Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(30K+)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: Molecular Plant-Microbe Interactions
March/30/1993
Abstract
The nucleotide sequence of a 4.8-kb ClaI-EcoRI DNA fragment of megaplasmid 2 of Rhizobium meliloti Rm2011 involved in succinoglucan (EPS I) synthesis and nodule infection was determined. Four open reading frames (ORFs) were identified on this fragment. A mutational analysis revealed that these ORFs represent genes that were termed exoX, exoY, exoF, and exoQ. The locations of transposon insertions in these exo genes were determined at the nucleotide level. Plasmid integration mutagenesis revealed that the genes exoY, exoF, and exoQ are organized in an operon. The exoX gene running in opposite direction forms a monocistronic transcriptional unit. The exoX gene was shown to negatively influence the amount of EPS I synthesized. The exoY gene is coding for a membrane associated protein homologous to the C-terminal part of the Xanthomonas campestris glucosyltransferase GumD and the Salmonella typhimurium galactose transferase RfbP. ExoF, a probable periplasmatic protein, is nearly identical to the protein encoded by ORF1 of Rhizobium sp. strain NGR234. ExoQ is most probably a membrane associated protein as deduced by its hydrophobic structural features. All three genes of the exoYFQ operon were shown to be essential for succinoglucan synthesis and nodule infection.
Publication
Journal: Quarterly Journal of Experimental Psychology
March/18/2008
Abstract
The "broken-mirror" theory of autism argues that dysfunction of the "mirror neuron system" is a root cause of social disability in autism. The present paper aims to scrutinize this theory and, when it breaks down, to provide an alternative. Current evidence suggests that children with autism are able to understand and emulate goal-directed actions, but may have specific impairments in automatic mimicry of actions without goals. These data are not compatible with the broken-mirror theory, but can be accounted for by a new model called EP-M. The EP-M model segments the mirror neuron system into an indirect, parietal route for goal emulation and planning (EP) and a direct occipital-frontal route for mimicry (M). This fractionation is consistent with neuroimaging and behavioural studies of the mirror neuron system in typical children and adults. I suggest that top-down modulation of the direct M route may be dysfunctional in individuals with autism, leading to abnormal behaviours on mimicry tasks as well as other social disabilities.
Publication
Journal: American Journal of Pathology
January/7/1997
Abstract
Ep-CAM, an epithelial adhesion molecule, is absent in normal squamous epithelia but can be detected in some squamous carcinomas. Using a panel of monoclonal antibodies to keratinocyte differentiation and proliferation markers, we investigated the association of EP-CAM expression with differentiation-related and/or neoplastic changes in cervical epithelium. Normal endocervical glandular epithelium (Both columnar and reserve cells) appeared strongly positive for EP-CAM, whereas ectocervical squamous epithelial cells did not express this molecule. Expression of Ep-CAM (in basal cells) was sometimes observed in morphologically normal ectocervical tissue but only in areas bordering cervical intraepithelial neoplasia (CIN) lesions. At the early stages of neoplasia the expression of Ep-CAM was regularly present in squamous epithelium, in general consistent with the areas of atypical, undifferentiated cells. Thus, in CIN grades I and II, the basal/suprabasal layers of the epithelia were positive, whereas in CIN grade III lesions, up to 100% of the cells over the whole thickness of the epithelium sometimes excluding the very upper layers, expressed Ep-CAM. A clear increase, not only in number of positive cells but also in levels of Ep-CAM expression (intensity) was observed during progression from CIN I to CIN III. Expression of Ep-CAM in ectocervical lesions did not coincide with a reappearance of the simple epithelium cytokeratins (CK8 and CK18). On the other hand, expression of Ep-CAM in atypical cells of CIN lesions correlated with the disappearance of CK13, which normally marks cells undergoing squamous differentiation. As was shown with Ki-67, a marker for proliferating cell populations, the areas of Ep-CAM expression were also the areas of enhanced proliferation. Cells expressing Ep-CAM did not express involucrin, a marker for cells committed to terminal differentiation. In the majority of both squamous and adenocarcinomas of the cervix a strong expression of Ep-CAM was observed, although some decrease in the expression (both the intensity and the number of positive cells), as compared with CIN III lesions, was observed in the areas of squamous differentiation. This study demonstrates that the expression of Ep-CAM in cervical squamous epithelium is associated with abnormal proliferation of cell populations that are not committed to terminal differentiation.
Publication
Journal: FEMS Microbiology Reviews
April/22/2015
Abstract
We summarize different studies describing mechanisms through which bacteria in a biofilm mode of growth resist mechanical and chemical challenges. Acknowledging previous microscopic work describing voids and channels in biofilms that govern a biofilms response to such challenges, we advocate a more quantitative approach that builds on the relation between structure and composition of materials with their viscoelastic properties. Biofilms possess features of both viscoelastic solids and liquids, like skin or blood, and stress relaxation of biofilms has been found to be a corollary of their structure and composition, including the EPS matrix and bacterial interactions. Review of the literature on viscoelastic properties of biofilms in ancient and modern environments as well as of infectious biofilms reveals that the viscoelastic properties of a biofilm relate with antimicrobial penetration in a biofilm. In addition, also the removal of biofilm from surfaces appears governed by the viscoelasticity of a biofilm. Herewith, it is established that the viscoelasticity of biofilms, as a corollary of structure and composition, performs a role in their protection against mechanical and chemical challenges. Pathways are discussed to make biofilms more susceptible to antimicrobials by intervening with their viscoelasticity, as a quantifiable expression of their structure and composition.
Publication
Journal: Vaccine
March/19/2008
Abstract
We evaluated EP HIV-1090 vaccine, a DNA plasmid encoding 21 cytotoxic T-lymphocyte (CTL) epitopes of human immunodeficiency virus type 1 (HIV-1) and the pan-DR helper T-lymphocyte epitope (PADRE), in a dose escalation, randomized, double-blinded, placebo-controlled Phase 1 trial. Vaccine, at 0.5, 2.0, or 4.0mg doses, or placebo was injected four times over 6 months. Forty-two healthy, HIV-1-uninfected adults were enrolled. Using an interferon-gamma ELISPOT assay, a response to PADRE was detected in one vaccine recipient. Three vaccine recipients raised anti-HIV-1 CD8+ CTL measured by chromium-release assay. The vaccine was safe and well-tolerated, but only weakly immunogenic.
Publication
Journal: Cytometry Part A
February/1/2009
Abstract
This review summarizes information regarding the rare population of very small embryonic-like stem cells (VSELs) that has been identified in adult tissues, emphasizing both their unique morphological features and potential biological significance. We focus on their pluripotent nature and expression of markers characteristic for embryonic stem cells (ESCs), epiblast (EP)SCs, and primordial germ cells (PGCs). Furthermore, we will discuss their rank in the developmental hierarchy of the SC compartment as well as their relationship to other bone marrow-derived, primitive, nonhematopoietic SCs including: (i) endothelial progenitor cells (EPCs); (ii) mesenchymal (M)SCs; (iii) multipotent adult progenitor cells (MAPCs); (iv) marrow-isolated adult multilineage inducible (MIAMIs) cells; (v) multipotent adult (MA)SCs; and (vi) OmniCytes. We will also present different populations of very "small SCs" that have been recently described in the literature (e.g., spore-like cells and Lin(-)/ALDH(high) long-term repopulating hematopoietic SCs).
Publication
Journal: Journal of Clinical Investigation
June/10/1977
Abstract
In the plasma clot culture system both normal and polycythemia vera (PV) bone marrow cells respond to erythropoietin (Ep), giving rise to large numbers of colonies of erythroid cells. In PV, but not in normal individuals, the marrow produced endogenous erythroid colonies (EED) in the absence of exogenous Ep. The number of EEC formed varied from patient to patient comprising anywhere from 6 to 29% of the total number of colonies formed in the presence of Ep. Exposure, before use in culture, of fetal calf serum and citrated bovine plasma to the gammaglobulin fraction of rabbit anti-Ep serum followed by treatment with goat anti-rabbit gamma-globulin re sulted in a significant decrease in EEC formation. Addition of anti-Ep directly to the culture medium produced similar results. In addition, the production of EEC in response to added Ep was inhibited in the presence of anti-Ep. Addition of very small doses of highly purified Ep to anti-Ep-treated cultures resulted in the reappearance of a significantnumber of EEC formation in PV may be due to a population of erythroid-committed precursors that are abnormally sensitive to small concentrations of Ep which may be present in fetal calf serum and citrated plasma. Although the mechanism of formation of these cells is not known, it appears that the final steps in the formation of red cells derived from this clone of precursors is subject to the usual Ep control.
Publication
Journal: Journal of the American Society of Nephrology : JASN
December/3/1996
Abstract
The diverse intrarenal effects of the prostaglandins (PG) are mediated by distinct guanine nucleotide regulatory protein (G-protein)-coupled receptors. The cDNA for these receptors have been cloned, their signal transduction mechanisms determined, and their intrarenal distribution mapped. PGE2, the major intrarenal prostaglandin, interacts with at least three distinct E-prostanoid (EP) receptors that are highly expressed in specific regions of the kidney. Each EP receptor not only selectively binds PGE2, but also preferentially couples to different signal transduction pathways, including: stimulation of cAMP generation, via Gq (EPEPEPEPEP receptors is responsible for a distinct renal effect of PGE2, including its well-described renal hemodynamic and transport effects along the nephron. Other intrarenal prostanoid receptors include the PGF2 alpha receptor (FP), the thromboxane A2 receptor (TP) and the prostacyclin receptor (IP). Knowledge about localization of these receptors and their affinities for receptor-selective agonists and antagonists should aid in the understanding of renal disease and the development of therapeutic strategies for the use of these prostaglandin analogs in select renal diseases.
Publication
Journal: Molecular Therapy
November/22/2010
Abstract
DNA vaccines have undergone important enhancements in their design, formulation, and delivery process. Past literature supports that DNA vaccines are not as immunogenic in nonhuman primates as live vector systems. The most potent recombinant vector system for induction of cellular immune responses in macaques and humans is adenovirus serotype 5 (Ad5), an important benchmark for new vaccine development. Here, we performed a head-to-head evaluation of the Merck Ad5 SIV vaccine and an optimized electroporation (EP) delivered SIV DNA vaccine in macaques. Animals receiving the Ad5 vaccine were immunized three times, whereas the DNA-vaccinated animals were immunized up to four times based on optimized protocols. We observed significant differences in the quantity of IFNgamma responses by enzyme-linked immunosorbent spot (ELISpot), greater proliferative capacity of CD8(+) T cells, and increased polyfunctionality of both CD4(+) and CD8(+) T cells in the DNA-vaccinated group. Importantly, Ad5 immunizations failed to boost following the first immunization, whereas DNA responses were continually boosted with all four immunizations demonstrating a major advantage of these improved DNA vaccines. These optimized DNA vaccines induce very different immune phenotypes than traditional Ad5 vaccines, suggesting that they could play an important role in vaccine research and development.
Publication
Journal: Journal of the National Cancer Institute
May/13/2009
Abstract
BACKGROUND
Clusterin expression in various types of human cancers may be higher or lower than in normal tissue, and clusterin may promote or inhibit apoptosis, cell motility, and inflammation. We investigated the role of clusterin in tumor development in mouse models of neuroblastoma.
METHODS
We assessed expression of microRNAs in the miR-17-92 cluster by real-time reverse transcription-polymerase chain reaction in MYCN-transfected SH-SY5Y and SH-EP cells and inhibited expression by transfection with microRNA antisense oligonucleotides. Tumor development was studied in mice (n = 66) that were heterozygous or homozygous for the MYCN transgene and/or for the clusterin gene; these mice were from a cross between MYCN-transgenic mice, which develop neuroblastoma, and clusterin-knockout mice. Tumor growth and metastasis were studied in immunodeficient mice that were injected with human neuroblastoma cells that had enhanced (by clusterin transfection, four mice per group) or reduced (by clusterin short hairpin RNA [shRNA] transfection, eight mice per group) clusterin expression. All statistical tests were two-sided.
RESULTS
Clusterin expression increased when expression of MYCN-induced miR-17-92 microRNA cluster in SH-SY5Y neuroblastoma cells was inhibited by transfection with antisense oligonucleotides compared with scrambled oligonucleotides. Statistically significantly more neuroblastoma-bearing MYCN-transgenic mice were found in groups with zero or one clusterin allele than in those with two clusterin alleles (eg, 12 tumor-bearing mice in the zero-allele group vs three in the two-allele group, n = 22 mice per group; relative risk for neuroblastoma development = 4.85, 95% confidence interval [CI] = 1.69 to 14.00; P = .005). Five weeks after injection, fewer clusterin-overexpressing LA-N-5 human neuroblastoma cells than control cells were found in mouse liver or bone marrow, but statistically significantly more clusterin shRNA-transfected HTLA230 cells (3.27%, with decreased clusterin expression) than control-transfected cells (1.53%) were found in the bone marrow (difference = 1.74%, 95% CI = 0.24% to 3.24%, P = .026).
CONCLUSIONS
We report, to our knowledge, the first genetic evidence that clusterin is a tumor and metastasis suppressor gene.
Publication
Journal: Journal of Immunology
March/26/2007
Abstract
PGI(2) (prostacyclin) is a lipid mediator with vasodilatory and antithrombotic effects used in the treatment of vasoconstrictive/ischemic diseases including pulmonary artery hypertension. However, emerging research supports a role for PGs, including PGI(2), in the regulation of both innate and acquired immunity. As PGI(2) is unstable, we sought to define the effects of various PGI(2) analogs on resident alveolar macrophage (AM) and peritoneal macrophage (PM) innate immune functions. The effects of iloprost, carbaprostacyclin, and treprostinil on the regulation of phagocytosis, bacterial killing, and inflammatory mediator production were determined in both macrophage populations from rats. Iloprost failed to suppress AM functions to the same degree that it did in PMs, a characteristic shared by carbaprostacyclin. This difference reflected greater expression of the G(alphas) protein-coupled I prostanoid receptor and greater cAMP generation in PMs than AMs. Treprostinil inhibited phagocytosis, bacterial killing, and cytokine generation in AMs to a much greater degree than the other PGI(2) analogs and more closely resembled the effects of PGE(2). Studies with the E prostanoid (<em>EP</em>) 2 receptor antagonist AH-6809 and <em>EP</em>2-null macrophages indicated that this was due in part to the previously unknown ability of treprostinil to stimulate the <em>EP</em>2 receptor. The present investigation for the first time identifies differences in immunoregulatory properties of clinically administered PGI(2) analogs. These studies are the first to explore the capacity of PGI(2) to regulate bacterial killing and phagocytosis in macrophages, and our findings may hold important consequences regarding the risk of infection for patients receiving such agents.
Publication
Journal: Journal of Biological Chemistry
August/12/1986
Abstract
In inside-out red cell membrane vesicles active calcium transport and the formation of the enzyme-phosphate complex (EP) of the calcium pump were simultaneously investigated and the effects of a limited proteolytic digestion examined. In order to visualize the proteolyzed EP forms we have induced the formation of a maximum level EP from [gamma-32P]ATP in the presence of Ca2+ + La3+ and applied a good-resolution acidic discontinuous sodium dodecyl sulfate-polyacrylamide gel electrophoresis system. Proteolysis of inside-out vesicle membranes by trypsin, Pronase, papain, or chymotrypsin produces a calmodulin-like activation of the calcium pump, abolishes its calmodulin sensitivity, and decreases the original 140-kDa EP complex to a limit polypeptide of 80 kDa. Trypsin digestion produces another major intermediary fragment of 90 kDa, which is still a low-activity calmodulin-sensitive form of the pump. The red cell calcium pump is activated by trypsin both in the absence and presence of Ca2+ during digestion although the rate of activation and the appearance of the 80-kDa polypeptide are enhanced by Ca2+. If proteolytic digestion is carried out by chymotrypsin, a calmodulin-insensitive maximum activation of the calcium pump coincides with the formation of a 125-130-kDa EP-forming polypeptide. Chymotrypsin and carboxypeptidase A have synergistic effects on the formation of this latter high-activity species. Based on these data we suggest a probable molecular arrangement for the functional parts of the red cell membrane calcium pump.
Publication
Journal: Journal of Psychosomatic Research
December/21/2005
Abstract
OBJECTIVE
The primary objective was to conduct a detailed analysis of individual variation in psychological morbidity in the year following surgery for breast cancer. The salience of the patients' "illness perceptions" to morbidity was examined as a secondary objective.
METHODS
Psychological morbidity was assessed with the General Health Questionnaire (GHQ-28) in a prospective study of 371 women having surgery for primary breast cancer. Patients also completed the Illness Perception Questionnaire (IPQ), Mental Adjustment to Cancer Scale (MAC) and the Eysenck Personality Scales (EPS). Assessments were made postoperatively and at 3, 6 and 12 months after surgery.
RESULTS
Whilst descriptive statistics indicated a general reduction in mean distress over the 12-month follow-up, close analysis showed that a quarter of all patients maintained clinically significant levels of distress throughout the period. Patients with chronically elevated distress were characterised by higher levels of neuroticism, greater symptom awareness, more pain and poorer self-rated general health. In the regression analysis, psychological morbidity across the 1-year follow-up was predicted principally by the immediate postoperative state of distress, IPQ symptom awareness and the perceived time line of the illness, general health and, to a more minor extent, by neuroticism.
CONCLUSIONS
There is marked individual variation in psychological morbidity in the year following breast cancer surgery, which is reliably predicted by the patient's immediate postoperative state of distress, her perception of the impact of the symptoms and the time line of the disease. Subgroups of patients with chronically high distress are characterised by factors including personality and negative perceptions and beliefs about their illness.
Publication
Journal: Psychopharmacology
February/4/2007
Abstract
OBJECTIVE
To compare the long-term efficacy and safety of aripiprazole with olanzapine in patients with either acute relapsing or chronic, stable schizophrenia.
METHODS
A 52-week, open-label extension to a 26-week, multicenter, randomized, double-blind, placebo-controlled trial in patients with chronic schizophrenia. Patients who completed the initial treatment or who met the protocol definition of relapse after>> or =2 weeks of double-blind treatment were randomized to aripiprazole (15-30 mg/day, n = 104) or olanzapine (10-20 mg/day, n = 110) for 52 weeks.
RESULTS
Sixty-nine percent of patients completed the study. Efficacy improvements were similar between groups at endpoint, mean reductions in Positive and Negative Syndrome Scale (PANSS) Total scores from baseline for patients completing the study (observed cases) were similar in chronic stable patients (aripiprazole, -7.94; olanzapine, -7.36) and in patients with acute relapse (aripiprazole, -31.19; olanzapine, -29.55). Olanzapine-treated patients reported more extrapyramidal symptoms (EPS)-related adverse events (18%) than aripiprazole-treated patients (10%). No significant differences in EPS were seen between treatments at endpoint. Olanzapine was associated with significantly greater weight gain than aripiprazole at all time points (week 52 [LOCF]: +2.54 vs +0.04 kg; p < 0.001). Changes in fasting glucose and lipid levels at endpoint favored aripiprazole over olanzapine, with significant differences observed for total cholesterol, low- and high-density lipoprotein. While differences observed for changes in fasting glucose and triglycerides favored aripiprazole, they were not statistically significant.
CONCLUSIONS
Aripiprazole showed similar efficacy to olanzapine for long-term treatment of acutely psychotic and chronic, stable schizophrenia patients, with a lower liability for weight gain or increased lipid levels.
Publication
Journal: Clinical Cancer Research
November/26/2006
Abstract
This phase I safety study aimed to identify the optimal dose of the vascular disrupting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) for combination studies. Using a crossover design, 15 patients with refractory tumors were allocated randomly to receive six sequential doses of DMXAA (300, 600, 1,200, 1,800, 2,400, and 3,000 mg m(-2)), each given once-weekly as a 20-minute i.v. infusion. The drug was generally well tolerated. Transient, moderate increases in the heart rate-corrected cardiac QT interval occurred at the two highest doses. DMXAA produced transient dose-dependent increases in blood pressure. Transient, dose-related visual disturbances occurred at the two highest doses. No significant changes in K(trans) and k(ep) were observed but V(e), a secondary dynamic contrast-enhanced magnetic resonance imaging variable, increased significantly after giving DMXAA. At 1,200 mg m(-2), the Cmax and the area under the concentration-time curve over 24 hours for total and free DMXAA plasma concentrations were 315 +/- 25.8 microg/mL, 29 +/- 6.4 microg/mL x d, 8.0 +/- 1.77 microg/mL, and 0.43 +/- 0.07 microg/mL x d, respectively. Plasma levels of the vascular damage biomarker 5-hydroxyindoleacetic acid increased in the 4 hours after treatment in a dose-dependent fashion up to 1,200 mg m(-2), with a plateau thereafter. Doses in the range of 1,200 mg m(-2) have been selected for further studies (phase II combination studies with taxanes and platins are under way) because this dose produced no significant effect on heart rate-corrected cardiac QT interval, produced near maximum levels of 5-hydroxyindoleacetic acid, achieved DMXAA plasma concentrations within the preclinical therapeutic range, and was well tolerated.
Publication
Journal: Glycobiology
June/22/2010
Abstract
Innate immunity is the first line of defense against invading microorganisms in vertebrates and the only line of defense in invertebrates and plants. Bacterial glyco-conjugates, such as lipopolysaccharides (LPS) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN) from the cell walls of both Gram-positive and Gram-negative bacteria, and fungal and oomycete glycoconjugates such as oligosaccharides derived from the cell wall components beta-glucan, chitin and chitosan, have been found to act as elicitors of plant innate immunity. These conserved indispensable microbe-specific molecules are also referred to as microbe-associated molecular patterns (MAMPs). Other glyco-conjugates such as bacterial extracellular polysaccharides (EPS) and cyclic glucan have been shown to suppress innate immune responses, thus conversely promoting pathogenesis. MAMPs are recognized by the plant innate immune system though the action of pattern recognition receptors (PRRs). A greater insight into the mechanisms of MAMP recognition and the description of PRRs for different microbial glyco-conjugates will have considerable impact on the improvement of plant health and disease resistance. Here we review the current knowledge about the bacterial MAMPs LPS and PGN, the fungal MAMPs beta-glucan, chitin and chitosan oligosaccharides and the bacterial suppressors EPS and cyclic glucan, with particular reference to the chemical structures of these molecules, the PRRs involved in their recognition (where these have been defined), and possible mechanisms underlying suppression.
Publication
Journal: Journal of Virology
February/12/2009
Abstract
Previously, we reported that three double-stranded RNA (dsRNA) segments, designated L-, M-, and S-dsRNAs, were detected in Sclerotinia sclerotiorum strain Ep-1PN. Of these, the M-dsRNA segment was derived from the genomic RNA of a potexvirus-like positive-strand RNA virus, Sclerotinia sclerotiorum debilitation-associated RNA virus. Here, we present the complete nucleotide sequence of the L-dsRNA, which is 6,043 nucleotides in length, excluding the poly(A) tail. Sequence analysis revealed the presence of a single open reading frame (nucleotide positions 42 to 5936) that encodes a protein with significant similarity to the replicases of the "alphavirus-like" supergroup of positive-strand RNA viruses. A sequence comparison of the L-dsRNA-encoded putative replicase protein containing conserved methyltransferase, helicase, and RNA-dependent RNA polymerase motifs showed that it has significant sequence similarity to the replicase of Hepatitis E virus, a virus infecting humans. Furthermore, we present convincing evidence that the virus-like L-dsRNA could replicate independently with only a slight impact on growth and virulence of its host. Our results suggest that the L-dsRNA from strain Ep-1PN is derived from the genomic RNA of a positive-strand RNA virus, which we named Sclerotinia sclerotiorum RNA virus L (SsRV-L). As far as we know, this is the first report of a positive-strand RNA mycovirus that is related to a human virus. Phylogenetic and sequence analyses of the conserved motifs of the RNA replicase of SsRV-L showed that it clustered with the rubi-like viruses and that it is related to the plant clostero-, beny- and tobamoviruses and to the insect omegatetraviruses. Considering the fact that these related alphavirus-like positive-strand RNA viruses infect a wide variety of organisms, these findings suggest that the ancestral positive-strand RNA viruses might be of ancient origin and/or they might have radiated horizontally among vertebrates, insects, plants, and fungi.
Publication
Journal: Radiology
June/1/2011
Abstract
OBJECTIVE
To image thrombus by using magnetic resonance (MR) imaging and positron emission tomography (PET) simultaneously in a rat arterial thrombus model with a dual PET/MR probe.
METHODS
Animal studies were approved by the institutional animal use committee. A dual PET/MR probe was synthesized by means of partial exchange of gadolinium for copper 64 ((64)Cu) in the fibrin-targeted MR probe EP-2104R. A preformed 25-mm thrombus was injected into the right internal carotid artery of a rat. Imaging was performed with a clinical 3.0-T MR imager with an MR-compatible human PET imager. Rats (n = 5) were imaged prior to and after systemic administration of the dual probe by using simultaneous PET/MR. The organ distribution of (64)Cu and gadolinium was determined ex vivo (n = 8), 2 hours after injection by using well counting and inductively coupled plasma mass spectrometry, respectively. Signal intensity ratios (SIRs) between the thrombus-containing and contralateral vessel were computed from PET images and MR data before and after probe administration.
RESULTS
The dual probe was synthesized with greater than 98% radiochemical purity. Thrombus enhancement was observed in all five animals at both MR (SIR([postprobe])/SIR([preprobe]) = 1.71 ± 0.35, P = .0053) and PET (SIR = 1.85 ± 0.48, P = .0087) after injection of the dual PET/MR probe. Ex vivo analysis at 2 hours after injection showed the highest (64)Cu and gadolinium concentrations, after the excretory organs (kidney and liver), to be in the thrombus.
CONCLUSIONS
A fibrin-targeted dual PET/MR probe enables simultaneous, direct MR and PET imaging of thrombus.
Publication
Journal: Annals of Clinical Psychiatry
January/3/2011
Abstract
BACKGROUND
Antidepressant-induced extrapyramidal symptoms (EPS) represent an underrecognized but important clinical entity. We reviewed the literature on new antidepressants and conducted an analysis of cases from the FDA Adverse Event Reporting System (AERS), which has not been published before.
METHODS
A literature review was conducted using PubMed, Ovid, MEDLINE, PsycINFO, and the Cochrane Database. Search terms used were extrapyramidal, antidepressants, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), norepinephrine-dopamine reuptake inhibitors (NDRIs), miscellaneous antidepressants, and monoamine oxidase inhibitors (MAOIs). Inclusion criteria for the FDA AERS analysis were cases of EPS reported by physicians, cases where patients were on one antidepressant, and cases reported between July 2005 and March 2008. Reports of patients who were on concurrent psychotropics were excluded.
RESULTS
Our literature review revealed 1 report each of EPS for duloxetine, nefazodone, and bupropion, 3 for escitalopram, and 4 for citalopram. For the FDA AERS analysis, 89 cases met our inclusion criteria: duloxetine was implicated in 66% of cases, sertraline in 10%, escitalopram in 7%, and bupropion in 6%.
CONCLUSIONS
EPS have been reported with different classes of antidepressants, are not dose related, and can develop with short-term or long-term use. In view of the risk for significant morbidity and decreased quality of life, clinicians must be aware of the potential for any class of antidepressants to cause these adverse effects.
Publication
Journal: American Journal of Roentgenology
January/6/2010
Abstract
OBJECTIVE
The purpose of this study was to compare apparent diffusion coefficients, metabolic ratios, and vascularity values within histologically defined prostate tumors with those in nontumor tissue to determine which functional parameter or combination of parameters is best for differentiating tumor from nontumor tissue.
METHODS
Twenty patients due for prostatectomy underwent endorectal MRI at 1.5 T. Transverse T2-weighted, diffusion-weighted, 2D chemical shift, and dynamic contrast-enhanced images were acquired. After prostatectomy, the gland was sectioned transversely. Fresh slices and stained whole-mount sections with histologically defined tumor outlines were photographed. The tumor outlines were mapped onto images, and the apparent diffusion coefficient (ADC), choline-to-citrate (Cho/cit) ratio, and vascularity of the histologically defined tumor, normal peripheral zone, and central gland were quantitatively measured. Area under the receiver operating characteristics (ROC) curve (A(z)) was used to determine the sensitivity and specificity of parameter combinations in cancer detection.
RESULTS
In tumor regions larger than 1 cm(2), the Cho/cit ratio was higher in tumor than in nontumor tissue (p < 0.001), in the peripheral zone alone (p = 0.007), and in the central gland alone (p = 0.005). ADC was lower and tumor vascularity greater in tumor than in nontumor tissue (ADC, p = 0.003; initial area under the gadolinium plasma concentration-time curve [initial gadolinium AUC], p = 0.012; forward rate constant [K(trans)], p = 0.011; return rate constant [k(ep)], p = 0.036). No single parameter had a significantly greater A(z) (ADC, 0.71; Cho/cit ratio, 0.79; initial gadolinium AUC, 0.60; K(trans), 0.62; k(ep), 0.65). Pairs of parameters, however, did increase A(z): ADC and initial gadolinium AUC (A(z) = 0.94) versus ADC (p = 0.001) and initial gadolinium AUC (p < 0.001); ADC and Cho/cit ratio (A(z) = 0.94) versus ADC (p = 0.001) and Cho/cit ratio (not significant); and Cho/cit ratio and initial gadolinium AUC (A(z) = 0.88) versus Cho/cit ratio (not significant) and initial gadolinium AUC (p < 0.001). All three functional techniques together had an A(z) of 0.95, showing no further improvement.
CONCLUSIONS
The combination of two functional parameters is associated with significant improvement in prostate cancer detection over use of any parameter alone. Use of a third parameter does not increase the rate of detection.
Publication
Journal: European Journal of Radiology
March/18/2012
Abstract
OBJECTIVE
The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on contrast-enhanced MR imaging (CE-MRI) obtained with Gd-EOB-DTPA.
METHODS
A total of 99 patients with cirrhotic liver (n=58; Child-Pugh class A, n=30; B, n=22; C, n=6) and normal liver (n=41) underwent Gd-EOB-DTPA-enhanced MR imaging. CE images were obtained before contrast injection, in the arterial phase (AP) at 25s or modified scan delay, in the portal phase (PP) at 70s, in the equilibrium phase (EP) at 3 min, and in the hepatobiliary phase (HP) at 3 times (10, 15 and 20 min). Signal intensity of the liver in all phases was defined using region-of-interest measurements for relative enhancement (RE) calculation.
RESULTS
In normal-liver and Child-Pugh class A and B patients, mean RE of liver parenchyma increased significantly (P<0.03-0.001) with time until 20-min HP. Conversely, mean RE for Child-Pugh class C patients did not show any increasing tendency after PP. Mean RE of liver parenchyma at EP and HP (10-, 15- and 20-min) was highest in normal liver, followed by Child-Pugh class A, B and C cirrhosis (P<0.02-0.001).
CONCLUSIONS
Hepatic parenchymal enhancement on CE-MR images obtained using Gd-EOB-DTPA is affected by the severity of cirrhosis.
Publication
Journal: Journal of Magnetic Resonance Imaging
November/22/2004
Abstract
OBJECTIVE
To differentiate prostate carcinoma from healthy peripheral zone and central gland using quantitative dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and two-dimensional (1)H MR spectroscopic imaging (MRSI) combined into one clinical protocol.
METHODS
Twenty-three prostate cancer patients were studied with a combined DCE-MRI and MRSI protocol. Cancer regions were localized by histopathology of whole mount sections after radical prostatectomy. Pharmacokinetic modeling parameters, K(trans) and k(ep), as well as the relative levels of the prostate metabolites citrate, choline, and creatine, were determined in cancer, healthy peripheral zone (PZ), and in central gland (CG).
RESULTS
K(trans) and k(ep) were higher (P < 0.05) in cancer and in CG than in normal PZ. The (choline + creatine)/citrate ratio was elevated in cancer compared to the PZ and CG (P < 0.05). While a (choline + creatine)/citrate ratio above 0.68 was found to be a reliable indicator of cancer, elevated K(trans) was only a reliable cancer indicator in the diagnosis of individual patients. K(trans) and (choline + creatine)/citrate ratios in cancer were poorly correlated (Pearson r(2) = 0.07), and thus microvascular and metabolic abnormalities may have complementary value in cancer diagnosis.
CONCLUSIONS
The combination of high-resolution spatio-vascular information from dynamic MRI and metabolic information from MRSI has excellent potential for improved localization and characterization of prostate cancer in a clinical setting. J. Magn. Reson. Imaging 2004;20:279-287.
Publication
Journal: Academic Emergency Medicine
July/7/2010
Abstract
OBJECTIVE
Patient management in emergency departments (EDs) is often based on management protocols developed for specific complaints like dyspnea, chest pain, or syncope. To the best of our knowledge, to date no protocols exist for patients with nonspecific complaints (NSCs) such as "weakness,""dizziness," or "feeling unwell." The objectives of this study were to provide a framework for research and a description of patients with NSCs presenting to EDs.
METHODS
Nonspecific complaints were defined as the entity of complaints not part of the set of specific complaints for which evidence-based management protocols for emergency physicians (EPs) exist. "Serious conditions" were defined as potentially life-threatening or those requiring early intervention to prevent health status deterioration. During a 6-month period, all adult nontrauma patients with an Emergency Severity Index (ESI) of 2 or 3 were prospectively enrolled, and serious conditions were identified within a 30-day period.
RESULTS
The authors screened 18,261 patients for inclusion. A total of 218 of 1,611 (13.5%) nontrauma ESI 2 and 3 patients presented with NSCs. Median age was 82 years (interquartile range [IQR]=72 to 87), and 24 of 218 (11%) were nursing home inhabitants. A median of 4 (IQR=3 to 5) comorbidities were recorded, most often chronic hypertension, coronary artery disease, and dementia. During the 30-day follow-up period a serious condition was diagnosed in 128 of 218 patients (59%). The 30-day mortality rate was 6%.
CONCLUSIONS
Patients with NSC presenting to the ED are at high risk of suffering from serious conditions. Sensitive risk stratification tools are needed to identify patients with potentially adverse health outcomes.
Publication
Journal: Journal of Microbiological Methods
August/22/2001
Abstract
The mechanical stability of biofilms is important for biotechnology, as sloughing of the biomass due to mechanical failure of the biofilm matrix can lead to severe interferences with biofilm processes. In cases of biofouling, biofilms have to be removed, in which case their mechanical stability must be overcome. The apparent modulus of elasticity and the yield strength as obtained from uniaxial compression experiments can be taken as parameters indicative for the mechanical stability of a biofilm. A film rheometer is presented which allows for the determination of these quantities, using model biofilms of Pseudomonas aeruginosa grown on membrane filters. The compressive stress-strain behaviour up to the point of failure is recorded at a compression speed of 1 microm s(-1). In accordance with the stress-strain curve, the investigated biofilm can be described as viscoelastic material, which demonstrates plastic flow properties. The extracellular polymeric substances (EPS), which keep biofilms together, form a temporary network of fluctuating junction points. Above the yield point, the gel structure fails and the system behaves as a highly viscous fluid. The apparent modulus of elasticity and the yield point are considered to be useful parameters for characterizing the mechanical properties of biofilms.
load more...