Effects of snow on reproduction of perennial Thalictrum dioicum: Plants survive but seedlings fail to recruit with reduced snow cover.

Premise: Future reductions in snow cover are expected in temperate climates, likely leading to more soil-freezing events and damage to plant tissues. However, whether and how plants can compensate for this damage may depend on the timing of damage and on plant allocations to seed size and number. We need more information about how seed production, germination, and seedling recruitment might respond to changes in snow cover.

Breaking Tradition to Bridge Bench and Bedside: Accelerating the MD-PhD-Residency Pathway.

Problem: Physician-scientists are individuals trained in both clinical practice and scientific research. Often, the goal of physician-scientist training is to address pressing questions in biomedical research. The established pathways to formally train such individuals are mainly MD-PhD programs and physician-scientist track residencies.

Intracellular pH Measurements in Glioblastoma Cells Using the pH-Sensitive Dye BCECF.

The regulation of pH in glioblastoma (GBM) has received significant attention, because it has been linked to tumor metabolism and the stem cell phenotype. The variability in blood perfusion and oxygen tension within tumors suggests that ambient pH values fluctuate across different tumor territories. This chapter describes a detailed protocol for measuring intracellular pH in patient-derived GBM cells in vitro, using the fluorescent pH sensitive dye BCECF.

Notch signaling regulates metabolic heterogeneity in glioblastoma stem cells.

Glioblastoma (GBM) stem cells (GSCs) reside in both hypoxic and vascular microenvironments within tumors. The molecular mechanisms that allow GSCs to occupy such contrasting niches are not understood. We used patient-derived GBM cultures to identify GSC subtypes with differential activation of Notch signaling, which co-exist in tumors but occupy distinct niches and match their metabolism accordingly.

Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue.

Electrical activity in the brain is accompanied by significant ion fluxes across membranes, resulting in complex changes in the extracellular concentration of all major ions. As these ion shifts bear significant functional consequences, their quantitative determination is often required to understand the function and dysfunction of neural networks under physiological and pathophysiological conditions. In the present study, we demonstrate the fabrication and calibration of double-barreled ion-selective microelectrodes, which have proven to be excellent tools for such measurements in brain tissue.

Carbonic anhydrase generates a pH gradient in Bombyx mori silk glands.

Silk is a protein of interest to both biological and industrial sciences. The silkworm, Bombyx mori, forms this protein into strong threads starting from soluble silk proteins using a number of biochemical and physical cues to allow the transition from liquid to fibrous silk. A pH gradient has been measured along the gland, but the methodology employed was not able to precisely determine the pH at specific regions of interest in the silk gland.

Autocrine boost of NMDAR current in hippocampal CA1 pyramidal neurons by a PMCA-dependent, perisynaptic, extracellular pH shift.

The plasma membrane Ca(2+)-ATPase (PMCA) is found near postsynaptic NMDARs. This transporter is a Ca(2+)-H(+) exchanger that raises cell surface pH. We tested whether the PMCA acts in an autocrine fashion to boost pH-sensitive, postsynaptic NMDAR currents.

Carbonic anhydrase generates CO2 and H+ that drive spider silk formation via opposite effects on the terminal domains.

Spider silk fibers are produced from soluble proteins (spidroins) under ambient conditions in a complex but poorly understood process. Spidroins are highly repetitive in sequence but capped by nonrepetitive N- and C-terminal domains (NT and CT) that are suggested to regulate fiber conversion in similar manners. By using ion selective microelectrodes we found that the pH gradient in the silk gland is much broader than previously known.

Intramanufacturer diameter and taper variability of rotary instruments and their corresponding Gutta-percha cones.

Introduction: To simplify endodontic treatment, manufacturers offer systems of nickel-titanium rotary files and matching gutta-percha cones. The aim of this study was to determine whether intramanufacturer file diameters and tapers matched the diameters and tapers of their corresponding cones.

Methods: Twenty files and corresponding cones ([ie, size #30, 0.

NMDA receptor-dependent afterdepolarizations are curtailed by carbonic anhydrase 14: regulation of a short-term postsynaptic potentiation.

In the hippocampus, extracellular carbonic anhydrase (Car) speeds the buffering of an activity-generated rise in extracellular pH that impacts H(+)-sensitive NMDA receptors (NMDARs). We studied the role of Car14 in this brain structure, in which it is expressed solely on neurons. Current-clamp responses were recorded from CA1 pyramidal neurons in wild-type (WT) versus Car14 knock-out (KO) mice 2 s before (control) and after (test) a 10 pulse, 100 Hz afferent train.

Preemptive regulation of intracellular pH in hippocampal neurons by a dual mechanism of depolarization-induced alkalinization.

Numerous studies have documented the mechanisms that regulate intracellular pH (pH(i)) in hippocampal neurons in response to an acid load. Here, we studied the response of pH(i) to depolarization in cultured hippocampal neurons. Elevation of external K+ (6-30 mm) elicited an acid transient followed by a large net alkaline shift.

Barium plateau potentials of CA1 pyramidal neurons elicit all-or-none extracellular alkaline shifts via the plasma membrane calcium ATPase.

In many brain regions, synchronous neural activity causes a rapid rise in extracellular pH. In the CA1 region of hippocampus, this population alkaline transient (PAT) enhances responses from postsynaptic, pH-sensitive N-methyl-d-aspartate (NMDA) receptors. Recently, we showed that the plasma membrane Ca(2+)-ATPase (PMCA), a ubiquitous transporter that exchanges internal Ca(2+) for external H(+), is largely responsible for the PAT.

Psychometric evaluation of the Impact of Cancer (IOC-CS) scale for young adult survivors of childhood cancer.

Introduction: Psychosocial outcomes derived from standardized and disease-specific measures are often used in pediatric oncology; however, the reliability, validity and utility of these instruments in adult survivors of childhood cancer have yet to be established.

Purpose: To develop and evaluate a new instrument that measures aspects of long-term survivorship not measured by existing tools.

Methods: A new candidate instrument--the Impact of Cancer for childhood cancer survivors (IOC-CS)--was administered to childhood cancer survivors aged 18-39 who were 21 years of age or younger when diagnosed with cancer.

Rapid rise of extracellular pH evoked by neural activity is generated by the plasma membrane calcium ATPase.

In hippocampus, synchronous activation of CA1 pyramidal neurons causes a rapid, extracellular, population alkaline transient (PAT). It has been suggested that the plasma membrane Ca(2+)-ATPase (PMCA) is the source of this alkalinization, because it exchanges cytosolic Ca(2+) for external H(+). Evidence supporting this hypothesis, however, has thus far been inconclusive.

To foster healing among adolescents and young adults with cancer: what helps? What hurts?

Purpose: The physical and emotional well-being of adolescents and young adults with cancer (AYA) rests on the ability of all concerned to promote helpful forms of care and reduce hurtful forms. The purpose of this study was to identify aspects of behavior that may promote or inhibit healthy psychosocial adjustment for this age-defined population.

Method: Seventeen young adult cancer survivors participated in focus groups to discuss what people said or did that they found helpful or hurtful.

Carbonic anhydrases CA4 and CA14 both enhance AE3-mediated Cl--HCO3- exchange in hippocampal neurons.

Carbonic anhydrase (CA) activity in the brain extracellular space is attributable mainly to isoforms CA4 and CA14. In brain, these enzymes have been studied mostly in the context of buffering activity-dependent extracellular pH transients. Yet evidence from others has suggested that CA4 acts in a complex with anion exchangers (AEs) to facilitate Cl(-)-HCO(3)(-) exchange in cotransfected cells.

Endogenous alkaline transients boost postsynaptic NMDA receptor responses in hippocampal CA1 pyramidal neurons.

In hippocampus, activation of the Schaffer collaterals generates an extracellular alkaline transient both in vitro and in vivo. This pH change may provide relief of the H+ block of NMDA receptors (NMDARs) and thereby increase excitability. To test this hypothesis, we augmented extracellular buffering in mouse hippocampal slices by adding 2 microM bovine type II carbonic anhydrase to the superfusate.

Long term survivors of childhood cancer: cure and care. The Erice statement.

The number of subjects that have successfully completed treatment for a cancer diagnosed during childhood and are entering adulthood is increasing over time. Members of the International Berlin-Frankfurt-Munster (I-BFM) Early and Late Toxicity Educational Committee (ELTEC) invited 45 paediatric cancer experts (representing oncologists, psychologists, nurses, epidemiologists, parents, and survivors) from 13 European countries (with five additional experts from North America) to Erice, Sicily (from October 27 to 29, 2006) to discuss the circumstances in which the word 'cure' should be used when speaking about children with cancer, and when and why continuing follow-up and care may be required. The objective of the gathering was to generate from the personal and professional experience of the participants an overview statement of the group's philosophy of cure and care of survivors of childhood cancer.

Regulation of postsynaptic Ca2+ influx in hippocampal CA1 pyramidal neurons via extracellular carbonic anhydrase.

Synchronous neural activity causes rapid changes of extracellular pH (pH(e)) in the nervous system. In the CA1 region of the hippocampus, stimulation of the Schaffer collaterals elicits an alkaline pH(e) transient in stratum radiatum that is limited by extracellular carbonic anhydrase (ECA). When interstitial buffering is diminished by inhibition of ECA, the alkalosis is enhanced and NMDA receptor (NMDAR)-mediated postsynaptic currents can be augmented.

Fabrication and use of high-speed, concentric h+- and Ca2+-selective microelectrodes suitable for in vitro extracellular recording.

Ion-selective microelectrodes (ISMs) have been used extensively in neurophysiological studies. ISMs selective for H(+) and Ca(2+) are notable for their sensitivity and selectivity, but suffer from a slow response time, and susceptibility to noise because of the high electrical resistance of the respective ion exchange cocktails. These drawbacks can be overcome by using a "coaxial" or "concentric" inner micropipette to shunt the bulk of the ion exchanger resistance.

Kinetics of activity-evoked pH transients and extracellular pH buffering in rat hippocampal slices.

The kinetics of activity-dependent, extracellular alkaline transients, and the buffering of extracellular pH (pH(e)), were studied in rat hippocampal slices using a fluorescein-dextran probe. Orthodromic stimuli generated alkaline transients < or = 0.05 pH units that peaked in 273 +/- 26 ms and decayed with a half-time of 508 +/- 43 ms.

Functional demonstration of surface carbonic anhydrase IV activity on rat astrocytes.

Buffering of the brain extracellular fluid is catalyzed by carbonic anhydrase (CA) activity. Whereas the extracellular isoform CA XIV has been localized exclusively to neurons in the brain, and to glial cells in the retina, there has been uncertainty regarding the form or forms of CA on the surface of brain astrocytes. We addressed this issue using physiological methods on cultured and acutely dissociated rat astrocytes.