Translational Research - Articles in Press

Dopamine receptor D1 mediates the inhibition of dopamine on the distal colonic motility - Uncorrected Proof

2012-01-27

The motility of distal colon could be inhibited by dopamine (DA), yet, the involved receptor is controversial according to the published reports. The goal of present study was to investigate DA receptor(s) mediated inhibition of DA on the colonic motility in rat. The contraction of isolated colon strips was assessed through isometric force transducer. The expressions of DA receptors in distal colon were detected through immunofluorescence and Western blot. DA concentration in colonic smooth muscle was measured by liquid chromatography/mass spectrometry. The results showed that DA inhibited the spontaneous motility of distal colon in a dose-dependent manner with EC50 8.3 μM. Tetrodotoxin increased colonic contractive frequency, but failed to affect the inhibition of DA on the colonic motility. Pretreatment with SCH-23390, an antagonist of dopaminergic receptor D1, shifted the dose-response curve to the right with EC50 of DA 37 μM. However, blocking dopaminergic receptor D2 with sulpiride, had no effect. The immunoreactivity of D1 and D2 were detected in the distal colon including myenteric plexus and smooth muscle. Acute cold-restraint stress (CRS) enhanced spontaneous contraction of rat distal colon, which was more sensitive to DA compared with control. Moreover, DA content and D1 expression in smooth muscle layer were increased under CRS condition. In conclusion, D1 in the smooth muscle is mediated DA inhibition on the spontaneous contraction of rat distal colon. The increased DA content and D1 receptor expression in the smooth muscle layer could be a compensatory effect under CRS condition to balance the enhanced colonic motility.

Developing and assessing cardiovascular biomarkers - Uncorrected Proof

Razvan T. Dadu, Vijay Nambi, Christie M. Ballantyne — 2012-01-27

Atherosclerosis is a slow process that over time can lead to fatal events. Early identification and prediction of future risk can allow for preventive strategies to be instituted. There is an increasing interest in utilizing novel biomarkers in cardiovascular disease screening and management. These novel biomarkers may help in cardiovascular disease risk assessment and treatment monitoring, and some may be treatment targets. To be useful for risk prediction, novel biomarkers need to show a significant association with cardiovascular disease events and bring additional value in risk stratification when added to known risk prediction models. Biomarkers used for treatment monitoring need to show that they can serve as good surrogates of cardiovascular disease status. In this article, we present 3 biomarkers that are currently approved by the U.S. Food and Drug Administration for use in cardiovascular disease management and risk assessment: C-reactive protein, lipoprotein-associated phospholipase A2, and myeloperoxidase. Other new biomarkers have also been shown recently to help in cardiovascular disease risk prediction and management. In this article, we will review 2 of these new biomarkers: cardiac troponin T measured by a highly sensitive assay and brain natriuretic peptide.

Genetic and immune predictors for hypersensitivity syndrome to antiepileptic drugs - Uncorrected Proof

Manuela G. Neuman, Lawrence Cohen, Radu M. Nanau, Paul A. Hwang — 2012-01-27

Hypersensitivity syndrome reactions (HSR) to antiepileptic drugs (AED) are associated with severe clinical cutaneous adverse reactions (SCAR). We aimed (1) to assess HSRs to AEDs using the in vitro lymphocyte toxicity assay (LTA) in patients who manifested HSRs clinically; (2) to correlate LTA results with the clinical syndrome; (3) to correlate LTA results with the human leukocyte antigen (HLA) allele B∗1502 (HLA-B∗1502) positivity in a Han Chinese-Canadian population; and (4) to determine the cytokine network in this population. Patients that developed fever and cutaneous eruptions in the presence or absence of organ involvement within 8 weeks of exposure to carbamazepine (CBZ), phenytoin (PHY), or lamotrigine (LTG) were enrolled. Control patients received AEDs without presenting HSR. We investigated 10 CBZ-HSR patients (4 with Stevens-Johnson syndrome [SJS]), 24 CBZ-controls, 10 PHY-HSR patients (4 with drug-induced liver injury [DILI]), 24 PHY-controls,6 LTG-HSR patients (1 with SJS and 1 with DILI), and 24 LTG-controls. There were 30 Han Chinese individuals (14 HSR patients and 16 controls) in our cohort. LTA toxicity greater than 12.5% ± 2.5% was considered positive. Differences among groups were determined by analysis of variance. In addition, we measured cytokine secretion in the patient sera between 1 month and 3 years after the event. All Han Chinese individuals and 30% of Caucasians were genotyped for HLA-B∗1502. A perfect correlation (r = 0.92) was observed between positive LTA and clinical diagnosis of DILI and SJS/toxic epidermal necrolysis (TEN). HLA-B∗1502 positivity in Han Chinese is a predictor of CBZ-HSR and PHY-HSR. HLA-B∗1502-negative Han Chinese receiving only CBZ or a combination of CBZ and PHY tolerated the drug(s) clinically, presenting negative CBZ-LTA and PHY-LTA. However, 3 patients presenting negative CBZ-LTA and PHY-LTA, as well as negative HLA-B∗1502, showed positive LTG-LTA (38%, 28%, and 25%, respectively), implying that they should not be prescribed LTG. Three patients had LTA positive to both PHY and CBZ, and 3 others had LTA positive to both PHY and LTG. Clinically, all 6 patients presented HSR to both drugs that they tested positive to (cross-reactivity). Patients were grouped based on the clinical presentation of their symptoms as only rash and fever or as a triad of rash, fever and DILI or SJS/TEN that characterizes “true” HSR. Levels of proinflammatory cytokines were significantly higher in patient sera compared with control sera. More specifically, the highest levels of tumor necrosis factor-α have been measured in patients presenting “true” HSR, as were the apoptotic markers Fas, caspase 8 activity, and M30. The LTA is sensitive for DILI and SJS/TEN regardless of drug or patient ethnicity. HSR prediction will prevent AED-induced morbidity. In Han Chinese, HLA-B∗1502 positivity is a predictor for CBZ-HSR and PHY-HSR. Its negativity does not predict a negative LTG-HSR. There is cross-reactivity between AEDs. Additionally, T-cell cytokines and chemokines control the pathogenesis of SJS/TEN and DILI, contributing to apoptotic processes in the liver and in the skin.

Translational research in infectious disease: current paradigms and challenges ahead - Uncorrected Proof

Judith M. Fontana, Elizabeth Alexander, Mirella Salvatore — 2012-01-16

In recent years, the biomedical community has witnessed a rapid scientific and technologic evolution after the development and refinement of high-throughput methodologies. Concurrently and consequentially, the scientific perspective has changed from the reductionist approach of meticulously analyzing the fine details of a single component of biology to the “holistic” approach of broadmindedly examining the globally interacting elements of biologic systems. The emergence of this new way of thinking has brought about a scientific revolution in which genomics, proteomics, metabolomics, and other “omics” have become the predominant tools by which large amounts of data are amassed, analyzed, and applied to complex questions of biology that were previously unsolvable. This enormous transformation of basic science research and the ensuing plethora of promising data, especially in the realm of human health and disease, have unfortunately not been followed by a parallel increase in the clinical application of this information. On the contrary, the number of new potential drugs in development has been decreasing steadily, suggesting the existence of roadblocks that prevent the translation of promising research into medically relevant therapeutic or diagnostic application. In this article, we will review, in a noninclusive fashion, several recent scientific advancements in the field of translational research, with a specific focus on how they relate to infectious disease. We will also present a current picture of the limitations and challenges that exist for translational research, as well as ways that have been proposed by the National Institutes of Health to improve the state of this field.

Role of advanced glycation endproducts and glyoxalase I in diabetic peripheral sensory neuropathy - Uncorrected Proof

M.M. Jack, D.E. Wright — 2012-01-11

Diabetic neuropathy is the most common and debilitating complication of diabetes mellitus with more than half of all patients developing altered sensation as a result of damage to peripheral sensory neurons. Hyperglycemia results in altered nerve conduction velocities, loss of epidermal innervation, and development of painful or painless signs and symptoms in the feet and hands. Current research has been unable to determine whether a patient will develop insensate or painful neuropathy or be protected from peripheral nerve damage all together. One mechanism that has been recognized to have a role in the pathogenesis of sensory neuron damage is the process of reactive dicarbonyls forming advanced glycation endproducts (AGEs) as a direct result of hyperglycemia. The glyoxalase system, composed of the enzymes glyoxalase I (GLO1) and glyoxalase II, is the main detoxification pathway involved in breaking down toxic reactive dicarbonyls before producing carbonyl stress and forming AGEs on proteins, lipids, or nucleic acids. This review discusses AGEs, GLO1, their role in diabetic neuropathy, and potential therapeutic targets of the AGE pathway.

Treating hepatitis C infection by targeting the host - Uncorrected Proof

Shadi Salloum, Andrew W. Tai — 2012-01-11

More than 130 million people worldwide are chronically infected with the hepatitis C virus (HCV), which can lead to cirrhosis, liver failure, and hepatocellular carcinoma. Although recently approved HCV NS3-4A protease inhibitors significantly improve treatment response rates, current HCV treatment is still frequently limited by side effects and by the low genetic barrier to viral resistance against direct-acting antiviral agents. A complementary strategy is to target the host cellular factors that support the HCV life cycle. Several studies, including RNA interference screens, demonstrated that HCV depends on dozens, if not hundreds, of cellular proteins to complete its life cycle. A better understanding of the interactions between HCV proteins and host factors may help to identify host targets for antiviral therapy. In this review, we highlight some of the host factors that are particularly attractive targets for the treatment of HCV.

Chronic kidney disease as a risk factor for acute coronary syndromes in patients presenting to the emergency room with chest pain - Uncorrected Proof

2012-01-10

We sought to determine whether persons with intermediate risk factors for cardiovascular disease presenting to an emergency department with chest pain and chronic kidney disease (CKD) were triaged effectively by chest pain units (CPUs). CPUs evaluate patients with intermediate risk and acute chest pain effectively. CKD is a risk factor for poor outcomes once cardiovascular disease has developed. However, current algorithms to risk stratify patients with acute chest pain do not include renal function. A total of 408 patients enrolled previously in the CHEER study of intermediate risk patients with chest pain, assigned randomly to hospitalization or observation in a CPU where an estimated glomerular filtration rate (GFR) was available, were included. No difference was found in short-term outcomes of patients including in-hospital death, myocardial infarction, or coronary revascularization based on renal function. For the 205 patients randomized to the CPU, the rate of admission to the hospital was significantly higher in the group with CKD compared with the group with normal renal function (68.2 vs 48.2%, P = 0.007). In a multivariate analysis, decreased renal function was not associated with adverse short-term outcomes. On 5 years follow-up, the overall long-term mortality was significantly higher in the group with CKD (14.1% vs 5.5%, P = 0.003). We concluded that CKD is a strong predictor of hospitalization and overall long-term mortality in patients presenting with chest pain to the emergency department. Current risk factor stratification scoring systems should consider CKD as a predictor of increased risk in patients with chest pain.

Effect of oxidative stress and endotoxin on human serum albumin in brain-dead organ donors - Uncorrected Proof

2012-01-09

Albumin, among other molecules, binds and detoxifies endotoxin in healthy people. Oxidative stress leads to protein oxidation and thus to the impaired binding properties of albumin. This property, in combination with increased gut permeability, leads to the appearance of endotoxin in the systemic circulation and to impaired organ function. We hypothesize that these processes occur in the serum of brain-dead organ donors. Endotoxin was determined with an adapted Limulus amoebocyte lysate assay. The albumin fractions and binding capacity were determined by high-performance liquid chromatography (HPLC). FlowCytomix (eBioscience, San Diego, Calif) was used to determine the cytokine levels. Carbonylated proteins (CPs) and myeloperoxidase (MPO) were measured by an enzyme-linked immunosorbent assay (ELISA). Eighty-four brain-dead organ donors were enrolled and categorized by the duration of intensive care unit (ICU) stay. The albumin-binding capacity for dansylsarcosine was reduced in brain-dead patients compared with controls. Endotoxin positivity in 16.7% of donors was associated with decreased binding capacity in donors and worse survival of recipients. The CP and MPO levels of organ donors were significantly higher than in healthy controls. The durations of ICU stay increased albumin oxidation. In addition, interleukin-6 (IL-6), IL-8, IL-10, and IL-1β levels were increased in patients, whereas the interferon-γ (IFN-γ) levels were within the normal range. We conclude that oxidative stress and systemic endotoxemia are present in brain-dead organ donors, which might affect recipient survival. High endotoxin levels might be caused by increased gut permeability and decreased binding capacity of albumin influenced not just by higher albumin oxidation.

Review of novel clinical applications of advanced, real-time, 3-dimensional echocardiography - Uncorrected Proof

Manjula V. Burri, Dipti Gupta, Richard E. Kerber, Robert M. Weiss — 2012-01-09

Advances in computer processing speed and memory along with the advent of the microbeam former that can sample an entire crystal of the ultrasound transducer made possible the performance of 3-dimensional echocardiography in real time (RT3DE). The miniaturization of a 3-dimensional transducer permitting its extension to transesophageal mode rapidly expanded its use in a variety of conditions. Recent development of user-friendly automated/semiautomated cropping and display software may make it rather simple, even for the novice to gather useful information from RT3DE. We discuss the background, technique, and cutting-edge research and novel clinical applications of advanced RT3DE, including left ventricular dyssynchrony assessment, 3-D speckle tracking, myocardial contrast echocardiography, complete 4-dimensional (4-D) shape and motion analysis of the left ventricle, 4-D volumetric analysis of the right ventricle, 3-D volume rendering of the mitral valve, and other percutaneous and surgical procedural applications.

Molecular imaging of disease with targeted contrast ultrasound imaging - Uncorrected Proof

Yoichi Inaba, Jonathan R. Lindner — 2012-01-06

To enhance clinical care for patients, methods for noninvasive imaging of specific disease-related molecular changes are being developed to expand and improve diagnostic capabilities. These new techniques are used in research programs to characterize pathophysiology and as a surrogate end point for therapeutic efficacy. Molecular imaging with contrast-enhanced ultrasound relies on the detection of microbubbles or other acoustically active particulate agents that are targeted to and retained at sites of disease. This review describes the progress that has been made in the development and testing of methods for contrast ultrasound molecular imaging with a specific focus on cardiovascular disease. Specific topics addressed include probe development, detection methods, and specific biologic processes that are important in clinical cardiovascular medicine and that have been targeted with microbubble contrast agents.

Silibinin modulates lipid homeostasis and inhibits nuclear factor kappa B activation in experimental nonalcoholic steatohepatitis - Uncorrected Proof

2012-01-04

Nonalcoholic steatohepatitis (NASH) is associated with increased liver-related mortality. Disturbances in hepatic lipid homeostasis trigger oxidative stress and inflammation (ie, lipotoxicity), leading to the progression of NASH. This study aimed at identifying whether silibinin may influence the molecular events of lipotoxicity in a mouse model of NASH. Eight-week-old db/db mice were fed a methionine-choline deficient (MCD) diet for 4 weeks and treated daily with silibinin (20 mg/kg intraperitoneally) or vehicle. Liver expression and enzyme activity of stearoyl-CoA desaturase-1 and acyl-CoA oxidase, and expression of liver fatty acid-binding protein were assessed. Hepatic levels of reactive oxygen species, thiobarbituric acid-reactive substances (TBARS), 3-nitrotyrosine (3-NT), inducible nitric oxide synthase (iNOS), and nuclear factor kappa B (NFkB) activities were also determined. Silibinin administration decreased serum alanine aminotransferase and improved liver steatosis, hepatocyte ballooning, and lobular inflammation in db/db mice fed an MCD diet. Gene expression and activity of stearoyl-CoA desaturase-1 were reduced in db/db mice fed an MCD diet compared with lean controls and were increased by silibinin; moreover, silibinin treatment induced the expression and activity of acyl-CoA oxidase and the expression of liver fatty acid-binding protein. Vehicle-treated animals displayed increased hepatic levels of reactive oxygen species and TBARS, 3-NT staining, and iNOS expression; silibinin treatment markedly decreased reactive oxygen species and TBARS and restored 3-NT and iNOS to the levels of control mice. db/db mice fed an MCD diet consistently had increased NFkB p65 and p50 binding activity; silibinin administration significantly decreased the activity of both subunits. Silibinin treatment counteracts the progression of liver injury by modulating lipid homeostasis and suppressing oxidative stress–mediated lipotoxicity and NFkB activation in experimental NASH.

Accelerated senescence of renal tubular epithelial cells is associated with disease progression of patients with immunoglobulin A (IgA) nephropathy - Uncorrected Proof

2011-12-28

The aim of this study is to determine the potential correlation between the accelerated senescence of renal tubular epithelial cells (RTECs) and the disease progression of patients with immunoglobulin A nephropathy (IgAN). A total of 108 IgAN patients with different Lee's pathologic grades were enrolled. Additionally, 18 patients with renal resection were recruited as controls. Cellular senescence was evaluated by senescence-associated β-galactosidase (SA-β-gal) staining and an immunohistochemical analysis of p21 and p16 protein expression. The expression of type III collagen (Col III) and fibronectin (FN) in renal interstitium and the levels of serum total and low-density lipoprotein (LDL) cholesterol, serum creatinine concentration (SCr), and 24-h urinary protein excretion were evaluated also. SA-β-gal staining and the expression of p16 and p21 were increased significantly in renal biopsy specimens obtained from grades I–II IgAN patients compared with controls (P < 0.05). The expression of these senescence-associated markers increased gradually with disease progression and correlated with the renal morphologic changes and the expression of Col III and FN in renal interstitium in IgAN patients. A correlation analysis showed that the expressions of p16, p21, and SA-β-gal staining were associated significantly with blood pressure and renal function (P < 0.05), but not with patient age, body mass index (BMI), LDL cholesterol level, or 24-h urinary protein value (P > 0.05). Our results indicated that the RTECs in IgAN patients exhibited features of accelerated senescence, which were unrelated to mechanisms associated with normal aging. Cellular senescence was associated closely with IgAN disease progression, which suggested the accelerated senescence of RTECs may contribute to this progression.

Inflammatory bowel disease and pregnancy: overlapping pathways - Uncorrected Proof

Noha Ahmed Nasef, Lynnette R. Ferguson — 2011-12-26

Several studies have reported on the association between inflammatory bowel disease (IBD) and adverse pregnancy outcomes, such as preterm birth. The exact mechanisms of action are unclear; however, several pathways and processes are involved in both IBD and pregnancy that may help explain this. In this review, we discuss the immune system's T helper cells and human leukocyte antigens, inflammation, its function, and the role of Toll-like receptors (TLRs), NOD-like receptors (NLRs), and prostaglandins in the inflammatory response. For each of these topics, we consider their involvement in IBD and pregnancy, and we speculate as to how they can lead to preterm birth. Finally, we review briefly corticosteroids, biologic therapies, and immunosuppressants for the treatment of IBD, as well as their safety in use during pregnancy, with special focus on preterm birth.

Canine tumors: a spontaneous animal model of human carcinogenesis - Uncorrected Proof

Salomé S Pinho, Sandra Carvalho, Joana Cabral, Celso A Reis, Fátima Gärtner — 2011-12-22

The enormous biologic complexity of human cancer has stimulated the development of more appropriate experimental models that could resemble in a natural and spontaneous manner the physiopathologic aspects of cancer biology. Companion animals have many desired characteristics that fill the gap between in vitro and in vivo studies, and these characteristics have proven to be important in understanding many complex molecular aspects of human cancer. Spontaneous tumors in dogs share a wide variety of epidemiologic, biologic, and clinical features with human cancer, which makes this animal model both attractive and underused in oncology research.In this review, we summarize the importance of naturally occurring canine tumors as valuable tools for studying numerous aspects of human cancer as well as the potential use of this animal model for the development of new cancer treatments. We address specifically the use of canine mammary tumors as an increasingly powerful model to study human breast cancer.

Keloids: what do we know and what do we do next? - Uncorrected Proof

Patrick H. Blit, Marc G. Jeschke — 2011-12-19

It is believed that the knowledge of excessive scarring and keloids as a pathologic consequence of cutaneous injury was first described in approximately 1700 bce as outlined in the Edwin Smith Papyrus. Keloids represent a pathologic response to dermal injuries resulting in firm, rubbery tumors with a shiny surface appearance that grow beyond initial wound boundaries. Keloid scarring is unique to human beings, and it occurs predominantly on the chest, back, shoulders, and earlobes, whereas it rarely occurs on the soles or palms. One plausible explanation stems from the fact that humans have different sebaceous glands than other mammals and that these higher risk areas of the human body may have higher concentrations of sebaceous glands. The so-called “sebum hypothesis” proposes that the sebum released by the sebaceous glands onto the skin surface may come into contact with T-cells after cutaneous injury and cause an inflammatory reaction that leads to keloid progression, but more in-depth studies to prove this hypothesis are warranted.

Cardiovascular translational imaging: From bench to bedside - Uncorrected Proof

Mario J. Garcia — 2011-12-15

Over the last 4 decades, heart disease mortality has declined at a rate of 2.5% per year. This remarkable achievement has been attributed primarily to advances in the management of cardiovascular risk factors, the treatment of myocardial infarction and heart failure, and the prevention of sudden cardiac death. Undeniably, cardiac imaging has played a significant role in this decline by leading to the early identification of patients at risk and helping in establishing a rapid, accurate, and complete diagnosis of cardiovascular syndromes. Cardiovascular imaging has also become an important tool for patient selection and evaluation of outcomes in clinical trials. Even though the ultimate proof of efficacy of a new drug, device, or therapeutic strategy is a reduction in mortality and improved quality of life, imaging endpoints, such as improved ventricular function and myocardial perfusion, are easier to identify earlier in smaller trials and usually translate into improved clinical outcomes. Thus, clinical trials with imaging endpoints can accelerate the process substantially and reduce the cost of clinical research by selecting which new therapeutics interventions are most likely to provide improved benefits and reduced risks, prior to conducting large randomized clinical trials with clinical endpoints.

Intracardiac T-wave alternans, ischemia, and arrhythmias, in a canine model - Uncorrected Proof

John E. Madias — 2011-12-12

I enjoyed reading the article by Kwofie et al in the November 2011 issue of Translational Research, pertaining to the employment of intracardiac bipolar electrograms (IBEs)-based T-wave alternans (TWA) and ventricular tachycardia/fibrillation (VT/VF) in a canine ischemic model. The authors were careful to measure IBEs from both the risk zone and the surrounding normal sites, although I am puzzled about the use of drop in the QRS voltage in IBEs, as proof of myocardial ischemia (MI), considering that sometimes an increase in the amplitude of R-waves and T-waves is observed in the hyperacute phase of MI. However, there is backing from the literature regarding this concept, but still I am curious whether ST-segment elevation or depression or any changes in the T-wave polarity was detected with the emergence of MI. The authors found a correlation between TWA and MI, and an increase in the number of sites, magnitude, and discordance of TWA immediately preceding VT/VF. Also, as shown previously in normal human subjects, TWA in the canine model of this study was observed even before the generation of MI. The finding of the reversibility of TWA is intriguing and deserves further study. I will appreciate the response of the authors on the following: (1) in scrutinizing panels A and B of Fig 1, one can immediately appreciate that the QRS duration of EN1, EN2, EP3, and EN3 is wider in B than in A (after the imposition of MI); (2) this is particularly supported by the fact that the recording in B is slower because the horizontal time calibration bar is the same in length in A and B, and it represents 300 ms in A and 400 ms in B; (3) this implies that the change in TWA magnitude from A to B may be a result of the secondary changes of the T-waves resulting from the corresponding QRS complex changes; and (4) if this the case, the authors need to deal with the confounding factor of the increasing QRS duration in diagnosing and measuring TWA changes.

Reply to “Intracardiac T-wave alternans, ischemia, and arrhythmias, in a canine model” - Uncorrected Proof

Michael A. Kwofie, James B. Martins — 2011-12-12

We appreciate the interest in the article on T-wave alternans (TWA) and arrhythmia. The issues of interest that were raised in the initial letter to the editor are addressed in the following paragraphs. As noted in the initial letter, an increase in amplitude of R-waves and T-waves is observed in the hyperacute phase of myocardial ischemia (MI); indeed we noted similar results with R-waves under our experimental conditions as well but in less than 2% of cases. As indicated in Reference 23 in the article of interest, the reduction in electrogram voltage is tightly correlated with blood flow measurements documenting ischemia; this is our routine measurement in all past studies in this model.

Biomarkers in acute myocardial injury - Uncorrected Proof

2011-12-09

Acute coronary syndrome (ACS) is a significant cause of morbidity and mortality worldwide. The proper diagnosis of ACS requires reliable and accurate biomarker assays to detect evidence of myocardial necrosis. Currently, troponin is the gold standard biomarker for myocardial injury and is used commonly in conjunction with creatine kinase-MB (CK-MB) and myoglobin to enable a more rapid diagnosis of ACS. A new generation of highly sensitive troponin assays with improved accuracy in the early detection of ACS is now available, but the correct interpretation of assay results will require a careful consideration of assay characteristics and the clinical setting prior to incorporation into routine practice. B-type natriuretic peptides, copeptin, ischemia-modified albumin, heart-type fatty-acid-binding protein, myeloperoxidase, C-reactive protein, choline, placental growth factor, and growth-differentiation factor-15 make up a promising group of other biomarkers that have shown the ability to improve prognosis and diagnosis of ACS compared with traditional markers.

Uncoupling protein-2 expression and effects on mitochondrial membrane potential and oxidant stress in heart tissue - Uncorrected Proof

2011-12-05

Myocardial uncoupling protein (UCP)-2 is increased with chronic peroxisome proliferator-activated receptor γ (PPARγ) stimulation, but the effect on membrane potential and superoxide is unclear. Wild-type (WT) and UCP-2 knockout (KO) mice were given a 3-week diet of control (C) or the PPARγ agonist pioglitazone (PIO; 50 μg/g-chow per day). In isolated mitochondria, UCP-2 content by Western blots, membrane potential (ΔΨm) by tetraphenylphosphonium (TPP), and relative superoxide levels by dihydroethidium (DHE) were measured. Oxygen respiration was determined at baseline and after 10 min anoxia-reoxygenation. PIO induced a 2-fold increase in UCP-2 and nuclear-bound PGC1α in WT mice with no UCP-2 expression in KO mice. Mitochondrial ΔΨm from WT mice on C and PIO diets was –166 ± 4 mV and –147 ± 6 mV, respectively (P < 0.05). These values were lower than UCP-2 KO mice on C and PIO (–180 ± 4 mV and –180 ± 4 mV, respectively; P < 0.05). Maximal complex III inhibitable superoxide from WT mice on C and PIO diets was 22.5 ± 1.3 and 17.8 ± 1.1 AU, respectively (P < 0.05), and were lower than UCP-2 KO on C and PIO (32.9 ± 2.3 and 29.2 ± 1.9 AU, respectively; P < 0.05). Postanoxia, the respiratory control index (RCI) in mitochondria from WT mice with and without PIO was 2.5 ± 0.3 and 2.4 ± 0.2, respectively, and exceeded that of UCP-2 KO mice on C and PIO (1.2 ± 0.1 and 1.4 ± 0.1, respectively (P < 0.05). In summary, chronic PPARγ stimulation leads to depolarization of the inner membrane and reduced superoxide of isolated heart mitochondria, which was critically dependent on increased expression of UCP-2. UCP-2 expression affords resistance to brief anoxia-reoxygenation.

Single-nucleotide polymorphisms in inflammatory bowel disease - Uncorrected Proof

Manuela G. Neuman, Radu M. Nanau — 2011-11-24

Strong evidence indicates that inflammatory bowel disease, including Crohn disease and ulcerative colitis, is a result of an inappropriate inflammatory response in which genetic and environmental factors play important roles. This review discusses several single-nucleotide polymorphisms with either susceptibility or protective effects on inflammatory bowel disease.

Genetic analysis of the promoter region of the GATA4 gene in patients with ventricular septal defects - Uncorrected Proof

Guanghua Wu, Jiping Shan, Shuchao Pang, Xiaodan Wei, Hao Zhang, Bo Yan — 2011-11-24

Ventricular septal defects (VSDs) are the most common type of congenital heart diseases (CHDs). To date, the genetic causes for sporadic VSDs remain largely unknown. GATA transcription factor 4 (GATA4) is a zinc-finger transcription factor that is expressed in developing heart and adult cardiomyocytes. Mutations in the coding region of the GATA4 gene have been identified in CHD patients, including VSD. As the GATA4 factor is a dosage-sensitive regulator, we hypothesized that the promoter region variants of the GATA4 gene may be genetic causes of VSD. In this study, we analyzed the promoter region of the GATA4 gene by bidirectional sequencing in 172 VSD patients and 171 healthy controls. The results showed that 5 heterozygous sequence variants (NG_008177:g.4071T>C, NG_008177:g.4148C>A, NG_008177:g.4566C>T, NG_008177:g.4653G>T, and NG_008177:g.4690G>deletion) within the promoter region of the GATA gene were identified in 5 VSD patients, but in none were found in controls. One heterozygous sequence variant (g.4762C>A) was found only in 1 control, which may have no functional significance. A functional analysis revealed that the transcriptional activity of variant NG_008177:g.4566C>T was reduced significantly, whereas the transcriptional activities of the variants (NG_008177:g.4071T>C, NG_008177:g.4148C>A, NG_008177:g.4653G>T, and NG_008177:g.4690G>deletion) were increased significantly compared with the wild-type GATA4 gene promoter. As GATA4 is a dosage-sensitive regulator during development, our data suggest that these sequence variants within the promoter region of the GATA4 gene may contribute to the VSD etiology by altering its gene expression. Additional studies in experimental animals will deepen our understanding of the genetic basis of VSD and shed light on designing novel molecular therapies for adult VSD patients carrying these variants.

Genetic origin and interaction of the Filipino β0-thalassemia with Hb E and α-thalassemia in a Thai family - Uncorrected Proof

Supawadee Yamsri, Kanokwan Sanchaisuriya, Goonnapa Fucharoen, Supan Fucharoen — 2011-11-18

We describe hematologic and molecular characteristics of a hitherto undescribed interaction between the Filipino deletional β0-thalassemia with Hb E and α-thalassemia in a Thai family. This study was conducted during the prenatal screening of a pregnant Thai woman and her family members. A prenatal diagnosis was performed at her second pregnancy by amniocentesis. Laboratory investigations identified that the pregnant woman was Hb E heterozygote with α+-thalassemia, whereas her husband was a double heterozygote for the Filipino deletional β0-thalassemia and α+-thalassemia. Their affected son was a patient with a previously undescribed condition of Hb E-β0-thalassemia with α+-thalassemia. Both a combined gap-polymerase chain reaction (PCR) and allele-specific PCR were used successfully in the prenatal diagnosis, which identified an affected fetus with Hb E-β0-thalassemia without α+-thalassemia. Beta globin gene haplotype analysis indicated the same origin of this Filipino β0-thalassemia in Asian populations.

Imaging atherosclerosis in HIV: carotid intima-media thickness and beyond - Uncorrected Proof

Chris T. Longenecker, Brian D. Hoit — 2011-11-15

Chronic immune activation and inflammation are associated with an increased risk of atherosclerosis in HIV-infected patients. In this review, we discuss the role of established and novel imaging modalities to define more accurately the structure and function of inflammation-mediated atherosclerosis in the context of HIV. Historically, carotid ultrasound studies were the first to show higher rates of subclinical atherosclerosis in HIV-infected subjects versus uninfected controls. However, computed tomography is the noninvasive gold standard for imaging the coronary arteries, and studies in HIV suggest a higher prevalence of noncalcified plaque. Endothelial dysfunction can be quantified by measuring flow-mediated brachial artery dilation by ultrasound and has been used extensively in antiretroviral switching trials and small pilot trials of therapeutics to assess cardiovascular risk in this population. In the future, novel imaging modalities such as intracoronary optical coherence tomography, positron emission tomography imaging of 18F-fluorodeoxyglucose uptake, and molecular-targeted magnetic resonance imaging will characterize the burden of vulnerable plaque and other unique features of inflammatory atherosclerosis in HIV.

Chronic inflammation and pain in a tumor necrosis factor receptor (TNFR) (p55/p75-/-) dual deficient murine model - Uncorrected Proof

Karin W. Westlund, Liping Zhang, Fei Ma, Helieh S. Oz — 2011-11-10

Many aspects of tissue damage after acute or chronic inflammatory reactions can be attributed directly to the concomitant biosynthesis and release of inducible early proinflammatory cytokine tumor necrosis factor alpha (TNFα). Conversely, systemic inflammation is impacted by the consequences of tissue damage. Dysregulated TNFα contributes to numerous pathophysiologic conditions including inflammatory bowel disease (IBD) and arthritis. Inflammatory stimuli trigger proteolytic cleavage and shedding of extracellular domains of TNFα receptors giving rise to 2 soluble fragments (p55 soluble tumor necrosis factor receptor 1 (sTNFR1) and p75 sTNFR2) that block the additional binding, activity, and synthesis of TNFα. We hypothesized that absence of sTNFR inhibitory feedback control would result in accumulated high levels of TNFα and other inflammatory factors promoting the cardinal signs of chronic inflammation and pain. The current study reports a translational murine model of chronic arthritis precipitated by 2 consecutive inflammatory insults. The “double hit” procedures provoke a chronic inflammatory response and pain-related behaviors in mice that are dually deficient in p55 (TNFR1) and p75 (TNFR2). The inflammation- and pain-related behaviors are transient in similarly treated wild-type (WT) mice. The complete Freund’s adjuvant (CFA) method was used initially to induce knee joint inflammation, tactile mechanical and heat hypersensitivity, and gait disturbance. After these transient effects of the insult were resolved, a recrudescence persisting at least through 23 weeks was promoted by gastrointestinal (GI) insult with dilute intracolonic mustard oil (MO) only in the mutant mice. A serum proteome profiling analysis revealed high levels of serum inflammatory factors TNFα, regulated upon activation normally T-cell expressed and secreted (RANTES), chemokine (C-X-C motif) ligand 9 [CXCL9 (MIG)], chemokine (C-X-C motif) ligand 10 [CXCL10 (IP-10)], and chemokine (C-C motif) ligand 2 [CCL2 (MCP-1)]. These data suggest that impaired signaling of TNFα as a result of the deficit of the 2 protective soluble p55 and p75 sTNFR inhibitory factors plays a pivotal role in the reactivation of the immune response to GI insult that can produce recrudescence of inflammatory injury and a chronic pain state through promotion of high levels of serum inflammatory factors.

Altered angiogenic balance in keloids: a key to therapeutic intervention - Uncorrected Proof

2011-11-07

Keloids are manifestations of abnormal wound repair with unresolved clinical complications. An effective therapeutic regimen has not been established for keloids, and current strategies are plagued by problems such as recurrence and side effects. Keloids, as a human-specific dermal fibroproliferative disorder, are characterized by an excessive accumulation of extracellular matrix (ECM), which is thickened basement membrane with unregulated expression of matrix metalloproteases, growth factors, and cytokines. The internal milieu in a keloid bears a strong resemblance to a tumor with both exhibiting striking similarities with respect to tissue environment and unregulated vasculature. Abnormal angiogenesis, which is manifested by the imbalance between proangiogenic and antiangiogenic factors has been recognized as a “common denominator” underlying many pathologic conditions. However, such an imbalance has not been investigated in keloids. In this study, the angiogenic imbalance in keloids was explored with reference to circulating and tissue level expression of vascular endothelial growth factor (VEGF) and endostatin/collagen XVIII. It was observed that VEGF levels were upregulated and endostatin levels were downregulated in keloid patients compared with normal controls in both sera and tissue. Hence, antiangiogenic therapeutics based on endostatin in combination with current curative strategies as in tumors would present a scope for the effective management of keloids.

Multimodal sentinel lymph node mapping with single-photon emission computed tomography (SPECT)/computed tomography (CT) and photoacoustic tomography - Uncorrected Proof

2011-10-24

The identification of cancer cells in the lymph nodes surrounding a tumor is important in establishing a prognosis. Optical detection techniques such as fluorescence and photoacoustic tomography (PAT) have been reported in preclinical studies for noninvasive sentinel lymph node (SLN) mapping. A method for validation of these techniques is needed for clinical trials. We report the use of a multimodal optical-radionuclear contrast agent as a validation tool for PAT in a preclinical model. Methylene blue (MB) was radiolabeled with 125I for multimodal SLN mapping and used in conjunction with MB to assess the feasibility of multimodal SLN mapping in a rat model by PAT and single-photon emission computed tomography (SPECT). MB provided sufficient contrast for identifying SLNs noninvasively with a PAT system adapted from a clinical ultrasound imaging system. The signal location was corroborated by SPECT using 125I labeled MB. The translation of PAT into the clinic can be facilitated by a direct comparison with established imaging methods using a clinically relevant dual SPECT and photoacoustic imaging agent. The new high-resolution PAT is a promising technology for the sensitive and accurate SLN detection in cancer patients.

Erythromycin ameliorates cigarette-smoke–induced emphysema and inflammation in rats - Uncorrected Proof

Yan Zhou, Xianshu Tan, Wenjuan Kuang, Litao Liu, Lihong Wan — 2011-10-24

The exposure to cigarette smoke (CS) is associated with emphysema. In addition to chronic lung inflammation, emphysema is known mainly for the complex pathogenesis associated with imbalance of proteolytic and antiproteolytic activities, oxidative stress, and apoptosis of lung structural cells. Increasing evidence shows that erythromycin, which is a macrolide antibiotic, ameliorates chronic inflammation via mechanisms independent of its antibacterial activity. We hypothesize that erythromycin protects against CS-induced emphysema and inflammation in rats via its anti-inflammation and antiapoptosis action. Sprague-Dawley (SD) rats were administered lipopolysaccharide (LPS) intratracheally solution twice and exposed to the CS, the control rats were administered saline intratracheally and exposed to ambient air for 3 weeks. Then, all the CS rats were distributed randomly into 3 groups and, respectively, treated orally with saline (LPS + CS + saline), Guilongkechuanning capsule (450 mg/kg) (LPS + CS + GLKCN), or erythromycin (100 mg/kg) (LPS + CS + ERY) 0.5 h before CS exposure for 2 weeks. On day 36, the rats were killed. The cytokines in serum were measured by enzyme-linked immunosorbent assay (ELISA). The middle lobe of the right lung was removed for histology and apoptosis analyses, respectively. Emphysematous lesions and inflammatory cell infiltrations in the CS group were evident by a histologic analysis. Erythromycin protected significantly against the alveolar enlargement levels (P = 0.0017), reduced the pathologic apoptosis (P = 0.0023) related with Bcl-2 (P = 0.0002) and Bax (P = 0.0002), and inhibited the expressions of matrix metalloproteinase (MMP)-9 (P = 0.0019) and TIMP-1 protein (P = 0.04) and the MMP-9/TIMP-1 ratio (P = 0.0002) in the lungs of CS-induced emphysema in rats. The protective effect of erythromycin on CS-induced emphysema and inflammation in rats is associated with a reduction in inflammation, imbalance of MMP-9/TIMP-1, and apoptosis of lung structural cells. However, erythromycin did not recover completely the emphysematous morphologic changes to the levels when compared with control rats. This distinctive pattern implies that erythromycin might have the potential to suppress airway inflammation and maintain the integrity of airway epithelium to some extent.

Inflammatory bowel disease: role of diet, microbiota, life style - Uncorrected Proof

Manuela G. Neuman, Radu M. Nanau — 2011-09-26

Inflammatory bowel disease (IBD) encompassed several chronic inflammatory disorders leading to damage of the gastrointestinal tract (GI). The 2 principal forms of these disorders are ulcerative colitis (UC) and Crohn disease (CD). Bacteria are involved in the etiology of IBD, and the genetic susceptibility, environmental factors, and lifestyle factors can affect the individual's predisposition to IBD. The review discusses the potential role of environmental factors such as diet and microbiota as well as genetics in the etiology of IBD. It is suggested that microbial ecosystem in the human bowel colonizing the gut in many different microhabitats can be influence by diet, leading to formation of metabolic processes that are essential form the bowel metabolism.

Metabolome and inflammasome in inflammatory bowel disease - Uncorrected Proof

Radu M. Nanau, Manuela G. Neuman — 2011-09-16

Inflammatory bowel disease (IBD) encompasses several chronic inflammatory disorders leading to the damage of the gastrointestinal tract. The 2 principal forms of these disorders are ulcerative colitis (UC) and Crohn’s disease (CD). Bacteria are involved in the etiology of IBD. Many microorganisms have been put forward as causative factors in IBD, but the primary etiologic agents are still not known. The underlying genetic, environmental, and lifestyle issues can affect the individual’s predisposition to these diseases. Immune factors identified in IBD are: dysregulation of the innate and adaptive immune system directed against luminal bacteria or their products found in the intestinal lumen and inappropriate immune responses to organisms in the intestine that normally do not elicit a response, possibly because of intrinsic alterations in mucosal barrier function. However, recent advances in basic science research revealed new insights into the role of specific immune cells and their mediators in intestinal inflammation. The inflammatory mediators known as “inflammasome” are a consequence of the metabolic products (metabolom) of cells and commensally or pathogenic bacteria. Elucidation of inflammasome and metabolom has led to the development of biomarkers specific for each disease that are involved into management strategies targeted at altering specific pathogenic mechanisms that have the potential to modify or change the natural course of these disease entities. The review discusses the potential role of biomarkers in monitoring the inflammasome and therefore the severity of intestinal damage. The microbial ecosystem in the human gut in different microhabitats and metabolic niches contribute to the bowel metabolome.In addition, this review will focus on our expanding understanding microbial factors associated with both the initiation and maintenance of IBD. New insights acquired from murine genetic models of inflammatory bowel disease will also be discussed.

Estrogen-related MxA transcriptional variation in hepatitis C virus-infected patients - Uncorrected Proof

Radwa Y. Mekky, Nabila Hamdi, Wafaa El-Akel, Gamal Esmat, Ahmed I. Abdelaziz — 2011-09-05

Sex has been reported to influence the rates of viral clearance in hepatitis C virus (HCV)-infected patients. However, little is known regarding the influence of sex on the host genetic response to HCV, which is mediated by the expression of interferon (IFN)-stimulated genes (ISGs) after the activation of janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway by IFN. Thus, we investigated gender differences in MxA genetic profile, which is a downstream reliable marker for JAK/STAT pathway activation. In all, 40 untreated HCV-infected patients were subclassified into premenopausal, postmenopausal, and male patients. The peripheral blood mononuclear cells(PBMCs) from premenopausal women showed the highest MxA gene expression compared to both postmenopausal females and males before and after IFN stimulation. The prestimulation of PBMCs with 17beta-estradiol prior to IFN treatment resulted in a decrease of MxA expression in all groups of patients. That was confirmed by the reversal of this effect using estrogen antagonist ICI182/780. This study demonstrates for the first time the presence of gender variations in the genetic response to chronic HCV infection and to interferon treatment. It also clarifies that estrogen is not the key player in enhancing the JAK/STAT pathway.

Molecular profiling of individual tumor cells by hyperspectral microscopic imaging - Uncorrected Proof

2011-09-05

We developed a hyperspectral microscopic imaging (HMI) platform that can precisely identify and quantify 10 molecular markers in individual cancer cells in a single pass. The exploitation of an improved separation of circulating tumor cells and the application of HMI provided an opportunity (1) to identify molecular changes in these cells, (2) to recognize the coexpression of these markers, (3) to pose an important opportunity for noninvasive diagnosis, and (4) to use targeted therapy. We balanced the intensity of 10 fluorochromes bound to 10 different antibodies, each specific to a particular tumor marker, so that the intensity of each fluorochrome can be discerned from overlapping emissions. Using 2 touch preps from each primary breast cancer, the average molecular marker intensities of 25 tumor cells gave a representative molecular signature for the tumor despite some cellular heterogeneity. The intensities determined by the HMI correlate well with the conventional 0–3+ analysis by experts in cellular pathology. Because additional multiplexes can be developed using the same fluorochromes but different antibodies, this analysis allows quantification of several molecular markers on individual tumor cells. HMI can be automated completely, and eventually, it could allow the standardization of protein biomarkers and improve reproducibility among clinical pathology laboratories.

γδ T cells and Th17 cytokines in hypersensitivity pneumonitis and lung fibrosis - Uncorrected Proof

2009-08-24

Hypersensitivity pneumonitis (HP) is an inflammatory lung disease caused by repeated inhalation of aerosolized antigens. With chronic exposure to an inhaled antigen, patients are at risk of developing irreversible pulmonary fibrosis and increased morbidity and mortality. Although αβ T cells have been shown to be important in the pathogenesis of HP, γδ T cells are also found and may protect against lung damage and fibrosis caused by chronic exposure to an inhaled pathogen. Th1 cytokines have been implicated in the pathogenesis of HP; yet patients with HP still develop pulmonary fibrosis suggesting that other T-cell cytokines may be involved. Th17 cytokines are a novel group of effector molecules expressed by various T lymphocytes, including γδ T cells. Th17-expressing γδ T cells are important for mucosal immunity against invading microbial pathogens and other inhaled antigens. An increased understanding of γδ T cells that express Th17 cytokines in HP may lead to the development of novel therapeutic and clinical strategies that prevent fibrotic lung disease in patients with HP.