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Deletion of a region of the human immunodeficiency virus type 2 (HIV-2) 5′ leader RNA reduces genomic RNA encapsidation to about 5% that of wild-type virus with no defect in viral protein production but severely limits virus spread in Jurkat T cells, indicating that this region contains a major cis -acting encapsidation signal, or psi (Ψ). Being upstream of the major splice donor, it is present on all viral transcripts. We have shown that HIV-2 selects its genomic RNA for encapsidation cotranslationally, rendering wild-type HIV-2 unable to encapsidate vector RNAs in trans . Virus with Ψ deleted, however, encapsidates an HIV-2 vector, demonstrating competition for Gag protein. HIV-2 overcomes the lack of packaging signal location specificity by two novel mechanisms, cotranslational packaging and competition for limiting Gag polyprotein.

Tissue oxygenation often plays a significant role in disease and is an essential design consideration for tissue engineering. Here, oxygen diffusion profiles of porcine aortic and mitral valve leaflets were determined using an oxygen diffusion chamber in conjunction with computational models. Results from these studies revealed the differences between aortic and mitral valve leaflet diffusion profiles and suggested that diffusion alone was insufficient for normal oxygen delivery in mitral valves. During fibrotic valve disease, leaflet thickening due to abnormal extracellular matrix is likely to reduce regional oxygen availability. To assess the impact of low oxygen levels on valve behaviour, whole leaflet organ cultures were created to induce leaflet hypoxia. These studies revealed a loss of layer stratification and elevated levels of hypoxia inducible factor 1-alpha in both aortic and mitral valve hypoxic groups. Mitral valves also exhibited altered expression of angiogenic factors in response to low oxygen environments when compared with normoxic groups. Hypoxia affected aortic and mitral valves differently, and mitral valves appeared to show a stenotic, rheumatic phenotype accompanied by significant cell death. These results indicate that hypoxia could be a factor in mid to late valve disease progression, especially with the reduction in chondromodulin-1 expression shown by hypoxic mitral valves.

Objective— Although valvular endothelial cells have unique responses compared with vascular endothelial cells, valvular regulation of hemostasis is not well-understood. Heart valves remodel throughout a person’s lifetime, resulting in changes in extracellular matrix composition and tissue mechanical properties that may affect valvular endothelial cell hemostatic function. This work assessed valvular endothelial cell regulation of hemostasis in situ and in vitro as a function of specimen age. Approach and Results— Porcine aortic valves were assigned to 1 of 3 age groups: Young (YNG) (6 weeks); Adult (ADT) (6 months); or Elderly (OLD) (2 years). Histological examination of valves showed that secreted thrombotic/antithrombotic proteins localize at the valve endothelium and tissue interior. Gene expression and immunostains for von Willebrand factor (VWF), tissue factor pathway inhibitor, and tissue plasminogen activator in YNG porcine aortic valve endothelial cells were higher than they were for OLD, whereas plasminogen activator inhibitor 1 levels in OLD were higher than those for YNG and ADT. Histamine-stimulated YNG porcine aortic valve endothelial cells released higher concentrations of VWF proteins than OLD, and the fractions of VWF-140 fragments was not different between age groups. A calcific aortic valve disease in vitro model using valvular interstitial cells confirmed that VWF in culture significantly increased valvular interstitial cell nodule formation and calcification. Conclusions— Hemostatic protein regulation in aortic valve tissues and in valvular endothelial cells changes with age. The presence of VWF and other potential hemostatic proteins increase valvular interstitial cell calcification in vitro. Therefore, the increased capacity of elderly valves to sequester the hemostatic proteins, together with age-associated loss of extracellular matrix organization, warrants investigation into potential role of these proteins in the formation of calcific nodules.

(1997). Food and Nutrition Issues of Importance to Hospitality Management Students in Australia. Journal of Hospitality & Tourism Education: Vol. 9, No. 3, pp. 68-74.

The hierarchical structure and organization of collagen plays an integral role in the mechanical behavior of heart valve tissues, but with few exceptions the degree of collagen fiber crimp has not been extensively quantified. Given our recent demonstration of age-dependent and region-dependent variations in mechanical behavior of heart valves, this study quantified crimp period and amplitude in all four heart valves as a function of orientation (circumferential vs. radial), age (6 week, 6 month, and 6 year old pigs), and region (mitral anterior leaflet center vs. free edge). Polarized light microscopy of picrosirius red stained sections revealed that collagen crimp was generally consistent between the circumferential and radial directions, although for the pulmonary valve there was a greater crimp period circumferentially than radially. Comparing all valves and orientations showed that the crimp period was greatest circumferentially in the center of the mitral anterior leaflet. With respect to age, crimp period was lowest in the 6 month old aortic valve (matching previously reported patterns of aortic valve leaflet extensibility) and highest in the 6 month old mitral anterior leaflet center. Interestingly, the differences in magnitudes of crimp amplitude mimicked the crimp period data, suggesting a scaling phenomenon in collagen fiber crimping.

Heart valves are thin, complex, layered connective tissues that direct blood flow in one di‐ rection through the heart. There are four valves in the heart, located at the entrance to and exit from the ventricular chambers. The normal function of the heart valves is essential to cardiovascular and cardiopulmonary physiology. The opening and closing of valve leaflets at precise times during the cardiac cycles contributes to the generation of sufficiently high pressure to eject blood from the ventricles, and also prevents blood from flowing backwards into the heart instead of forward towards the systemic circulation and the lungs.

Introduction . It is critical continually to monitor the influence of race/ethnicity and socioeconomic status in health information-seeking, confidence, and trust to ensure that health messages reach those most in need. Methods . Using data from the 2007 Health Information National Trends Survey (HINTS), multivariable logistic regression assessed the effects of race/ethnicity, education, and income on health information-seeking, confidence in obtaining health information, and trust of information sources. Results . Respondents of lower education were less likely to seek health information, and along with those of lower incomes had decreased confidence in their ability to obtain health information. Blacks, Hispanics, and those of lower income endorsed a lower level of trust in doctors and other health care professionals than non-Hispanic Whites and those of higher income, respectively. Conclusions . Improving the development and delivery of health information intended for minority and vulnerable populations may help reduce existing disparities in health information-seeking and care.

The aortic valve consists of valvular interstitial cells (VICs) and endothelial cells (VECs). While these cells are understood to work synergistically to maintain leaflet structure and valvular function, few co-culture models of these cell types exist. In this study, aortic valve co-cultures (AVCCs) were assembled using magnetic levitation and cultured for 3 days. Immunohistochemistry and quantitative reverse-transcriptase polymerase chain reaction were used to assess the maintenance of cellular phenotype and function, and the formation of extracellular matrix. AVCCs stained positive for CD31 and α-smooth muscle actin (αSMA), demonstrating that the phenotype was maintained. Functional markers endothelial nitric oxide synthase (eNOS), von Willebrand factor (VWF) and prolyl-4-hydroxylase were present. Extracellular matrix components collagen type I, laminin and fibronectin also stained positive, with reduced gene expression of these proteins in three dimensions compared to two dimensions. Genes for collagen type I, lysyl oxidase and αSMA were expressed less in AVCCs than in 2-D cultures, indicating that VICs are quiescent. Co-localization of CD31 and αSMA in the AVCCs suggests that endothelial–mesenchymal transdifferentiation might be occurring. Differences in VWF and eNOS in VECs cultured in two and three dimensions also suggests that the AVCCs possibly have anti-thrombotic potential. Overall, a co-culture model of the aortic valve was designed, and serves as a basis for future experiments to understand heart valve biology.

Gentamicin is a widely employed antibiotic, but may reduce calcium uptake by eukaryotic cells. This study was conducted to determine whether gentamicin reduces calcification by porcine aortic valvular interstitial cells (pAVICs) grown in 2D culture, which is a common model for calcific aortic valve disease (CAVD). The presence of gentamicin (up to 0.2 mM) in the medium of pAVICs cultured for 8 days significantly lowered calcification and alkaline phosphatase content in a dose-dependent manner compared to pAVICs cultured without gentamicin. Gentamicin also significantly increased cell proliferation and apoptosis at concentrations of 0.1–0.2 mM compared to controls. Next, gentamicin was applied to previously calcified pAVIC cultures (grown for 8 days) to determine whether it could stop or reverse the calcification process. Daily application of gentamicin for 8 additional days significantly reduced calcification to below the pre-calcification levels. These results confirm that gentamicin should be used cautiously with in vitro studies of calcification, and suggest that gentamicin may have the ability to reverse calcification by pAVICs. Given the nephrotoxicity and ototoxicity of this antibiotic, its clinical potential for the treatment of calcification in heart valves is limited. However, further investigation of the pathways through which gentamicin alters calcium uptake by valvular cells may provide insight into novel therapies for CAVD.

A major tissue engineering challenge is the creation of multilaminate scaffolds with layer-specific mechanical properties representative of native tissues, such as heart valve leaflets, blood vessels, and cartilage. For this purpose, poly(ethylene glycol) diacrylate (PEGDA) hydrogels are attractive materials due to their tunable mechanical and biological properties. This study explored the fabrication of trilayer hydrogel quasilaminates. A novel sandwich method was devised to create quasilaminates with layers of varying stiffnesses. The trilayer structure was comprised of two “stiff” outer layers and one “soft” inner layer. Tensile testing of bilayer quasilaminates demonstrated that these scaffolds do not fail at the interface. Flexural testing showed that the bending modulus of acellular quasilaminates fell between the bending moduli of the “stiff” and “soft” hydrogel layers. The bending modulus and swelling of trilayer scaffolds with the same formulations were not significantly different than single layer gels of the same formulation. The encapsulation of cells and the addition of phenol red within the hydrogel layers decreased bending modulus of the trilayer scaffolds. The data presented demonstrates that this fabrication method can make quasilaminates with robust interfaces, integrating layers of different mechanical properties and biofunctionalization, and thus forming the foundation for a multilaminate scaffold that more accurately represents native tissue.

With the expansion of public health nursing beyond cities into rural areas, leaders in nursing education early on recognized the need for additional training to prepare nurses for the rural experience. To this end, nursing faculty at Teachers College, Columbia University developed a pilot program designed to prepare nurses for work in rural areas. These leaders recognized the unique conditions confronting the rural public health nurse in her daily work, including distances to be covered, isolation, and the dearth of facilities for health work. The pilot program discussed in this reprint, published in The Public Health Nurse in 1925, describes the genesis of this project, and the collaborative relationship that was developed with Dutchess County, a rural county about 2 hours north of New York City, to provide practical experiences for students. The project included a series of lectures on rural health issues and rural nursing, as well as field work that included school nursing, and nursing care of special populations such as tuberculosis and maternal and child health, as well as experiences in population-based nursing akin to what we think of as community development today.

Understanding the biology of the mitral valve is becoming increasing important as surgical valve repair, percutaneous techniques and potential medical therapies are becoming important in this disease process. The mitral valve’s structure, anatomy and function are quite complex making it a difficult valve lesion to treat with interventions and medical therapies. The pathology has many classifications in terms of degrees of valve severity and classification of disease pathology. As the science in the field of mitral valve biology increases so will our understanding towards treatment options for these patients. This chapter will discuss the scientific studies to date and approaches for future studies.

Objective Calcific aortic valve disease is a progressive condition that shares some common pathogenic features with atherosclerosis. Transforming growth factor-β1 is a recognized mediator of atherosclerosis and is expressed in aortic valve lesions. Transforming growth factorβ1 stimulates glycosaminoglycan elongation of proteoglycans that is associated with increased lipid binding. We investigated the presence of transforming growth factor-β1 and downstream signaling intermediates in diseased human aortic valves and the effects of activated transforming growth factor-β1 receptor signaling on aortic valve interstitial cell proteoglycan synthesis and lipid binding as a possible mechanism for the initiation of the early lesion of calcific aortic valve disease. Methods and results Diseased human aortic valve leaflets demonstrated strong immunohistochemical staining for transforming growth factor-β1 and phosphorylated Smad2/3. In primary porcine aortic valve interstitial cells, Western blots showed that transforming growth factor-β1 stimulated phosphorylation in both the carboxy and linker regions of Smad2/3, which was inhibited by the transforming growth factor-β1 receptor inhibitor SB431542. Gel electrophoresis and size exclusion chromatography demonstrated that SB431542 decreased transforming growth factor-β1-mediated [ 35 S]-sulfate incorporation into proteoglycans in a dose-dependent manner. Further, in proteoglycans derived from transforming growth factor-β1-treated valve interstitial cells, gel mobility shift assays demonstrated that inhibition of transforming growth factor-β1 receptor signaling resulted in decreased lipid binding. Conclusions Classic transforming growth factor-β1 signaling is present in human aortic valves in vivo and contributes to the modification of proteoglycans expressed by valve interstitial cells in vitro. These findings suggest that transforming growth factor-β1 may promote increased low-density lipoprotein binding in the early phases of calcific aortic valve disease.

The aim of this study was to measure resting energy expenditure (REE) and energy intake in children with quadriplegic cerebral palsy (CP), to relate these to anthropometric measurements, and to determine the influence of nutritional rehabilitation on REE.Fifty-six children (20 females, 36 males; age range 3y 11mo-18y; mean age 10y; SD 3y 11mo) with CP (Gross Motor Function Classification System level V) participated in this cross-sectional study. Children were excluded if they had a known metabolic disorder, genetic syndrome, or chromosomal abnormality. Thirty-three of the children were tube fed and 23 were fed orally. A comparison group comprised 111 (42 females, 69 males) healthy children who had undergone anthropometric and REE measurements and were of similar age to the children with CP (4-19y). REE was measured by indirect calorimetry and energy intake was determined from weighed food records.The REE in the children with CP was low (79.5%) compared with that predicted and highly variable (SD 38.4%). Fat-free mass was the strongest predictor of REE, accounting for 27% of the variation. Energy intake as a percentage of REE in was greatly overestimated in oral-fed children with CP (293%). In a subset of children with CP (n=14), an increased energy intake by gastrostomy tube feeding resulted in an increase in REE from 70.0% to 101.9% of that predicted.The REE of children with CP is low and variable and is not strongly related to any one anthropometric measurement. Food records in oral-fed children with CP are of little value owing to their inaccuracy. This study provided support for the hypothesis that the low REE found in malnourished children with CP is partly due to a low energy intake.

Calcific aortic valve disease (CAVD) is a condition of the heart characterized by thickening and calcification of the aortic valve and can lead to aortic stenosis, narrowing of the aortic valve that can obstruct left ventricular outflow. CAVD is thought to have similarities with atherosclerosis, in which the aortic wall demonstrates thickening due to plaque buildup. A notable similarity seen between CAVD and atherosclerosis is the accumulation of lipids in the tissues. One important chemical component involved in atherosclerosis is lysophosphatidylcholine (LPC), a phospholipid derived from phosphatidylcholine. LPC concentrations have been shown to increase in atherosclerotic conditions, and induce expression of osteogenic factors by vascular smooth muscle cells. The potential for LPC to affect valve cell calcification, however, has not been previously investigated. In addition, calcification of cells from different valves warrants investigation because the aortic valve becomes more bone-like and experiences onset of calcification sooner than the mitral valve during the calcification process. This study investigated the effect of LPC on the propensity for calcification by porcine valve interstitial cells (VICs) from aortic and mitral valves. On day 0 VICs were seeded at a density of 50 000 cells/cm2 in low serum media. On day 1, the media is changed to media containing LPC in concentrations ranging from 0 to 100 µM. The cells are cultured for 8 days and then assessed for mineralization using histological stains (Alizarin Red S for calcium deposition and Von Kossa for phosphate deposition) and biochemical assays (Alkaline phosphatase activity). Significance (p

Because of the degeneration and thrombosis in artificial heart valve implants, it is important to understand the anti-thrombotic mechanisms of cardiac valve endothelial cells (VECs). These anti-thrombotic mechanisms can be integrated into poly(ethylene glycol) diacrylate (PEGDA) tissue-engineered heart valve (TEHV) design. This work will study the effects of (1) PEGDA hydrogel stiffness and (2) specific extracellular matrix (ECM) adhesive peptides on VEC phenotype and anti-thrombotic mechanisms. PEGDA 10% (w/v) hydrogels of MWs 3.4 and 20kDa were polymerized to apply different substrate rigidities in VEC culture. Thiol-ene reactions were used to covalently bind laminin- and fibronectin- derived peptides to the acrylate groups on PEGDA hydrogel surfaces. Laminin-derived peptide motif RKRLQVQLSIRT (RKR) and fibronectin adhesive peptide RGD were modified to include an additional cysteine at the end of each sequence, introducing a free thiol to undergo the thiol-ene reaction. Thiol-PEG-fluorescein (SH-PEG-FITC) served as a negative adhesive substrate control. Porcine aortic VECs were seeded onto each of the ECM-hydrogel combinations and cultured for 2, 6, and 10 days. Cell phenotype, adhesion, and proliferation were then assessed. Analysis of specific VEC anti-thrombotic protein regulation is in progress. At each time point, samples will be analyzed for maintenance of VEC phenotype and expression of thrombotic (von Willebrand Factor [VWF]) and anti-thrombotic (VWF cleaving enzyme [ADAMTS-13], eNOS, PGI2, tPA) proteins using histochemistry and qRT-PCR. Addition of histamine has been shown to stimulate rapid release of thrombogenic ultra-large VWF (ULVWF) strings by vascular endothelial cells. This method will be used to study VEC ULVWF string production and the associated cleavage activity of ADAMTS-13. Control of the hemostatic process will be quantified via western blot and ELISAs. The 3.4 and 20kDa MW PEGDA hydrogels had compressive moduli of 131±5 and 7.5±2kPa, respectively. Binding different concentrations of SH-PEG-FITC onto the gel surfaces showed that acrylate saturation was achieved for both MW compositions using ~5mM of peptide solution. After 2 days, the VECs on the stiffer 3.4kDa RKR gels appeared spread and elongated, whereas the 3.4kDa RGD seeded VECs had cobblestone morphology. VEC adhesion on the RKR and RGD 20kDa gels was observed, but with limited spreading. The cultured VECs may prefer the stiffer 3.4kDa gels over the softer 20kDa gels. After 10 days, VECs on the 3.4kDa RGD gels had minimal proliferation, while VECs on RKR grew confluent, were cobblestone shaped, and expressed VWF. Results suggest that both substrate rigidity and adhesive substrate greatly influence VEC survival, and likely affects anti-thrombotic regulation. Future studies include the use of basal lamina components collagen IV and perlecan peptides to evaluate changes in VEC behavior.

Objectives. We examined patterns in cigar use among young adults, aged 18–25 years, focusing on race/ethnicity and brand. Methods. We conducted a secondary data analysis of cross-sectional waves of the National Survey on Drug Use and Health, 2002–2008, using multivariate logistic regression to assess time trends in past 30 days cigar use, past 30 days use of a “top 5” cigar brand, cigar use intensity, and age at first cigar use. Results. Cigar use has increased among White non-Hispanic men aged 18 to 25 years, from 12.0% in 2002 to 12.7% in 2008. Common predictors of all outcomes included male gender and past 30 days use of cigarettes, marijuana, and blunts. Additional predictors of past 30 days cigar and “top 5” brand use included younger age, non-Hispanic Black or White race, lower income, and highest level of risk behavior. College enrollment predicted intensity of use and “top 5” brand use. Conclusions. Recent legislative initiatives have changed how cigars are marketed and may affect consumption. National surveys should include measures of cigar brand and little cigar and cigarillo use to improve cigar use estimates.

Congenitally diseased valves are relatively frequent causes of significant morbidity and mortality. Pathology descriptions of such valves have primarily focused on gross structural features including the number of leaflets or commissures (bicuspid/bicommissural valve) and alterations in the contour, thickness and consistency of the leaflets (dysplastic valve). Functional correlates of these pathologic alterations are valvar stenosis, insufficiency or both. Further characterization of the microstructural abnormalities seen in these malformed valves may not only provide insight into the correlation of distinct pathologies with their respective pathogenesis and clinical sequelae, but also may prove pivotal in uncovering new avenues for therapeutic interventions and prevention regimens. This review summarizes microstructural findings in congenital semilunar valve disease (CSVD) and discusses their relevance in light of recent advances in knowledge of normal valve microstructure, biology, and function. Specifically, the biological and mechanical roles of various matrix components and their interactions are discussed in the context of CSVD. Indeed, recent research in normal valves adds significant insight into CSVD, and raises many hypotheses that will need to be addressed by future studies.

To determine the quantity of tobacco use in network television programming popular among US youth and to examine variation in tobacco depictions by TV Parental Guidelines system rating and television network.A content analysis was conducted of broadcast network television programming popular among youth. Nielsen viewership rating data were used to identify a sample of top-rated television series for youth aged 12 to 17 years during the fall 2007 television season. Depictions of tobacco use per television episode were examined by TV Parental Guidelines rating and television network. χ(2) testing was used to examine differences in proportions of tobacco depictions across television episode ratings and networks.Data collection and analysis were conducted at the American Legacy Foundation (now known as Legacy).Broadcast television viewers in 2007.Tobacco use depictions on broadcast television were examined.Forty percent of television episodes examined had at least 1 depiction of tobacco use. Of these depictions, 89% were of cigarettes. Among episodes rated TV-PG (ie, parental guidance suggested) (N = 73), 50% showed 1 or more incidents of cigarette use, in contrast to 26% of TV-14 (ie, parents strongly cautioned) episodes. The percentage of episodes with any tobacco use depictions was highest on the FOX network (44%; n = 32), followed closely by The CW (CBS-Warner Brothers) (41%; n = 30).Substantial tobacco use was observed in television shows popular among youth. It is projected that almost 1 million youth were exposed to tobacco depictions through the programming examined. Tobacco use on television should be a cause for concern, particularly because of the high volume of television viewing among younger audiences.

Objectives. We used longitudinal data to examine the relationship between confirmed awareness of a national, branded, mass media smoking cessation campaign and cessation outcomes. Methods. We surveyed adult smokers (n = 4067) in 8 designated market areas (“media markets”) at baseline and again approximately 6 months later. We used multivariable models to examine campaign effects on cognitions about quitting, quit attempts, and 30-day abstinence. Results. Respondents who demonstrated confirmed awareness of the EX campaign were significantly more likely to increase their level of agreement on a cessation-related cognitions index from baseline to follow-up (odds ratio [OR] = 1.6; P = .046). Individuals with confirmed campaign awareness had a 24% greater chance than did those who were not aware of the campaign of making a quit attempt between baseline and follow-up (OR = 1.24; P = .048). Conclusions. A national, branded, mass media smoking cessation campaign can change smokers' cognitions about quitting and increase quit attempts. We strongly recommend that federal and state governments provide funding for media campaigns to increase smoking cessation, particularly for campaigns that have been shown to impact quit attempts and abstinence.

This study characterized the elastic fiber structure within the aortic valve spongiosa, the middle layer of the tri-laminate leaflet. The layer is rich in glycosaminoglycans and proteoglycans, through which it resists compression and lubricates shear between the outer layers. Elastin in this layer forms a fine, interweaving structure, yet it is unclear how this particular structure, which uses elasticity to preload the leaflet, assists spongiosa function. In this study, immunohistochemistry and scanning electron microscopy were used to characterize spongiosa elastin, as well as investigate regional differences in structure. Immunohistochemistry for elastin highlighted an intermediate structure that varied in thickness and density between regions. In particular, the spongiosa elastin was thicker in the hinge and coaptation region than in the belly. Scanning electron microscopy of NaOH-digested leaflets showed a rectilinear pattern of elastic fibers in the hinge and coaptation region, as opposed to a radially oriented stripe pattern in the belly. In conclusion, elastic fibers in the spongiosa connect the two outer layers and vary regionally in structure, while possible playing a role in responding to regionally specific loading patterns.

There are very compelling reasons to develop a tissue engineered mitral valve, but this endeavor has not received the same attention as tissue engineering strategies for the semilunar valves. Challenges in regenerating a mitral valve include recapitulating the complex heterogeneity in terms of anatomy (differently sized leaflets, numerous chordae), extracellular matrix composition, biomechanical behavior, valvular interstitial cell and endothelial cell phenotypes, and interior vasculature and innervation. It will also be essential to restore the functional relationships between the native mitral valve and left ventricle. A growing amount of information relevant to tissue engineering a mitral valve has been recently collected through investigations of cell mechanobiology and collagen organization. It is hoped that the development of tissue engineered mitral valves can build on knowledge derived from engineering semilunar valves, but the mitral valve will presents its own unique challenges as investigators move towards a first generation prototype.

Myxomatous mitral valves (MVs) contain elevated proportions of myofibroblasts, a valve interstitial cell (VIC) subpopulation that may be important in disease pathogenesis. A novel technique was recently developed for the isolation of VIC myofibroblasts using time-dependent adhesion to fibronectin (FN). Cells that adhere rapidly to FN ('FAST') demonstrate myofibroblast cell phenotype markers, in contrast to cells that fail to adhere after a longer time ('SLOW'). The study aim was to characterize the functionality of these subpopulations using three-dimensional (3D) collagen constructs.The VICs were harvested from porcine mitral valve posterior leaflets. FAST and SLOW subpopulations, as well as unseparated VIC populations grown on FN and tissue culture plastic (TCP) (UNSEP FN, UNSEP TCP), were seeded within 3D collagen gels and cultured for three weeks. Collagen gel contraction was assessed throughout the culture duration; the mechanical properties of the resultant collagen constructs were assessed using uniaxial tensile testing.FAST cells demonstrated a greater contraction of collagen gels compared to SLOW cells, particularly after 10 days (p0.05). Interestingly, the collagen gel contraction by both FN-separated VIC subpopulations (FAST and SLOW) was greater than for gels seeded with UNSEP TCP VICs (p0.05). Further, the contraction of UNSEP FN gels was greater than UNSEP TCP throughout the culture duration (pOR = 0.002), suggesting that the subculture of VICs on FN potentiated these phenotypic changes. Finally, the collagen constructs seeded with FAST cells were stiffer than those seeded with SLOW, followed by UNSEP TCP (p0.001). The same pattern was found for failure stress (p = 0.006).Time-dependent adhesion to FN produced a VIC subpopulation (FAST), the function of which in 3D culture was consistent with that of myofibroblasts; FN exposure alone also caused VICs to function similarly to myofibroblasts. This novel isolation method may prove valuable in future studies of myofibroblasts in valve disease.

Mass media campaigns can be effectively used to reduce youth smoking prevalence and promote adult cessation within the general population, particularly when combined with other tobacco control efforts (CDC, 2007; National Cancer Institute, 2008). As a result, mass media campaigns are one of the CDC’s recommended “best practices” for tobacco control (CDC, 2007). However, there is less evidence about the effectiveness of mass media campaigns to prevent or reduce smoking among socioeconomically disadvantaged or racial and ethnic minority populations. In general, evaluations of youth prevention campaigns have not included analyses by socioeconomic status (SES). Analyses by race/ethnicity have been conducted inconsistently – even by evaluators of “model” youth campaigns – and some studies have used such crude measures of race and ethnicity that it is difficult to interpret the findings. A recent review of the studies evaluating adult smoking cessation campaigns finds that they are often less effective among low SES smokers as compared with high SES smokers (Fagan, 2008; Niederdeppe, Fiore, Baker, & Smith, 2008; Niederdeppe, Kuang, Crock, & Skelton, 2008). Even among those campaigns that are specifically designed to reach low SES audiences, there are mixed or inconclusive results (Niederdeppe, Kuang, et al., 2008). Like youth campaigns, adult smoking cessation campaigns are not routinely evaluated by race/ethnicity; those that have been yield mixed results in terms of campaign effectiveness (Bala, Strzeszynski, & Cahill, 2008).

Although the late effects of serotonergic valve disease are known, the early mechanisms of the characteristic plaque formation are poorly understood.To model conditions leading to plaque formation on mitral valves, samples (n = 6-8 per treatment) cultured in a splashing bioreactor were exposed to serotonin (5HT) and norfenfluramine (NF). In order to assess the role of 5HT2B receptor activation, the effects of these drugs were also tested with a 5HT2B receptor antagonist. After two weeks, tissue samples were stained immunohistochemically to localize changes in multiple extracellular matrix (ECM) components and synthesis mediators.Decorin and versican expression tended to increase with 5HT treatment compared to NF or baseline controls, regardless of the presence of the receptor antagonist. Samples treated with 5HT or with the receptor antagonist tended to express less collagen (types I and III) and biglycan than NF or the baseline controls. Heat shock protein 47, prolyl-4-hydroxylase, matrix metalloproteinase 9 (MMP9) and MMP13 tended to be down-regulated with 5HT or NF exposure, although some samples treated with the antagonist displayed normal levels of these mediators. Superficial plaques grew on a subgroup of the NF-treated organ cultures, but on none of the 5HT and control valves.Although both serotonin agents lead to plaque formation in a clinical setting, the early effects of exposure to the different drugs were found to be quite different. Additionally, the different drug responses suggest that a mechanism other than 5HT2B receptor activation might contribute to plaque formation.

In this study, electrospun poly(ɛ-caprolactone) (PCL) microfiber scaffolds, coated with cartilaginous extracellular matrix (ECM), were fabricated by first culturing chondrocytes under dynamic conditions in a flow perfusion bioreactor and then decellularizing the cellular constructs. The decellularization procedure yielded acellular PCL/ECM composite scaffolds containing glycosaminoglycan and collagen. PCL/ECM composite scaffolds were evaluated for their ability to support the chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro using serum-free medium with or without the addition of transforming growth factor-β1 (TGF-β1). PCL/ECM composite scaffolds supported chondrogenic differentiation induced by TGF-β1 exposure, as evidenced in the up-regulation of aggrecan (11.6 ± 3.8 fold) and collagen type II (668.4 ± 317.7 fold) gene expression. The presence of cartilaginous matrix alone reduced collagen type I gene expression to levels observed with TGF-β1 treatment. Cartilaginous matrix further enhanced the effects of growth factor treatment on MSC chondrogenesis as evidenced in the higher glycosaminoglycan synthetic activity for cells cultured on PCL/ECM composite scaffolds. Therefore, flow perfusion culture of chondrocytes on electrospun microfiber scaffolds is a promising method to fabricate polymer/extracellular matrix composite scaffolds that incorporate both natural and synthetic components to provide biological signals for cartilage tissue engineering applications.

Previous research in our lab suggested that heart valve tissues cultured without mechanical stimulation do not retain their in vivo microstructure, i.e., cell density decreased within the deep tissue layers and increased at the periphery. In this study, a splashing rotating bioreactor was designed to apply mechanical stimulation to a mitral valve leaflet segment. Porcine valve segments (n=9–10 per group) were cultured in the bioreactor for two weeks (dynamic culture); negative controls were cultured without mechanical stimulation (static culture), and baseline controls were fresh uncultured samples. Overall changes in cellularity and ECM structure were assessed by H&E and Movat pentachrome stains. Tissues were also immunostained for multiple extracellular matrix (ECM) components and turnover mediators. After two weeks of culture, proliferating cells were distributed throughout the tissue in segments cultured in the bioreactor, in contrast to segments cultured without mechanical stimulation. Most ECM components, especially collagen types I and III, better maintained normal expression patterns and magnitudes (as found in baseline controls) over two weeks of dynamic organ culture compared to static culture. Lack of mechanical stimulation changed several aspects of the tissue microstructure, including the cell distribution and ECM locations. In conclusion, mechanical stimulation by the bioreactor maintained tissue integrity, which will enable future in vitro investigation of mitral valve remodeling.

The material properties of heart valves depend on the subject’s age, the state of the disease and the complex valvular microarchitecture. Furthermore, valvular interstitial cells (VICs) are mechanosensitive, and their synthesis of extracellular matrix not only determines the valve’s material properties but also provides an adhesive substrate for VICs. However, the interrelationship between substrate stiffness and VIC phenotype and synthetic properties is poorly understood. Given that the local mechanical environment (substrate stiffness) surrounding VICs differs among different age groups and different anatomic regions of the valve, it was hypothesized that there may be an age- and valve-region-specific response of VICs to substrate stiffness. Therefore, 6-week-, 6-month- and 6-year-old porcine VICs from the center of the mitral valve anterior leaflet (MVAC) and posterior leaflet (PML) were seeded onto poly(ethylene) glycol hydrogels of different stiffnesses and stained for markers of VIC activation (smooth muscle alpha-actin (SMaA)) and collagen synthesis (heat shock protein-47 (HSP47), prolyl 4-hydroxylase (P4H)). Six-week-old MVAC demonstrated decreased SMaA, P4H and HSP47 on stiffer gels, while 6-week-old PML only demonstrated decreased HSP47. Six-month-old MVAC demonstrated no difference between substrates, while 6-month-old PML demonstrated decreased SMaA, P4H and HSP47. Six-year-old MVAC demonstrated decreased P4H and HSP47, while 6-year-old PML demonstrated decreased P4H and increased HSP47. In conclusion, the age-specific and valve-region-specific responses of VICs to substrate stiffness link VIC phenotype to the leaflet regional matrix in which the VICs reside. These data provide further rationale for investigating the role of substrate stiffness in VIC remodeling within diseased and tissue engineered valves.

Heart valves are complex tri-layered structures that ensure the unidirectional flow of blood. Scientists are actively investigating how characteristics of the two major cell types, valvular endothelial cells (VECs) and valvular interstitial cells (VICs), and their mechanical relationships with the valvular extracellular matrix promote structural integrity and age-related remodeling. Abnormal changes in VECs, VICs, and the extracellular matrix at the molecular level lead to gross tissue malformations and dysfunction. This review addresses current advances in the field of valve biology, mechanisms underlying valvular leaflet remodeling, and common pathological manifestations. Improving our understanding of heart valve biology, the impact of cardiovascular drugs, and remodeling changes will be critical to the development of novel therapies for heart valve diseases.

Myxomatous mitral valves (MVs) contain elevated proportions of unique cell populations such as myofibroblasts. Without a reliable technique to isolate such cell populations, however, it has been difficult to study the role of these cells. The goal of this study was to use fibronectin (FN) to isolate distinct cell subpopulations from normal porcine MVs. Cells from porcine posterior MV leaflets were separated based on time-dependent adhesion to either tissue culture plastic (TCP) flasks or FN-coated flasks. The resultant “FAST” and “SLOW” adhering subpopulations from each technique were phenotyped using flow cytometry and immunocytochemistry to detect expression of myofibroblast markers, enzymes for collagen synthesis, and MAP kinases. Compared with FN SLOW, FN FAST showed significantly higher expression of prolyl 4-hydroxylase, heat shock protein-47 (HSP47), smooth muscle alpha-actin (SMαA), nonmuscle myosin (Smem), extracellular-related signaling kinase (ERK) 1, ERK2, and phosphorylated-ERK. In contrast, TCP FAST showed higher expression of only HSP47, SMαA, and Smem compared with TCP SLOW. In conclusion, differential adhesion to FN successfully separated a myofibroblast-like subpopulation from the posterior leaflet of the MV. This subpopulation may be useful in studying myxomatous MV disease, although additional studies remain to verify that this myofibroblast-like population resembles that observed in myxomatous MV disease. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010

Autism is currently detected only at about three years of age. This study aimed to establish if detection of autism was possible at 18 months of age. We screened 41 18–month-old toddlers who were at high genetic risk for developing autism, and 50 randomly selected 18–month-olds, using a new instrument, the CHAT, administered by GPs or health visitors. More than 80% of the randomly selected 18–month-old toddlers passed on all items, and none failed on more than one of pretend play, protodeclarative pointing, joint-attention, social interest, and social play. Four children in the high-risk group failed on two or more of these five key types of behaviour. At follow-up at 30 months of age, the 87 children who had passed four or more of these key types of behaviour at 18 months of age had continued to develop normally. The four toddlers who had failed on two or more of these key types of behaviour at 18 months received a diagnosis of autism by 30 months.

This paper describes a set of specialized spreadsheets that model the cost and performance of transit system options including light rail transit, guideway bus, express bus, and ride sharing. These spreadsheets are demonstrated by comparing a guideway bus (GWB) transit system and a light rail transit (LRT) system proposed for construction in an active rail corridor. The comparisons for assumed levels of transit ridership include guideway geometry, travel time, headways, vehicle requirements, grade crossing protection, and capital and operating costs. The planned GWB system runs on an exclusive dual guideway in the rail right-of-way, and the alternative LRT system operates on the existing rails with new bridges and track as needed for a dual guideway system. The analysis compares the two options for mode splits between 0.5% and 50%. Results show that while both options have approximately the same travel time, the GWB system costs approximately 30% less than the LRT system. The cost difference results primarily from lower GWB vehicle purchase and operating costs. The spreadsheets are available through the McTrans Center at the University of Florida, Gainesville, Florida.

Background— Dilated cardiomyopathy (DCM) involves significant remodeling of the left ventricular–mitral valve (MV) complex, but little is known regarding the remodeling of the mitral leaflets. The aim of this study was to assess changes in matrix composition and turnover in MV leaflets with DCM. Methods and Results— Radiopaque markers were implanted in 24 sheep to delineate the MV; 10 sheep underwent tachycardia-induced cardiomyopathy (TIC), whereas 14 sheep remained as controls. Biplane videofluoroscopy was performed before and after TIC. Immunohistochemistry was performed on leaflet cross-sections taken from the septal, lateral, anterior, and posterior commissures attachment segments. Staining intensity was quantified within each attachment segment and leaflet region (basal, mid-leaflet, and free edge). Mitral regurgitation increased from 0.2±0.4 before TIC to 2.2±0.9 after TIC ( P P P Conclusions— This study shows that the MV leaflets are significantly remodeled in DCM with changes in leaflet composition, structure, and valve cell phenotype. Understanding how alterations in leaflet mechanics, such as those induced by DCM, drive cell-mediated remodeling of the extracellular matrix will be important in developing future treatment strategies.

For many tissues, cyclic mechanical stimulation is considered necessary to maintain the normal morphology in vitro. The aim of this study was to design and evaluate a simple bioreactor system capable of medium-term (more than 2 weeks) culture of native and engineered aortic valves. The system consists of three pistons in separate cylindrical chambers that are simultaneously driven through the culture medium by a crank and cam assembly. The faces of these pistons have unidirectional valves mounted in opposing orientations that permit flow from one side of the face to the other. A custom designed stent was employed to secure either native or engineered tri-leaflet valves to the pistons. Computational fluid dynamics and finite element modeling was used to assist selection of materials and components in the system. Finally, sterility testing using base culture medium was performed to verify the ability of the system to retain sterile conditions. The current design permits the cyclic opening and closing of three aortic valves, however this device can be modified to accommodate up to 12 valves simultaneously. This new bioreactor system has applications not only for development of tissue-engineered valves, but for also studying disease models in the aortic valve.

The proteoglycan decorin putatively inhibits cell adhesion and cell migration on various extracellular matrix substrates through interactions with β1 integrins. This study, therefore, examined the adhesive, migration, and proliferative characteristics of decorin knockout (Dcn−/−) murine embryonic fibroblasts compared to wild-type controls on collagen-coated, fibronectin-coated, and uncoated tissue culture plates. The Dcn−/− cells showed significantly greater proliferation than wild-type controls on all substrates. The Dcn−/− cells also showed significantly greater adhesion to both collagen and fibronectin; both cell types showed greater adhesion to collagen. The addition of exogenous decorin had a differential effect on adhesion to collagen between cell types, but not on fibronectin. For collagen, blocking either α2 or β1 integrin subunits significantly reduced adhesion for Dcn−/− cells; whereas for fibronectin, blocking either the α5 or β1 integrin subunits reduced adhesion for both cell types. Decorin and the α5β1 integrin may have lesser roles in adhesion to fibronectin than previously presumed. Finally, compared to wild-type cells, Dcn−/− cells showed greater migration on both uncoated and collagen substrates. This study demonstrates that decorin affects the biology of various integrins that participate in cell proliferation, adhesion, and migration on various substrates. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010

Mass media campaigns can be an effective strategy to increase quitting activity among smokers, particularly when aired in the context of other anti-tobacco efforts.A longitudinal study using data collected from smokers identified in a random-digit-dial survey of adults in Grand Rapids MI, prior to the campaign and approximately 6 months after the launch of the campaign.Adult smokers who were interviewed in the fall of 2006 and agreed to participate in a follow-up interview approximately 6 months later (n=212).A pilot mass media campaign, branded EX, which used empathy to encourage smokers to "relearn" life without cigarettes, and focused on disassociating smoking from common activities that would otherwise function as smoking cues, such as driving or drinking coffee. The campaign averaged 100 targeted rating points per week on television.Primary outcome measures were five campaign-related cognitions and confidence in quitting. Secondary outcome measures were quitting behaviors.This 2007 analysis suggests that the campaign generated a high level of awareness of EX, with 62% of the sample demonstrating confirmed awareness and 79% reporting aided awareness. Awareness of EX was associated with significant change in two of five campaign-related cognitions. Awareness was not associated with confidence in quitting or having made a quit attempt.These findings demonstrate that a branded, empathetic media campaign that offers smokers practical advice on how to approach quitting can change cognitions related to successful cessation over a relatively short time period.

Purpose. Document changes from 2000 to 2004 in youth reports of exposure to pro-tobacco messages in the mass media, including images of smoking and tobacco advertising. Design. Comparison of cross-sectional data from three waves of the school-based National Youth Tobacco Surveys conducted in 2000 (N = 33,772), 2002 (N = 23,439), and 2004 (N = 23,540). Setting. Public and private middle schools and high schools across the United States. Subjects. Students in grades 6 through 12. Measures. Smoking status; exposure to images of smoking on television and in movies; exposure to advertisements for tobacco products in stores, on the Internet, and in newspapers and magazines; demographic data. Results. Youth exposure to pro-tobacco messages declined within all media channels studied from 2000 to 2004, except the Internet. Despite these declines, most youth in the United States remain exposed to pro-tobacco messages: 81% saw images of smoking on television or in movies (down from 90%), 85% saw tobacco ads in stores (down from 88%), 50% saw tobacco ads in newspapers and magazines (down from 66%), and 33% saw tobacco ads on the Internet (up from 22%). Conclusion. Despite recent progress in this area, most youth in the United States are still at increased risk of smoking as a result of exposure to pro-tobacco messages in the mass media.

Background Over the past decade, tobacco companies have introduced cigarettes and smokeless tobacco products (known as Potential Reduced Exposure Products, PREPs) with purportedly lower levels of some toxins than conventional cigarettes and smokeless products. It is essential that public health agencies monitor awareness, interest, use, and perceptions of these products so that their impact on population health can be detected at the earliest stages. Methods This paper reviews and critiques existing strategies for measuring awareness of PREPs from 16 published and unpublished studies. From these measures, we developed new surveillance items and subjected them to two rounds of cognitive testing, a common and accepted method for evaluating questionnaire wording. Results Our review suggests that high levels of awareness of PREPs reported in some studies are likely to be inaccurate. Two likely sources of inaccuracy in awareness measures were identified: 1) the tendency of respondents to misclassify "no additive" and "natural" cigarettes as PREPs and 2) the tendency of respondents to mistakenly report awareness as a result of confusion between PREPs brands and similarly named familiar products, for example, Eclipse chewing gum and Accord automobiles. Conclusion After evaluating new measures with cognitive interviews, we conclude that as of winter 2006, awareness of reduced exposure products among U.S. smokers was likely to be between 1% and 8%, with the higher estimates for some products occurring in test markets. Recommended measurement strategies for future surveys are presented.

purpose: To retrospectively study the prophylaxis of invasive aspergillosis in neutropenic patients and to relate the frequency of this fungal disease to any causal or modifying factors that could be identified patients and methods: Between 1977 and 1988, 130 patients underwent 158 intensive treatment episodes to control acute leukemia, lymphoma, and aplastic anemia, and the frequency of complicating aspergillus infection was determined. results: Proven invasive aspergillus infections occurred in 22 cases, 12 of which were fatal. Invasive aspergillosis was suspected in a further 16 cases and all these patients recovered with amphotericin B treatment. Colonization by Aspergillus in the absence of clinically significant infection was seen in 31 treatment episodes. Invasive aspergillosis involved mainly the upper and lower respiratory tract and skin. Control of the infection was closely related to the control of the underlying disease, with subsequent return of normal marrow function and resolution of neutropenia. The incidence of aspergillus infection has decreased dramatically since 1985, most probably due to the introduction of intranasal amphotericin B. This occurred despite the persistence of aspergillus spores in the hematology ward air during the 1986 to 1988 period. conclusion: Intranasal aerosolized amphotericin B may protect against invasive aspergillosis, even when neutropenic patients are cared for in conventional wards without HEPA filtration.

No significant difference in the lateralisation of tactile-evoked potentials was found when a tactile stimulus was applied to the index finger of 14 schizophrenic patients and 14 age- and sex-matched controls. The early tactile responses, recorded from contralateral and ipsilateral parietal scalp electrodes, were compared. Our results differ from previously reported results.

Background The truth® campaign is credited with preventing approximately 450,000 youth from starting to smoke, from 2000 through 2004 [Farrelly, M.C., Nonnemaker, J., Davis, K.C., Hussin, A., 2009. The Influence of the National truth® Campaign on Smoking Initiation. Am. J. Prev. Med. February 9 [Epub ahead of print]]. However, no research has been conducted to determine whether lower socioeconomic status (SES) youth benefit equally from the campaign. This study examines whether socioeconomic status is associated with awareness of and receptivity to the truth® campaign among youth ages 12–17. Methods This study is based on seven waves of Legacy Media Tracking Survey (LMTS) data, collected from September 2000 through January 2004 (n = 30,512). LMTS is a nationally representative, cross-sectional telephone survey. Median household income and median household education at the zip code level were appended to the LMTS data. Results Females had lower levels of confirmed awareness of the truth® campaign as compared with males. Youth who lived in lower education zip codes were less likely to have confirmed campaign awareness as compared with those in higher education zip codes. Zip code level median household income was not associated with confirmed awareness. Receptivity to the campaign was not associated with zip code level median household income or education. Conclusions These findings suggest that the effectiveness of the truth® campaign could be enhanced by developing strategies to increase campaign awareness among females and youth from lower education zip codes. Increased campaign exposure within these populations could result in lower smoking rates and, ultimately, lower rates of tobacco-related disease.

Background—— Although chronic mitral regurgitation results in adverse left ventricular remodeling, its effect on the mitral valve leaflets per se is unknown. In a chronic ovine model, we tested whether isolated mitral regurgitation alone was sufficient to remodel the anterior mitral leaflet. Methods and Results— Twenty-nine sheep were randomized to either control (CTRL, n=11) or experimental (HOLE, n=18) groups. In HOLE, a 2.8- to 4.8-mm diameter hole was punched in the middle scallop of the posterior mitral leaflet to create “pure” mitral regurgitation. At 12 weeks, the anterior mitral leaflet was analyzed immunohistochemically to assess markers of collagen and elastin synthesis as well as matrix metalloproteinases and proteoglycans. A semiquantitative grading scale for characteristics such as intensity and delineation of stain between layers was used to quantify differences between HOLE and CTRL specimens across the heterogeneous leaflet structure. At 12 weeks, mitral regurgitation grade was greater in HOLE versus CTRL (3.0±0.8 versus 0.4±0.4, P P ≤0.05). Conclusions— In HOLE anterior mitral leaflet, the increased expression of proteins related to collagen synthesis and matrix degradation suggests active matrix turnover. These are the first observations showing that regurgitation alone can stimulate mitral leaflet remodeling. Such leaflet remodeling needs to be considered in reparative surgical techniques.

Background: Articular cartilage is a highly functional tissue which covers the ends of long bones and serves to ensure proper joint movement. A tissue engineering approach that recapitulates the developmental characteristics of articular cartilage can be used to examine the maturation and degeneration of cartilage and produce fully functional neotissue replacements for diseased tissue. Methadology/Principal Findings: This study examined the development of articular cartilage neotissue within a self-assembling process in two phases, in the first phase, articular cartilage constructs were examined at 1, 4, 7, 10, 14, 28, 42, and 56 days immunohistochemically, histologically, and through biochemical analysis for total collagen and glycosaminoglycan (GAG) content. Based on statistical changes in GAG and collagen levels, four time points from the first phase (7, 14, 28, and 56 days) were chosen to carry into the second phase, where the constructs were studied in terms of their mechanical characteristics, relative amounts of collagen type II and VI, and specific GAG types (chondroitin 4-sulfate, chondroitin 6-sulfate, dermatan sulfate, and hyaluronan), Collagen type VI was present in initial abundance and then localized to a pericellular distribution at 4 wks. N-cadherin activity also spiked at early stages of neotissue development, suggesting that self-assembly is mediated through minimization of free energy. The percentage of collagen type II to total collagen significantly increased over time, while the proportion of collagen type VI to total collagen decreased between 1 and 2 wks, The chondroitin 6- to 4- sulfate ratio decreased steadily during construct maturation. In addition, the compressive properties reached a plateau and tensile characteristics peaked at 4 wks. Conclusions/Significance: The indices of cartilage formation examined in this study suggest that tissue maturation in self-assembled articular cartilage mirrors known developmental processes for native tissue. In terms of tissue engineering, it is suggested that exogenous stimulation may be necessary after 4 wks to further augment the functionality of developing constructs. © 2008 Ofek et al.

The addition of exogenous hyaluronan to biomaterial scaffolds has been an important area of investigation for many decades. The ability to manipulate endogenous production of hyaluronan via the hyaluronan syntheses has offered another mechanism to study the effect of hyaluronan. While the literature suggests that exogenously added hyaluronan and endogenously produced hyaluronan will have varying impacts on extracellular matrix organization and function, no studies have directly shown this phenomenon. In this investigation, we demonstrate that the addition of exogenous high molecular weight (approximately 1 MDa) hyaluronan and hyaluronan oligosaccharides have a distinct impact on both contraction and strength of smooth muscle cell-seeded collagen gels when compared to the effects of hyaluronan that is endogenously produced by the hyaluronan synthases. More specifically, the addition of exogenous high molecular weight hyaluronan resulted in more compact collagen gels with a higher ultimate tensile strength, whereas the endogenous overproduction of hyaluronan resulted in the opposite effect. We suggest that the addition of exogenous HA to collagen gels represents a model for the therapeutic administration of HA, whereas the addition of excess HA to a tissue via the endogenous overexpression of has represents a model for the pathological accumulation of HA.

Objectives: This study was designed to quantify the specific glycosaminoglycans (GAGs) in the midmembranous vocal fold (VF) lamina propria (LP) and to interpret their presence in relation to the known stresses borne by each LP layer. Methods: GAGs from normal human LP and from both normal and scarred canine LPs were analyzed by fluorophore-assisted carbohydrate electrophoresis (FACE). Immunostaining was conducted to give insight into the spatial distribution of each GAG type. Results: Hyaluronan composes roughly 0.64% ± 0.41% of the human LP as measured relative to tissue total protein. Chondroitin sulfate and/or dermatan sulfate (CS/DS), keratan sulfate, and heparan sulfate chains constitute approximately 23.9% ± 12.1%, 14.7% ± 6.1%, and 61.4% ± 13.6%, respectively, of human LP sulfated GAGs. Conclusions: Observed CS/DS sulfation patterns imply that versican is a major contributor to human LP CS levels. In addition, examination of LP GAG with respect to gender revealed a significant variation in total levels of CS/DS and a potential difference in the levels of versican relative to decorin and biglycan. In dogs, LP scarring appeared to result in a reduction in hyaluronan and CS/DS. These FACE results were combined with histologic data to update current descriptive models linking LP microstructure with the regional variations in LP loading.