bluuebunny/crossref_metadata_2025 huggingface dataset:
The Interaction between the Major Capsid Protein and the Smallest Capsid Protein of Human Cytomegalovirus Is Dependent on Two Linear Sequences in the Smallest Capsid Protein
Authors: Lai Lilin , Britt William J.
Published: January 2003

The assembly of human cytomegalovirus (HCMV) with recombinant systems has not been accomplished. An understanding of specific interactions between individual capsid proteins could point to unique characteristics of the assembly process of HCMV capsids. Similar to its herpes simplex virus counterpart, VP26 (UL35), the HCMV smallest capsid protein (SCP; UL48/49) decorates hexons in the mature capsid. In contrast to VP26, the HCMV SCP is essential for virus assembly. In this study we have shown that the major capsid protein (MCP) and the SCP interact in the cytoplasm of transfected cells and can be coprecipitated from insect cells expressing the MCP and the SCP. Using a two-hybrid reporter assay, we demonstrated that two linear sequences within the SCP are sufficient for SCP and MCP interactions.
Expression of the Major Histocompatibility Complex Class I Molecule Mamu-A*01 Is Associated with Control of Simian Immunodeficiency Virus SIVmac239 Replication
Authors: Mothé Bianca R. , Weinfurter Jason , Wang Chenxi , Rehrauer William , Wilson Nancy , Allen Todd M. , Allison David B. , Watkins David I.
Published: January 2003

Several HLA alleles are associated with attenuated human immunodeficiency virus disease progression. We explored the relationship between the expression of particular major histocompatibility complex (MHC) class I alleles and viremia in simian immunodeficiency virus SIVmac239-infected macaques. Of the common MHC class I alleles, animals that expressed Mamu-A*01 exhibited the best control of viral replication.
Adeno-Associated Virus Type 2-Mediated Gene Transfer: Role of Cellular T-Cell Protein Tyrosine Phosphatase in Transgene Expression in Established Cell Lines In Vitro and Transgenic Mice In Vivo
Authors: Qing Keyun , Li Weiming , Zhong Li , Tan Mengqun , Hansen Jonathan , Weigel-Kelley Kirsten A. , Chen Linyuan , Yoder Mervin C. , Srivastava Arun
Published: January 2003

The use of adeno-associated virus type 2 (AAV) vectors has gained attention as a potentially useful alternative to the more commonly used retrovirus and adenovirus vectors for human gene therapy. However, the transduction efficiency of AAV vectors varies greatly in different cells and tissues in vitro and in vivo. We have documented that a cellular protein that binds the immunosuppressant drug FK506, termed the FK506-binding protein (FKBP52), interacts with the single-stranded D sequence within the AAV inverted terminal repeats, inhibits viral second-strand DNA synthesis, and consequently limits high-efficiency transgene expression (K. Qing, J. Hansen, K. A. Weigel-Kelley, M. Tan, S. Zhou, and A. Srivastava, J. Virol., 75: 8968-8976, 2001). FKBP52 can be phosphorylated at both tyrosine and serine/threonine residues, but only the phosphorylated forms of FKBP52 interact with the D sequence. Furthermore, the tyrosine-phosphorylated FKBP52 inhibits AAV second-strand DNA synthesis by greater than 90%, and the serine/threonine-phosphorylated FKBP52 causes ∼40% inhibition, whereas the dephosphorylated FKBP52 has no effect on AAV second-strand DNA synthesis. In the present study, we have identified that the tyrosine-phosphorylated form of FKBP52 is a substrate for the cellular T-cell protein tyrosine phosphatase (TC-PTP). Deliberate overexpression of the murine wild-type (wt) TC-PTP gene, but not that of a cysteine-to-serine (C-S) mutant, caused tyrosine dephosphorylation of FKBP52, leading to efficient viral second-strand DNA synthesis and resulting in a significant increase in AAV-mediated transduction efficiency in HeLa cells in vitro. Both wt and C-S mutant TC-PTP expression cassettes were also used to generate transgenic mice. Primitive hematopoietic stem/progenitor cells from wt TC-PTP-transgenic mice, but not from C-S mutant TC-PTP-transgenic mice, could be successfully transduced by recombinant AAV vectors. These studies corroborate the fact that tyrosine phosphorylation of the cellular FKBP52 protein strongly influences AAV transduction efficiency, which may have important implications in the optimal use of AAV vectors in human gene therapy.
Targeted Retroviral Infection of Tumor Cells by Receptor Cooperation
Authors: Martin Francisco , Chowdhury Simon , Neil Stuart J. , Chester Kerry A. , Cosset Francois-Loic , Collins Mary K.
Published: January 2003

Retroviruses expressing two different receptor-binding domains linked by proline-rich spacers infect only cells expressing both retroviral receptors (Valsesia-Wittman et al., EMBO J. 6:1214-1223, 1997). Here we apply this receptor cooperation strategy to target human tumor cells by linking single-chain antibodies recognizing tumor antigens via proline-rich spacers to the 4070A murine leukemia virus surface protein.
Identification of a TAP-Independent, Immunoproteasome-Dependent CD8+T-Cell Epitope in Epstein-Barr Virus Latent Membrane Protein 2
Authors: Lautscham Georg , Haigh Tracey , Mayrhofer Sabine , Taylor Graham , Croom-Carter Debbie , Leese Alison , Gadola Stephan , Cerundolo Vincenzo , Rickinson Alan , Blake Neil
Published: January 2003

We have identified an HLA-A2-restricted CD8+T-cell epitope, FLYALALLL, in the Epstein-Barr virus (EBV) latent membrane protein 2 (LMP2), an important target antigen in the context of EBV-associated malignancies. This epitope is TAP independent, like other hydrophobic LMP2-derived epitopes, but uniquely is dependent upon the immunoproteasome for its generation.
Human Immunodeficiency Virus Type 1 Attachment, Coreceptor, and Fusion Inhibitors Are Active against both Direct andtransInfection of Primary Cells
Authors: Ketas Thomas J. , Frank Ines , Klasse Per Johan , Sullivan Brian M. , Gardner Jason P. , Spenlehauer Catherine , Nesin Mirjana , Olson William C. , Moore John P. , Pope Melissa
Published: January 2003

Inhibitors of human immunodeficiency virus type 1 attachment (CD4-immunoglobulin G subclass 2), CCR5 usage (PRO 140), and fusion (T-20) were tested on diverse primary cell types that represent the major targets both for infection in vivo and for the inhibition oftransinfection of target cells by virus bound to dendritic cells. Although minor cell-type-dependent differences in potency were observed, each inhibitor was active on each cell type andtransinfection was similarly vulnerable to inhibition at each stage of the fusion cascade.
Characterization of Tissue Tropism Determinants of Adeno-Associated Virus Type 1
Authors: Hauck Bernd , Xiao Weidong
Published: January 2003

Muscle is an attractive target for gene delivery because of its mass and because vectors can be delivered in a noninvasive fashion. Adeno-associated virus (AAV) has been shown to be effective for muscle-targeted gene transfer. Recent progress in characterization of AAV serotype 1 (AAV1) and AAV6 demonstrated that these two AAV serotypes are far more efficient in transducing muscle than is the traditionally used AAV2. Since all
cis
elements are identical in these vectors, the potential determinants for their differences in transducing muscle appear to be located within the AAV capsid proteins. In the present study, a series of AAV capsid mutants were generated to identify the major regions affecting AAV transduction efficiency in muscle. Replacement of amino acids 350 to 736 of AAV2 VP1 with the corresponding amino acids from VP1 of AAV1 resulted in a hybrid vector that behaved very similarly to AAV1 in vitro and in vivo in muscle. Characterization of additional mutants carrying smaller regions of the AAV1 VP1 amino acid sequence in the AAV2 capsid protein suggested that amino acids 350 to 430 of VP1 function as a major tissue tropism determinant. Further analysis showed that the heparin binding domain and the major antigenic determinants in the AAV capsid region were not necessary for the efficiency of AAV1 transduction of muscle.
Kinetics of Virus-Specific CD8+-T-Cell Expansion and Trafficking following Central Nervous System Infection
Authors: Marten Norman W. , Stohlman Stephen A. , Zhou Jiehao , Bergmann Cornelia C.
Published: January 2003

CD8+T cells control acute infection of the central nervous system (CNS) by neurotropic mouse hepatitis virus but do not suffice to achieve sterile immunity. To determine the lag between T-cell priming and optimal activity within the CNS, the accumulation of virus-specific CD8+T cells in the CNS relative to that in peripheral lymphoid organs was assessed by using gamma interferon-specific ELISPOT assays and class I tetramer staining. Virus-specific CD8+T cells were first detected in the cervical lymph nodes. Expansion in the spleen was delayed and less pronounced but also preceded accumulation in the CNS. The data further suggest peripheral acquisition of cytolytic function, thus enhancing CD8+-T-cell effector function upon cognate antigen recognition in the CNS.
The Latency-Associated Nuclear Antigen of Kaposi's Sarcoma-Associated Herpesvirus Permits Replication of Terminal Repeat-Containing Plasmids
Authors: Grundhoff Adam , Ganem Don
Published: January 2003

The latency-associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus can associate with mitotic chromosomes and promote latent episome maintenance and segregation. Here we report that LANA also mediates the replication of plasmid DNAs bearing viral terminal repeats. The predicted secondary structure of LANA's C terminus reveals striking similarity to the known structure of the DNA-binding domain of Epstein-Barr virus EBNA1, despite the absence of primary sequence homology between these proteins, suggesting conservation of the key mechanistic features of latent gammaherpesvirus DNA replication.
Molecular Chaperone GRP78/BiP Interacts with the Large Surface Protein of Hepatitis B Virus In Vitro and In Vivo
Authors: Cho Dae-Yeon , Yang Gi-Hyeok , Ryu Chun Jeih , Hong Hyo Jeong
Published: January 2003

The proper folding and assembly of viral envelope proteins are mediated by host chaperones. In this study, we demonstrated that an endoplasmic reticulum luminal chaperone GRP78/BiP bound specifically to the pre-S1 domain of the L protein in vitro and in vivo where complete viral particles were secreted, suggesting that GRP78/BiP plays an essential role in the proper folding of the L protein and/or assembly of viral envelope proteins.
Molecular Characterization of Bovine Enteric Caliciviruses: a Distinct Third Genogroup of Noroviruses (Norwalk-Like Viruses) Unlikely To Be of Risk to Humans
Authors: Oliver S. L. , Dastjerdi A. M. , Wong S. , El-Attar L. , Gallimore C. , Brown D. W. G. , Green J. , Bridger J. C.
Published: January 2003

Bovine enteric caliciviruses (BoCVs) have been classified in theNorovirus(Norwalk-like virus) genus of theCaliciviridae,raising questions about zoonotic transmission and an animal reservoir for the human Norwalk-like viruses (NLVs), an important cause of nonbacterial gastroenteritis in humans. We examined the genetic relationship of human NLVs to BoCVs that were identified by using reverse transcription-PCR with primer pairs originally designed to detect human NLVs. Polymerase, capsid, and open reading frame 3 (ORF3) gene sequence analyses of BoCVs that were identified from 1976 to 2000 from throughout the United Kingdom showed that BoCVs formed a distinct third genogroup of closely related viruses distinct from the human genogroup I and II NLVs. Evidence was not obtained to support the concept that BoCVs are circulating in humans and pose a threat to human health.
Exposure-response relations among laboratory animal workers exposed to rats
Authors: Nieuwenhuijsen M J , Putcha V , Gordon S , Heederik D , Venables K M , Cullinan P , Newman-Taylor A J
Published: January 2003

Aim:To explore exposure-response relations in a cohort of laboratory animal workers.

Methods:Exposure-response modelling was carried out in a cohort of 342 laboratory animal workers. Three exposure indices, divided into different exposure categories, were used in the analyses: intensity of exposure to rat urinary aeroallergen (RUA, the main allergen workers were exposed to), weekly duration of exposure to rats, and the product of the intensity and weekly duration of exposure. Outcomes studied were work related chest, eyes and nose, and skin symptoms that had started after employment at the sites, specific sensitisation, and a combination of symptoms and sensitisation. Cox proportional hazard modelling was used to explore exposure-response relations. Smoking, atopic status, age, and gender were taken into account.

Results:We observed the clearest exposure-response relations for the intensity of exposure to RUA and the various endpoints. No clear exposure-response relations were observed for the weekly duration of exposure or the product of the intensity and weekly duration of exposure. The strongest and clearest exposure-response relations for symptoms were observed among rat sensitised workers, while the non-sensitised workers only showed small increased risks of developing symptoms without clear exposure-response relations. Sensitised workers were almost four times more likely to go on to develop chest symptoms compared to non-sensitised workers.
A longitudinal observation of early pulmonary responses to cotton dust
Authors: Wang X-R , Pan L-D , Zhang H-X , Sun B-X , Dai H-L , Christiani D C
Published: January 2003

Aims:To examine early adverse pulmonary effects of exposure to cotton dust, and to identify potential risk factors, including atopy for pulmonary responses to cotton dust.

Methods:Spirometry, methacholine challenge testing, and questionnaire; performed among 101 non-smoking newly hired textile workers at baseline (prior to starting work), and at 3, 12, and 18 months after starting work. Concentrations of airborne cotton dust in various work areas were measured at each follow up survey using vertical elutriators.

Results:The incidence of non-specific respiratory symptoms was 8% at three months, then diminished afterwards. Substantial acute cross shift drops in FEV1at each follow up survey, and longitudinal declines in FVC and FEV1after 12 months of exposure were observed. Airway responsiveness to methacholine increased with follow up time, and was more pronounced among atopics. Increasing airway responsiveness was strongly correlated with cross shift drops in FEV1. In addition, one or more respiratory symptoms at three months was significantly, and pre-existing atopy marginally significantly, associated with cross shift drops in FEV1after adjusting for other covariates and confounders.

Conclusion:Results suggest that non-specific respiratory symptoms, decreasing lung function, and increasing airway responsiveness are early pulmonary responses to cotton dust. In addition, the occurrence of respiratory symptoms and increasing airway responsiveness, as well as atopy, may be important predictors for acute changes in lung function among cotton textile workers.
Occupational silica exposure and risk of various diseases: an analysis using death certificates from 27 states of the United States
Authors: Calvert G M , Rice F L , Boiano J M , Sheehy J W , Sanderson W T
Published: January 2003

Background:Although crystalline silica exposure is associated with silicosis, lung cancer, pulmonary tuberculosis, and chronic obstructive pulmonary disease (COPD), there is less support for an association with autoimmune disease, and renal disease.

Methods:Using data from the US National Occupational Mortality Surveillance (NOMS) system, a matched case-control design was employed to examine each of several diseases (including silicosis, lung cancer, stomach cancer, oesophageal cancer, COPD, pulmonary tuberculosis, sarcoidosis, systemic lupus erythematosus, systemic sclerosis, rheumatoid arthritis, and various types of renal disease). Cases were subjects whose death certificate mentioned the disease of interest. A separate control group for each of the diseases of interest was selected from among subjects whose death certificate did not mention the disease of interest or any of several diseases reported to be associated with crystalline silica exposure. Subjects were assigned into a qualitative crystalline silica exposure category based on the industry/occupation pairing found on their death certificate. We also investigated whether silicotics had a higher risk of disease compared to those without silicosis.

Results:Those postulated to have had detectable crystalline silica exposure had a significantly increased risk for silicosis, COPD, pulmonary tuberculosis, and rheumatoid arthritis. In addition, a significant trend of increasing risk with increasing silica exposure was observed for these same conditions and for lung cancer. Those postulated to have had the greatest crystalline silica exposure had a significantly increased risk for silicosis, lung cancer, COPD, and pulmonary tuberculosis only. Finally, those with silicosis had a significantly increased risk for COPD, pulmonary tuberculosis, and rheumatoid arthritis.

Conclusions:This study corroborates the association between crystalline silica exposure and silicosis, lung cancer, COPD, and pulmonary tuberculosis. In addition, support is provided for an association between crystalline silica exposure and rheumatoid arthritis.
Reported incidence of occupational asthma in France, 1996–99: the ONAP programme
Authors: Ameille J , Pauli G , Calastreng-Crinquand A , Vervloët D , Iwatsubo Y , Popin E , Bayeux-Dunglas M C , Kopferschmitt-Kubler M C
Published: January 2003

Aims:To estimate the general and specific incidence of occupational asthma in France in 1996–99; and to describe the distribution of cases by age, sex, suspected causal agents, and occupation.

Methods:New cases of occupational asthma were collected by a national surveillance programme, based on voluntary reporting, named Observatoire National des Asthmes Professionnels (ONAP), involving a network of occupational and chest physicians. For each case, the reporting form included information on age, sex, location of workplace, occupation, suspected causal agent, and methods of diagnosis. Estimates of the working population, used to calculate incidence rates by age, sex, region, and occupation, were obtained from the Institut National de la Statistique et des Etudes Economiques (INSEE) and from the French Securite Sociale statistics.

Results:In 1996–99, 2178 cases of occupational asthma were reported to the ONAP, giving a mean annual rate of 24/million. Rates in men were higher than rates in women (27/million versus 19/million). The highest rate was observed in the 15–29 years age group (30/million). The most frequently incriminated agents were flour (20.3%), isocyanates (14.1%), latex (7.2%), aldehyde (5.9%), persulphate salts (5.8%), and wood dusts (3.7%). The highest risks of occupational asthma were found in bakers and pastry makers (683/million), car painters (326/million), hairdressers (308/million), and wood workers (218/million).

Conclusion:Despite likely underreporting, the number of cases of occupational asthma reported to the ONAP was approximately twice the number of compensated cases over the same period. The relevance of the programme is confirmed by the reproducibility of the results year after year, and its consistency with other surveillance programmes. The ONAP programme is useful for the identification of targets for primary prevention.
Fluid losses and hydration status of industrial workers under thermal stress working extended shifts
Authors: Brake D J , Bates G P
Published: January 2003

Aims:To assess whether workers under significant thermal stress necessarily dehydrated during their exposure and whether “involuntary dehydration” was inevitable, as supported by ISO 9866 and other authorities. Other objectives were to quantify sweat rates against recommended occupational limits, to develop a dehydration protocol to assist with managing heat exposures, and to understand the role of meal breaks on extended shifts in terms of fluid replacement.

Methods:A field investigation to examine the fluid consumption, sweat rates, and changes in the hydration state of industrial workers on extended (10, 12, and 12.5 hour) shifts under significant levels of thermal stress (wet bulb globe temperature (WBGT) >28°C) was conducted on 39 male underground miners. Urinary specific gravity was measured before, during, and at the completion of the working shift. Environmental conditions were measured hourly during the shift. Fluid replacement was measured during the working periods and during the meal breaks.

Results:Average environmental conditions were severe (WBGT 30.9°C (SD 2.0°C), range 25.7–35.2°C). Fluid intake averaged 0.8 l/h during exposure (SD 0.3 l/h, range 0.3–1.5 l/h). Average urinary specific gravity at start, mid, and end of shift was 1.0251, 1.0248, and 1.0254 respectively; the differences between start and mid shift, mid and end shift, and start and end shift were not significant. However, a majority of workers were coming to work in a moderately hypohydrated state (average urinary specific gravity 1.024 (SD 0.0059)). A combined dehydration and heat illness protocol was developed. Urinary specific gravity limits of 1.022 for start of shift and 1.030 for end of shift were selected; workers exceeding these values were not allowed into the workplace (if the start of shift limit was exceeded) or were retested prior to their next working shift (if the end of shift limit was exceeded). A target of 1.015 as a euhydrated state for start of shift was adopted for workforce education.

Conclusions:This study found that “involuntary dehydration” did not occur in well informed workers, which has implications for heat stress standards that do not make provision for full fluid replacement during heat exposure. Fluid replacement during meal breaks was not significantly increased above fluid replacement rates during work time, with implications for the duration and spacing of meal breaks on long shifts. Testing of urinary specific gravity was found to be a good indication of hydration status and a practical method of improving workforce awareness and understanding of this important risk factor. Approximately 10 000 dehydration tests have been conducted under the dehydration protocol in a workforce of 2000 persons exposed to thermal stress and has proved practical and reliable.
Exposure related mutagens in urine of rubber workers associated with inhalable particulate and dermal exposure
Authors: Vermeulen R , Bos R P , Pertijs J , Kromhout H
Published: January 2003

Aims:To determine the relation of the inhalation and dermal exposure routes and mutagenic activity in the urine of rubber workers (n = 105).

Methods:Mutagenic activity of ambient total suspended particulate matter (TSPM), surface contamination wipes, and Sunday and weekday urine samples was assessed withS typhimuriumYG1041 in the presence of a metabolic activation system. Each subject was grouped into one of two exposure categories for dermal exposure (high (≥25 revertants/cm2), low (<25 revertants/cm2)) based on the mutagenic activity detected on likely skin contact surfaces and into two airborne mutagenic exposure categories (high (≥210 revertants/m3), low (<210 revertants/m3)). The potential influence of skin aberrations and acetylation status (NAT2) on urinary mutagenicity levels was also evaluated.

Results:A non-significant increase of +1605 revertants/g creatinine in urinary mutagenicity during the workweek relative to levels observed on Sunday was observed for the total population. Subsequent multivariate regression analyses, with the subjects’ weekday urinary mutagenicity levels as the dependent variable, revealed associations with environmental and mainstream tobacco smoke exposure, with the level of mutagenic contamination on surfaces with which the subjects had likely contact, with the subjects’ inhalable particulate exposure level, with observed mild skin aberrations, and when the subjects had a slow acetylation phenotype. Similar associations, although weaker were observed with Sunday urinary mutagenicity levels as well, except for the association with slow acetylation phenotype. Based on measured exposure levels it could be estimated that a high potential for exposure to surface contamination with mutagenic activity increased weekday urinary mutagenicity by about 62% when compared to low exposed workers, while high inhalable particulate exposure levels increased weekday urinary mutagenicity levels by about 21%. Subjects with mild skin aberrations had an additional, non-significant, increase in weekday urinary mutagenic activity compared to subjects without any skin aberrations.

Discussion:Results suggest that the dermal exposure route may contribute more to the level of genotoxic compounds in urine of rubber workers than the inhalation route. Although the study was limited in size, the results warrant further investigation in the importance of and ways to effectively control the dermal exposure route in the rubber industry.
Localization, Macromolecular Associations, and Function of the Small Heat Shock–Related Protein HSP20 in Rat Heart
Authors: Pipkin Walter , Johnson John A. , Creazzo Tony L. , Burch Jarrett , Komalavilas Padmini , Brophy Colleen
Published: January 2003

Background—

The small heat shock proteins HSP20, HSP25, αB-crystallin, and myotonic dystrophy kinase binding protein (MKBP) may regulate dynamic changes in the cytoskeleton. For example, the phosphorylation of HSP20 has been associated with relaxation of vascular smooth muscle. This study examined the function of HSP20 in heart muscle.

Methods and Results—

Western blotting identified immunoreactive HSP20, αB-crystallin, and MKBP in rat heart homogenates. Subcellular fractionation demonstrated that HSP20, αB-crystallin, and MKBP were predominantly in cytosolic fractions. Chromatography with molecular sieving columns revealed that HSP20 and αB-crystallin were associated in an aggregate of ≈200 kDa, and αB-crystallin coimmunoprecipitated with HSP20. Immunofluorescence microscopy demonstrated that the pattern of HSP20, αB-crystallin, and actin staining was predominantly in transverse bands. Treatment with sodium nitroprusside led to increases in the phosphorylation of HSP20, as determined with 2-dimensional immunoblots. Incubation of transiently permeabilized myocytes with phosphopeptide analogues of HSP20 led to an increase in the rate of shortening. The increased shortening rate was associated with an increase in the rate of lengthening and a more rapid decay of the calcium transient.

Conclusions—

HSP20 is associated with αB-crystallin, possibly at the level of the actin sarcomere. Phosphorylated HSP20 increases myocyte shortening rate through increases in calcium uptake and more rapid lengthening.
Noninvasive Assessment of Angiogenesis by Ultrasound and Microbubbles Targeted to α
v
-Integrins
Authors: Leong-Poi Howard , Christiansen Jonathan , Klibanov Alexander L. , Kaul Sanjiv , Lindner Jonathan R.
Published: January 2003

Background—

Noninvasive methods for characterizing neovessel formation during angiogenesis are currently lacking. We hypothesized that angiogenesis could be imaged with the use of contrast-enhanced ultrasound (CEU) with microbubbles targeted to α
v
-integrins.

Methods and Results—

Microbubbles targeted to α
v
-integrins were prepared by conjugating echistatin (MB
E
) or monoclonal antibody against murine α
v
(MB
α
) to their surface. Control microbubbles (MB
c
) were also prepared. The microvascular behavior of these microbubbles was assessed by intravital microscopy of the cremaster muscle in mice treated for 4 days with sustained-release FGF-2. Microvascular retention was much greater (
P
<0.01) for MB
E
(11±6 mm
−3
) and MB
α
(10±7 mm
−3
) than that for MB
c
(1±1 mm
−3
). Retained MB
E
and MB
α
attached directly to the microvascular endothelial surface. Microbubble retention in 4 control mice was minimal. Subcutaneous matrigel plugs enriched with FGF-2 were created in 12 mice and studied 10 days later. Neovessels within the matrigel stained positive for α
v
-integrins. CEU demonstrated greater (
P
<0.01) acoustic intensity for MB
E
(16.0±5.9 U) and MB
α
(17.0±5.5 U) compared with MB
c
(5.8±2.6 U). The signal from targeted microbubbles (MB
E
and MB
α
) correlated well (
r
=0.90) with the matrigel blood volume determined by CEU perfusion imaging.

Conclusions—

CEU with microbubbles targeted for α
v
-integrins may provide a noninvasive method for assessing therapeutic angiogenesis.
FKBP12.6-Mediated Stabilization of Calcium-Release Channel (Ryanodine Receptor) as a Novel Therapeutic Strategy Against Heart Failure
Authors: Yano Masafumi , Kobayashi Shigeki , Kohno Masateru , Doi Masahiro , Tokuhisa Takahiro , Okuda Shinichi , Suetsugu Masae , Hisaoka Takayuki , Obayashi Masakazu , Ohkusa Tomoko , Kohno Michihiro , Matsuzaki Masunori
Published: January 2003

Background—

The development of heart failure is tightly correlated with a decrease in the stoichiometric ratio for FKBP12.6 binding to the ryanodine receptor (RyR) in the sarcoplasmic reticulum (SR). We report that a new drug, the 1,4-benzothiazepine derivative JTV519, reverses this pathogenic process. JTV519 is known to have a protective effect against Ca
2+
overload–induced myocardial injury.

Methods and Results—

Heart failure was produced by 4 weeks of rapid right ventricular pacing, with or without JTV519; SR were then isolated from dog left ventricular (LV) muscles. First, in JTV519-treated dogs, no signs of heart failure were observed after 4 weeks of chronic right ventricular pacing, LV systolic and diastolic functions were largely preserved, and LV remodeling was prevented. Second, JTV519 acutely inhibited both the FK506-induced Ca
2+
leak from RyR in normal SR and the spontaneous Ca
2+
leak in failing SR. Third, there was no abnormal Ca
2+
leak in SR vesicles isolated from JTV519-treated hearts. Fourth, in JTV519-treated hearts, both the stoichiometry of FKBP12.6 binding to RyR and the amount of RyR-bound FKBP12.6 were restored toward the values seen in normal SR. Fifth, in JTV519-untreated hearts, RyR was PKA-hyperphosphorylated, whereas it was reversed in JTV519-treated hearts, returning the channel phosphorylation toward the levels seen in normal hearts.

Conclusions—

During the development of experimental heart failure, JTV519 prevented the amount of RyR-bound FKBP12.6 from decreasing. This in turn reduced the abnormal Ca
2+
leak through the RyR, prevented LV remodeling, and led to less severe heart failure.
Impact of Glucose Intolerance and Insulin Resistance on Cardiac Structure and Function
Authors: Rutter Martin K. , Parise Helen , Benjamin Emelia J. , Levy Daniel , Larson Martin G. , Meigs James B. , Nesto Richard W. , Wilson Peter W.F. , Vasan Ramachandran S.
Published: January 2003

Background—

Although insulin resistance has been implicated in the pathogenesis of left ventricular (LV) hypertrophy, previous studies have yielded inconsistent results and are limited by referral bias.

Methods and Results—

We examined the relations between echocardiographic LV measurements and glucose tolerance status in 2623 Framingham Study subjects (1514 women, mean age 53 years) free of myocardial infarction and heart failure. We also evaluated the relations of insulin resistance (homeostasis model, HOMA-IR) and LV and left atrial (LA) measures within the normal and abnormal glucose tolerance categories (the latter included impaired glucose tolerance, impaired fasting glucose, and newly diagnosed diabetes). LV mass (adjusted for age, height, heart rate, and systolic blood pressure) increased across categories of worsening glucose tolerance; the trend was more striking in women (
P
<0.001) compared with men (
P
=0.054). In subjects with normal (n=2022) and abnormal glucose tolerance (n=327), covariate-adjusted LV mass and LV wall thickness increased across HOMA-IR quartiles in women (
P
<0.001) but not men. In contrast, covariate-adjusted LA size increased with worsening glucose tolerance and across HOMA-IR quartiles in the normal and abnormal glucose tolerance groups in both sexes. Adjustment for body mass index considerably attenuated the relations of LV/LA measures and HOMA-IR, rendering them statistically nonsignificant in the normal glucose tolerance group.

Conclusions—

In our large community-based sample, LV mass and wall thickness increased with worsening glucose intolerance, an effect that was more striking in women compared with men. Insulin resistance was associated with increased LV mass in women alone, but this relation was largely accounted for by obesity.
Taurine and Vitamin C Modify Monocyte and Endothelial Dysfunction in Young Smokers
Authors: Fennessy F.M. , Moneley D.S. , Wang J.H. , Kelly C.J. , Bouchier-Hayes D.J.
Published: January 2003

Background—

Endothelial dysfunction initiated by monocyte-endothelial interactions has previously been observed in many vasculopathies, including chronic cigarette smoking. Taurine, a semiessential amino acid, and vitamin C, a naturally occurring antioxidant, have previously been shown to have endothelial protective effects when exposed to proinflammatory insults. Therefore, we hypothesized that taurine and vitamin C would restore endothelial function in young smokers by modifying monocyte-endothelial interactions.

Methods and Results—

Endothelial-dependent vasodilatation was assessed in vivo using duplex ultrasonography, and monocyte-endothelial interactions were assessed in vitro using endothelial cell culture (human umbilical vein endothelial cells [HUVECs]) with monocyte-conditioned medium (MCM). Endothelial-dependent vasodilatation was significantly impaired in young smokers compared with nonsmokers. Pretreatment of young smokers for 5 days with 2 g/d vitamin C and, more significantly, with 1.5 g/d taurine attenuated this response. MCM taken from smokers impaired the release of nitric oxide and increased the levels of endothelin-1 release from HUVECs. When HUVECs were cultured with MCM from smokers who had been treated with taurine, the levels of nitric oxide and endothelin-1 returned toward control levels. This was attributed to an upregulation in endothelial nitric oxide synthase expression.

Conclusions—

These observations suggest that taurine supplementation has a beneficial impact on macrovascular endothelial function, and an investigation of its effect on altered endothelial function in dyslipidemic states is warranted.
Intramyocardial Transplantation of Autologous Endothelial Progenitor Cells for Therapeutic Neovascularization of Myocardial Ischemia
Authors: Kawamoto Atsuhiko , Tkebuchava Tengis , Yamaguchi Jun-Ichi , Nishimura Hiromi , Yoon Young-Sup , Milliken Charles , Uchida Shigeki , Masuo Osamu , Iwaguro Hideki , Ma Hong , Hanley Allison , Silver Marcy , Kearney Marianne , Losordo Douglas W. , Isner Jeffrey M. , Asahara Takayuki
Published: January 2003

Background—

We investigated whether catheter-based, intramyocardial transplantation of autologous endothelial progenitor cells can enhance neovascularization in myocardial ischemia.

Methods and Results—

Myocardial ischemia was induced by placement of an ameroid constrictor around swine left circumflex artery. Four weeks after constrictor placement, CD31+ mononuclear cells (MNCs) were freshly isolated from the peripheral blood of each animal. After overnight incubation of CD31+ MNCs in noncoated plates, nonadhesive cells (NA/CD31+ MNCs) were harvested as the endothelial progenitor cell–enriched fraction. Nonadhesive CD31− cells (NA/CD31− MNCs) were also prepared. Autologous transplantation of 10
7
NA/CD31+ MNCs, 10
7
NA/CD31− MNCs, or PBS was performed with a NOGA mapping injection catheter to target ischemic myocardium. In a parallel study, 10
5
human CD34+ MNCs, 10
5
human CD34− MNCs, or PBS was transplanted into ischemic myocardium of nude rats 10 minutes after ligation of the left anterior descending coronary artery. In the swine study, ischemic area by NOGA mapping, Rentrop grade angiographic collateral development, and echocardiographic left ventricular ejection fraction improved significantly 4 weeks after transplantation of NA/CD31+ MNCs but not after injection of NA/CD31− MNCs or PBS. Capillary density in ischemic myocardium 4 weeks after transplantation was significantly greater in the NA/CD31+ MNC group than the control groups. In the rat study, echocardiographic left ventricular systolic function and capillary density were significantly better preserved in the CD34+ MNC group than in the control groups 4 weeks after myocardial ischemia.

Conclusions—

These favorable outcomes encourage future clinical trials of catheter-based, intramyocardial transplantation of autologous CD34+ MNCs in the setting of chronic myocardial ischemia.
Effect of Nifedipine and Cerivastatin on Coronary Endothelial Function in Patients With Coronary Artery Disease
Authors:   The ENCORE Investigators
Published: January 2003

Background—

Endothelial dysfunction is an important feature of atherosclerosis. Inhibition of the HMG-CoA pathway and of calcium channels improves endothelial function experimentally and in the forearm circulation. Thus, we investigated the effects of a statin and/or a calcium antagonist on coronary endothelial function in patients with coronary artery disease (CAD).

Methods and Results—

In 343 patients undergoing percutaneous coronary intervention in 29 centers, acetylcholine (10
−6
to 10
−4
mol/L) was infused in a coronary segment without angiographically significant CAD. Changes in coronary diameter were measured by quantitative angiography. Endothelium-independent responses were assessed by intracoronary adenosine (1.2 mg/mL) and nitroglycerin (250 μg). Thereafter, patients were randomized in a double-blind manner to placebo, cerivastatin 0.4 mg/d, nifedipine 30 to 60 mg/d, or their combination. Studies were repeated at 6 months. In the most constricted segment, nifedipine but not cerivastatin reduced vasoconstriction to acetylcholine (18.8% versus placebo 10.0%;
P
<0.05). Patients not taking ACE inhibitors showed a smaller improvement in the placebo group (6.0%), but nifedipine still had an effect (17.0%;
P
<0.05 versus placebo). Analysis of all evaluable coronary segments revealed an 11% reduction of acetylcholine-induced vasoconstriction in patients receiving nifedipine and cerivastatin (
P
<0.05 versus placebo). Cerivastatin lowered LDL cholesterol by 35% (
P
<0.001).

Conclusions—

The ENCORE I trial demonstrates that multicenter studies on coronary endothelial function are feasible. After 6 months’ treatment, nifedipine improved coronary endothelial function in the most constricted segment. The combination of nifedipine and cerivastatin tended to improve endothelial function; however, this only reached significance in an analysis of all coronary segments.
Acute Intravenous
l
-Arginine Infusion Decreases Endothelin-1 Levels and Improves Endothelial Function in Patients With Angina Pectoris and Normal Coronary Arteriograms
Authors: Piatti PierMarco , Fragasso Gabriele , Monti Lucilla D. , Setola Emanuela , Lucotti Pietro , Fermo Isabella , Paroni Rita , Galluccio Elena , Pozza Guido , Chierchia Sergio , Margonato Alberto
Published: January 2003

Background—

We tested the hypothesis that asymmetric dimethylarginine (ADMA) levels could be elevated and influence endothelin-1 and nitric oxide release and action in patients with cardiac syndrome X (CSX). In addition, we evaluated whether an intravenous infusion of
l
-arginine would improve endothelial function in these subjects.

Methods and Results—

Nine patients with CSX and 14 control subjects underwent a continuous infusion of
l
-arginine (0.125 g/min) or saline for 120 minutes. Sixty minutes after
l
-arginine or saline infusions, an intravenous insulin bolus (0.1 U/kg) combined with a euglycemic clamp was performed. Basal ADMA and endothelin-1 levels were higher in patients with CSX than in controls. At the end of the first hour of infusion, compared with saline,
l
-arginine infusion increased basal forearm blood flow, nitrite and nitrate (NOx), and forearm cGMP release and decreased endothelin-1. After insulin bolus, during saline, insulin-induced NOx, endothelin-1, and forearm cGMP release was almost abolished. Conversely,
l
-arginine restored a physiological profile of all endothelial variables compared with control subjects. In control subjects, compared with saline infusion,
l
-arginine infusion did not modify any parameter. ADMA levels were positively correlated with basal endothelin-1 levels and negatively correlated with insulin-induced incremental levels of NOx and forearm cGMP release.

Conclusions—

Plasma ADMA levels are increased in patients with CSX, and they are correlated with increases in endothelin-1 and reductions in insulin-induced increments in plasma NOx and cGMP, effects that are reversed by intravenous
l
-arginine. These data suggest that increased ADMA levels play a role in the abnormal vascular reactivity that is observed in patients with CSX.
Selective COX-2 Inhibition Improves Endothelial Function in Coronary Artery Disease
Authors: Chenevard Rémy , Hürlimann David , Béchir Markus , Enseleit Frank , Spieker Lukas , Hermann Matthias , Riesen Walter , Gay Steffen , Gay Renate E. , Neidhart Michel , Michel Beat , Lüscher Thomas F. , Noll Georg , Ruschitzka Frank
Published: January 2003

Background—

There is an ongoing debate as to whether the gastrointestinal safety of COX-2 inhibition compared with nonsteroidal antiinflammatory drugs (NSAIDs) may come at the cost of increased cardiovascular events. In view of the large number of patients at cardiovascular risk requiring chronic analgesic therapy with COX-2 inhibitors for arthritic and other inflammatory conditions, the effects of selective COX-2 inhibition on clinically useful surrogates for cardiovascular disease, particularly endothelial function, need to be determined.

Methods and Results—

Fourteen male patients (mean age, 66±3 years) with severe coronary artery disease (average of 2.6 vessels with stenosis >75%) undergoing stable background therapy with aspirin and statins were included. The patients received celecoxib (200 mg BID) or placebo for a duration of 2 weeks in a double-blind, placebo-controlled, crossover fashion. After each treatment period, flow-mediated dilation of the brachial artery, high-sensitivity C-reactive protein, oxidized LDL, and prostaglandins were measured. Celecoxib significantly improved endothelium-dependent vasodilation compared with placebo (3.3±0.4% versus 2.0±0.5%,
P
=0.026), whereas endothelium-independent vasodilation, as assessed by nitroglycerin, remained unchanged (9.0±1.6% versus 9.5±1.3%,
P
=0.75). High-sensitivity C-reactive protein was significantly lower after celecoxib (1.3±0.4 mg/L) than after placebo (1.8±0.5 mg/L,
P
=0.019), as was oxidized LDL (43.6±2.4 versus 47.6±2.6 U/L,
P
=0.028), whereas prostaglandins did not change.

Conclusions—

This is the first study to demonstrate that selective COX-2 inhibition improves endothelium-dependent vasodilation and reduces low-grade chronic inflammation and oxidative stress in coronary artery disease. Thus, selective COX-2 inhibition holds the potential to beneficially impact outcome in patients with cardiovascular disease.
Two-Year Angiographic and Intravascular Ultrasound Follow-Up After Implantation of Sirolimus-Eluting Stents in Human Coronary Arteries
Authors: Sousa J. Eduardo , Costa Marco A. , Sousa Amanda G.M.R. , Abizaid Alexandre C. , Seixas Ana C. , Abizaid Andrea S. , Feres Fausto , Mattos Luiz A. , Falotico Robert , Jaeger Judith , Popma Jeffrey J. , Serruys Patrick W.
Published: January 2003

Background—

The safety and efficacy of sirolimus-eluting stenting have been demonstrated, but the outcome of patients treated with this novel technology beyond the first year remains unknown. We sought to evaluate the angiographic, intravascular ultrasound (IVUS), and clinical outcomes of patients treated with sirolimus-eluting stents 2 years after implantation.

Methods and Results—

This study included 30 patients treated with sirolimus-eluting Bx Velocity stenting (slow release [SR], n=15, and fast release [FR], n=15) in São Paulo, Brazil. Twenty-eight patients underwent 2-year angiographic and IVUS follow-up. No deaths occurred during the study period. In-stent late loss was slightly greater in the FR group (0.28±0.4 mm) than in the SR group (−0.09±0.23 mm,
P
=0.007). No patient had in-stent restenosis. At 2-year follow-up, only 1 patient (FR group) had a 52% diameter stenosis within the lesion segment, which required repeat revascularization. The target-vessel revascularization rate for the entire cohort was 10% (3/30) at 2 years. All other patients had ≤35% diameter stenosis. Angiographic lumen loss at the stent edges was also minimal (in-lesion late loss was 0.33±0.42 mm [FR] and 0.13±0.29 mm [SR]). In-stent neointimal hyperplasia volume, as detected by IVUS, remained minimal after 2 years (FR= 9.90±9 mm
3
and SR=10.35±9.3 mm
3
).

Conclusions—

This study demonstrates the safety and efficacy of sirolimus-eluting Bx Velocity stents 2 years after implantation in humans. In-stent lumen dimensions remained essentially unchanged at 2-year follow-up in the 2 groups, although angiographic lumen loss was slightly higher in the FR group. Restenosis “catch-up” was not found in our patient population.
A Critical Study of the Mechanical and Electrical Properties of the PHANToM Haptic Interface and Improvements for Highperformance Control
Authors: Çavuşoğlu Murat Cenk , Feygin David , Tendick Frank
Published: January 2003

This paper presents a critical study of the mechanical and electrical properties of the PHANToM haptic interface and improvements to overcome its limitations for applications requiring high-performance control. Target applications share the common requirements of low-noise/granularity/latency measurements, an accurate system model, high bandwidth, the need for an open architecture, and the ability to operate for long periods without interruption while exerting significant forces. To satisfy these requirements, the kinematics, dynamics, high-frequency dynamic response, and velocity estimation of the PHANToM system are studied. Furthermore, this paper presents the details of how the unknown subsystems of the stock PHANToM can be replaced with known, high-performance systems and how additional measurement electronics can be interfaced to compensate for some of the PHANToM's shortcomings. With these modifications, it is possible to increase the maximum achievable virtual wall stiffness by 35%, active viscous damping by 120%, and teleoperation loop gain by 50% over the original system. With the modified system, it is also possible to maintain higher forces for longer periods without causing motor overheating.
Enhanced Presence in Driving Simulators Using Autonomous Traffic with Virtual Personalities
Authors: Wright Steve , Ward Nicholas J. , Cohn Anthony G.
Published: January 2003

The paper summarizes a project to increase the sense of presence within a driving simulator while interacting with autonomous traffic. The project sought to model natural variations in ambient traffic to emulate identifiable driving styles for different categories of driver. Probability distributions combined with decision histories were employed to characterize speed choice while providing a mechanism for introducing temporal and spatial variation in speed changes. These efforts produced “virtual personalities” representing different categories of ambient traffic including generic, male, female, old, drunk, aggressive, cautious, and fatigued. A user evaluation of the ambient traffic concluded that naturalistic variation in behavior can significantly contribute to the subjective realism of the interaction with traffic simulation.