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1.
Int J Impot Res ; 29(6): 258-261, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28835714

ABSTRACT

Tunica albuginea plication (TAP) surgery for Peyronie's disease (PD) is classically described using nonabsorbable suture. Many patients are aware of nodularity at the suture sites (50-88%), and some find them painful (10-33%). We explore whether limiting permanent sutures provides a durable correction of curve and report the incidence of bothersome nodules. Beginning in 2007, we modified our TAP procedure to limit the use of permanent sutures. We reviewed all patients who underwent TAP procedures from 2007 to 2014 at our institution. Patients were contacted to complete a previously published survey regarding postoperative satisfaction. In total, 142 PD patients underwent the TAP procedure and 81/142 (57%) completed the postoperative survey. Mean office follow-up and survey follow-up were 17.3 and 56.3 months, respectively. Of the surveyed patients, 6.2% complained of a bothersome residual curve, 19.8% experienced nodularity and 4.9% reported bothersome nodules. Men with dorsal curves experienced less painful nodularity than those with ventral (P=0.047) or lateral curves (P=0.017). In total, 4/142 (2.8%) of men underwent repeat intervention. At long-term follow-up, limiting permanent sutures during TAP procedures for PD is durable with respect to curvature correction and has encouragingly low levels of nodularity and bother at suture sites.


Subject(s)
Penile Induration/surgery , Penis/surgery , Sutures , Urogenital Surgical Procedures/methods , Adult , Aged , Humans , Male , Middle Aged , Patient Satisfaction , Postoperative Period , Retrospective Studies , Treatment Outcome
2.
Conserv Biol ; 28(1): 244-57, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24471784

ABSTRACT

Market-based, supply-side interventions such as domestication, cultivation, and wildlife farming have been proposed as legal substitutes for wild-collected plants and animals in the marketplace. Based on the literature, we devised a list of the conditions under which supply-side interventions may yield positive conservation outcomes. We applied it to the trade of the orchid Rhynchostylis gigantea, a protected ornamental plant. We conducted a survey of R. gigantea at Jatujak Market in Bangkok, Thailand. Farmed (legal) and wild (illegal, protected) specimens of R. gigantea were sold side-by-side at market. These results suggest farmed specimens are not being substituted for wild plants in the marketplace. For any given set of physical plant characteristics (size, condition, flowers), the origin of the plants (wild vs. farmed) did not affect price. For all price classes, farmed plants were of superior quality to wild-collected plants on the basis of most physical variables. These results suggest wild and farmed specimens represent parallel markets and may not be substitutable goods. Our results with R. gigantea highlight a range of explanations for why supply-side interventions may lack effectiveness, for example, consumer preferences for wild-collected products and low financial incentives for farming. Our results suggest that market-based conservation strategies may not be effective by themselves and may be best utilized as supplements to regulation and education. This approach represents a broad, multidisciplinary evaluation of supply-side interventions that can be applied to other plant and animal species.


Subject(s)
Conservation of Natural Resources/methods , Orchidaceae , Commerce , Conservation of Natural Resources/economics , Thailand
4.
Acta Psychiatr Scand ; 126(6): 395-401, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22900986

ABSTRACT

OBJECTIVE: For psychiatric diagnoses, solving the problem of false positives is thought to be a matter of tightening diagnostic criteria. But low prevalence illnesses by their nature have high false positive rates. A recent study of bipolar disorder found the predictive value of bipolar diagnoses to be <50%. Is it possible to achieve much higher diagnostic accuracy for psychiatric diagnoses? METHOD: We calculate predictive values while varying diagnostic sensitivity and holding specificity constant, and vice versa, for a given prevalence of illness. We then calculate predictive values while holding sensitivity and specificity constant, but varying prior probability (clinically feasible by assessing other factors associated with bipolar outcomes, such as family history and degree of recurrence). RESULTS: Assuming a sample in which the prevalence of illness is 10%, achieving positive predictive values (PPV) >50% requires diagnostic specificity of >95%. Holding specificity at a level already achieved clinically (86%), increasing prior probability yields predictive values as high as 83%. CONCLUSION: Systematic assessment of clinical factors that increase the prior probability of illness, before applying DSM/ICD criteria, could raise PPV substantially compared with targeting greater specificity via more stringent diagnostic criteria.


Subject(s)
Bipolar Disorder/diagnosis , Diagnostic and Statistical Manual of Mental Disorders , Psychiatric Status Rating Scales/standards , Humans , International Classification of Diseases/classification , Prevalence
6.
Clin Dermatol ; 29(5): 511-22, 2011.
Article in English | MEDLINE | ID: mdl-21855727

ABSTRACT

Commonly used dermatologic eponyms and characteristic skin signs are enormously helpful in guiding a diagnosis, even though they may not be pathonemonic. They include, on the nails, Aldrich-Mees' lines (syn.: Mees' lines), Beau's lines, Muehrcke's lines, Terry's nails, and half and half nails, often associated, respectively, with arsenic poisoning, acute stress or systemic illness, severe hypertension, liver disease and uremia, and, around the nails, Braverman's sign, associated with collagen-vascular disease. Elsewhere, one may see the Asboe-Hansen and Nikolsky's signs, indicative of the pemphigus group of diseases, Auspitz's sign, a classic finding in psoriasis, Borsieri's and Pasita's signs, seen in early scarlet fever, the butterfly rash, indicative of systemic lupus erythematosus, and the buffalo hump, seen in Cushing's disease and also in the more common corticosteroid toxicity. Gottron's papules and the heliotrope rash are signs of dermatomyositis. Janeway's lesions and Osler's nodes are seen in bacterial endocarditis. A Dennie-Morgan fold under the eye is seen in association with atopic disease. Koplik's spots are an early sign of rubeola. Fitzpatrick's sign is indicative of a benign lesion (dermatofibroma), whereas Hutchinson's sign is indicative of a malignant one (subungual melanoma). Petechiae are seen in many diseases, including fat embolization, particularly from a large bone fracture following trauma. Palpable purpura is indicative of leukocytoclastic vasculitis, and is an early, critical sign in Rickettsial diseases, including Rocky Mountain Spotted Fever, which must be diagnosed and treated early. Hyperpigmentation of areolae and scars is seen in Addison's disease. Acanthosis nigricans may indicate internal cancer, especially stomach cancer, whereas Bazex's syndrome occurs in synchrony with primary, usually squamous cancer, in the upper aerodigestive tract or metastatic cancer in cervical lymph nodes. Perioral pigmented macules or one or more cutaneous sebaceous neoplasms may be a sign of the Peutz-Jeghers or Muir-Torre syndrome, respectively, both associated also with intestinal polyps that have a malignant potential. Telangiectasiae in the perioral region may be associated with similar lesions internally in Osler-Weber-Rendu disease. Kerr's sign is indicative of spinal cord injury and Darier's sign of mastocytosis. Post proctoscopic periobital purpura (PPPP) is a phenomenon observed in some patients with systemic amyloidosis. Koebner's isomorphic response refers to the tendency of an established dermatosis, such as psoriasis, to arise in (a) site(s) of trauma, whereas Wolf's isotrophic response refers to a new dermatosis, such as tinea, not yet seen in the patient, arising in (a) site(s) of a former but different dermatosis, such as zoster.


Subject(s)
Skin Diseases/pathology , Acanthosis Nigricans/pathology , Addison Disease/pathology , Carcinoma, Basal Cell/pathology , Cushing Syndrome/pathology , Erythema Induratum/pathology , Female , Gastrointestinal Neoplasms/pathology , Histiocytoma, Benign Fibrous/pathology , Humans , Hypotrichosis/pathology , Melanoma/pathology , Muir-Torre Syndrome/pathology , Neoplasms, Squamous Cell/pathology , Nevus, Blue/pathology , Skin Neoplasms/nursing , Skin Neoplasms/pathology
7.
Clin Dermatol ; 29(2): 140-50, 2011.
Article in English | MEDLINE | ID: mdl-21396553

ABSTRACT

Common shapes encountered in dermatologic diseases include linear, nummular, annular, polycyclic, and arciform. The last three have a relatively restricted differential, which must be entirely explored. It is not uncommon for a single disease to present in annular, arciform or polycyclic configurations; moreover, the lesions may evolve from being arciform to annular and then become polycyclic. Regardless, recognizing the arrangement of the defect will undoubtedly help in making a diagnosis and guiding subsequent management. We explore diseases that often present in annular, arciform, and/or polycyclic forms.


Subject(s)
Dermatitis/pathology , Skin Diseases, Infectious/pathology , Humans , Leprosy/pathology , Mycosis Fungoides/pathology , Sarcoidosis/pathology , Skin Neoplasms/pathology , Syphilis/pathology
8.
Am J Transplant ; 8(4): 897-904, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18324979

ABSTRACT

This case report focuses on the University of Wisconsin Hospital and Clinics Organ Procurement Organization (UWHC-OPO) efforts to produce a verifiable and demonstrable increase in organ donations by developing a replicable, transferable and feasible model intervention for increasing health care professionals' support for donation after cardiac death (DCD). A grant from the US Department of Health and Human Services funded a 3-year study allowing the UWHC-OPO to (i) identify barriers to and opportunities for increasing DCD support among those involved in the donation request process, (ii) implement this better understanding of these support factors in the creation of intervention materials designed to increase knowledge of and support for DCD and finally (iii) to track and document the progress made in increasing knowledge, support, number of hospitals with DCD protocols, actual requests made and number of DCD donors. The results of the model intervention were extremely positive, showing lasting increases in DCD knowledge and support, adoption of DCD protocols and referrals in the two tracking survey stages following the intervention. Perhaps most notably, DCD donor numbers within the UWHC-OPO region increased 93% in the year following the intervention and 179% to date.


Subject(s)
Death, Sudden, Cardiac , Tissue Donors , Cadaver , Documentation , Health Knowledge, Attitudes, Practice , Health Personnel , Humans , Professional-Patient Relations , Social Support , Tissue and Organ Harvesting , Tissue and Organ Procurement/organization & administration , United States , Waiting Lists
9.
Am J Transplant ; 8(1): 193-200, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17973964

ABSTRACT

Findings are reported from a US Department of Health and Human Services (DHHS) funded study to identify barriers to increasing support for donations after cardiac death by health professionals. A donations after cardiac death (DCD) acceptance model is conceptualized and tested via 806 survey responses from certified requestors, all of whom had their identities protected through Institutional Review Board (IRB) protocol. The overall model was significant and explained 35% of the variation in DCD support. Greater knowledge about DCD, greater trust in the organ procurement organization (OPO) and a belief that futility has been reached were all positively associated with DCD acceptance. Negative perceptions of DCD versus brain death, transitioning from caregiving to donation advocate, concerns about the DCD process and the idea that DCD leads to active participation in the death reduced its support. The three greatest impediments to support of DCD exist when health professionals feel they are playing an active role in killing the patient, that a state of death has not yet been reached, and that DCD has more psychological barriers than does the brain death donation process. Opportunities and strategic initiatives are discussed to overcome these barriers, including the value of communication and education initiatives and the need for well-trained requestors. The implementation of these strategic guidelines helped to increase the number of DCD donors by 225%.


Subject(s)
Attitude to Health , Death , Professional-Family Relations , Tissue Donors , Tissue and Organ Procurement , Female , Humans , Longitudinal Studies , Male , Models, Psychological , Tissue Donors/psychology , Tissue and Organ Harvesting/psychology
10.
Expert Opin Ther Targets ; 11(5): 589-99, 2007 May.
Article in English | MEDLINE | ID: mdl-17465719

ABSTRACT

Cells require the ability to appropriately respond to signals in their extracellular environment. To initiate, inhibit and control these processes, the cell has developed a complex network of signaling cascades. The phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways regulate several responses including mitosis, apoptosis, motility, proliferation, differentiation and many others. It is not surprising, therefore, that many viruses target the PI3K and MAPK pathways as a means to manipulate cellular function. Recently, Kaposi's sarcoma-associated herpes virus (KSHV) has been added to the list. KSHV manipulates the PI3K and MAPK pathways to control such divergent processes as cell survival, cellular migration, immune responses, and to control its own reactivation and lytic replication. Manipulation of the PI3K and MAPK pathways also plays a role in malignant transformation. Here, the authors review the potential to target the PI3K and MAPK signaling pathways to inhibit KSHV infection and pathogenesis.


Subject(s)
Antiviral Agents/therapeutic use , Drug Delivery Systems , Herpesviridae Infections/drug therapy , Herpesvirus 8, Human/pathogenicity , MAP Kinase Signaling System/drug effects , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/therapeutic use , Sarcoma, Kaposi/prevention & control , Signal Transduction/drug effects , Tumor Virus Infections/drug therapy , Acquired Immunodeficiency Syndrome/complications , Adolescent , Adult , Antiviral Agents/pharmacology , Child , Gene Expression Regulation, Viral , Herpesvirus 8, Human/physiology , Humans , MAP Kinase Signaling System/physiology , Neovascularization, Pathologic/drug therapy , Phosphatidylinositol 3-Kinases/physiology , Protein Kinase Inhibitors/pharmacology , Sarcoma, Kaposi/etiology , Signal Transduction/physiology , Virus Activation , Virus Latency , raf Kinases/antagonists & inhibitors , raf Kinases/physiology
11.
Intervirology ; 50(4): 245-53, 2007.
Article in English | MEDLINE | ID: mdl-17460413

ABSTRACT

OBJECTIVE: Angiogenesis is defined as the formation of new blood vessels. In a recently concluded study, we identified Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells derived from primary effusion lymphoma (PEL) to overexpress vascular endothelial growth factor (VEGF) that had the propensity to mediate tubule formation on a Matrigel, an indicator of angiogenesis. The objective of this study was to determine the receptor molecules that mediate the tubule formation induced by the supernatant derived from KSHV-infected PEL cells. METHODS: The identity of receptor(s) that play a role in mediating tubule formation driven by PEL supernatant was determined by the classical in vitro angiogenesis assay conducted on a Matrigel. RESULTS: RGD peptides, antibodies, and siRNA specific to beta1 integrins significantly lowered the ability of the PEL supernatants to induce tubule formation by endothelial cells. beta1 Integrins mediated tubule formation to comparable levels in endothelial cells that were incubated with supernatants derived from uninduced or TPA-induced PEL cells. Interestingly, the beta1 integrins did not seem to have a major role in cellular attachment. CONCLUSION: We report for the first time a critical role for beta1 integrins in angiogenesis supported by the supernatant from KSHV-infected PEL cells.


Subject(s)
Culture Media, Conditioned/pharmacology , Endothelial Cells/metabolism , Herpesvirus 8, Human/pathogenicity , Integrin beta1/metabolism , Neovascularization, Pathologic , B-Lymphocytes/virology , Cell Line, Transformed , Cell Transformation, Viral , Cells, Cultured , Collagen , Drug Combinations , Endothelium, Vascular/cytology , Herpesviridae Infections/virology , Humans , Laminin , Proteoglycans , Vascular Endothelial Growth Factor A/metabolism
12.
J Electron Microsc (Tokyo) ; 56(1): 27-36, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17392397

ABSTRACT

Following an infection, Kaposi's sarcoma-associated herpes virus (KSHV) exists predominantly in its latent state, with only 1-2% of infected cells undergoing lytic reactivation. We have previously demonstrated along with others a relationship between lytic reactivation and cell cycle progression (Bryan et al., 2006. J. Gen. Virol. 87: 519; McAllister et al., 2005. J. Virol. 79: 2626). Infected cells in the S phase are much more likely to undergo lytic reactivation when compared to those in G(0)/G(1) phase. Through the use of scanning electron microscopy (SEM), we analyzed changes occurring on the surface of cells undergoing KSHV reactivation. KSHV reactivation was observed predominantly in cells with smoother surface topology; a hallmark of cells derived from S phase. Interestingly, during the late stages of the reactivation process, we observed KSHV particles to egress cells through budding. Taken together, based on scanning electron microscopy and transmission electron microscopy evidences, we demonstrate for the first time the existence of a direct link between cell surface topology, cell cycle progression and KSHV reactivation.


Subject(s)
Cell Membrane/ultrastructure , Cell Membrane/virology , Herpesviridae Infections/pathology , Herpesviridae Infections/virology , Herpesvirus 8, Human/physiology , Herpesvirus 8, Human/ultrastructure , Base Sequence , Cell Cycle , Cell Line , DNA Primers/genetics , Herpesvirus 8, Human/drug effects , Herpesvirus 8, Human/genetics , Humans , Microscopy, Electron , Microscopy, Electron, Scanning , Polymerase Chain Reaction , Tetradecanoylphorbol Acetate/pharmacology , Virus Activation/drug effects , Virus Activation/physiology , Virus Assembly
13.
Virol J ; 3: 51, 2006 Jun 28.
Article in English | MEDLINE | ID: mdl-16805914

ABSTRACT

In the molecular world, researchers act as detectives working hard to unravel the mysteries surrounding cells. One of the researchers' greatest tools in this endeavor has been Raman spectroscopy. Raman spectroscopy is a spectroscopic technique that measures the unique Raman spectra for every type of biological molecule. As such, Raman spectroscopy has the potential to provide scientists with a library of spectra that can be used to unravel the makeup of an unknown molecule. However, this technique is limited in that it is not able to manipulate particular structures without disturbing their unique environment. Recently, a novel technology that combines Raman spectroscopy with optical tweezers, termed Raman tweezers, evades this problem due to its ability to manipulate a sample without physical contact. As such, Raman tweezers has the potential to become an incredibly effective diagnostic tool for differentially distinguishing tissue, and therefore holds great promise in the field of virology for distinguishing between various virally infected cells. This review provides an introduction for a virologist into the world of spectroscopy and explores many of the potential applications of Raman tweezers in virology.


Subject(s)
Spectrum Analysis, Raman/instrumentation , Spectrum Analysis, Raman/methods , Virology/instrumentation , Virology/methods , Antiviral Agents/therapeutic use , Cell Line , Humans , Virus Diseases/diagnosis , Virus Diseases/drug therapy , Virus Diseases/virology , Viruses/chemistry , Viruses/pathogenicity
16.
Mutat Res ; 521(1-2): 103-12, 2002 Nov 26.
Article in English | MEDLINE | ID: mdl-12438008

ABSTRACT

The in vitro micronucleus test is currently used as a screening assay during the early stages of drug development by pharmaceutical companies to identify chemicals likely to produce positive outcomes in the in vitro chromosome aberration assay. For several reasons the assay is being considered as an alternative to the aberration assay-it requires less laboratory time, less material and less training. However, the current screening protocols are not rigorous enough to fully satisfy concerns about genotoxic safety. Using a protocol previously developed by testing 16 chemicals, this manuscript contributes to the validation of the protocol using 10 additional chemicals. Furthermore, conclusions drawn from the developmental effort regarding the need for an extended exposure in the absence of metabolic activation, the number of cells to be counted, and the preferred statistical procedure for the assay are re-examined. The recommended, validated protocol utilizes cytochalasin B and 4h exposures in the presence and in the absence of metabolic activation, specifies the need to test to a relative survival rate of approximately 50%, requires the counting of 2,000 binucleated cells per treatment concentration, and employs a trend test for statistical analysis of the data.


Subject(s)
Micronucleus Tests/methods , Micronucleus Tests/standards , Animals , CHO Cells , Cell Division/drug effects , Cell Division/genetics , Cricetinae , Cricetulus , Cytochalasin B/toxicity , Data Interpretation, Statistical , Dose-Response Relationship, Drug , Mutagens/toxicity
17.
Mutat Res ; 517(1-2): 123-34, 2002 May 27.
Article in English | MEDLINE | ID: mdl-12034314

ABSTRACT

The in vitro micronucleus (IVM) test is currently used as a screen during the early stages of pharmaceutical development to identify chemicals likely to produce positive outcomes in the in vitro chromosome aberration assay. For several reasons, the assay is being considered as an alternative to the aberration assay, but the current screening protocols are not rigorous enough to fully satisfy concerns about genotoxic safety. This manuscript describes the investigation of several protocol parameters to assist with the development of a regulatory guideline for the IVM test. The parameters investigated are: the effect of cytochalasin B on the outcome of the assay when conducted with continually growing cell lines; the need for an extended exposure in the absence of metabolic activation; and the number of cells to be counted for a valid assay. In addition, two statistical procedures for the analysis of data from the test are described. The results of the investigation indicate that cytochalasin B does not effect the outcome of the test, that the extended exposure treatment is not necessary, that counting 2000 cells is preferable to counting 1000, and that the data can be appropriately analyzed using a trend test.


Subject(s)
Cytochalasin B , Micronucleus Tests/methods , Mutagenicity Tests/methods , Mutagens , Animals , CHO Cells , Cricetinae
18.
Arch Sex Behav ; 30(6): 591-602, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11725457

ABSTRACT

The sexual behaviors, functioning, needs, and sexual satisfaction levels of men with spinal cord injuries (SCI) were studied. A sample of 50 men with SCI (median age = 50; median age at injury = 25.0), either married or in a committed relationship, responded to an anonymous survey of a large southern California regional spinal injury rehabilitation center. Multiple regression analyses indicated that perceived partner satisfaction, relationship quality, and sexual desire were significant predictors of sexual satisfaction and behavior. Erectile function, level of genital sensation, and orgasmic capacity all varied widely in the sample, as well. However, none of these variables were significantly related to sexual satisfaction. A varied sexual repertoire was independently related to sexual satisfaction and behavior, but did not offer additional predictive power. Results suggest that for married or partnered men with SCI, relationship factors including partner satisfaction and relationship quality are significantly and positively related to sexual satisfaction. Married or partnered men with SCI who report low relationship satisfaction, have difficulty satisfying their partner, and/or report low sexual desire may benefit from assessments and interventions that address these issues.


Subject(s)
Erectile Dysfunction/etiology , Health Services Needs and Demand , Marriage/psychology , Sexual Behavior , Sexual Dysfunction, Physiological/epidemiology , Sexual Dysfunction, Physiological/etiology , Social Adjustment , Spinal Cord Injuries/complications , Spinal Cord Injuries/psychology , Adaptation, Psychological , Adult , Aged , Aged, 80 and over , Erectile Dysfunction/diagnosis , Erectile Dysfunction/epidemiology , Humans , Male , Middle Aged , Personal Satisfaction
19.
Mol Hum Reprod ; 7(11): 1033-8, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11675469

ABSTRACT

Prolactin is mainly known for its role in breast development and lactation, but has been also implicated in other physiological functions such as immunoregulation and ovarian steroid production. Although prolactin and prolactin receptor (PRL-R) transcripts have been previously identified in the human ovary, the spatial localization of the receptor is unknown. To investigate the presence of PRL-R within the follicular apparatus, human luteinized granulosa cells were obtained at the time of follicular aspiration from women undergoing ovarian stimulation for IVF. RNA extracted from these cells was subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) using specific primers for the PRL-R gene. In addition, paraffin sections of isolated granulosa cells and sections of premenopausal human ovaries were immunostained with a mouse anti-human PRL-R monoclonal antibody. PRL-R were immunolocalized to the cell membrane of isolated luteinized granulosa cells and PRL-R transcripts were detected in the extracted RNA. No detectable staining was noted in secondary and early antral follicles in archived paraffin sections. These findings confirm the presence of PRL-R in human luteinized granulosa cells and suggest a localized role for PRL within the mature follicle. The absence of PRL-R in the early follicle suggests that the effects of prolactin are exerted around the time of ovulation.


Subject(s)
Granulosa Cells/physiology , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolism , Adult , Antigens, Differentiation, Myelomonocytic/metabolism , Female , Gene Expression Regulation , Humans , Luteal Phase , Ovary/physiology , Ovulation Induction , Receptors, Prolactin/immunology
20.
Ann Biomed Eng ; 29(8): 648-56, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11556721

ABSTRACT

The morphological and functional status of organs, tissues, and cells can be assessed by evaluating their electrical impedance. Fluid shear stress regulates the morphology and function of endothelial cells in vitro. In this study, an electrical biosensor was used to investigate the dynamics of flow-induced alterations in endothelial cell morphology in vitro. Quantitative, real-time changes in the electrical impedance of endothelial monolayers were evaluated using a modified electric cell-substrate impedance sensing (ECIS) system. This ECIS/Flow system allows for a continuous evaluation of the cell monolayer impedance upon exposure to physiological fluid shear stress forces. Bovine aortic endothelial cells grown to confluence on thin film gold electrodes were exposed to fluid shear stress of 10 dynes/cm2 for a single uninterrupted 5 h time period or for two consecutive 30 min time periods separated by a 2 h no-flow interval. At the onset of flow, the monolayer electrical resistance sharply increased reaching 1.2 to 1.3 times the baseline in about 15 min followed by a sustained decrease in resistance to 1.1 and 0.85 times the baseline value after 30 min and 5 h of flow, respectively. The capacitance decreased at the onset of flow, started to recover after 15 min and after slightly overshooting the baseline values, decreased again with a prolonged exposure to flow. Measured changes in capacitance were in the order of 5% of the baseline values. The observed changes in endothelial impedance were reversible upon flow removal with a recovery rate that varied with the duration of the preceding flow exposure. These results demonstrate that the impedance of endothelial monolayers changes dynamically with flow indicating morphological and/or functional changes in the cell layer. This in vitro model system (ECIS/Flow) may be a very useful tool in the quantitative evaluation of flow-induced dynamic changes in cultured cells when used in conjunction with biological or biochemical assays able to determine the nature and mechanisms of the observed changes.


Subject(s)
Endothelium, Vascular/physiology , Animals , Biomedical Engineering/instrumentation , Cattle , Cells, Cultured , Electric Impedance , Endothelium, Vascular/cytology , Hemodynamics , Models, Cardiovascular
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