1. In 13 of 15 experiments, prostaglandin E2 (PGE2) and sulprostone (a prostanoid EPEP> or = 5 and>> or = 0.5 nM respectively). Tissue was obtained from patients undergoing surgery mainly for carcinoma of the lung. Characterization of the receptors involved was complicated by loss of sensitivity to the contractile PGE action over the experimental period. In contrast, contractile responses to KCl, phenylephrine and the specific thromboxane (TP-) receptor agonist, U-46619, did not decrease with time. 2. The relative contractile potencies for seven PGE analogues, measured during the first few hours after setting up the preparations, were as follows: sulprostone>> misoprostol = gemeprost>> or = PGE2>> or = GR 63799X>> 17-phenyl-omega-trinor PGE2>> or = 11-deoxy PGE1. This ranking indicates that an EPEP 169 and GR 32191, and the EPEPEPEPEPEP-receptor agonists in man.

The advantages of steady-state EP recording include (1) speed in assessing sensory function in normal and sick infants (e.g., in amblyopia) and in sick adults (e.g., in multiple sclerosis); (2) monitoring certain activities of sensory pathways that do not intrude into conscious perception; (3) rapidly assessing sensory function when a large number of subjects must be tested (e.g., in refraction); (4) objective measurement at very high suprathreshold levels where psychophysical methods are difficult or ineffective; (5) rapidly assessing sensory function in normal subjects when EP variability and nonstationarity preculde lengthy experiments; and (6) proving a speedy objective equivalent to behavioral test in animals.

To identify the E-prostanoid (EP) receptors that mediate the hemodynamic actions of PGE2, we studied acute vascular responses to infusions of PGE2 using lines of mice in which each of four EP receptors (EPEPEPEPEPEPEP receptors in males and females. We found that the relative contribution of each EP-receptor subclass was strikingly different in males from that in females. In females, the EPEPEPEPEPEP-receptor subtypes, and the role of individual EP receptors differs dramatically in males from that in females. These differences may contribute to sexual dimorphism of blood pressure regulation.

Mouse coat colour genes have long been studied as a paradigm for genetic interactions in development. A number of these genes have been cloned and most correspond to human genetic disease loci. The proteins encoded by these genes include transcription factors, receptor tyrosine kinases and growth factors, G-protein coupled receptors and their ligands, membrane proteins, structural proteins and enzymes. Many of the mutations have pleiotropic effects, indicating that these proteins play a wider role in developmental or cellular processes. In this review I tabulate the available data on all pigmentation genes cloned from mouse or human, and I focus on three particular systems. One family of genes, including LYST and HPS/ep, shows the relationship between melanosomes and lysosomes. The G-protein coupled receptor, endothelin receptor-B, and its ligand, endothelin-3, are required for the development of both melanocytes and enteric neurons. The melanocortin-1 receptor is expressed only on melanocytes, but mutations that cause overexpression of agouti protein, an antagonist of the receptor, result in obesity, and highlight a role of melanocortins in weight homoeostasis.

BACKGROUND

Epidemiological studies have suggested a beneficial effect of fish oil supplementation in halting the initial progression of Alzheimer's disease. However, it remains unclear whether fish oil affects cognitive function in older people with mild cognitive impairment (MCI).

OBJECTIVE

This study investigated the effects of fish oil supplementation on cognitive function in elderly person with MCI.

METHODS

This was a 12-month, randomised, double-blind, placebo-controlled study using fish oil supplementation with concentrated docosahexaenoic acid (DHA). Thirty six low-socioeconomic-status elderly subjects with MCI were randomly assigned to receive either concentrated DHA fish oil (n = 18) or placebo (n = 18) capsules. The changes of memory, psychomotor speed, executive function and attention, and visual-constructive skills were assessed using cognitive tests. Secondary outcomes were safety and tolerability of the DHA concentrate.

RESULTS

The fish oil group showed significant improvement in short-term and working memory (F = 9.890; ηp (2) = 0.254; p < 0.0001), immediate verbal memory (F = 3.715; ηp (2) = 0.114; p < 0.05) and delayed recall capability (F = 3.986; ηp (2) = 0.121; p < 0.05). The 12-month change in memory (p < 0.01) was significantly better in the fish oil group. Fish oil consumption was well tolerated, and the side effects were minimal and self-limiting.

CONCLUSIONS

This study suggested the potential role of fish oil to improve memory function in MCI subjects. Studies with larger sample sizes, longer intervention periods, different fish oil dosages and genetic determinations should be investigated before definite recommendations can be made.

Galactose is a common monosaccharide that can be utilized by all living organisms via the activities of three main enzymes that make up the Leloir pathway: GalK, GalT, and GalE. In Bacillus subtilis, the absence of GalE causes sensitivity to exogenous galactose, leading to rapid cell lysis. This effect can be attributed to the accumulation of toxic galactose metabolites, since the galE mutant is blocked in the final step of galactose catabolism. In a screen for suppressor mutants restoring viability to a galE null mutant in the presence of galactose, we identified mutations in sinR, which is the major biofilm repressor gene. These mutations caused an increase in the production of the exopolysaccharide (EPS) component of the biofilm matrix. We propose that UDP-galactose is the toxic galactose metabolite and that it is used in the synthesis of EPS. Thus, EPS production can function as a shunt mechanism for this toxic molecule. Additionally, we demonstrated that galactose metabolism genes play an essential role in B. subtilis biofilm formation and that the expressions of both the gal and eps genes are interrelated. Finally, we propose that B. subtilis and other members of the Bacillus genus may have evolved to utilize naturally occurring polymers of galactose, such as galactan, as carbon sources.

OBJECTIVE

Bacteria switch from unicellular to multicellular states by producing extracellular matrices that contain exopolysaccharides. In such aggregates, known as biofilms, bacteria are more resistant to antibiotics. This makes biofilms a serious problem in clinical settings. The resilience of biofilms makes them very useful in industrial settings. Thus, understanding the production of biofilm matrices is an important problem in microbiology. In studying the synthesis of the biofilm matrix of Bacillus subtilis, we provide further understanding of a long-standing microbiological observation that certain mutants defective in the utilization of galactose became sensitive to it. In this work, we show that the toxicity observed before was because cells were grown under conditions that were not propitious to produce the exopolysaccharide component of the matrix. When cells are grown under conditions that favor matrix production, the toxicity of galactose is relieved. This allowed us to demonstrate that galactose metabolism is essential for the synthesis of the extracellular matrix.

BACKGROUND

Gardnerella vaginalis is described as a common vaginal bacterial species whose presence correlates strongly with bacterial vaginosis (BV). Here we report the genome sequencing and comparative analyses of three strains of G. vaginalis. Strains 317 (ATCC 14019) and 594 (ATCC 14018) were isolated from the vaginal tracts of women with symptomatic BV, while Strain 409-05 was isolated from a healthy, asymptomatic individual with a Nugent score of 9.

RESULTS

Substantial genomic rearrangement and heterogeneity were observed that appeared to have resulted from both mobile elements and substantial lateral gene transfer. These genomic differences translated to differences in metabolic potential. All strains are equipped with significant virulence potential, including genes encoding the previously described vaginolysin, pili for cytoadhesion, EPS biosynthetic genes for biofilm formation, and antimicrobial resistance systems, We also observed systems promoting multi-drug and lantibiotic extrusion. All G. vaginalis strains possess a large number of genes that may enhance their ability to compete with and exclude other vaginal colonists. These include up to six toxin-antitoxin systems and up to nine additional antitoxins lacking cognate toxins, several of which are clustered within each genome. All strains encode bacteriocidal toxins, including two lysozyme-like toxins produced uniquely by strain 409-05. Interestingly, the BV isolates encode numerous proteins not found in strain 409-05 that likely increase their pathogenic potential. These include enzymes enabling mucin degradation, a trait previously described to strongly correlate with BV, although commonly attributed to non-G. vaginalis species.

CONCLUSIONS

Collectively, our results indicate that all three strains are able to thrive in vaginal environments, and therein the BV isolates are capable of occupying a niche that is unique from 409-05. Each strain has significant virulence potential, although genomic and metabolic differences, such as the ability to degrade mucin, indicate that the detection of G. vaginalis in the vaginal tract provides only partial information on the physiological potential of the organism.

Streptococcus pneumoniae forms biofilms, but little is known about its extracellular polymeric substances (EPS) or the kinetics of biofilm formation. A system was developed to enable the simultaneous measurement of cells and the EPS of biofilm-associated S. pneumoniae in situ over time. A biofilm reactor containing germanium coupons was interfaced to an attenuated total reflectance (ATR) germanium cell of a Fourier transform infrared (FTIR) laser spectrometer. Biofilm-associated cells were recovered from the coupons and quantified by total and viable cell count methods. ATR-FTIR spectroscopy of biofilms formed on the germanium internal reflection element (IRE) of the ATR cell provided a continuous spectrum of biofilm protein and polysaccharide (a measure of the EPS). Staining of the biofilms on the IRE surface with specific fluorescent probes provided confirmatory evidence for the biofilm structure and the presence of biofilm polysaccharides. Biofilm protein and polysaccharides were detected within hours after inoculation and continued to increase for the next 141 h. The polysaccharide band increased at a substantially higher rate than did the protein band, demonstrating increasing coverage of the IRE surface with biofilm polysaccharides. The biofilm total cell counts on germanium coupons stabilized after 21 h, at approximately 10(5) cells per cm(2), while viable counts decreased as the biofilm aged. This system is unique in its ability to detect and quantify biofilm-associated cells and EPS of S. pneumoniae over time by using multiple, corroborative techniques. This approach could prove useful for the study of biofilm processes of this or other microorganisms of clinical or industrial relevance.

Encapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD) with a 50% mortality rate. EPS is characterized by progressive and excessive fibrotic thickening of the peritoneum, leading to encapsulation of the bowels and intestinal obstruction. At present, EPS cannot be detected with certainty during its early stages; however, a progressive loss of ultrafiltration capacity often precedes its development. Studies that attempted to elucidate the pathogenesis of EPS have shown that the duration of exposure to PD fluids is the most important risk factor for EPS, and that young age and possibly the effects of peritonitis are additional contributory factors. The pathophysiology of EPS is probably best described as a multiple-hit process with a central role for transforming growth factor β. A form of EPS that develops shortly after kidney transplantation has also been recognized as a distinct clinical entity, and may be a common form of EPS in countries with a high transplantation rate. Criteria have been developed to identify EPS by abdominal CT scan at the symptomatic stage, but further clinical research is needed to identify early EPS in asymptomatic patients, to clarify additional risk factors for EPS and to define optimal treatment strategies.

OBJECTIVE

To derive and implement a method for correcting spatial distortion caused by in vivo inhomogeneous static magnetic fields in echo-planar imaging (EPI).

METHODS

The reversed gradient method, which was initially devised to correct distortion in images generated by spin-warp MRI, was adapted to correct distortion in EP images. This method provides point-by-point correction of distortion throughout the image. EP images, acquired with a 3 T MRI system, of a phantom and a volunteer's head were used to test the correction method.

RESULTS

Good correction was observed in all cases. Spatial distortion in the uncorrected images ranged up to 4 pixels (12 mm) and was corrected successfully.

CONCLUSIONS

The correction was improved by the application of a nonlinear interpolation scheme. The correction requires that two EP images be acquired at each slice position. This increases the acquisition time, but an improved signal-to-noise ratio (SNR) is seen in the corrected image. The local SNR gain decreases with increasing distortion. In many EPI acquisition schemes, multiple images are averaged at each slice position to increase the SNR; in such cases the reversed gradient correction method can be applied with no increase in acquisition duration.

Recently, we purified rare CXC chemokine receptor 4 expressing (CXCR4(+)) small stem cells (SCs) from the murine bone marrow (BM) that express markers characteristic for embryonic (E)SCs, epiblast (EP)SCs, and primordial germ cells (PGCs). We named these primitive cells very small embryonic-like (VSEL) SCs (VSELs). Our data indicate that VSELs are also present in many other organs in mice and that they may differentiate into cells from all three germ layers. Similar SCs were also isolated from human cord blood (CB) and mobilized peripheral blood (mPB). We hypothesize that VSELs are deposited during gastrulation and organogenesis in developing organs/tissues of mammals as a population of pluripotent stem cells (PSCs) that give rise to tissue committed monopotent SCs and that their number decreases with age. Therefore VSELs could play a pivotal role in normal rejuvenation of adult tissues as well as involvement in regeneration of damaged organs. Thus, these cells are potential SCs candidates for regenerative medicine and we envision that the regenerative potential of these cells could be harnessed to decelerate the aging processes.

Clinical and experimental evidence suggest that sympathoadrenal activation contributes to mortality in patients with ischemic heart disease. To determine the level of sympathoadrenal activation in the very early phase of acute myocardial infarction (AMI) and to determine if location of infarction (anterior versus inferior) was related to sympathoadrenal activation, we studied norepinephrine (NE) and epinephrine (E) within 4 hours after the onset of symptoms and prior to any rise in plasma creatine kinase (CK). Mean (+/- SE) initial (NE = 591 +/- 111 pg/ml and E = 73 +/- 19 pg/ml), peak (NE = 1356 +/- 178 and E +/- 1098 +/- 608) and average (NE = 815 +/- 142 and E = 252 +/- 68) plasma catecholamine concentrations were considerably above normal (NE = 228 +/- 10 and E = 34 +/- 2 pg/ml, n 60) and values were similar for inferior and anterior infarctions. During an 18-month follow-up, three patients died in whom the AMI mean NE and E and peak CK were higher than in the eight late survivors. Thus the three AMI patients with peak EP values greater than 1000 died, whereas the eight AMI patients with peak EP values less than 1000 survived (p less than 0.01). The magnitude of sympathoadrenal activation early in the course of clinical AMI appeared related to the extent of myocardial damage and late mortality.

Prostaglandin (PG) E(2) produces a broad range of physiological and pharmacological actions in diverse tissues through specific receptors on plasma membranes for maintenance of local homeostasis in the body. PGE receptors are divided into four subtypes, <em>EP</em>1, <em>EP</em>2, <em>EP</em>3, and <em>EP</em>4, which have been identified and cloned. These <em>EP</em> receptors are members of the G-protein coupled receptor family. Among these subtypes, the <em>EP</em>3 receptor is unique in its ability to couple to multiple G proteins. <em>EP</em>3 receptor signals are primarily involved in inhibition of adenylyl cyclase via G(i) activation, and in Ca(2+)-mobilization through G(beta)(gamma) from G(i). Along with G(i) activation, the <em>EP</em>3 receptor can stimulate cAMP production via G(s) activation. Recent evidence indicates that the <em>EP</em>3 receptor can augment G(s)-coupled receptor-stimulated adenylyl cyclase activity, and can also be coupled to the G(13) protein, resulting in activation of the small G protein Rho followed by morphological changes in neuronal cells. This article focuses on recent studies on the novel pathways of <em>EP</em>3 receptor signaling.

OBJECTIVE

To determine the ability of dynamic contrast enhanced (DCE-MRI) to predict pathological complete response (pCR) after preoperative chemotherapy for rectal cancer.

METHODS

In a prospective clinical trial, 23/34 enrolled patients underwent pre- and post-treatment DCE-MRI performed at 1.5T. Gadolinium 0.1 mmol/kg was injected at a rate of 2 mL/s. Using a two-compartmental model of vascular space and extravascular extracellular space, K(trans), k(ep), v(e), AUC90, and AUC180 were calculated. Surgical specimens were the gold standard. Baseline, post-treatment and changes in these quantities were compared with clinico-pathological outcomes. For quantitative variable comparison, Spearman's Rank correlation was used. For categorical variable comparison, the Kruskal-Wallis test was used. P ≤ 0.05 was considered significant.

RESULTS

Percentage of histological tumour response ranged from 10 to 100%. Six patients showed pCR. Post chemotherapy K(trans) (mean 0.5 min(-1) vs. 0.2 min(-1), P = 0.04) differed significantly between non-pCR and pCR outcomes, respectively and also correlated with percent tumour response and pathological size. Post-treatment residual abnormal soft tissue noted in some cases of pCR prevented an MR impression of complete response based on morphology alone.

CONCLUSIONS

After neoadjuvant chemotherapy in rectal cancer, MR perfusional characteristics have been identified that can aid in the distinction between incomplete response and pCR.

CONCLUSIONS

Dynamic contrast enhanced (DCE) MRI provides perfusion characteristics of tumours. These objective quantitative measures may be more helpful than subjective imaging alone Some parameters differed markedly between completely responding and incompletely responding rectal cancers. Thus DCE-MRI can potentially offer treatment-altering imaging biomarkers.

An assessment of lectin-binding analysis for the characterization of extracellular glycoconjugates as part of the extracellular polymeric substances in environmental microbial communities was performed using fully hydrated river biofilms. The applicability of the method was evaluated for single, dual and triple staining with a panel of fluor-conjugated lectins. It was shown that lectin-binding analysis was able to stain glycoconjugates within biofilm communities. Lectin staining also demonstrated spatial heterogeneity within the biofilm matrix. Furthermore, the application of two or even three lectins was possible if suitable combinations were selected. The lectin-binding analysis can be combined with general nucleic acid stains to collect both nucleic acid and glycoconjugate signals. The effects of incubation time, lectin concentration, fluor labelling, carbohydrate inhibition, order of addition and lectin interactions were studied. An incubation time of 20 min was found to be sufficient for completion of lectin binding. It was not possible to ascertain saturating concentration for individual lectins, therefore a standard concentration was used for the assay. Carbohydrate inhibition tests indicated that fluorescein isothiocyanate (FITC)-conjugated lectins had more specific binding characteristics than tetramethyl rhodamine isothiocyanate (TRITC)- or cyanine dye (CY5)-labelled lectins. The order of addition and the nature of the fluor conjugate were also found to influence the binding pattern of the lectins. Therefore the selection of a panel of lectins for investigating the EPS matrix must be based on a full evaluation of their behaviour in the biofilm system to be studied. Despite this necessity, lectin-binding analysis represents a valuable tool to examine the glycoconjugate distribution in fully hydrated biofilms. Thereby, chemical heterogeneities within extracellular biofilm locations can be identified in order to examine the role (e.g. sorption properties, microenvironments, cell-extracellular polymeric substance interactions) of the extracellular polymeric substances in environmental biofilm systems.

Previous work has suggested that functional interrelationships may exist between inhibition of insulin secretion by interleukin (IL)-1beta and the endogenous synthesis of prostaglandin E(2) (PGE(2)) in the pancreatic islet. These studies were performed to ascertain the relative abundance of E prostaglandin (<em>EP</em>) receptor mRNAs in tissues that are major targets, or major degradative sites, of insulin; to identify which <em>EP</em> receptor type mediates PGE(2) inhibition of insulin secretion in pancreatic islets; and to examine possible sites of action through which sodium salicylate might affect IL-1beta/PGE(2) interactions. Real-time fluorescence-based RT-PCR indicated that <em>EP</em>3 is the most abundant <em>EP</em> receptor type in islets, liver, kidney, and epididymal fat. <em>EP</em>3 mRNA is the least, whereas <em>EP</em>2 mRNA is the most, abundant type in skeletal muscle. Misoprostol, an <em>EP</em>3 agonist, inhibited glucose-induced insulin secretion from islets, an event that was prevented by preincubation with pertussis toxin, by decreasing cAMP. Electromobility shift assays demonstrated that sodium salicylate inhibits IL-1beta-induced nuclear factor-kappaB (NF-kappaB) activation. Sodium salicylate also prevented IL-1beta from inducing <em>EP</em>3 and cyclooxygenase (COX)-2 gene expression in islets and thereby prevented IL-1beta from inhibiting glucose-induced insulin secretion. These findings indicate that the sites of action through which sodium salicylate inhibits these negative effects of IL-1beta on beta-cell function include activation of NF-kappaB as well as generation of PGE(2) by COX-2.

We observed previously in vitro that the cytotoxicity of bleomycin (BLM), an anticancer drug in current use, was greatly potentiated by exposing cultured cells to appropriately chosen electric pulses. We then showed in vivo, on tumor-bearing mice, that the same electric pulses also potentiated the antitumoral activity of BLM. In the present work, we demonstrate on DC-3F cells in vitro, that this potentiation is closely related to cell electropermeabilization and the consequent direct internalization of BLM molecules in the cytosol. The survival response curve (SRC) of the electropermeabilized (EP) cells exposed to BLM (plotted as logarithm of survival versus external drug concentration) shows a linear pattern usual for the SRCs of intact cells exposed to current cytotoxic drugs, though in the nanomolar range of concentrations. We have succeeded in determining the relation between BLM cytotoxicity on EP cells and the number of electroloaded BLM molecules per cell (that is the average number, per cell, of BLM molecules internalized into the cytosol). We conclude that (1) BLM molecules possess very intense cytotoxic activity which in non-EP cells is drastically limited by the intact plasma membrane; and (2) in these intact cells, the plasma membrane is responsible for the unusual upward concave curvature of the SRC resulting from exposure to BLM.

OBJECTIVE

The aim of this study was to quantify the blue light that passes through different incremental thicknesses of bulk fill in comparison to conventional resin-based composites (RBCs) and to relate it to the induced mechanical properties.

METHODS

Seven bulk fill, five nanohybrid and two flowable RBCs were analysed. Specimens (n = 5) of three incremental thicknesses (2, 4 and 6 mm) were cured from the top for 20 s, while at the bottom, a spectrometer monitored in real time the transmitted irradiance. Micro-mechanical properties (Vickers hardness, HV, and indentation modulus, E) were measured at the top and bottom after 24 h of storage in distilled water at 37 °C. Electron microscope images were taken for assessing the filler distribution and size.

RESULTS

Bulk fill RBCs (except SonicFill) were more translucent than conventional RBCs. Low-viscosity bulk fill materials showed the lowest mechanical properties. HV depends highly on the following parameters: material (ηp (2) = 0.952), incremental thickness (0.826), filler volume (0.747), filler weight (0.746) and transmitted irradiance (0.491). The bottom-to-top HV ratio (HVbt) was higher than 80 % in all materials in 2- and 4-mm increments (except for Premise), whereas in 6-mm increments, this is valid only in four bulk fill materials (Venus Bulk Fill, SDR, x-tra fil, Tetric EvoCeram Bulk Fill).

CONCLUSIONS

The depth of cure is dependent on the RBC's translucency. Low-viscosity bulk fill RBCs have lower mechanical properties than all other types of analysed materials. All bulk fill RBCs (except SonicFill) are more translucent for blue light than conventional RBCs.

CONCLUSIONS

Although bulk fill RBCs are generally more translucent, the practitioner has to follow the manufacturer's recommendations on curing technique and maximum incremental thickness.

In some cancers cyclooxygenase (COX) inhibition appears to be anti-mitogenic and anti-angiogenic, but the actions of COX-derived prostaglandins in pancreatic cancer (PaCa) are unknown. In this study COX-2 was detected in three of six PaCa cell lines while COX-1 was identified in all cell lines. COX-2 expression correlated with basal and arachidonic acid (AA) stimulated PGE(2) production. PGE(2) production was inhibited by the COX-2 inhibitor nimesulide. In COX-2 expressing cells, exogenous AA and PGE(2) increased VEGF synthesis via the EP(2) receptor. Whereas PGE(2) stimulated intracellular cAMP formation in COX-2 positive and negative cells, 8-bromo cAMP stimulated VEGF production only in COX-2 expressing cells. Stimulating COX-2 expressing PaCa cell lines with AA enhanced migration of endothelial cells, an effect which was inhibited by a COX-2 inhibitor and EP(2) receptor antagonist. These data identify a subset of human PaCa cell lines that express functional COX-2 enzyme. PGE(2) generated by specific COX-2 activity increases VEGF secretion in human PaCa cells through an autocrine mechanism.

Of all known cultured stem cell types, pluripotent stem cells (PSCs) sit atop the landscape of developmental potency and are characterized by their ability to generate all cell types of an adult organism. However, PSCs show limited contribution to the extraembryonic placental tissues in vivo. Here, we show that a chemical cocktail enables the derivation of stem cells with unique functional and molecular features from mice and humans, designated as extended pluripotent stem (EPS) cells, which are capable of chimerizing both embryonic and extraembryonic tissues. Notably, a single mouse EPS cell shows widespread chimeric contribution to both embryonic and extraembryonic lineages in vivo and permits generating single-EPS-cell-derived mice by tetraploid complementation. Furthermore, human EPS cells exhibit interspecies chimeric competency in mouse conceptuses. Our findings constitute a first step toward capturing pluripotent stem cells with extraembryonic developmental potentials in culture and open new avenues for basic and translational research. VIDEO ABSTRACT.

The effect of various lectins and sugars on adhesion of five strains of Candida albicans to buccal and vaginal epithelial cells in vitro was investigated. Adhesion of C. albicans GDH 2346 was inhibited primarily by L-fucose and winged-pea lectin, whereas adhesion of strain GDH 2023 was inhibited by N-acetyl-D-glucosamine, or D-glucosamine, and wheat-germ agglutinin. Three other strains of C. albicans (MRL 3153, GRI 681 and GRI 682) gave results similar to those obtained with strain GDH 2346. Extracellular polymeric material (EP) isolated from strain GDH 2346 inhibited adhesion of strains MRL 3153, GRI 681 and GRI 682 by more than 50%, but that of strain GDH 2023 by only 30%. EP from strain GDH 2023 had little or no effect on the adhesion of any other yeast strain. Lectin-like proteins with affinities for L-fucose, N-acetyl-D-glucosamine and D-mannose were detected in EP from all five strains in different amounts. These results indicate that there are at least two types of adhesion mechanism and that glycosides containing L-fucose or N-acetyl-D-glucosamine can function as epithelial cell receptors for C. albicans.

Pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) time-course data allows estimation of quantitative parameters such as K (trans) (rate constant for plasma/interstitium contrast agent transfer), v e (extravascular extracellular volume fraction), and v p (plasma volume fraction). A plethora of factors in DCE-MRI data acquisition and analysis can affect accuracy and precision of these parameters and, consequently, the utility of quantitative DCE-MRI for assessing therapy response. In this multicenter data analysis challenge, DCE-MRI data acquired at one center from 10 patients with breast cancer before and after the first cycle of neoadjuvant chemotherapy were shared and processed with 12 software tools based on the Tofts model (TM), extended TM, and Shutter-Speed model. Inputs of tumor region of interest definition, pre-contrast T1, and arterial input function were controlled to focus on the variations in parameter value and response prediction capability caused by differences in models and associated algorithms. Considerable parameter variations were observed with the within-subject coefficient of variation (wCV) values for K (trans) and v p being as high as 0.59 and 0.82, respectively. Parameter agreement improved when only algorithms based on the same model were compared, e.g., the K (trans) intraclass correlation coefficient increased to as high as 0.84. Agreement in parameter percentage change was much better than that in absolute parameter value, e.g., the pairwise concordance correlation coefficient improved from 0.047 (for K (trans)) to 0.92 (for K (trans) percentage change) in comparing two TM algorithms. Nearly all algorithms provided good to excellent (univariate logistic regression c-statistic value ranging from 0.8 to 1.0) early prediction of therapy response using the metrics of mean tumor K (trans) and k ep (=K (trans)/v e, intravasation rate constant) after the first therapy cycle and the corresponding percentage changes. The results suggest that the interalgorithm parameter variations are largely systematic, which are not likely to significantly affect the utility of DCE-MRI for assessment of therapy response.

Working memory (WM), the ability to briefly retain and manipulate information in mind, is central to intelligent behavior. Here we take advantage of the high temporal resolution of electrophysiological measures to obtain a millisecond timescale view of the activity induced in distributed cortical networks by tasks that impose significant WM demands. We examined how these networks are affected by the type and amount of information to be remembered, and by the amount of task practice. Evoked potentials (EPs) were obtained from eight subjects performing spatial and verbal versions of a visual n-back WM task (n = 1, 2, 3) on each of three testing days. In well-trained subjects, WM tasks elicited transient responses reflecting different subcomponents of task processing, including transient (lasting 0.02-0.3 s) task-sensitive and load-sensitive EPs, as well as sustained responses (lasting 1-1.5 s), including the prestimulus Contingent Negative Variation (CNV), and post-stimulus frontal and parietal Slow Waves. The transient responses, with the exception of the P300, differed between the verbal and spatial task versions, and between trials with different response requirements. The P300 and the Slow Waves were not affected by task version but were affected by increased WM load. These results suggest that WM emerges from the formation of a dynamic cortical network linking task-specific processes with non-specific, capacity-limited, higher-order attentional processes. Practice effects on the EPs suggested that practice led to the development of a more effective cognitive strategy for dealing with lower-order aspects of task processing, but did not diminish demands made on higher order processes. Thus a simple WM task is shown to be composed of numerous elementary subsecond neural processes whose characteristics vary with type and amount of information being remembered, and amount of practice.

The COX-2 product prostaglandin E(2) (PGE(2)) contributes to the high metastatic capacity of breast tumors. Our published data indicate that inhibiting either PGE(2) production or PGE(2)-mediated signaling through the PGE(2) receptor <em>EP</em>4 reduces metastasis by a mechanism that requires natural killer (NK) cells. It is known that NK cell function is compromised by PGE(2), but very little is known about the mechanism by which PGE(2) affects NK effector activity. We now report the direct effects of PGE(2) on the NK cell. Endogenous murine splenic NK cells express all four PGE(2) receptors (<em>EP</em>1-4). We examined the role of <em>EP</em> receptors in three NK cell functions: migration, cytotoxicity, and cytokine release. Like PGE(2), the <em>EP</em>4 agonist PGE(1)-OH blocked NK cell migration to FBS and to four chemokines (ITAC, MIP-1α, SDF-1α, and CCL21). The <em>EP</em>2 agonist, Butaprost, inhibited migration to specific chemokines but not in response to FBS. In contrast to the inhibitory actions of PGE(2), the <em>EP</em>1/<em>EP</em>3 agonist Sulprostone increased migration. Unlike the opposing effects of <em>EP</em>4 vs. <em>EP</em>1/<em>EP</em>3 on migration, agonists of each <em>EP</em> receptor were uniformly inhibiting to NK-mediated cytotoxicity. The <em>EP</em>4 agonist, PGE(1)-OH, inhibited IFNγ production from NK cells. Agonists for <em>EP</em>1, <em>EP</em>2, and <em>EP</em>3 were not as effective at inhibiting IFNγ. Agonists of <em>EP</em>1, <em>EP</em>2, and <em>EP</em>4 all inhibited TNFα; <em>EP</em>4 agonists were the most potent. Thus, the <em>EP</em>4 receptor consistently contributed to loss of function. These results, taken together, support a mechanism whereby inhibiting PGE(2) production or preventing signaling through the <em>EP</em>4 receptor may prevent suppression of NK functions that are critical to the control of breast cancer metastasis.