laser

We report the development and characterization of an efficient diode-pumped surface-emitting semiconductor laser operating at approximately 870 nm. By using a semiconductor Bragg reflector stack/multiple GaAs quantum well structure, mounted within a conventional laser cavity, we achieved single transverse mode laser output powers of 153 mW. Self-tuning over a 15-nm spectral range has been obtained.

[Defecation disorders. Characteristics of manometric studies and rehabilitation]

The authors review the literature and their personal experience about the systematic exploration of defecation disorders by anorectal manometry and colpocystodefecography. They stress the importance of combining functional and morphological evaluation, in order to avoid inappropriate surgery. Concerning anorectal manometry, the determination of the smallest volume of rectal distention inducing a complete relaxation of the internal anal sphincter was found more useful than the maximal tolerable volume in the exploration of defecation disorders. Finally, the authors report the results of biofeedback conditioning prescribed in 30 patients (27 women, 3 men, mean age: 55 years) with defecation disorders (terminal constipation in 21, fecal incontinence in 9 patients). Several characteristics of anorectal manometry and of defecography were significantly improved after biofeedback conditioning.