Does the granular matter?

Granular materials, such as sand, gravel, powders, and pharmaceutical pills, are large aggregates of macroscopic, individually solid particles, or "grains." Far from being simple materials with simple properties, they display an astounding range of complex behavior that defies their categorization as solid, liquid, or gas. Just consider how sand can stream through the orifice of an hourglass yet support one's weight on the beach; how it can form patterns strikingly similar to a liquid when vibrated, yet respond to stirring by "unmixing" of large and small grains. Despite much effort, there still is no comprehensive understanding of other forms of matter, like ordinary fluids or solids. In what way, therefore, is granular matter special, and what makes it so difficult to understand? An emerging interdisciplinary approach to answering these questions focuses directly on the material's discontinuous granular nature.     

Does size matter in platelet production?

Platelet (PLT) production represents the final stage of megakaryocyte (MK) development. During differentiation, bone marrow MKs extend and release long, branched proPLTs into sinusoidal blood vessels, which undergo repeated abscissions to yield circulating PLTs. Circular-prePLTs are dynamic intermediate structures in this sequence that have the capacity to reversibly convert into barbell-proPLTs and may be related to "young PLTs" and "large PLTs" of both inherited and acquired macrothrombocytopenias. Conversion is regulated by the diameter and thickness of the peripheral microtubule coil, and PLTs are capable of enlarging in culture to generate barbell-proPLTs that divide to yield 2 smaller PLT products. Because PLT number and size are inversely proportional, this raises the question: do macrothrombocytopenias represent a failure in the intermediate stages of PLT production? This review aims to bring together and contextualize our current understanding of terminal PLT production against the backdrop of human macrothrombocytopenias to establish how "large PLTs" observed in both conditions are similar, how they are different, and what they can teach us about PLT formation. A better understanding of the cytoskeletal mechanisms that regulate PLT formation and determine PLT size offers the promise of improved therapies for clinical disorders of PLT production and an important source of PLTs for infusion.     

Does age matter in palliative care?

PURPOSE: To assess whether age has an impact on symptoms, problems and needs of hospitalized advanced cancer patients. PATIENTS AND METHODS: A prospective analysis of 181 patients referred to a Palliative Care Team was done using a standardized list of symptoms, problems and needs. Differences between 3 age groups (<60; 60-70; > or =70) were analyzed. RESULTS: Patients > or =70 years had a significantly different prevalence of depressed mood (48% versus 13% of patients 60-70 years and 24% of patients <60 years, p=0.002), urinary tract problems (20% versus 3% versus 8%, p=0.024) and drowsiness (18% versus 42% versus 25%, p=0.039). They expressed more problems with a shortage of informal caregivers (45% versus 42% versus 17%, p<0.001) and less need for support in coping (40% versus 61% versus 63%, p=0.043), relational support (3% versus 8% versus 14%, p=0.019) and support in communication (0% versus 8% versus 11%, p=0.013). CONCLUSION: Fewer differences than expected were found. Elderly cancer patients admitted to a hospital have more or less the same symptoms, problems and needs as their younger counterparts. Despite these findings, age-specific assessment of symptoms, problems and needs ought to be part of optimal symptom management.