40 research outputs found
Acyanotic fallot's tetralogy: a clinical report of six cases
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Ca2+-induced changes in energy metabolism and viability of melanoma cells
Cancer cells are characterized by a high rate of glycolysis, which is their primary energy source. We show here that a rise in intracellular-free calcium ion (Ca2+), induced by Ca2+-ionophore A23187, exerted a deleterious effect on glycolysis and viability of B16 melanoma cells. Ca2+-ionophore caused a dose-dependent detachment of phosphofructokinase (EC 2.7.1.11), one of the key enzymes of glycolysis, from cytoskeleton. It also induced a decrease in the levels of glucose 1,6-bisphosphate and fructose 1,6-bisphosphate, the two stimulatory signal molecules of glycolysis. All these changes occurred at lower concentrations of the drug than those required to induce a reduction in viability of melanoma cells. We also found that low concentrations of Ca2+-ionophore induced an increase in adenosine 5′-triphosphate (ATP), which most probably resulted from the increase in mitochondrial-bound hexokinase, which reflects a defence mechanism. This mechanism can no longer operate at high concentrations of the Ca2+-ionophore, which causes a decrease in mitochondrial and cytosolic hexokinase, leading to a drastic fall in ATP and melanoma cell death. The present results suggest that drugs which are capable of inducing accumulation of intracellular-free Ca2+ in melanoma cells would cause a reduction in energy-producing systems, leading to melanoma cell death. © 1999 Cancer Research Campaig
Prophylactic Mastectomy in BRCA1/2 Mutation Carriers and Women at Risk of Hereditary Breast Cancer: Long-Term Experiences at the Rotterdam Family Cancer Clinic
Background BRCA1/2 mutation carriers and women from a hereditary breast(/ovarian) cancer family have a highly increased risk of developing
breast cancer (BC). Prophylactic mastectomy (PM) results in the greatest BC risk reduction. Long-term data on the efficacy
and sequels of PM are scarce.
Methods From 358 high-risk women (including 236 BRCA1/2 carriers) undergoing PM between 1994 and 2004, relevant data on the occurrence
of BC in relation to PM, complications in relation to breast reconstruction (BR), mutation status, age at PM and preoperative
imaging examination results were extracted from the medical records, and analyzed separately for women without (unaffected,
n = 177) and with a BC history (affected, n = 181).
Results No primary BCs occurred after PM (median follow-up 4.5 years). In one previously unaffected woman, metastatic BC was detected
almost 4 years after PM (primary BC not found). Median age at PM was younger in unaffected women (P < .001), affected women more frequently were 50% risk carriers (P < .001). Unexpected (pre)malignant changes at PM were found in 3% of the patients (in 5 affected, and 5 unaffected women,
respectively). In 49.6% of the women opting for BR one or more complications were registered, totaling 215 complications,
leading to 153 surgical interventions (71%). Complications were mainly related to cosmetic outcome (36%) and capsular formation
(24%).
Conclusions The risk of developing a primary BC after PM remains low after longer follow-up. Preoperative imaging and careful histological
examination is warranted because of potential unexpected (pre)malignant findings. The high complication rate after breast
reconstruction mainly concerns cosmetic issues
The COGs (context, object, and goals) in multisensory processing
Our understanding of how perception operates in real-world environments has been substantially advanced by studying both multisensory processes and “top-down” control processes influencing sensory processing via activity from higher-order brain areas, such as attention, memory, and expectations. As the two topics have been traditionally studied separately, the mechanisms orchestrating real-world multisensory processing remain unclear. Past work has revealed that the observer’s goals gate the influence of many multisensory processes on brain and behavioural responses, whereas some other multisensory processes might occur independently of these goals. Consequently, other forms of top-down control beyond goal dependence are necessary to explain the full range of multisensory effects currently reported at the brain and the cognitive level. These forms of control include sensitivity to stimulus context as well as the detection of matches (or lack thereof) between a multisensory stimulus and categorical attributes of naturalistic objects (e.g. tools, animals). In this review we discuss and integrate the existing findings that demonstrate the importance of such goal-, object- and context-based top-down control over multisensory processing. We then put forward a few principles emerging from this literature review with respect to the mechanisms underlying multisensory processing and discuss their possible broader implications