bluuebunny/crossref_metadata_2025 huggingface dataset:
Attenuation of Equine Influenza Viruses through Truncations of the NS1 Protein
Authors: Quinlivan Michelle , Zamarin Dmitriy , García-Sastre Adolfo , Cullinane Ann , Chambers Thomas , Palese Peter
Published: June 2005

Equine influenza is a common disease of the horse, causing significant morbidity worldwide. Here we describe the establishment of a plasmid-based reverse genetics system for equine influenza virus. Utilizing this system, we generated three mutant viruses encoding carboxy-terminally truncated NS1 proteins. We have previously shown that a recombinant human influenza virus lacking the NS1 gene (delNS1) could only replicate in interferon (IFN)-incompetent systems, suggesting that the NS1 protein is responsible for IFN antagonist activity. Contrary to previous findings with human influenza virus, we found that in the case of equine influenza virus, the length of the NS1 protein did not correlate with the level of attenuation of that virus. With equine influenza virus, the mutant virus with the shortest NS1 protein turned out to be the least attenuated. We speculate that the basis for attenuation of the equine NS1 mutant viruses generated is related to their level of NS1 protein expression. Our findings show that the recombinant mutant viruses are impaired in their ability to inhibit IFN production in vitro and they do not replicate as efficiently as the parental recombinant strain in embryonated hen eggs, in MDCK cells, or in vivo in a mouse model. Therefore, these attenuated mutant NS1 viruses may have potential as candidates for a live equine influenza vaccine.
DNA Vaccines Expressing Different Forms of Simian Immunodeficiency Virus Antigens Decrease Viremia upon SIVmac251 Challenge
Authors: Rosati Margherita , von Gegerfelt Agneta , Roth Patricia , Alicea Candido , Valentin Antonio , Robert-Guroff Marjorie , Venzon David , Montefiori David C. , Markham Phil , Felber Barbara K. , Pavlakis George N.
Published: June 2005

We have tested the efficacy of DNA immunization as a single vaccination modality for rhesus macaques followed by highly pathogenic SIVmac251 challenge. To further improve immunogenicity of the native proteins, we generated expression vectors producing fusion of the proteins Gag and Env to the secreted chemokine MCP3, targeting the viral proteins to the secretory pathway and to a β-catenin (CATE) peptide, targeting the viral proteins to the intracellular degradation pathway. Macaques immunized with vectors expressing the MCP3-tagged fusion proteins developed stronger antibody responses. Following mucosal challenge with pathogenic SIVmac251, the vaccinated animals showed a statistically significant decrease in viral load (P= 0.010). Interestingly, macaques immunized with a combination of vectors expressing three forms of antigens (native protein and MCP3 and CATE fusion proteins) showed the strongest decrease in viral load (P= 0.0059). Postchallenge enzyme-linked immunospot values for Gag and Env as well asgag-specific T-helper responses correlated with control of viremia. Our data show that the combinations of DNA vaccines producing native and modified forms of antigens elicit more balanced immune responses able to significantly reduce viremia for a long period (8 months) following pathogenic challenge with SIVmac251.
Activation of the Kaposi's Sarcoma-Associated Herpesvirus Major Latency Locus by the Lytic Switch Protein RTA (ORF50)
Authors: Matsumura Satoko , Fujita Yuriko , Gomez Evan , Tanese Naoko , Wilson Angus C.
Published: June 2005

Kaposi's sarcoma-associated herpesvirus (KSHV) maintains a latent infection in primary effusion lymphoma cells but can be induced to enter full lytic replication by exposure to a variety of chemical inducing agents or by expression of the KSHV-encoded replication and transcription activator (RTA) protein. During latency, only a few viral genes are expressed, and these include the three genes of the so-called latency transcript (LT) cluster: v-FLIP (open reading frame 71 [ORF71]), v-cyclin (ORF72), and latency-associated nuclear antigen (ORF73). During latency, all three open reading frames are transcribed from a common promoter as part of a multicistronic mRNA. Subsequent alternative mRNA splicing and internal ribosome entry allows for the expression of each protein. Here, we show that transcription of LT cassette mRNA can be induced by RTA through the activation of a second promoter (LTi) immediately downstream of the constitutively active promoter (LTc). We identified a minimalcis-regulatory region, which overlaps with the promoter for the bicistronic K14/v-GPCR delayed early gene that is transcribed in the opposite direction. In addition to a TATA box at −30 relative to the LTimRNA start sites, we identified three separate RTA response elements that are also utilized by the K14/v-GPCR promoter. Interestingly, LTiis unresponsive to sodium butyrate, a potent inducer of lytic replication. This suggests there is a previously unrecognized class of RTA-responsive promoters that respond to direct, but not indirect, induction of RTA. These studies highlight the fact that induction method can influence the precise program of viral gene expression during early events in reactivation and also suggest a mechanism by which RTA contributes to establishment of latency during de novo infections.
Characterization of a Novelvpu-Harboring Simian Immunodeficiency Virus from a Dent's Mona Monkey (Cercopithecus mona denti)
Authors: Dazza Marie-Christine , Ekwalanga Michel , Nende Monique , Shamamba Karhemere Bin , Bitshi Pitchou , Paraskevis Dimitrios , Saragosti Sentob
Published: June 2005

We report the identification of a new simian immunodeficiency virus (SIV), designated SIVden, in a naturally infected Dent's Mona monkey (Cercopithecus mona denti), which was kept as pet in Kinshasa, capital of the Democratic Republic of Congo. SIVden is genetically distinct from the previously characterized primate lentiviruses. Analysis of the full-length genomic sequence revealed the presence of avpuopen reading frame. This gene is also found in the virus lineage of human immunodeficiency virus type 1 (HIV-1) and chimpanzee immunodeficiency virus (SIVcpz) and was recently described in viruses isolated fromCercopithecus nictitans,Cercopithecus mona, andCercopithecus cephus. The SIVdenvpucoding region is shorter than the HIV-1/SIVcpz and the SIVgsn, SIVmon, and SIVmus counterparts. UnlikePan troglodytes schweinfurthiiviruses (SIVcpzPts) andCercopithecusmonkey viruses (SIVgsn, SIVmon, and SIVmus), the SIVden Vpu contains the characteristic DSGXES motif which was shown to be involved in Vpu-mediated CD4 and IκBα proteolysis in HIV-1 infected cells. Although it harbors avpugene, SIVden is phylogenetically closer to SIVdeb isolated from De Brazza's monkeys (Cercopithecus neglectus), which lacks avpugene, than toCercopithecusmonkey viruses, which harbor avpusequence.
pH-Induced Conformational Change of the Rotavirus VP4 Spike: Implications for Cell Entry and Antibody Neutralization
Authors: Pesavento Joseph B. , Crawford Sue E. , Roberts Ed , Estes Mary K. , Prasad B. V. Venkataram
Published: June 2005

The rotavirus spike protein, VP4, is a major determinant of infectivity and neutralization. Previously, we have shown that trypsin-enhanced infectivity of rotavirus involves a transformation of the VP4 spike from a flexible to a rigid bilobed structure. Here we show that at elevated pH the spike undergoes a drastic, irreversible conformational change and becomes stunted, with a pronounced trilobed appearance. These particles with altered spikes, at a normal pH of 7.5, despite the loss of infectivity and the ability to hemagglutinate, surprisingly exhibit sialic acid (SA)-independent cell binding in contrast to the SA-dependent cell binding exhibited by native virions. Remarkably, a neutralizing monoclonal antibody that remains bound to spikes throughout the pH changes (pH 7 to 11 and back to pH 7) completely prevents this conformational change, preserving the SA-dependent cell binding and hemagglutinating functions of the virion. A hypothesis that emerges from the present study is that high-pH treatment triggers a conformational change that mimics a post-SA-attachment step to expose an epitope recognized by a downstream receptor in the rotavirus cell entry process. This process involves sequential interactions with multiple receptors, and the mechanism by which the antibody neutralizes is by preventing this conformational change.
Initiation and Exacerbation of Autoimmune Demyelination of the Central Nervous System via Virus-Induced Molecular Mimicry: Implications for the Pathogenesis of Multiple Sclerosis
Authors: Croxford J. Ludovic , Olson Julie K. , Anger Holly A. , Miller Stephen D.
Published: June 2005

Epidemiological studies indicate that infectious agents are important in the pathogenesis of multiple sclerosis (MS). Our previous reports showed that the infection of SJL mice with a nonpathogenic variant of Theiler's murine encephalomyelitis virus (TMEV) engineered to express a naturally occurringHaemophilus influenzae-encoded molecular mimic (HI574-586) of an immunodominant self-myelin proteolipid protein epitope (PLP139-151) induced a rapid-onset demyelinating disease associated with the activation of PLP139-151-specific Th1 responses. The current results extend our previous findings in four critical respects. We show that disease initiation by theH. influenzaemimic is prevented by tolerance to the self PLP139-151epitope, definitively proving the occurrence of infection-induced molecular mimicry. We demonstrate that theH. influenzaemimic epitope can be processed from the flanking sequences within the native mimic protein. We show that theH. influenzaemimic epitope only induces an immunopathologic self-reactive Th1 response and subsequent clinical disease in the context of the TMEV infection and not when administered in complete Freund's adjuvant, indicating that molecular mimicry-induced disease initiation requires virus-activated innate immune signals. Lastly, we show that the infection of SJL mice with TMEV expressing theH. influenzaemimic can exacerbate a previously established nonprogressive autoimmune disease of the central nervous system. Collectively, these findings illustrate the evolving mechanisms by which virus infections may contribute to both the initiation and exacerbation of autoimmune diseases, and they have important implications for MS pathogenesis.
Identification of Paramyxovirus V Protein Residues Essential for STAT Protein Degradation and Promotion of Virus Replication
Authors: Nishio Machiko , Tsurudome Masato , Ito Morihiro , Garcin Dominique , Kolakofsky Daniel , Ito Yasuhiko
Published: June 2005

Some paramyxovirus V proteins induce STAT protein degradation, and the amino acids essential for this process in the human parainfluenza virus type 2 (hPIV2) V protein have been studied. Various recombinant hPIV2s and cell lines constitutively expressing various mutant V proteins were generated. We found that V proteins with replacement of Cys residues of the Cys cluster were still able to bind STATs but were unable to induce their degradation. The hPIV2 V protein binds STATs via a W-(X)
3
-W-(X)
9
-W Trp motif located just upstream of the Cys cluster. Replacements of two or more Trp residues in this motif resulted in a failure to form a V/STAT2 complex. We have also identified two Phe residues of the hPIV2 V protein that are essential for STAT degradation, namely, Phe207, lying within the Cys cluster, and Phe143, in the P/V common region of the protein. Interestingly, infection of BHK cells with hPIV2 led to the specific degradation of STAT1 and not STAT2. Other evidence for the cell species specificity of hPIV2-induced STAT degradation is presented. Finally, a V-minus hPIV2, which can express only the P protein from its P gene, was generated and partially characterized. In contrast to V-minus viruses of other paramyxovirus genera, this V-minus rubulavirus was highly debilitated, and its growth even in Vero cells was very limited. The structural rubulavirus V proteins, as expected, are thus clearly important in promoting virus growth, independent of their anti-interferon (IFN) activity. Interestingly, many of the residues that are essential for anti-IFN activity, e.g., the Cys of this cluster and Phe207 within this cluster, as well as the Trp of this motif, are also essential for promoting virus growth.
A Small Interfering RNA Targeting Coxsackievirus B3 Protects Permissive HeLa Cells from Viral Challenge
Authors: Ahn Jeonghyun , Jun Eun Seok , Lee Hui Sun , Yoon Seung Yong , Kim DongHou , Joo Chul-Hyun , Kim Yoo Kyum , Lee Heuiran
Published: June 2005

We examined the ability of small interfering RNAs (siRNAs) to disrupt infection by coxsackievirus B3 (CVB3). The incorporation of siRNAs dramatically decreased cell death in permissive HeLa cells in parallel with a reduction in viral replication. Three of four siRNAs had potent anti-CVB3 activity. The present study thus demonstrates that the antiviral effect is due to the downregulation of viral replication. In addition, an effective CVB3-specific siRNA had similar antiviral effects in other related enteroviruses possessing sequence homology in the targeted region. Because the CVB3-specific siRNA is effective against other enteroviruses, siRNAs have potential for a universal antienterovirus strategy.
Growth of Respiratory Syncytial Virus in Primary Epithelial Cells from the Human Respiratory Tract
Authors: Wright Peter F. , Ikizler Mine R. , Gonzales Ricardo A. , Carroll Kecia N. , Johnson Joyce E. , Werkhaven Jay A.
Published: June 2005

Respiratory syncytial virus (RSV) is the most important cause of lower respiratory tract disease in infants and children. To study RSV replication, we have developed an in vitro model of human nasopharyngeal mucosa, human airway epithelium (HAE). RSV grows to moderate titers in HAE, though they are significantly lower than those in a continuous epithelial cell line, HEp-2. In HAE, RSV spreads over time to form focal collections of infected cells causing minimal cytopathic effect. Unlike HEp-2 cells, in which wild-type and live-attenuated vaccine candidate viruses grow equally well, the vaccine candidates exhibit growth in HAE that parallels their level of attenuation in children.
Risk, rationality, and regret: responding to the uncertainty of childhood food anaphylaxis
Authors: Hu W , Kerridge I , Kemp A
Published: June 2005

Risk and uncertainty are unavoidable in clinical medicine. In the case of childhood food allergy, the dysphoric experience of uncertainty is heightened by the perception of unpredictable danger to young children. Medicine has tended to respond to uncertainty with forms of rational decision making. Rationality cannot, however, resolve uncertainty and provides an insufficient account of risk. This paper compares the medical and parental accounts of two peanut allergic toddlers to highlight the value of emotions in decision making. One emotion in particular,regret, assists in explaining the actions taken to prevent allergic reactions, given the diffuse nature of responsibility for children. In this light, the assumption that doctors make rational judgments while patients have emotion led preferences is a false dichotomy. Reconciling medical and lay accounts requires acknowledgement of the interrelationship between the rational and the emotional, and may lead to more appropriate clinical decision making under conditions of uncertainty.
The medical palimpsest ofThe Scarlet Letter: an interdisciplinary reading
Authors: Dolezal J
Published: June 2005

The multiple historical layers of Roger Chillingworth’s character have been overlooked in criticism ofThe Scarlet Letter. By considering the possible influence of Robert Browning’s dramatic poemParacelsus(1835) on Hawthorne’s romance (1850), as well as the ways in which overtones of both herbalism and clinical medicine complicate Chillingworth’s character, one rediscovers Chillingworth as Hawthorne’s audience likely experienced him: as a fictional palimpsest bearing multiple inscriptions of medical history that reveal an interplay between integrity and corruption. Thus, an interdisciplinary reading ofThe Scarlet Letterchallenges the conventional critical assessment of Chillingworth as a satanic or Faustian figure.
Medicine through the novel:Lying Awake
Authors: Glannon W
Published: June 2005

Narrative fiction can engage readers in generating imaginative recreations of the inner worlds of doctors and patients, which are largely inaccessible through typical clinical case analysis. Fiction about medicine can yield insight into patients’ subjective experience of illness and can highlight the need for an empathetic response from doctors to patients affected by illness. Mark Salzman’s novel,Lying Awake,invites us to reflect on social, psychological, and spiritual dimensions of neurological illness in particular and of the doctor/patient relationship in general.
“Of the edgelands”: broadening the scope of qualitative methodology
Authors: Rapport F , Wainwright P , Elwyn G
Published: June 2005

In an editorial in a previous issue of this journal Rapportet alintroduced the metaphor of the edgelands, arguing that the area between urban and rural landscapes serves to illustrate some of the difficulties of interdisciplinarity experienced by those who work in the medical humanities. In this paper the authors explore some specific issues of qualitative research methodology in health care research. The paper describes a broadening out of the scope of qualitative inquiry in social scientific research in health and social care. The paper explains why some new methodologies have emerged and how both old and new methodologies are grouped around three interlocking strands: narrative based, arts based, and redefined, methodology. In order to illustrate developments in this field, the authors present three examples of the use of these methodologies in practice: photo elicitation technique; discourse analytic, and interpretive anthropological, method. Finally the authors illustrate how these methodologies can give added value to health services research.
Jane Austen’s lifelong health problems and final illness: New evidence points to a fatal Hodgkin’s disease and excludes the widely accepted Addison’s
Authors: Upfal A
Published: June 2005

Jane Austen is typically described as having excellent health until the age of 40 and the onset of a mysterious and fatal illness, initially identified by Sir Zachary Cope in 1964 as Addison’s disease. Her biographers, deceived both by Cassandra Austen’s destruction of letters containing medical detail, and the cheerful high spirits of the existing letters, have seriously underestimated the extent to which illness affected Austen’s life. A medical history reveals that she was particularly susceptible to infection, and suffered unusually severe infective illnesses, as well as a chronic conjunctivitis that impeded her ability to write. There is evidence that Austen was already suffering from an immune deficiency and fatal lymphoma in January 1813, when her second and most popular novel,Pride and Prejudice, was published. Four more novels would follow, written or revised in the shadow of her increasing illness and debility. Whilst it is impossible now to conclusively establish the cause of her death, the existing medical evidence tends to exclude Addison’s disease, and suggests there is a high possibility that Jane Austen’s fatal illness was Hodgkin’s disease, a form of lymphoma.
How to make the most of history and literature in the teaching of medical humanities: the experience of the University of Geneva
Authors: Louis-Courvoisier M , Wenger A
Published: June 2005

In this paper the authors discuss the benefits of history and literature in the teaching of medical humanities. They suggest that human sciences produce a common effect, which they calldistancing. Distancing is the awareness that one natural way to describe a given situation does not exist and that any point of view—scientific or not—is context dependant and culturally shaped. Distancing is important to medical students, by allowing them to become aware of the specificity of their own professional point of view. The authors offer a reflection on the specificities of both historical and literary approaches and on the tools they provide for medical students. This paper assumes there is a close link between the theoretical debate on the benefits provided by human sciences and the concrete framework of a given programme. The authors describe team teaching, which has been the solution adopted in the School of Medicine at the University of Geneva to obtain the most from history and literature.
IL-6 is not required for parathyroid hormone stimulation of RANKL expression, osteoclast formation, and bone loss in mice
Authors: O'Brien Charles A. , Jilka Robert L. , Fu Qiang , Stewart Scott , Weinstein Robert S. , Manolagas Stavros C.
Published: June 2005

Continuous elevation of parathyroid hormone (PTH) increases osteoclast precursors, the number of osteoclasts on cancellous bone, and bone turnover. The essential molecular mediators of these effects are controversial, however, and both increased receptor activator of NF-κB ligand (RANKL) and IL-6 have been implicated. The goal of these studies was to determine whether continuous elevation of endogenous PTH alters IL-6 gene expression in vivo and whether IL-6 is required for PTH-induced bone loss. To accomplish this, we generated transgenic mice harboring a luciferase reporter gene under the control of IL-6 gene regulatory regions to allow accurate quantification of IL-6 gene activity in vivo. In these mice, induction of secondary hyperparathyroidism using a calcium-deficient diet did not alter IL-6-luciferase transgene expression, whereas RANKL mRNA expression was elevated in bone tissue. Moreover, secondary hyperparathyroidism induced an equivalent amount of bone loss in wild-type and IL-6-deficient mice, and PTH elevated RANKL mRNA and osteoclast formation to the same extent in bone marrow cultures derived from wild-type and IL-6-deficient mice. These results demonstrate that IL-6 is not required for the osteoclast formation and bone loss that accompanies continuous elevation of PTH.
Bax translocates from cytosol to mitochondria in cardiac cells during apoptosis: development of a GFP-Bax-stable H9c2 cell line for apoptosis analysis
Authors: Hou Qi , Hsu Yi-Te
Published: June 2005

The proapoptotic protein Bax plays an important role in cardiomyocytic cell death. Ablation of this protein has been shown to diminish cardiac damage in Bax-knockout mice during ischemia-reperfusion. Presently, studies of Bax-mediated cardiac cell death examined primarily the expression levels of Bax and its prosurvival factor Bcl-2 rather than the localization of this protein, which dictates its function. Using immunofluorescence labeling, we have shown that in neonatal rat cardiomyocytes and in H9c2 cardiomyoblasts, Bax translocates from cytosol to mitochondria upon the induction of apoptosis by hypoxia-reoxygenation-serum withdrawal and by the presence of the free-radical inducer menadione. Also, we found that Bax translocation to mitochondria was associated with the exposure of an NH2-terminal epitope, and that this translocation could be partially blocked by the prosurvival factors Bcl-2 and Bcl-XL. To visualize the translocation of Bax in living cells, we have developed an H9c2 cell line that stably expresses green fluorescent protein (GFP)-tagged Bax. This cell line has GFP-Bax localized primarily in the cytosol in the absence of apoptotic inducers. Upon induction of apoptosis by a number of stimuli, including menadione, staurosporine, sodium nitroprusside, and hypoxia-reoxygenation-serum withdrawal, we could observe the translocation of Bax from cytosol to mitochondria. This translocation was not affected by retinoic acid-induced differentiation of H9c2 cells. Additionally, this translocation was associated with loss of mitochondrial membrane potential, release of cytochrome c, and fragmentation of nuclei. Finally, using a tetramethylrhodamine-based dye, we have shown that a rapid screening process based on the loss of mitochondrial membrane potential could be developed to monitor GFP-Bax translocation to mitochondria. Overall, the GFP-Bax-stable H9c2 cell line that we have developed represents a unique tool for examining Bax-mediated apoptosis, and it could be of great importance in screening therapeutic compounds that could block Bax translocation to mitochondria to attenuate apoptosis.
Transcriptional reprogramming during reloading of atrophied rat soleus muscle
Authors: Flück Martin , Schmutz Silvia , Wittwer Matthias , Hoppeler Hans , Desplanches Dominique
Published: June 2005

The hypothesis was tested that differential, coregulated transcriptional adaptations of various cellular pathways would occur early with increased mechanical loading of atrophied skeletal muscle and relate to concurrent damage of muscle fibers. Atrophy and slow-to-fast fiber transformation of rat soleus muscle was provoked by 14 days of hindlimb suspension (HS). Subsequent reloading of hindlimbs caused a fourfold increase in the percentage of muscle fibers, demonstrating endomysial tenascin-C staining. Five days after reloading, when 10% of the fibers were damaged, the normal muscle weight and slow-type fiber percentage were reestablished. Microarray analysis revealed major, biphasic patterns of gene expressional alterations with reloading that distinguish between treatments and gene ontologies. Transcript levels of factors involved in protein synthesis and certain proteasomal mRNAs were increased after 1 day of reloading and correlated to the percentage of fibers surrounded by tenascin-C. By contrast, levels of gene messages for fatty acid transporters, respiratory chain constituents, and voltage-gated cation channels were transiently reduced after 1 day of muscle loading and associated with the number of damaged fibers and the regain in muscle weight. This coregulation points toward important retooling of oxidative metabolism and the T- and SR-tubular systems with rebuilding of slow fibers. The observations demonstrate that early nuclear reprogramming with reloading of atrophic soleus muscle is coordinated and links to the processes involved in mechanical damage and regeneration of muscle fibers.
Involvement of tyrosine kinase and PI3K in the regulation of OAT3-mediated estrone sulfate transport in isolated rabbit renal proximal tubules
Authors: Soodvilai S. , Wright S. H. , Dantzler W. H. , Chatsudthipong V.
Published: June 2005

It was shown previously that OAT3 activity was differentially regulated by protein kinases including MAPK, PKA, and PKC. The present study investigated the short-term effect of tyrosine kinase and phosphatidylinositol 3-kinase (PI3K) on OAT3-mediated organic anion transport in S2 segments of renal proximal tubules. Genistein, a tyrosine kinase inhibitor, and wortmannin, a PI3K inhibitor, inhibited transport of estrone sulfate, a prototypic substrate for OAT3, in a dose-dependent manner. Previously, we showed that epidermal growth factor (EGF) stimulated OAT3 activity via the MAPK pathway. In the present study, we investigated whether EGF-stimulated OAT3 activity was dependent on tyrosine kinase and PI3K. We showed that EGF stimulation of OAT3 was reduced by inhibition of tyrosine kinase or PI3K, suggesting that they play a role in the stimulatory process. Inhibitory effects also indicated that tyrosine kinase and PI3K are involved in the MAPK pathway for EGF stimulation of OAT3 in intact renal proximal tubules, with PI3K acting upstream and tyrosine kinase acting downstream of mitogen-activated/extracellular signal-regulated kinase kinase activation.
Accumulation of CXCR3-Expressing Eosinophils and Increased Concentration of Its Ligands (IP10 and Mig) in Bronchoalveolar Lavage Fluid of Patients with Chronic Eosinophilic Pneumonia
Authors: Katoh Shigeki , Fukushima Kiyoyasu , Matsumoto Nobuhiro , Ehara Naomi , Matsumoto Kiyoshi , Yamauchi Akira , Hirashima Mitsuomi
Published: June 2005

Background: Since human peripheral eosinophils have been shown to migrate to the CXC chemokine receptor 3 (CXCR3) ligands IFN-γ-inducible protein 10 (IP10) and monokine induced by IFN-γ (Mig), this confirms that CXCR3 is functionally expressed on these cells. IP10 expression has been shown to be increased in the airways of asthmatics. Eosinophil accumulations are found in bronchoalveolar lavage fluid (BALF) from patients with chronic eosinophilic pneumonia (CEP). To examine the contribution of IP10 and Mig in the pathogenesis of CEP, we measured the concentration of IP10 and Mig, and evaluated the expression of CXCR3 on eosinophils in BALF taken from patients with CEP. Methods: The concentrations of IP10 and Mig in BALF were measured by ELISA. The proportion of CXCR3-expressing CD4+ T cells and CD16-negative eosinophils was determined by flow cytometry. Results: The BALF concentrations of IP10 and Mig were higher in patients with CEP, as well as in patients with sarcoidosis, when compared to healthy controls. The absolute number of CXCR3+ CD4+ T cells was significantly higher in the BALF of patients with sarcoidosis, but not in the patients with CEP, when compared to healthy volunteers. There were higher percentages of CXCR3-expressing eosinophils in the BALF than in the peripheral blood of patients with CEP. Conclusions: Our findings suggest that IP10 and Mig contribute to the accumulation of CXCR3-expressing eosinophils in the lungs of patients with CEP, and modulate the eosinophilic inflammation of the lung.
Non-Occlusive Mesenteric Ischemia in Chronically Dialyzed Patients: A Disease with Multiple Risk Factors
Authors: Ori Yaacov , Chagnac Avry , Schwartz Ariel , Herman Michal , Weinstein Talia , Zevin Dina , Gafter Uzi , Korzets Asher
Published: June 2005

Background: Non-occlusive mesenteric ischemia (NOMI) can be a fatal complication in dialysis patients. Intradialytic hypotension is usually the precipitating factor. The occurrence of 16 cases in 5 years (1998–2002), compared with only 4 in previous years, led us to investigate other risk factors contributing to NOMI. A control group of stable hemodialysis patients was used for comparison. Results: 20 patients were studied: 17 diagnosed surgically, and 3 clinically. The mean age was 70.8 ± 1.8 years, and the male:female ratio 7:13. Nineteen patients were on hemodialysis. Clinically overt atherosclerosis was present in 17 patients. Preceding dialysis-associated hypotension was identified in all patients studied and access thrombosis in 6 patients. In all patients, abdominal pain was the presenting symptom. Initial abdominal examination was unimpressive in 16 patients. The hemoconcentration, leukocytosis and metabolic acidosis were the most prominent laboratory findings. 5/11 abdominal sonograms showed intestinal pathology. 2/3 angiographies were diagnostic. Three patients responded to early fluid challenge and did not require surgery. Pathology was related to the area of the superior mesenteric artery in all 15 patients operated. Twelve (60%) patients died from the event. The 1-year mortality rate was 17/20 patients (85%). Possible contributing factors, other than dialysis-associated hypotension, included: high-dose recombinant human erythropoietin (rhEPO) therapy (179 ± 35 vs. 116 ± 10 U/kg/week in the control group, p < 0.05); metastatic calcifications (abdominal aorta 14/14, aortic valve 11/18; medial calcification of mesenteric arteries in 2/11 pathology specimens); digoxin, and hypoalbuminemia. Conclusions: The increased incidence of NOMI in dialysis patients may be related to overly aggressive rhEPO therapy and the unsuspected presence of mesenteric arterial medial calcifications. Identification of patients at risk, prevention of intradialytic hypotension and a controlled increase in dry weight may help to reduce the incidence of NOMI in chronically dialyzed patients.
Case-Control Study on Cellular and Cordless Telephones and the Risk for Acoustic Neuroma or Meningioma in Patients Diagnosed 2000–2003
Authors: Hardell Lennart , Carlberg Michael , Hansson Mild Kjell
Published: June 2005

We performed a case-control study on the use of cellular and cordless telephones and the risk for brain tumors. We report the results for benign brain tumors with data from 413 cases (89% response rate), 305 with meningioma, 84 with acoustic neuroma, 24 with other types and 692 controls (84% response rate). For meningioma, analogue phones yielded odds ratio (OR) = 1.7, 95% confidence interval (CI) = 0.97–3.0, increasing to OR = 2.1, 95% CI = 1.1–4.3 with a >10-year latency period. Also digital cellular phones and cordless phones increased the risk to some extent. For acoustic neuroma, analogue phones gave OR = 4.2, 95% CI = 1.8–10 increasing to OR = 8.4, 95% CI = 1.6–45 with a >15-year latency period, but based on low numbers. Digital phones yielded OR = 2.0, 95% CI = 1.05–3.8, whereas for cordless phones OR was not significantly increased. In the multivariate analysis, analogue phones represented a significant risk factor for acoustic neuroma.
Hyperinsulinemia and Insulin Insensitivity in Women with Nonclassical Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency: The Relationship between Serum Leptin Levels and Chronic Hyperinsulinemia
Authors: Saygılı F. , Oge A. , Yilmaz C.
Published: June 2005

Background/Aim: Nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NC-CAH) is associated with hyperandrogenemia, chronic anovulation, hirsutism, acne and adrenal hyperplasia. A few studies have shown hyperinsulinemia and insulin insensitivity in NC-CAH. Hyperinsulinemia can stimulate leptin secretion, and androgens can inhibit leptin secretion. Thus, we designed a study to investigate the insulin levels and insulin sensitivity and the effect of chronic endogenous hyperinsulinemia and androgens on leptin in patients with NC-CAH. Methods: Eighteen women with untreated NC-CAH and 26 normally cycling control women with a similar body mass index (BMI) were studied. Basal hormones, fasted and fed insulin levels, leptin and stimulated 17-hydroxyprogesterone (17-OHP) concentrations were studied. Homeostasis model assessment was used to assess insulin sensitivity. Results: The basal 17-OHP, the free testosterone (fT) and dehydroepiandrosterone sulfate (DHEA-S) were significantly different in the 2 groups (p < 0.05). Fasting and fed insulin levels of the NC-CAH group were higher than those of the control group (p < 0.05) and insulin sensitivity was lower in NC-CAH than in controls (p < 0.05). Insulin levels were correlated with fT and 17-OHP (p < 0.05). Serum leptin levels for NC-CAH (25.9 ± 12.5 µg/l) did not differ from the controls (25.4 ± 12.06 µg/l) and were positively correlated with BMI (r = 0.725) and percent body fat (r = 0.710) for both groups (both p < 0.001). Leptin levels were not correlated with estrogen or androgens, gonadotropins or insulin levels. Conclusion: Hyperinsulinemia and insulin insensitivity associated with hyperandrogenism were detected in untreated NC-CAH patients as in previous reports, whereas serum leptin levels did not differ from those of controls.
Oxidative Stress and Antioxidant Treatment in Hypertension and the Associated Renal Damage
Authors: Manning Jr. R. Davis , Tian Niu , Meng Shumei
Published: June 2005

Reactive oxygen species (ROS) are elevated in humans with hypertension many of which develop end-stage renal disease (ESRD), and antioxidant capacity is decreased. About one-half of essential hypertensives have a salt-sensitive type of hypertension, and the amount of renal damage that occurs in salt-sensitive hypertensives greatly exceeds that of non-salt-sensitive hypertensives. Antioxidant therapy can improve cardiovascular outcomes in humans but only if sufficient doses are used. Salt-sensitive hypertensive animal models, especially Dahl salt-sensitive rats, have been used to investigate the relationship between hypertension, ROS and end-stage renal damage. In experimental salt-sensitive hypertension, ROS increase and significant renal damage occur. In the Dahl salt-sensitive (S) rat on high Na for 3 weeks, renal damage is mild, renal levels of superoxide dismutase are decreased, and treatment with Tempol reduces arterial pressure. In the Dahl S rat on high Na for 5 weeks, renal damage is severe, GFR and renal plasma flow are decreased, and renal superoxide production is high. Treatment with vitamins C and E decreases renal superoxide production and renal damage and prevents the decrease in renal hemodynamics. Antioxidant treatment reduces arterial pressure, aortic superoxide production and renal inflammation in DOCA-salt rats, and decreases blood pressure and aortic superoxide release and increases bioactive nitric oxide in SHR stroke-prone rats. In conclusion, in both human and experimental salt-sensitive hypertension, superoxide production and renal damage are increased, antioxidant capacity is decreased, and antioxidant therapy can be helpful.
Therapeutic Potential of Endothelial Progenitor Cells in Cardiovascular Diseases
Authors: Dzau Victor J. , Gnecchi Massimiliano , Pachori Alok S. , Morello Fulvio , Melo Luis G.
Published: June 2005

Endothelial dysfunction and cell loss are prominent features in cardiovascular disease. Endothelial progenitor cells (EPCs) originating from the bone marrow play a significant role in neovascularization of ischemic tissues and in re-endothelialization of injured blood vessels. Several studies have shown the therapeutic potential of EPC transplantation in rescue of tissue ischemia and in repair of blood vessels and bioengineering of prosthetic grafts. Recent small-scale trials have provided preliminary evidence of feasibility, safety, and efficacy in patients with myocardial and critical limb ischemia. However, several studies have shown that age and cardiovascular disease risk factors reduce the availability of circulating EPCs (CEPCs) and impair their function to varying degrees. In addition, the relative scarcity of CEPCs limits the ability to expand these cells in sufficient numbers for some therapeutic applications. Priority must be given to the development of strategies to enhance the number and improve the function of CEPCs. Furthermore, alternative sources of EPC such as chord blood need to be explored. Strategies for improvement of cell adhesion, survival, and prevention of cell senescence are also essential to ensure therapeutic viability. Genetic engineering of EPCs may be a useful approach to developing these cells into efficient therapeutic tools. In the clinical arena there is pressing need to standardize the protocols for isolation, culture, and therapeutic application of EPC. Large-scale multi-center randomized trials are required to evaluate the long-term safety and efficacy of EPC therapy. Despite these hurdles, the outlook for EPC-based therapy for cardiovascular disease is promising.
C-Reactive Protein Elevation Predicts Pulse Pressure Reduction in Hypertensive Subjects
Authors: Amar Jacques , Ruidavets Jean-Bernard , Peyrieux Jean-Claude , Mallion Jean-Michel , Ferrières Jean , Safar Michel E. , Chamontin Bernard
Published: June 2005

Cross-sectional studies have shown a positive association between increased pulse pressure (PP) and an increased likelihood of a C-reactive protein (CRP) level >3 mg/L. In a retrospective subgroup analysis of the hypertensive subjects of the multicenter double-blind study, REASON (P
RE
terax in Regression of
A
rterial
S
tiffness in a Contr
O
lled Double-Bli
N
d), in which fixed first-line antihypertensive combination therapy with an angiotensin converting enzyme (ACE) inhibitor, perindopril (2 mg), and a diuretic, indapamide (0.625 mg), proved significantly more effective than atenolol in normalizing PP, we sought to determine whether perindopril plus indapamide was also more effective than atenolol in lowering CRP levels and, if so, whether this effect correlated with a preferential reduction in PP. At the final visit (12 months) in the 269 patients studied, the decrease in PP was greater, and the proportion of patients with CRP >3 mg/L lower (17.9% versus 28. 9%,
P
=0.03; adjusted odds ratio, 1.02 to 4.08,
P
=0.01), in the perindopril plus indapamide group than in the atenolol group. After adjustment for confounders, patients with a baseline CRP >3 mg/L displaying the greatest decrease in PP were more likely (
P
=0.04) to have a CRP ≤3 mg/L at 12 months. No such relationship was found with systolic or diastolic blood pressure. Perindopril–indapamide combination therapy is more effective than β-blockade in lowering elevated CRP in hypertensive subjects. This effect is significantly associated with a more effective PP reduction in patients with baseline CRP >3 mg/L.
Participation of Prostacyclin in Endothelial Dysfunction Induced by Aldosterone in Normotensive and Hypertensive Rats
Authors: Blanco-Rivero Javier , Cachofeiro Victoria , Lahera Vicente , Aras-Lopez Rosa , Márquez-Rodas Iván , Salaices Mercedes , Xavier Fabiano E. , Ferrer Mercedes , Balfagón Gloria
Published: June 2005

The aim of the present study was to analyze the possible involvement of vasoconstrictors prostanoids on the reduced endothelium-dependent relaxations produced by chronic administration of aldosterone in Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). For this purpose, acetylcholine (ACh) relaxations in aortic segments from both strains were analyzed in absence and presence of the cyclooxygenase-1 (COX-1) and COX-2 inhibitor indomethacin, the specific COX-2 inhibitor NS-398, the TP receptor antagonist (SQ 29 548), the thromboxane A
2
(TXA
2
) synthase inhibitor furegrelate, and the prostacyclin (PGI
2
) synthesis inhibitor tranylcypromine (TCP). In addition, COX-2 protein expression was studied by Western blot analysis. Release of prostaglandin E
2
(PGE
2
) and the metabolites of PGF
2α
, TXA
2
, and PGI
2
, 13,14-dihydro-15-keto PGF
2a
, TXB
2
, and 6-keto-PGF
1α
, respectively, were measured. Treatment with aldosterone did not modify blood pressure levels in any strain. However, aldosterone markedly reduced (
P
<0.05) ACh-induced relaxations in segments from both strains in a similar extent. Indomethacin, NS-398, SQ 29 548, and TCP enhanced (
P
<0.05) ACh relaxations in both strains treated with aldosterone. Aortic COX-2 protein expression was higher in both strains of rats treated with aldosterone. In normotensive animals, aldosterone increases the ACh-stimulated aortic production of 13,14-dihydro-15-keto PGF
2a,
PGE
2
, and 6-keto-PGF
1α
(
P
<0.05). In SHR, ACh only increased the 6-keto-PGF
1α
production (
P
<0.05). It could be concluded that chronic treatment with aldosterone was able to produce endothelial dysfunction through COX-2 activation in normotensive and hypertensive conditions. PGI
2
seems to be the main factor accounting for endothelial dysfunction in hypertensive rats, whereas other prostanoids besides PGI
2
appear to be involved in endothelial dysfunction under normotensive conditions.
Beneficial Effect of Oral Sildenafil Therapy on Childhood Pulmonary Arterial Hypertension
Authors: Humpl Tilman , Reyes Janette T. , Holtby Helen , Stephens Derek , Adatia Ian
Published: June 2005

Background—

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease. Sildenafil is a type 5 phosphodiesterase inhibitor and pulmonary vasodilator. Therefore, we hypothesized that sildenafil would improve distance walked in 6 minutes and hemodynamics in children with PAH.

Methods and Results—

After baseline assessment of hemodynamics by cardiac catheterization and distance walked in 6 minutes, we administered oral sildenafil at 0.25 to 1 mg/kg 4 times daily to 14 children (median age, 9.8 years; range, 5.3 to 18). Diagnoses were primary (n=4) and secondary (n=10) PAH. We repeated the 6-minute walk test at 6 weeks and at 3, 6, and 12 months (n=14) and cardiac catheterization (n=9) after a median follow-up of 10.8 months (range, 6 to 15.3). During sildenafil therapy, the mean distance walked in 6 minutes increased from 278±114 to 443±107 m over 6 months (
P
=0.02), and at 12 months, the distance walked was 432±156 m (
P
=0.005). A plateau was reached between 6 and 12 months (
P
=0.48). Mean pulmonary artery pressure decreased from a median of 60 mm Hg (range, 50 to 105) to 50 mm Hg (range, 38 to 84) mm Hg (
P
=0.014). Median pulmonary vascular resistance decreased from 15 Wood units m
2
(range, 9 to 42) to 12 Wood Units m
2
(range, 5 to 29) (
P
=0.024).

Conclusions—

Oral sildenafil has the potential to improve hemodynamics and exercise capacity for up to 12 months in children with PAH. Confirmation of these results in a randomized, controlled trial is essential.
Assessment of Endogenous and Therapeutic Arteriogenesis by Contrast Ultrasound Molecular Imaging of Integrin Expression
Authors: Leong-Poi Howard , Christiansen Jonathan , Heppner Peter , Lewis Christopher W. , Klibanov Alexander L. , Kaul Sanjiv , Lindner Jonathan R.
Published: June 2005

Background—

We hypothesized that molecular imaging with contrast-enhanced ultrasound (CEU) and microbubbles targeted to endothelial integrins could be used to noninvasively assess early angiogenic responses to ischemia and growth factor therapy.

Methods and Results—

Hindlimb ischemia was produced in 48 rats by ligation of an iliac artery. Half of the animals received intramuscular sustained-release fibroblast growth factor-2 (FGF-2). Immediately after ligation and at subsequent intervals from 4 to 28 days, blood flow and oxygen tension in the proximal adductor muscles were measured by CEU perfusion imaging and phosphor quenching, respectively. Targeted CEU imaging of α
v
- and α
5
β
1
-integrin expression was performed with microbubbles bearing the disintegrin echistatin. Iliac artery ligation produced a 65% to 70% reduction in blood flow and oxygen tension. In untreated ischemic muscle, muscle flow and oxygen tension partially recovered by days 14 to 28. In these animals, signal from integrin-targeted microbubbles was intense and peaked before flow increase (days 4 to 7). In comparison to untreated animals, FGF-2–treated muscle had a greater rate and extent of blood flow recovery and greater signal intensity from integrin-targeted microbubbles, which peaked before maximal recovery of flow. On immunohistology, arteriolar but not capillary density increased in the ischemic limb after ligation, the rate and degree of which were greater in FGF-2–treated rats. Immunofluorescence demonstrated intense staining for α
v
in arterioles, the temporal course of which correlated with targeted imaging.

Conclusions—

Targeted CEU can be used to assess endogenous and therapeutic arteriogenesis before recovery of tissue perfusion. These results suggest that molecular imaging of integrin expression may be useful for evaluating proangiogenic therapies.