Effects of preexposure to a subthreshold dose of helium particles on the changes in performance produced by exposure to helium particles.

On exploratory class missions, such as a mission to Mars, astronauts will be exposed to doses of particles of high energy and charge and protons up to 30 - 40 cGy. These exposures will most likely occur at random intervals across the estimated 3-yr duration of the mission. As such, the possibility of an interaction between particles must be taken into account: a prior subthreshold exposure to one particle may prevent or minimize the effect of a subsequent exposure (adaptation), or there may be an additive effect such that the prior exposure may sensitize the individual to a subsequent exposure of the same or different radiations.

Mutual impact of clinically translatable near-infrared dyes on photoacoustic image contrast and in vitro photodynamic therapy efficacy (Erratum).

The erratum corrects an error in the y-axis labels of Fig. 4 and Fig. S2.

Optical changes in THP-1 macrophage metabolism in response to pro- and anti-inflammatory stimuli reported by label-free two-photon imaging.

Temporal changes in macrophage metabolism are likely crucial to their role in inflammatory diseases. Label-free two-photon excited fluorescence (TPEF) and fluorescence lifetime imaging microscopy are well suited to track dynamic changes in macrophage metabolism. We performed TPEF imaging of human macrophages following either pro- or an anti-inflammatory stimulation.

Effects of exposure to C and He particles on cognitive performance of intact and ovariectomized female rats.

Exposure to the types of radiation encountered outside the magnetic field of the earth can disrupt cognitive performance. Exploratory class missions to other planets will include both male and female astronauts. Because estrogen can function as a neuroprotectant, it is possible that female astronauts may be less affected by exposure to space radiation than male astronauts.

Polysaccharides in Spirulina platensis Improve Antioxidant Capacity of Chinese-Style Sausage.

Unlabelled: This study examined the effect of Spirulina platensis polysaccharides (SPP) at 0.1%, 0.25%, and 0.

Psychometric validation of the Psoriasis Symptom Diary using Phase III study data from patients with chronic plaque psoriasis.

Objectives: This analysis aimed to confirm the reliability, validity, and responsiveness of the Psoriasis Symptom Diary (PSD) using data from two Phase III studies in patients with moderate to severe chronic plaque psoriasis.

Methods: Data from two randomized, double-blind, double-dummy, placebo-controlled, multicenter Phase III studies (n = 820) assessing the efficacy and safety of secukinumab were used. The PSD (24-h recall; 0-10 numeric rating scale) was electronically administered each evening.

Modulation of outer medullary NaCl transport and oxygenation by nitric oxide and superoxide.

We expanded our region-based model of water and solute exchanges in the rat outer medulla to incorporate the transport of nitric oxide (NO) and superoxide (O(2)(-)) and to examine the impact of NO-O(2)(-) interactions on medullary thick ascending limb (mTAL) NaCl reabsorption and oxygen (O(2)) consumption, under both physiological and pathological conditions. Our results suggest that NaCl transport and the concentrating capacity of the outer medulla are substantially modulated by basal levels of NO and O(2)(-). Moreover, the effect of each solute on NaCl reabsorption cannot be considered in isolation, given the feedback loops resulting from three-way interactions between O(2), NO, and O(2)(-).

Transport and retention of fullerene nanoparticles in natural soils.

Commercial production and use of fullerene (C60) nanomaterials will inevitably lead to their release into the environment, where knowledge of C60 fate and transport is limited. In this study, a series of one-dimensional column experiments was conducted to assess the transport and retention of nanoscale fullerene aggregates (nC60) in water-saturated soils. Under the experimental conditions, complete retention of nC60 was observed in columns (2.

Effectiveness and efficacy of conservation options after potato harvest.

Soil erosion and phosphorus (P) runoff can be severe in potato production systems in the Northeast USA, which are characterized by intensive tillage, minimal ground cover, low crop residue return, and steep slopes. We used rainfall simulators in the greenhouse and field to assess sediment and P movement associated with two conservation practices: straw mulching and application of polyacrylamide (PAM). In the greenhouse, a Nokomis sandy loam soil (fine-loamy, mixed, frigid Typic Haplorthods) was packed into 0.

SK2 channels are required for function and long-term survival of efferent synapses on mammalian outer hair cells.

Cochlear hair cells use SK2 currents to shape responses to cholinergic efferent feedback from the brain. Using SK2(-/-) mice, we demonstrate that, in addition to their previously defined role in modulating hair cell membrane potentials, SK2 channels are necessary for long-term survival of olivocochlear fibers and synapses. Loss of the SK2 gene also results in loss of electrically driven olivocochlear effects in vivo, and down regulation of ryanodine receptors involved in calcium-induced calcium release, the main inducer of nAChR evoked SK2 activity.

A model of glucose transport and conversion to lactate in the renal medullary microcirculation.

In this study, we modeled mathematically the transport of glucose across renal medullary vasa recta and its conversion to lactate by anaerobic glycolysis. Uncertain parameter values were determined by seeking good agreement between predictions and experimental measurements of lactate generation rates, as well as glucose and lactate concentration ratios between the papilla and the corticomedullary junction; plausible kinetic rate constant and permeability values are summarized in tabular form. Our simulations indicate that countercurrent exchange of glucose from descending (DVR) to ascending vasa recta (AVR) in the outer medulla (OM) and upper inner medulla (IM) severely limits delivery to the deep inner medulla, thereby limiting medullary lactate generation.

Activation of cAMP-guanine exchange factor confers PKA-independent protection from hepatocyte apoptosis.

cAMP has previously been shown to promote cell survival in a variety of cell types, but the downstream signaling pathway(s) of this antiapoptotic effect is unclear. Thus the role of cAMP signaling through PKA and cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs) in cAMP's antiapoptotic action was investigated in the present study. cAMP's protective effect against bile acid-, Fas ligand-, and TNF-alpha-induced apoptosis in rat hepatocytes was largely unaffected by the selective PKA inhibitor, Rp-8-(4-chlorophenylthio)-cAMP (Rp-cAMP).

The dual imperative in refugee research: some methodological and ethical considerations in social science research on forced migration.

Social scientists doing fieldwork in humanitarian situations often face a dual imperative: research should be both academically sound and policy relevant. We argue that much of the current research on forced migration is based on unsound methodology, and that the data and subsequent policy conclusions are often flawed or ethically suspect. This paper identifies some key methodological and ethical problems confronting social scientists studying forced migrants or their hosts.

Mechanisms by which cAMP increases bile acid secretion in rat liver and canalicular membrane vesicles.

Bile acid secretion induced by cAMP and taurocholate is associated with recruitment of several ATP binding cassette (ABC) transporters to the canalicular membrane. Taurocholate-mediated bile acid secretion and recruitment of ABC transporters are phosphatidylinositol 3-kinase (PI3K) dependent and require an intact microtubular apparatus. We examined mechanisms involved in cAMP-mediated bile acid secretion.

Decreased expression of p16 gene in gastric cancer.

We analyzed gastric cancers for p16 gene alterations. Homozygous deletion of the p16 gene was found in 1 of 8 gastric cancer cell lines and none of 20 primary gastric cancers. Mutations of the p16 gene were not detected in exon 1-3.

MDM2 overexpression in benign and malignant lesions of the human breast.

MDM2 overexpression has been detected in women with benign or cancerous lesions of the breast. Immunohistochemical methods were used to identify overexpression in 11 of 27 benign cases (41%) and 15 of 22 (68%) cancer cases. MDM2 overexpression correlated well with immunohistochemically detected estrogen receptor (ER), suggesting that expression of these proteins was coordinately regulated.

Reexpression of the major histocompatibility complex (MHC) class-I antigen h-2k(b) by m1 (b16-f10) murine melanoma-cells.

We monitored the expression of MHC class I antigens in a clonal isolate (M1) of B16-F10 murine melanoma cells, under various condition of growth in vitro. We found that, compared to exponentially growing cultures, cells from confluent M1 cultures expressed higher levels of H-2D(b) and H-2K(b) surface antigens. Expression of MHC class I antigens could be enhanced further by incubation of M1 cells in serum-free medium for 24-48 hours.

Induction by human interferon and murine h-2l(d) gene of the surface expression of endogenous hla class-I free heavy-chains in hct human colon-carcinoma cells, deficient in Beta-2-microglobulin.

The colon cancer cell line HCT fails to express HLA class I antigens on the cell surface as a consequence of two independent mutations occurring in both copies of the beta2-microglobulin (beta2-mu) gene. Restoration of HLA class I antigen expression in HCT cells transfected with the wild-type human beta2-mu gene is accompanied by the expression of beta2-mu-free HLA class I heavy chains on the cell surface. HCT cells expressing a transfected H-2L(d) gene (HCT-L(d) transfectants) exhibited high levels of H-2L(d) heavy chains on the cell surface, following treatment with human interferon a (IFN-alpha).

Sudden death in idiopathic dilated cardiomyopathy: role of ventricular arrhythmias.

Sudden cardiac death (SCD) is associated with idiopathic congestive cardiomyopathy (IDCM) and most commonly is due to ventricular tachyarrhythmias. The recurrence rate of SCD in the absence of specific therapy is thought to be around 20%-30% per year. Asymptomatic and symptomatic ventricular arrhythmias are common in patients with IDCM and the direct causal link of such arrhythmias with SCD in IDCM patients remains to be established.

Decreased GABAA receptor subunit mRNA concentrations following chronic lorazepam administration.

Chronic benzodiazepine administration has been associated with alterations in binding and function at the GABAA receptor. To evaluate effects of chronic benzodiazepine exposure on messenger RNA (mRNA) concentrations for several GABAA receptor subunits, we treated mice with lorazepam, 2 mg kg-1 daily for 1-28 days and evaluated mRNAs for the alpha 1 and gamma 2 subunits by Northern hybridization. In cerebral cortex, concentrations of mRNA for the alpha 1 and gamma 2 subunits were unchanged from vehicle or control after 1-10 days of lorazepam.

Chronic benzodiazepine administration: effects in vivo and in vitro.

Chronic benzodiazepine administration is associated with neurochemical alterations in the GABAergic system, as determined in a variety of animal models and tissue culture systems. In animals, effects of chronic benzodiazepine agonists on receptor binding are uncertain, but several studies indicate a decrease in GABA-dependent chloride uptake. In contrast, limited data indicate that chloride uptake is increased after chronic antagonist administration, and results of inverse agonist administration are uncertain.