Search tips
Search criteria

Results 1-25 (65)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  Accessible knowledge for tomorrow's surgeons and doctors 
PMCID: PMC4078641  PMID: 25002796
2.  Prostate specific antigen testing is associated with men’s psychological and physical health and their healthcare utilisation in a nationally representative sample: a cross-sectional study 
BMC Family Practice  2014;15:121.
Prostate cancer incidence has risen considerably in recent years, primarily due to Prostate Specific Antigen (PSA) testing in primary care. The objective of this study was to investigate associations between PSA testing and the psychological and physical health, and healthcare utilisation of men in a population where PSA testing is widespread.
A cross-sectional study was carried out in a population-representative sample of men ≥50 years enrolled in The Irish Longitudinal Study on Ageing (TILDA). TILDA participants underwent structured interviews, health assessments and completed standardised questionnaires. Men were classified as ever/never having received a PSA test. Multivariate logistic regression (Odds Ratios (OR) and 95% Confidence Intervals (CI) was used to determine associations between PSA testing, and men’s psychological and physical health and healthcare utilisation.
This analysis included 3,628 men, 68.2% of whom ever had a PSA test. In adjusted analysis, men with sub-threshold depression were significantly less likely to have had a PSA test, (OR = 0.79, 95% CI 0.64-0.97). Likelihood of having a PSA test was inversely associated with anxiety, but this was not significant (OR = 0.79, 95% CI 0.57-1.09). Frailty (OR = 0.61, 95% CI 0.31-1.05) and eligibility for free primary care (OR = 0.63, 95% CI 0.52-0.77) were also inversely associated with PSA testing. Positive associations were observed between PSA testing and more chronic illnesses (OR = 1.11, 95% CI 1.05-1.19), more primary care visits (OR = 1.03, 95% CI 1.01-1.05) and preventative health practices, including cholesterol testing and influenza vaccination (OR = 1.35, 95% CI 1.13-1.60).
Men’s psychological and physical health and their healthcare utilisation are associated with PSA testing in primary care. The association between poorer psychological health, in particular sub-threshold depression, and reduced likelihood of PSA testing in primary care requires further investigation. These findings may have wider implications for other cancer screening.
PMCID: PMC4065544  PMID: 24938184
4.  Micropatterning of 3D Microenvironments for Living Biosensor Applications 
Biosensors  2014;4(1):28-44.
Micro-scale printing and patterning of living cells has multiple applications including tissue engineering, cell signaling assays, and the fabrication of cell-based biosensors. In this work, a molecular printing instrument, the Bioforce Nano eNabler, was modified to enable micron-scale —quill-pen based printing of mammalian cells in a 3D hyaluronan/gelatin based hydrogel. Specifically, photo-initiated —thiol-ene click chemistry was used to couple the thiol groups of thiolated hyaluronan/thiolated gelatin to the alkene groups of 4-arm polyethylene glycol (PEG)-norbornene molecules. Rapid photopolymerization enabled direct printing and controlled curing of living cells within the hydrogel matrix. The resulting hydrogels were biocompatible with human adipose-derived stem cells, NIH-3T3 cells, and mouse embryonic stem cells. The utility of this printing approach was also explored for cell-based biosensors. Micro-printed cells expressing a redox sensitive variant of the green fluorescent protein (roGFP-R12) showed a measurable fluorescent response to addition of oxidizing and then reducing agents. This work represents a novel approach to micron-scale cell patterning, and its potential for living, cell-based biosensors.
PMCID: PMC4004032  PMID: 24791214
microprinting; biosensor; hydrogel; reactive oxygen species; roGFP-R12; ROS; hyaluronan; hyaluronic acid; gelatin; PEG norbornene; Irgacure
5.  Autonomic Dysfunction in Women with Chronic Pelvic Pain 
We compared the Autonomic Symptom Profile results in 16 women with chronic pelvic pain (CPP) and 15 age-matched healthy subjects. Moderately severe generalized autonomic symptomology occurs in women with CPP, but not in controls. Further study including autonomic testing is needed to confirm results and explore the mechanism of dysfunction.
PMCID: PMC3600066  PMID: 23229018
6.  Recent progress and clinical importance on pharmacogenetics in cancer therapy 
Recent advances have provided unprecedented opportunities to identify prognostic and predictive markers of efficacy of cancer therapy. Genetic markers can be used to exclude patients who will not benefit from therapy, exclude patients at high risk of severe toxicity, and adjust dosing.
Genomic approaches for marker discovery now include genome-wide association studies and tumor DNA sequencing. The challenge is now to select markers for which there is enough evidence to transition them to the clinic.
The hurdles include the inherent low frequency of many of these markers, the lengthy validation process through trials, as well as legislative and economic hurdles. Attempts to answer questions about certain markers more quickly have led to an increased popularity of trials with enrichment design, especially in the light of the dramatic phase I results seen in recent months.
Personalized medicine in oncology is a step closer to reality.
PMCID: PMC3858908  PMID: 21950596
biomarkers; cancer therapy; pharmacogenetics
7.  The translational imperative: Making cell therapy simple and effective ☆ 
Acta biomaterialia  2012;8(12):4200-4207.
The current practice of cell therapy, in which multipotent or terminally differentiated cells are injected into tissues or intravenously, is inefficient. Few therapeutic cells are retained at the site of administration and engraftment is low. An injectable and biologically appropriate vehicle for delivery, retention, growth and differentiation of therapeutic cells is needed to improve the efficacy of cell therapy. We focus on a hyaluronan-based semi-synthetic extracellular matrix (sECM), HyStem®, which is a manufacturable, approvable and affordable clinical product. The composition of this sECM can be customized for use with mesenchymal stem cells as well as cells derived from embryonic or induced pluripotent sources. In addition, it can support therapeutic uses of progenitor and mature cell populations obtained from skin, fat, liver, heart, muscle, bone, cartilage, nerves and other tissues. This overview presents four pre-clinical uses of HyStem® for cell therapy to repair injured vocal folds, improve post-myocardial infarct heart function, regenerate damaged liver tissue and restore brain function following ischemic stroke. Finally, we address the real-world limitations – manufacture, regulation, market acceptance and financing – surrounding cell therapy and the development of clinical combination products.
PMCID: PMC3488131  PMID: 22776825
HyStem®; Cell therapy; ECM; Hyaluronic acid; Cell engraftment
8.  Peroxisome proliferator-activated receptor gamma B cell-specific deficient mice have an impaired antibody response1 
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily. PPARγ, a ligand activated transcription factor, has important anti-inflammatory and anti-proliferative functions and it has been associated with diseases including diabetes, scarring and atherosclerosis among others. PPARγ is expressed in most bone marrow derived cells and influences their function. PPARγ ligands can stimulate human B cell differentiation and promote antibody production. A knowledge gap is that the role of PPARγ in B cells under physiological conditions is not known. We developed a new B cell-specific PPARγ (B-PPARγ) knockout mouse and explored the role of PPARγ during both the primary and secondary immune response. Here, we show that PPARγ deficiency in B cells decreases germinal center B cells and plasma cell development as well as the levels of circulating antigen-specific antibodies during a primary challenge. Inability to generate germinal center B cells and plasma cells is correlated to decreased MHC class II expression and decreased Bcl-6 and Blimp-1 levels. Furthermore, B-PPARγ-deficient mice have an impaired memory response, characterized by low titers of antigen-specific antibodies and low numbers of antigen-experienced antibody-secreting cells. However, B-PPARγ-deficient mice have no differences in B cell population distribution within neither primary nor secondary lymphoid organs during development. This is the first report to show under physiological conditions that PPARγ expression in B cells is required for an efficient B cell-mediated immune response as it regulates B cell differentiation and antibody production.
PMCID: PMC3490033  PMID: 23041568
9.  In vivo stimulus-induced vasodilation occurs without IP3 receptor activation and may precede astrocytic calcium increase 
Calcium-dependent release of vasoactive gliotransmitters is widely assumed to trigger vasodilation associated with rapid increases in neuronal activity. Inconsistent with this hypothesis, intact stimulus-induced vasodilation was observed in inositol 1,4,5-triphosphate (IP3) type-2 receptor (R2) knockout (KO) mice, in which the primary mechanism of astrocytic calcium increase – the release of calcium from intracellular stores following activation of an IP3-dependent pathway – is lacking. Further, our results in wild type (WT) mice indicate that in vivo onset of astrocytic calcium increase in response to sensory stimulus could be considerably delayed relative to the simultaneously measured onset of arteriolar dilation. Delayed calcium increases in WT mice were observed in both astrocytic cell bodies and perivascular endfeet. Thus, astrocytes may not play a role in the initiation of blood flow response, at least not via calcium-dependent mechanisms. Moreover, an increase in astrocytic intracellular calcium was not required for normal vasodilation in the IP3R2-KO animals.
PMCID: PMC3712855  PMID: 23658179
astrocyte; two-photon microscopy; blood flow; somatosensory cortex; neurovascular coupling
10.  Analyzing LC-MS/MS data by spectral count and ion abundance: two case studies 
Statistics and its interface  2012;5(1):75-87.
In comparative proteomics studies, LC-MS/MS data is generally quantified using one or both of two measures: the spectral count, derived from the identification of MS/MS spectra, or some measure of ion abundance derived from the LC-MS data. Here we contrast the performance of these measures and show that ion abundance is the more sensitive. We also examine how the conclusions of a comparative analysis are influenced by the manner in which the LC-MS/MS data is ‘rolled up’ to the protein level, and show that divergent conclusions obtained using different rollups can be informative. Our analysis is based on two publicly available reference data sets, BIATECH-54 and CPTAC, which were developed for the purpose of assessing methods used in label-free differential proteomic studies. We find that the use of the ion abundance measure reveals properties of both data sets not readily apparent using the spectral count.
PMCID: PMC3806317  PMID: 24163717
mass spectrometry; comparative proteomics; ion abundance; spectral count; ion competition
12.  Proton pump inhibitors and hypomagnesemia monitoring 
PMCID: PMC3754484  PMID: 23986645
13.  Characterization of the Pichia pastoris Protein-O-mannosyltransferase Gene Family 
PLoS ONE  2013;8(7):e68325.
The methylotrophic yeast, Pichiapastoris, is an important organism used for the production of therapeutic proteins. However, the presence of fungal-like glycans, either N-linked or O-linked, can elicit an immune response or enable the expressed protein to bind to mannose receptors, thus reducing their efficacy. Previously we have reported the elimination of β-linked glycans in this organism. In the current report we have focused on reducing the O-linked mannose content of proteins produced in P. pastoris, thereby reducing the potential to bind to mannose receptors. The initial step in the synthesis of O-linked glycans in P. pastoris is the transfer of mannose from dolichol-phosphomannose to a target protein in the yeast secretory pathway by members of the protein-O-mannosyltransferase (PMT) family. In this report we identify and characterize the members of the P. pastoris PMT family. Like Candida albicans, P. pastoris has five PMT genes. Based on sequence homology, these PMTs can be grouped into three sub-families, with both PMT1 and PMT2 sub-families possessing two members each (PMT1 and PMT5, and PMT2 and PMT6, respectively). The remaining sub-family, PMT4, has only one member (PMT4). Through gene knockouts we show that PMT1 and PMT2 each play a significant role in O-glycosylation. Both, by gene knockouts and the use of Pmt inhibitors we were able to significantly reduce not only the degree of O-mannosylation, but also the chain-length of these glycans. Taken together, this reduction of O-glycosylation represents an important step forward in developing the P. pastoris platform as a suitable system for the production of therapeutic glycoproteins.
PMCID: PMC3698189  PMID: 23840891
14.  BAK additive influence on results 
PMCID: PMC3678897  PMID: 23766632
16.  Prescribing tests must have curriculum support 
PMCID: PMC3726647  PMID: 23901306
18.  Relationship between interblink interval and dopamine 
PMCID: PMC3673966  PMID: 23761959
19.  Research skills for undergraduates: a must! 
PMCID: PMC3722370  PMID: 23670691
20.  Research skills for undergraduates: a must! 
PMCID: PMC3722370  PMID: 23670691
21.  Variability in the Perception of Informed Consent for IV-tPA during Telestroke Consultation 
Objective: To study the perception of informed consent among various raters for thrombolysis in acute ischemic stroke patients receiving intravenous tissue plasminogen activator (IV-tPA). Methods: Twenty randomly selected videotaped telestroke consultations of acute stroke patients administered IV-tPA were retrospectively reviewed. Adequacy of informed consent was reviewed by five raters: a neurologist and emergency physician who routinely treat stroke, a medical risk management paralegal, a bioethicist, and a lay person. Raters assessed the quality of the informed consent presentation by the treating physician and the degree of understanding demonstrated by the patient/family authorizing consent. Factors associated with adequacy of consent were analyzed. Results: Consent was rated as adequately understood by the patient-family in 78.6% cases. Agreement between all five raters with regard to the patient-family understanding of consent was poor and also between the subgroups of non-physician and physician (all k < 0.20). Similarly, the quality of the physician consent process was poor for agreement between all five raters (k = 0.07) or between the subgroup of the three non-physician raters (k = −0.06) and fair between the two physician raters (k = 0.24). The legal reviewer and the bioethicist rated the physician consent process as being of lower quality than did the two physicians and the layperson. Conclusion: Despite high variability in the perception of informed consent among raters in this time-sensitive clinical situation, almost 80% of patients were rated by all reviewers as having adequate understanding of risks and benefits of tPA. This suggests the need for a standardized but brief tPA consent process that includes patient/family demonstration of understanding.
PMCID: PMC3449489  PMID: 23015805
informed consent; IV-tPA; stroke; telestroke; ischemic stroke patients
22.  Beta-adrenergic blocking drugs in breast cancer: a perspective review 
The purpose of this review is to present the preclinical, epidemiological and clinical data relevant to the association between β-blockers and breast cancer progression. Preclinical studies have shown that β-adrenergic receptor (β-AR) signalling can inhibit multiple cellular processes involved in breast cancer progression and metastasis, including extracellular matrix invasion, expression of inflammatory and chemotactic cytokines, angiogenesis and tumour immune responses. This has led to the hypothesis that the commonly prescribed class of β-AR antagonist drugs (β-blockers) may favourably impact cancer progression. A number of recent pharmacoepidemiological studies have examined the association between β-blocker exposure and breast cancer progression. The results from these studies have suggested a potential role for targeting the β-AR pathway in breast cancer patients. Larger observational studies are, however, required to confirm these results. Questions regarding the type of β-blocker, predictive biomarkers or tumour characteristics, appropriate treatment paradigms and, most importantly, efficacy must also be answered in randomized clinical studies before β-blockers can be considered a therapeutic option for patients with breast cancer.
PMCID: PMC3349076  PMID: 22590485
adrenergic beta-agonists; adrenergic beta-antagonists; adrenergic receptors; breast neoplasms; neoplasms; propranolol
23.  Disorder targets misorder in nuclear quality control degradation: a disordered ubiquitin ligase directly recognizes its misfolded substrates 
Molecular cell  2011;41(1):93-106.
Protein quality control (PQC) degradation systems protect the cell from the toxic accumulation of misfolded proteins. Because any protein can become misfolded, these systems must be able to distinguish abnormal proteins from normal ones, yet be capable of recognizing the wide variety of distinctly shaped misfolded proteins they are likely to encounter. How individual PQC degradation systems accomplish this remains an open question. Here we show that the yeast nuclear PQC ubiquitin ligase San1 directly recognizes its misfolded substrates via intrinsically disordered N- and C-terminal domains. These disordered domains are punctuated with small segments of order and high sequence conservation that serve as substrate-recognition sites San1 uses to target its different substrates. We propose that these substrate-recognition sites, interspersed among flexible, disordered regions, provide San1 an inherent plasticity that allows it to bind its many, differently shaped misfolded substrates.
PMCID: PMC3042722  PMID: 21211726
24.  A putative role for platelet-derived PPARγ in vascular homeostasis demonstrated by anti-PPARγ induction of bleeding, thrombocytopenia and compensatory megakaryocytopoiesis 
Journal of biotechnology  2010;150(3):417-427.
Widely known for its role in adipogenesis and energy metabolism, PPARγ also plays a role in platelet function. To further understand functions of platelet-derived PPARγ, we produced rabbit polyclonal (PoAbs) and mouse monoclonal (MoAbs) antibodies against PPARγ 14mer/19mer peptide-immunogens. Unexpectedly, our work produced two key findings. First, MoAbs but not PoAbs produced against PPARγ peptide-immunogens displayed antigenic crossreactivity with highly conserved PPARα and PPARβ/δ. Similarly, Santa Cruz PoAb sc-7196 was monospecific for PPARγ while MoAb sc-7273 crossreacted with PPARα and PPARβ/δ. Second, immunized rabbits and mice exhibited unusual pathology including cachexia, excessive bleeding, and low platelet counts leading to thrombocytopenia. Spleens from immunized mice were fatty, hemorrhagic and friable. Although passive administration of anti-PPARγ PoAbs failed to induce experimental thrombocytopenia, megakaryocytopoiesis was induced 4–8–fold in mouse spleens. Similarly, marrow megakaryocytopoiesis was enhanced 1.8–4–fold in immunized rabbits. These peptide-immunogens are 100% conserved in human, rabbit and mouse; thus, immune-mediated platelet destruction via crossreactivity with platelet-derived PPARγ likely caused bleeding, thrombocytopenia, and compensatory megakaryocytopoiesis. Such overt pathology would cause significant problems for large-scale production of anti-PPARγ PoAbs. Furthermore, a major pitfall associated with MoAb production against closely related molecules is that monoclonicity does not guarantee monospecificity, an issue worth further scientific scrutiny.
PMCID: PMC2990772  PMID: 20888877
Monoclonal Antibody Production; MAP Technology; Thrombocytopenia; Megakaryocytopoiesis; Peroxisome Proliferator-Activated Receptors; Platelets

Results 1-25 (65)