Breast carcinoma is the most commonly diagnosed cancer among women worldwide, with approximately 1 in 7 expected to be affected during her lifetime. The spread of breast cancer to secondary sites is generally incurable. Bone is the preferred site of metastasis, where the development of a secondary tumour causes severe osteolysis, hypercalcemia and a considerable pain burden. However, how breast cancer cells establish supportive interactions with bone cells is not well understood. We have examined the effects of factors released from MDA-MB-231 and 4T1 breast cancer cells on the differentiation of C57BL6 mouse bone marrow cells. Treatment with cancer-derived factors resulted in a sustained 40–60% decrease in osteoblast differentiation markers, and induced an osteoclastogenic change in the ratio of receptor activator of NF-κB ligand (RANKL) to osteoprotegerin (OPG). Importantly, exposure of bone cells to breast cancer-derived factors stimulated the subsequent attachment of cancer cells to immature osteoblasts. Inhibition of γ-secretase using pharmacological inhibitors DAPT and Compound E completely reversed cancer-induced osteoclastogenesis as well as cancer-induced enhancement of cancer cell attachment, identifying γ-secretase activity as a key mediator of these effects. We next evaluated the effects of breast cancer cells on the energy metabolism of bone cells. Treatment of bone marrow cells with conditioned medium from 4T1 breast cancer cells resulted in an increase in glucose consumption by bone cells, higher mitochondrial transmembrane potential, and a 2.3-fold rise in cellular ATP content. In addition, breast cancer derived factors stimulated the expression of mRNA and protein levels of metabolic sensor, AMP-regulated protein kinase (AMPK). To assess if such change in cell bioenergetics may have consequences for cell differentiation and activity, we used defined models of osteoclastogenesis, and increased precursor metabolic activity by providing excess energy substrates. We have found that an increase in mitochondrial transmembrane potential and cellular ATP levels during osteoclastogenesis resulted in the formation of larger osteoclasts that demonstrate higher resorptive activity. Thus, we have uncovered that osteoblasts act as a critical intermediate of premetastatic signalling by breast cancer cells, and pinpointed γ-secretase as a robust target for developing therapeutics potentially capable of reducing both the homing and progression of cancer metastases to bone. In addition, we have discovered heightened energetics in bone cells exposed to breast cancer cell-released factors, which may contribute to the formation of larger, more active osteoclasts. Modification of the AMPK pathway may prove an important therapeutic target for breast cancer metastasis to bone. / Le cancer du sein est le cancer plus diagnostiqué chez les femmes. On estime qu'environ une femme sur sept en sera affectée. La diffusion du cancer du sein aux emplacements secondaires est généralement incurable. L'os est l'emplacement préféré de la métastase, où le développement d'une tumeur secondaire cause de l'osteolyse, de l'hypercalcemie, et une douleur considérable. Cependant, comment les cellules de cancer du sein établissent des interactions supportifs avec des cellules d'os n'est pas bien compris. Nous avons examiné les effets des facteurs libérés des cellules du cancer du sein MDA-MB-231 et 4T1 sur la différentiation des cellules de moelle de la souris C57BL6. Le traitement avec des facteurs cancer-dérivés a produit une diminution de 40-60% des marqueurs de différentiation d'osteoblast, comparé au traitement par l'acide ascorbique, et a induit un changement osteoclastogenique dans le rapport du RANKL/osteoprotegerin. L'exposition des cellules d'os à des facteurs dérivés du cancer du sein a ensuite stimulé l'attachement des cellules cancéreuses aux osteoblasts non mûrs. L'inhibition du γ-secretase utilisant les inhibiteurs pharmacologiques DAPT et le Compound E a complètement inversé l'osteoclastogenise cancer-induit aussi bien que le perfectionnement cancer-induit de l'attachement de cellules cancéreuses, identifiant l'activité de le γ-secretase comme étant le médiateur principal de ces effets. Nous avons ensuite évalué les effets des cellules cancereuse sur le métabolisme énergétique des cellules d'os. Le traitement des cellules de moelle avec le medium conditionné des cellules du cancer du sein 4T1 a eu comme conséquence une augmentation des mitochondries à haut-potentiel de membrane, une augmentation de 2.3 fois le contenu cellulaire de triphosphate d'adénosine, et une consommation plus rapide du glucose. Ce changement de l'énergétique a été accompagné d'une stimulation d'AMPK dans la protéine et l'ADN messagère. Pour évaluer les effets du statut de haute énergie dans les osteoclasts, nous avons élevé l'énergique des osteoclasts avec du pyruvate de sodium. Cette addition a causée une croissance des osteoclasts, avec des plus grands nucleus, et la résorption de plus de substrat. Ainsi, nous avons découvert l'osteoblast comme étant un intermédiaire clé à la signalisation prémetastatique par des cellules du cancer du sein. Nous avons aussi indiqué le γ-secretase comme cible robuste pour le developpement de thérapeutique potentiellement capable de réduire l'autoguidage et la progression des métastases de cancer à l'os. Additonellement, nous avons découvert l'énergétique intensifiée chez les cellules d'os exposées aux facteurs cellule-libérés par le cancer du sein, qui mène à une osteoclastogenesise plus active et plus importante. La modification de la voie d'AMPK peut s'avérer être une cible thérapeutique importante pour que la métastase de cancer du sein aux os.

Bread wheat (Triticum aestivum L. em. Thell.) is the most important cultivated crop in Canada. Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein) Petch] is the principal disease of wheat in North America, causing severe losses in grain yield and quality. Breeding for cultivar resistance is considered the most practical way to manage this disease. High spatiotemporal variance makes screening for disease resistance based on visual assessment of symptoms slow, difficult, and expensive. Development of a cheaper, rapid, accurate, and high throughput tool for screening resistance is the highest priority for wheat breeders. A novel method based on metabolite profiling technology was applied to discriminate resistance in wheat genotypes against FHB. The present investigation reports on three linked studies. The first study involved the detection and application of metabolites to distinguish susceptible (Roblin) and resistant (Sumai3) wheat cultivars. In the second study, cultivars varying in level of resistance were discriminated (descending order: Wangshubai, AW488, Nobeoka Bozu, BRS177, Frontana, CEP24). Finally, biomarker metabolites related to susceptible and resistant near isogenic lines (NILs) with alternate alleles for FHB resistance on the 2DL chromosome were identified. The metabolites were extracted from spikelets in a mixture of methanol-water/chloroform, and analyzed using GC-ion trap-MS (studies 1-2) or GC-TOF-MS (study 3). Compound identification and quantification was achieved manually and/or using automated software for peak deconvolution (AMDIS), library search (MSRI and NIST libraries), and peak alignment and quantification (MET-IDEA). Several hundred peaks were detected, but only 55, 79, and 120 metabolites were identified in studies 1, 2, and 3, respectively. The metabolites significantly varied in abundance among cultivars/NILs varying in resistance. A resistance biomarker metabolite was define / Le blé à pain (Triticum aestivum L. em. Thell.) est la culture la plus importante au Canada. Le flétrissement des plantules des céréales causé par Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein) Petch] est la maladie du blé la plus dévastatrice en Amérique du Nord. Elle cause des pertes tant dans le rendement que dans la qualité du grain. La résistance est le moyen le plus efficace pour gérer cette maladie. Une variabilité spatio-temporelle élevée rend difficile et coûteuse l'évaluation de la résistance basée sur les symptômes. Le développement de moyens abordables, rapides, et à haut débit pour le criblage de la résistance est la priorité des sélectionneurs. Une nouvelle méthode s'appuyant sur le profilage métabolique a été utilisée pour déterminer la résistance à la fusariose dans des lignées de blé. Trois études ont été accomplies lors de la présente investigation : 1) la détection et l'usage de métabolites afin d'identifier les cultivars de blé étant sensibles (Roblin) et résistants (Sumai3) 2) l'identification de cultivars variants dans leur résistance 3) l'identification de biomarqueurs métaboliques dans des lignées isogéniques ayant un contraste d'allèles au locus quantitatif (LQ) FHB-résistant, sur le chromosome 2DL. Les métabolites ont été extraits dans des épillets dans une mixture de méthanol, d'eau et de chloroforme et analysés par CG-piège à ions-SM (étude 1-2) ou par CG-temps de vol-SM (étude 3). L'identification et la quantification des composés ont été accomplies manuellement et/ou en utilisant un logiciel automatisé pour la déconvolution des pics (AMDIS), pour la recherche dans la librairie (NIST) et pour l'alignement et la quantification des pics (MET-IDEA). Plusieurs centaines de pics ont été détectés mais seulement 55, 51 et 120 métabolites ont été identifiés dans les études 1, 2, et 3, respectivement. Afin d'évaluer la résistance, nous avons consi

The present study traces changes in linguistic complexity in the context of fluency development in four preschool children treated with the Lidcombe Program for Early Stuttering Intervention. Standardized tests of language and phonology were administered pre-treatment. Spontaneous language samples were collected for each participant at 5 preset intervals during the treatment phase. Samples were analyzed for Mean Length of Utterance, Number of Simple and Complex Sentences, Number of Different Words, Morphosyntactic Accuracy, Percentage of Stuttered Syllables and Normal Speech Dysfluencies, and Loci of Stuttered Moments. Analysis of the data revealed that all participants presented with language skills in the average and above average range, and achieved an increase in stutter-free speech without decreasing their linguistic complexity. However, all children scored consistently below the average range in Number of Different Words. Theoretical implications, as well as clinical implications and directions for future research are discussed.

Compensatory articulation was investigated in normal and brain-damaged individuals by comparing vowel production under normal and perturbed speaking conditions. The effects of fixed mandibular positioning on first and second formant frequencies of the vowels (u i ae a) were investigated in ten normal subjects, six nonfluent aphasics and six fluent aphasics. Adaptation to perturbation was examined under compensatory and noncompensatory conditions, in which the degree of mandibular opening posed maximal and minimal interference respectively, with reference to normal articulatory positioning. F1 and F2 values, determined by linear predictive coding, were measured at the onset and midpoint of glottal pulsing to identify changes in compensation over time. Results of statistical analyses indicated variable effects of perturbation in both the normal and aphasic subject groups. Analyses of the data with respect to perceptual difference limens suggested that formant deviations in compensatory and noncompensatory productions of all subjects groups would have resulted in changes in vowel quality. The results were interpreted as indicating that compensatory performance, although evident, was neither complete nor immediate in any of the subject groups tested. Moreover, articulatory reorganization and compensation for fixed mandibular positioning appeared to be preserved in nonfluent and fluent aphasics. The findings are discussed with respect to models of speech motor programming and neurogenic models of speech production.

Background. Apoptosis is postulated as a mechanism involved in lung ischemia-reperfusion (IR) injury, however, the relative contributions of ischemia and reperfusion are unclear. / Methods. Heart-lung blocks were harvested from New Zealand white rabbits (3.0--4.0 kg) and exposed to 0, 6, or 18 hours of cold ischemia (4°C), followed by 3 hours of reperfusion in an ex vivo model. Terminal dUTP nick-end labeling (TUNEL), the technique used most often for detection of apoptosis, was performed on the tissue sections. / Results. TUNEL demonstrated minimal apoptosis in lungs exposed to 0, 6, or 18 hours of ischemia with insignificant differences (p = 0.6 for 0 h vs. 18 h). After one hour of reperfusion, the level of TUNEL in the 18 hour ischemic tissue was significantly increased (p < 0.05 for 0 h vs. 18 h). During the period of reperfusion, the extent of apoptosis increased in direct proportion to the duration of ischemia; the level of TUNEL staining after 2 hours of reperfusion was significantly greater in the 18 hour ischemic tissue compared to the 6 hour ischemic tissue (p < 0.05), as was the 6 hour compared to the 0 hour (p < 0.01). The hallmark of apoptosis, nucleosomal ladders of 180--200 base pair DNA fragments, corresponded in intensity on gel electrophoresis to the quantitation of TUNEL. The characteristics of apoptotic cells including cell membrane blebbing, chromatin condensation and fragmentation were confirmed by electron microscopy. / Conclusions. These results provide evidence that apoptosis may be a specific feature of IR injury in pulmonary tissue.

A review of the literature on speech prosody suggests that the right hemisphere may be crucial in expressing and perceiving prosodic information, although hypotheses concerning the underlying nature of this specialization remain disparate (e.g., Behrens, 1988; Ross, 1981; Van Lancker & Sidtis, 1992). To illuminate the right hemisphere's role in prosodic processing, and to explore the interaction between linguistic and emotional suprasegmental cues in speech production and perception, two experiments were conducted. In Experiment 1, utterances conveying three prosodic distinctions (emphatic stress, sentence modality, emotional tone) were elicited from normal (NC) and right-hemisphere-damaged (RHD) adults and then subjected to acoustic analysis. Results indicated that the intonation patterns produced by RHD patients were relatively normal in overall shape, but significantly restricted in fundamental frequency (F$ sb0$) variation relative to those produced by normal subjects. The RHD speakers also supplied fewer duration and F$ sb0$ cues to emphatic stress, and demonstrated aberrant control of speech rate and mean F$ sb0$ in expressing discrete emotions relative to the NC speakers. In Experiment 2, six receptive tasks in which the F$ sb0$ or duration parameters of prosodic stimuli were systematically altered, were presented to NC, RHD, and left-hemisphere-damaged (LHD) adults for linguistic or emotional identification. Results obtained for this experiment revealed that both the RHD and LHD patients were impaired in the recognition of emotional prosody, but that only the LHD patients were disturbed in perceiving linguistic specifications via prosodic cues. The outcome of both experiments is discussed with respect to current theories of the lateralization of prosodic processing.

No description available.

Approximately 70% of patients with prostatic cancer develop bone metastases. Metastatic prostate adenocarcinomas are associated with high mortality rates and represent a leading cause of cancer-related deaths among males. To study the host-tumor interactions underlying the predilection of prostate cancer cells for skeletal bone, an experimental model was developed using rat Dunning carcinoma Mat-LyLu cells. Inoculations of these cells into the left ventricle of the heart led to the development of spinal metastases in 100% of inoculated animals. A subline of Mat-LyLu (Mat-LyLu-B5) was subsequently selected through sequential inoculation of bone marrow derived carcinoma cells into the left ventricle of the heart and was found to have an increased metastatic potential compared to the parental line. The possible role of tumor cell adhesion to host cells in the process of bone marrow colonization was then investigated in vitro using the metastatic line and primary cultures of rat bone marrow-derived stromal cells. It was found that the adhesion of the metastatic Mat-LyLu cells to a bone marrow stromal cell culture highly enriched for endothelial cells (BMEC) was significantly higher than the adhesion to other bone-derived cells including non-endothelial BM stromal cells (3x) and osteoblasts (1.4x). It was also significantly higher than the adhesion to rat fibroblasts (5.5x) and to hepatic endothelial cells (7x). The results suggest that the adhesion of prostate carcinoma cells to the bone marrow endothelium may play a role in their metastasis to bone.

In humans, the overall birth frequency of trisomy 21 (Downs syndrome) is 1 per 700 livebirths. The incidence at conception is greater, but more than 80% will not reach term (Connor and Ferguson-Smith 1985). Presumably, numerous factors, genetic and environmental are influencing this process. Therefore, an analysis of the factors modulating the survival of murine aneuploid embryos has been initiated. / A maternal genetic control modulating the survival of murine trisomic embryos has been observed at day 15 of gestation (Vekemans and Trasler 1987; Epstein and Vekemans 1990). To determine whether this modulation is taking place, before or after implantation, the analysis of aneuploid blastocysts has been started. / The frequency of aneuploidy observed at the blastocyst stage has been found not to differ when the maternal genotype varied for both murine chromosomes 19 and 16. Therefore, we can conclude that the maternal genetic control modulating the survival of trisomic embryos at day 15 of gestation is not in effect at the preimplantation stage. / Also we observed that genetic factors are modifying the blastocyst development (e.i. the cavitation process).

Arterial Glycosaminoglycans (GAGs) have gained importance in artherogenesis due to their ability to trap lipid inside the vessel wall. Atherosclerotic lesions have displayed an altered GAG content and distribution. Diabetes is a recognized risk factor for atherosclerosis, but no information is available on the arterial GAGs in human diabetes. To improve our understanding of the atherogenic proccss we examined GAGs in normal and atherosclerotic intima of nondiabetic and type-II diabetic humans. Intima was stripped from the autopsy samples of thoracic aortas, normal and plaque areas were separated. GAGs were isolated by delipidatlon, proteolytic digestion, and precipitation. They were assayed biochemically and their distribution evaluated by electrophoresis and densitometry. Results indicate a significant decrease in total GAGs and a change in GAG distribution in plaques of nondiabetics. Similar changes of lesser magnitude were found in normal intima of diabetics, while changes in plaque areas were more pronounced. This indicates that changes in arterial GAGs precede the development of lesions in diabetes and may be important in atherogenesis.