Learn More
On induction of cell differentiation, distinct cell phenotypes are encoded by complex genetic networks. These networks can prevent the reversion of established phenotypes even in the presence of significant fluctuations. Here we explore the key parameters that determine the stability of cellular memory by using the yeast galactose-signalling network as a(More)
A classic problem in population and evolutionary biology is to understand how a population optimizes its fitness in fluctuating environments. A population might enhance its fitness by allowing individual cells to stochastically transition among multiple phenotypes, thus ensuring that some cells are always prepared for an unforeseen environmental(More)
Coping with variations in network dosage is crucial for maintaining optimal function in gene networks. We explored how network structure facilitates network-level dosage compensation. By using the yeast galactose network as a model, we combinatorially deleted one of the two copies of its four regulatory genes and found that network activity was robust to(More)
Although there is an increased prevalence of pulmonary hypertension in hemodialysis patients, the relationship between arteriovenous (AV) fistula blood flow and pulmonary hemodynamics is not known. The aim of this study was to evaluate the relationshipship between blood flow rate of AV fistula and pulmonary artery pressure (PAP) in hemodialysis patients.(More)
The purpose of this article is to highlight the imaging features of cystic pancreatic tumors. Common cystic pancreatic tumors include serous microcystic adenomas, mucinous cystic tumors, intraductal papillary mucinous neoplasms and solid pseudopapillary tumors. These tumors have characteristic imaging features, especially on magnetic resonance imaging (MRI)(More)
We aimed to evaluate the effects of l-dopa use on apparent diffusion coefficient (ADC) values of different brain regions in Parkinson's disease (PD) patients. Thirty-five subjects underwent magnetic resonance imaging (MRI), including 21 PD patients (13 men, 8 women; mean age, 63 years+/-8), and 14 sex and age-matched control subjects. PD patients were(More)
BACKGROUND AND PURPOSE The upper airway lumen is narrower in patients with obstructive sleep apnea syndrome (OSAS) than normal subjects. In this study, we examined changes of the upper airway cross-sectional area in each phase of respiration in different degrees of severity of OSAS with dynamic CT and investigated whether these changes have any correlation(More)
We describe a case of ganglioglioma of the right optic tract in a 52-year-old woman. Review of the general literature discloses only 11 cases of tumors of the visual pathway that meet the histological criteria for such neoplasm. A detailed radiological description of our case and a review of the literature is provided.
PURPOSE To measure with Doppler sonography the velocity and volume of blood flow in the extracranial internal carotid artery (ICA) and vertebral artery (VA) of healthy adults and to calculate total cerebral blood flow volume (tCBFV). METHODS Bilateral ICA and VA were examined sonographically in 180 healthy adults. Angle-corrected peak systolic (Vps),(More)
BACKGROUND Impaired flow mediated dilatation (FMD) and increased wall thickness (WT) of the brachial artery have been associated with atherosclerosis and its risk factors. In this study we sought to determine brachial artery wall thickness in chronic smokers and the instantaneous effect of smoking on brachial artery endothelium dependent vasodilator(More)