Breast Cancer Affects Both the Hippocampus Volume and the Episodic Autobiographical Memory Retrieval

International audienceBACKGROUND: Neuroimaging studies show the hippocampus is a crucial node in the neural network supporting episodic autobiographical memory retrieval. Stress-related psychiatric disorders, namely Major Depression and Post Traumatic Stress Disorder (PTSD), are related to reduced hippocampus volume. However, this is not the case for remitted breast cancer patients with co-morbid stress-related psychiatric disorders. This exception may be due to the fact that, consequently to the cancer experience as such, this population might already be characterized by a reduced hippocampus with an episodic autobiographical memory deficit. METHODOLOGY: We scanned, with a 3T Siemens TRIO, 16 patients who had lived through a "standard experience of breast cancer" (breast cancer and a standard treatment in remission since 18 month) in the absence of any associated stress-related psychiatric or neurological disorder and 21 matched controls. We then assessed their episodic autobiographical memory retrieval ability. PRINCIPAL FINDINGS: Remitted breast cancer patients had both a significantly smaller hippocampus and a significant deficit in episodic autobiographical memory retrieval. The hippocampus atrophy was characterized by a smaller posterior hippocampus. The posterior hippocampus volume was intimately related to the ability to retrieve negative memories and to the past experience of breast cancer or not. CONCLUSIONS/SIGNIFICANCE: These results provide two main findings: (1) we identify a new population with a specific reduction in posterior hippocampus volume that is independent of any psychiatric or neurological pathology; (2) we show the intimate relation of the posterior hippocampus to the ability to retrieve episodic autobiographical memories. These are significant findings as it is the first demonstration that indicates considerable long-term effects of living through the experience of breast cancer and shows very specific hippocampal atrophy with a functional deficit without any presence of psychiatric pathology

Conception d'un doigt artificiel à fibre optique polymérique pour application du toucher de surfaces textiles

L'objectif de ce travail est de mettre au point un capteur mécanique capable de retranscrire le toucher en utilisant une fibre optique polymérique comme élément senseur. Le développement d'un doigt artificiel permet de raccourcir le temps de développement de nouvelles surfaces en évitant l'utilisation d'un panel humain. L'avantage essentiel de ce type de technologie est de ne pas être sensible à l'humidité. Le capteur étudié est composé d'une structure aluminium, d'un corps mou en PDMS (Sylgard®184) dans lequel est noyée une fibre polymérique développée à l'EMPA et de longueur 20 mm. Le contact entre la surface frottée et le capteur se fait par un téton de PDMS (Sylgard®184) de dureté plus importante. La surface considérée est un textile. Le coefficient de frottement observable entre le textile et le téton est comparable à celui que l'on peut trouver lors d'un frottement entre le doigt et le même textile. Le téton est moulé avec une texture concentrique aux dimensions des dermatoglyphes (100 µm de profondeur et 500 µm de période). Le montage d'étude permettant de caractériser la réponse du capteur en fonction des stimuli mécaniques est composé d'une source lumineuse Avalight Hal mini (lampe halogène 10W), de deux fibres optiques de verre large bande 250-2500 nm et d'un spectromètre Avantes AvaspecULS2048CL-Evo. Le capteur à fibre optique fonctionne selon le principe suivant : le spectromètre en fin de montage nous permet de mesurer l'intensité lumineuse transmise au travers de la fibre optique du capteur. La fibre est non couverte, ce qui implique que le saut d'indice de réfraction entre la fibre et le PDMS ne convient pas pour une transmission précise du flux lumineux, nous avons des fuites de lumière tout au long de cette fibre. De plus, la fibre éjecte plus de lumière à chaque courbure, sa déformation lors d'un stimulus mécanique est détectable par l'intensité transmise. La fibre est positionnée dans le capteur avec un angle imposé de 45° par rapport au plan horizontal à chaque extrémité. Deux méthodes de de caractérisation du capteur à fibre optique sont utilisées par mesure du comportement à l'indentation et au frottement. Un capteur de force, d'amplitude maximale 5N, est couplé à une platine de translation permettant une pénétration du matériau. Ce dispositif nous permet d'étudier le comportement du capteur à fibre optique en termes d'enfoncement en fonction de la force normale appliquée à la charge et à la décharge. Pour l'étude du comportement au frottement du doigt artificiel, celui-ci est monté à la place du frotteur d'un tribomètre. Il permet de mesurer les forces tangentielle et normale lors d'un frottement linéaire alternatif sur une platine mobile pour un déplacement choisi ici de 50mm, à 20mm/s avec une accélération de 50 mm/s². La force normale peut être : i) constante, elle est alors appliquée par une masse morte, le déplacement vertical du doigt artificiel est alors mesuré ou ii) mesurée à l'aide d'un capteur de force et alors le doigt artificiel est fixé à une altitude donnée. Les informations provenant de la fibre optique et de l'indenteur ou du tribomètre sont alors comparées. Il est montré que le capteur, bien qu'avec une seule fibre, permet de percevoir des influences mécaniques et ceci quelle que soit la direction de l'effort dans le cas d'une sollicitation en frottement. Différentes surfaces textiles, présentant ou non une anisotropie de surface, sont testées et montrent l'intérêt que peut présenter un tel capteur à fibre optique pour la caractérisation du toucher des surfaces textiles

Ultrastructural effects of sleep and wake on the parallel fiber synapses of the cerebellum

Multiple evidence in rodents shows that the strength of excitatory synapses in the cerebral cortex and hippocampus is greater after wake than after sleep. The widespread synaptic weakening afforded by sleep is believed to keep the cost of synaptic activity under control, promote memory consolidation, and prevent synaptic saturation, thus preserving the brain's ability to learn day after day. The cerebellum is highly plastic and the Purkinje cells, the sole output neurons of the cerebellar cortex, are endowed with a staggering number of excitatory parallel fiber synapses. However, whether these synapses are affected by sleep and wake is unknown. Here, we used serial block face scanning electron microscopy to obtain the full 3D reconstruction of more than 7000 spines and their parallel fiber synapses in the mouse posterior vermis. This analysis was done in mice whose cortical and hippocampal synapses were previously measured, revealing that average synaptic size was lower after sleep compared to wake with no major changes in synapse number. Here, instead, we find that while the average size of parallel fiber synapses does not change, the number of branched synapses is reduced in half after sleep compared to after wake, corresponding to similar to 16% of all spines after wake and similar to 8% after sleep. Branched synapses are harbored by two or more spines sharing the same neck and, as also shown here, are almost always contacted by different parallel fibers. These findings suggest that during wake, coincidences of firing over parallel fibers may translate into the formation of synapses converging on the same branched spine, which may be especially effective in driving Purkinje cells to fire. By contrast, sleep may promote the off-line pruning of branched synapses that were formed due to spurious coincidences

International Society of Sports Nutrition position stand: meal frequency

Position Statement: Admittedly, research to date examining the physiological effects of meal frequency in humans is somewhat limited. More specifically, data that has specifically examined the impact of meal frequency on body composition, training adaptations, and performance in physically active individuals and athletes is scant. Until more research is available in the physically active and athletic populations, definitive conclusions cannot be made. However, within the confines of the current scientific literature, we assert that:1. Increasing meal frequency does not appear to favorably change body composition in sedentary populations.2. If protein levels are adequate, increasing meal frequency during periods of hypoenergetic dieting may preserve lean body mass in athletic populations.3. Increased meal frequency appears to have a positive effect on various blood markers of health, particularly LDL cholesterol, total cholesterol, and insulin.4. Increased meal frequency does not appear to significantly enhance diet induced thermogenesis, total energy expenditure or resting metabolic rate.5. Increasing meal frequency appears to help decrease hunger and improve appetite control.The following literature review has been prepared by the authors in support of the aforementioned position statement

International society of sports nutrition position stand: caffeine and performance

Position Statement: The position of The Society regarding caffeine supplementation and sport performance is summarized by the following seven points: 1.) Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (~3-6 mg/kg) and overall does not result in further enhancement in performance when consumed in higher dosages (≥ 9 mg/kg). 2.) Caffeine exerts a greater ergogenic effect when consumed in an anhydrous state as compared to coffee. 3.) It has been shown that caffeine can enhance vigilance during bouts of extended exhaustive exercise, as well as periods of sustained sleep deprivation. 4.) Caffeine is ergogenic for sustained maximal endurance exercise, and has been shown to be highly effective for time-trial performance. 5.) Caffeine supplementation is beneficial for high-intensity exercise, including team sports such as soccer and rugby, both of which are categorized by intermittent activity within a period of prolonged duration. 6.) The literature is equivocal when considering the effects of caffeine supplementation on strength-power performance, and additional research in this area is warranted. 7.) The scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance that would negatively affect performance

Fertility in four regions spanning large contrasts in serum levels of widespread persistent organochlorines: a cross-sectional study

BACKGROUND: Persistent organochlorine pollutants (POPs) may interfere with reproductive function but direct evidence in humans is very limited. METHODS: Fertility was examined in four regions with contrasting blood levels of POPs. Pregnant women and their partners in Warsaw (Poland), Kharkiv (Ukraine) and Greenland were consecutively enrolled during antenatal visits. Swedish fishermen and their spouses were recruited separately and independently of current pregnancy. Lipid adjusted serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE) were available for both partners. Time to pregnancy interviews were obtained among 2269 women and 798 men provided a semen sample. RESULTS: Inuits had high levels of both POP markers, Swedish fishermen were high in CB-153 but low in DDE, men from Kharkiv were high in DDE and low in CB-153 while men from Warsaw were low in CB-153 and had intermediate DDE levels. Compared to Warsaw couples, fecundability was reduced among couples from Kharkiv [adjusted fecundability ratio (FR) 0.64 (95% CI 0.5-0.8)] and elevated in Swedish fishermen families [FR 1.26 (95% CI 1.0-1.6)]. Adjusted geometric means of sperm counts and morphology did not differ between regions while sperm motility was higher in men living in Warsaw. CONCLUSION: We observed regional differences in time to pregnancy and sperm motility that may be related to regional differences in POP blood levels, but other interpretations are also plausible. In particular, differences in access to safe contraception and in the prevalence of contraceptive failures are most likely to bias comparisons of time to pregnancy

Fertility in four regions spanning large contrasts in serum levels of widespread persistent organochlorines: a cross-sectional study.

BACKGROUND: Persistent organochlorine pollutants (POPs) may interfere with reproductive function but direct evidence in humans is very limited. METHODS: Fertility was examined in four regions with contrasting blood levels of POPs. Pregnant women and their partners in Warsaw (Poland), Kharkiv (Ukraine) and Greenland were consecutively enrolled during antenatal visits. Swedish fishermen and their spouses were recruited separately and independently of current pregnancy. Lipid adjusted serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE) were available for both partners. Time to pregnancy interviews were obtained among 2269 women and 798 men provided a semen sample. RESULTS: Inuits had high levels of both POP markers, Swedish fishermen were high in CB-153 but low in DDE, men from Kharkiv were high in DDE and low in CB-153 while men from Warsaw were low in CB-153 and had intermediate DDE levels. Compared to Warsaw couples, fecundability was reduced among couples from Kharkiv [adjusted fecundability ratio (FR) 0.64 (95% CI 0.5-0.8)] and elevated in Swedish fishermen families [FR 1.26 (95% CI 1.0-1.6)]. Adjusted geometric means of sperm counts and morphology did not differ between regions while sperm motility was higher in men living in Warsaw. CONCLUSION: We observed regional differences in time to pregnancy and sperm motility that may be related to regional differences in POP blood levels, but other interpretations are also plausible. In particular, differences in access to safe contraception and in the prevalence of contraceptive failures are most likely to bias comparisons of time to pregnancy

Assessment of epidermal growth factor receptor (EGFR) expression in primary colorectal carcinomas and their related metastases on tissue sections and tissue microarray

Metastatic colorectal carcinomas (CRC) resistant to chemotherapy may benefit from targeting monoclonal therapy cetuximab when they express the epidermal growth factor receptor (EGFR). Because of its clinical implications, we studied EGFR expression by immunohistochemistry on tissue sections of primary CRC (n=32) and their related metastases (n=53). A tissue microarray (TMA) was generated from the same paraffin blocks to determine whether this technique could be used for EGFR screening in CRC. On tissue sections, 84% of the primary CRC and 94% of the metastases were EGFR-positive. When matched, they showed a concordant EGFR-positive status in 78% of the cases. Moreover, staining intensity and extent of EGFR-positive cells in the primary CRC correlated with those observed in the synchronous metastases. On TMA, 65% of the primary CRC, 66% of the metastases, and 43% of the matched primary CRC metastases were EGFR-positive. There was no concordant EGFR status between the primary and the metastatic sites. A strong discrepancy of EGFR status was noted between TMA and tissue sections. In conclusion, EGFR expression measured in tissue sections from primary CRC and their related metastases was found to be similar and frequent, but it was significantly underestimated by the TMA technique