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1.
J Fr Ophtalmol ; 46(8): 921-928, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37085363

ABSTRACT

PURPOSE: To evaluate the safety and efficacy of combined simultaneous photorefractive keratectomy (PRK) with collagen cross-linking (CXL) in keratoconus suspects (KCS). METHODS: This was a retrospective, non-randomized study of KCS patients who underwent combined simultaneous PRK with CXL. The efficacy, safety, refractive outcomes, and corneal wavefront aberration changes were assessed after the surgery and compared with existing preoperative data. RESULTS: Fifty-six eyes of 28 patients, including 20 females (71.4%), with a mean age of 30.92±4.09 years, were enrolled. The mean follow-up was 19.46±8.48 months (range: 7-35). At the conclusion of the study, mean uncorrected distance visual acuity LogMAR improved from 0.89±0.44 preoperatively to 0.04±0.09 postoperatively (P<0.001). In addition, a statistically significant corneal flattening was observed postoperatively, with a decrease in manifest refraction. A statistically significant increase was found in higher-order aberrations (P<0.001), horizontal coma (P<0.001), and spherical aberration (P<0.001) compared with preoperatively. Postoperatively, 41% exhibited refractive astigmatism of 0.50 diopter (D) or less; 83.8% showed 1.00 D or less. CONCLUSION: The results of our study indicate that combined simultaneous PRK with CXL can be a safe and effective method for treating refractive instability in KCS patients.


Subject(s)
Keratoconus , Photorefractive Keratectomy , Female , Humans , Adult , Photorefractive Keratectomy/adverse effects , Photorefractive Keratectomy/methods , Keratoconus/diagnosis , Keratoconus/drug therapy , Keratoconus/surgery , Visual Acuity , Photosensitizing Agents/adverse effects , Retrospective Studies , Riboflavin/adverse effects , Corneal Topography , Corneal Stroma/surgery , Collagen , Cross-Linking Reagents/adverse effects
2.
J Fr Ophtalmol ; 44(3): 391-396, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33618908

ABSTRACT

OBJECTIVES: To evaluate the corneal biomechanics before and after daily use of contact lenses (CLs), measured by Scheimpflug-based devices. METHODS: This prospective clinical study includes participants who were scheduled to use CLs daily for refractive error. The biomechanical parameters were measured by the Corneal Visualization Scheimpflug Technology (Corvis ST) before and one month after using the soft CLs. RESULTS: Twenty-three subjects (46 eyes), including 16 female (76.2%) with a mean age of 28±7.29 years, were enrolled. There was no significant difference among biomechanical factors measured before and after contact lens wear (P>0.05). Using regression analysis of the biomechanical markers, we found a statistically significant association between second applanation length (A2 length) (P=0.001), highest concavity radius (HCR) (P=0.05), deflection amplitude ratio (DA_ratio) (P=0.05) and integrated radius (P<0.001) with age. Regarding spherical equivalent, we found a statistically significant association between central corneal thickness (CCT) (P=0.05), A2 length (P=0.03) and stiffness parameter at first applanation (SPA1) (P=0.02). CONCLUSIONS: We did not find a significant difference in terms of corneal biomechanical parameters between baseline and month 1; but regression analyses showed a statistically significant association between A2 length, HCR, DA_ratio, integrated radius, CCT and SPA1 and certain subject characteristics.


Subject(s)
Contact Lenses, Hydrophilic , Tonometry, Ocular , Adult , Biomechanical Phenomena , Cornea , Female , Humans , Intraocular Pressure , Prospective Studies , Young Adult
3.
Phys Med Biol ; 61(4): 1500-14, 2016 Feb 21.
Article in English | MEDLINE | ID: mdl-26815765

ABSTRACT

Numerical dosimetry studies require the development of accurate numerical 3D models of the human body. This paper proposes a novel method for building 3D heterogeneous young children models combining results obtained from a semi-automatic multi-organ segmentation algorithm and an anatomy deformation method. The data consist of 3D magnetic resonance images, which are first segmented to obtain a set of initial tissues. A deformation procedure guided by the segmentation results is then developed in order to obtain five young children models ranging from the age of 5 to 37 months. By constraining the deformation of an older child model toward a younger one using segmentation results, we assure the anatomical realism of the models. Using the proposed framework, five models, containing thirteen tissues, are built. Three of these models are used in a prospective dosimetry study to analyze young child exposure to radiofrequency electromagnetic fields. The results lean to show the existence of a relationship between age and whole body exposure. The results also highlight the necessity to specifically study and develop measurements of child tissues dielectric properties.


Subject(s)
Algorithms , Imaging, Three-Dimensional/methods , Radiation Monitoring/methods , Radiotherapy Planning, Computer-Assisted/methods , Child, Preschool , Electromagnetic Fields/adverse effects , Female , Humans , Infant , Male , Models, Anatomic , Radio Waves/adverse effects
4.
Int J Prev Med ; 3(10): 718-22, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23112899

ABSTRACT

BACKGROUND: Silicon hydrogel bandage contact lenses are used to enhance epithelial healing, control surface-generated pain, and prevent epithelial erosions after refractive surgery. Considering the importance of faster reepithelialization in preventing complications of photorefractive keratectomy (PRK) and the fact that the features and specifications of these commercially-available lenses are different and their performance as a postoperative bandage lenses would be different also, the aim of this study was comparison the efficacy of senofilcon A and lotrafilcon A after PRK. METHODS: In this prospective study, 44 patients with PRK in both eyes randomly received a silicon hydrogel contact lens of senofilcon A in one eye and lotrafilcon A in other eye. Then the epithelial defect size, visual acuity and subjective level of pain and discomfort were measured for both eyes and compared on day 1, 3 and 5 postoperatively. RESULTS: There was no statistical difference in rate of reepithelialization between senofilcon A and lotrafilcon A (P > 0.05). The mean pain and discomfort index was significantly lower in eyes with senofilcon A (P < 0.05). The mean subjective visual scores were similar with both bandage contact lenses (BCLs) (P > 0.05). CONCLUSION: Silicon hydrogel BCLs are safe and effective for corneal reepithelialization and have great therapeutic outcome on visual outcomes after PRK. But, senofilcon A had better effect on postoperative pain and discomfort which made it superior than lotrafilcon A. However for more conclusive results, it is recommended to study larger sample size with evaluation the possible factors responsible for the obtained findings regarding postoperative pain and discomfort.

5.
Phys Med Biol ; 57(19): N339-44, 2012 Oct 07.
Article in English | MEDLINE | ID: mdl-22982710

ABSTRACT

Dielectric properties of porcine glandular tissues and gonads (in vivo) and body fluids (in vitro) have been obtained in the frequency range of 50 MHz to 20 GHz. The experimental data were fitted to a two term Cole-Cole expression. The data presented complement the available dielectric properties of tissues in the literature and can be used in numerical simulations of the exposure of people to electromagnetic fields.


Subject(s)
Body Fluids , Gonads , Swine , Animals , Body Temperature , Electric Impedance , Organ Specificity
6.
Phys Med Biol ; 57(8): 2103-16, 2012 Apr 21.
Article in English | MEDLINE | ID: mdl-22451243

ABSTRACT

The dielectric properties of rat embryos/foetuses have been acquired at several stages of gestation at 37 °C and in the frequency range of 40 MHz-20 GHz. Measurements were carried out on homogenized tissues, as trial experiments did not show any systematic difference between the dielectric data of intact and homogenized tissues at microwave frequencies. The results showed that dielectric properties of the foetus are generally higher than adult muscle and brain. The measured data also showed some decline for both permittivity and conductivity as the foetus grew from 18 to 20 days old; however, these changes were not statistically significant. Data were also collected for placenta and amniotic fluid which were in good agreement with those recently obtained from human tissues. Finally, tabulated numerical dielectric data for rat foetal tissues are presented for a wide range of medical and telecommunication frequencies.


Subject(s)
Body Composition , Embryo, Mammalian/physiology , Fetus/physiology , Amniotic Fluid/cytology , Amniotic Fluid/radiation effects , Animals , Electric Impedance , Embryo, Mammalian/radiation effects , Female , Fetus/radiation effects , Male , Microwaves , Placenta/cytology , Placenta/radiation effects , Pregnancy , Rats , Rats, Sprague-Dawley
7.
Health Phys ; 100(6): 594-612, 2011 Jun.
Article in English | MEDLINE | ID: mdl-22004929

ABSTRACT

Laboratory measurements have been carried out with examples of Wi-Fi devices used in UK schools to evaluate the radiofrequency power densities around them and the total emitted powers. Unlike previous studies, a 20 MHz bandwidth signal analyzer was used, enabling the whole Wi-Fi signal to be captured and monitored. The radiation patterns of the laptops had certain similarities, including a minimum toward the torso of the user and two maxima symmetrically opposed across a vertical plane bisecting the screen and keyboard. The maxima would have resulted from separate antennas mounted behind the top left and right corners of the laptop screens. The patterns for access points were more symmetrical with generally higher power densities at a given distance. The spherically-integrated radiated power (IRP) ranged from 5 to 17 mW for 15 laptops in the 2.45 GHz band and from 1 to 16 mW for eight laptops in the 5 GHz band. For practical reasons and because access points are generally wall-mounted with beams directed into the rooms, their powers were integrated over a hemisphere. These ranged from 3 to 28 mW for 12 access points at 2.4 GHz and from 3 to 29 mW for six access points at 5 GHz. In addition to the spherical measurements of IRP, power densities were measured at distances of 0.5 m and greater from the devices, and consistent with the low radiated powers, these were all much lower than the ICNIRP reference level.


Subject(s)
Electromagnetic Fields , Local Area Networks , Radiation Monitoring , Humans , Laboratories , Schools
8.
Prog Biophys Mol Biol ; 107(3): 412-20, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21856328

ABSTRACT

The growing use of wireless local area networks (WLAN) in schools has prompted a study to investigate exposure to the radio frequency (RF) electromagnetic fields from Wi-Fi devices. International guidelines on limiting the adverse health effects of RF, such as those of ICNIRP, allow for time-averaging of exposure. Thus, as Wi-Fi signals consist of intermittent bursts of RF energy, it is important to consider the duty factors of devices in assessing the extent of exposure and compliance with guidelines. Using radio packet capture methods, the duty factor of Wi-Fi devices has been assessed in a sample of 6 primary and secondary schools during classroom lessons. For the 146 individual laptops investigated, the range of duty factors was from 0.02 to 0.91%, with a mean of 0.08% (SD 0.10%). The duty factors of access points from 7 networks ranged from 1.0% to 11.7% with a mean of 4.79% (SD 3.76%). Data gathered with transmit time measuring devices attached to laptops also showed similar results. Within the present limited sample, the range of duty factors from laptops and access points were found to be broadly similar for primary and secondary schools. Applying these duty factors to previously published results from this project, the maximum time-averaged power density from a laptop would be 220 µW m(-2), at a distance of 0.5 m and the peak localised SAR predicted in the torso region of a 10 year old child model, at 34 cm from the antenna, would be 80 µW kg(-1).


Subject(s)
Computers , Electromagnetic Fields , Environmental Exposure/analysis , Radio Waves , Schools/statistics & numerical data , Wireless Technology/instrumentation , Electromagnetic Fields/adverse effects , Environmental Exposure/adverse effects , Humans , Radio Waves/adverse effects , Time Factors
9.
Phys Med Biol ; 56(7): N93-8, 2011 Apr 07.
Article in English | MEDLINE | ID: mdl-21364261

ABSTRACT

The dielectric properties of freshly delivered human placenta, umbilical cord and amniotic fluid have been acquired at 37 °C and in the frequency range of 200 MHz-10 GHz. The experimental data were fitted to a Cole-Cole expression. The results show that dielectric properties of the umbilical cord are significantly higher than placenta due to the presence of high water content Wharton's jelly. The results also demonstrate large differences in the dielectric properties of amniotic and cerebrospinal fluids. The data presented can be used in numerical simulations of the exposure of pregnant women to electromagnetic fields.


Subject(s)
Amniotic Fluid , Placenta , Umbilical Cord , Electric Impedance , Female , Humans , Pregnancy
10.
Phys Med Biol ; 55(15): N413-9, 2010 Aug 07.
Article in English | MEDLINE | ID: mdl-20647605

ABSTRACT

We have applied the Cole-Cole expression to the dielectric properties of tissues in the frequency range 0.4-10 GHz. The data underpinning the model relate to pig tissue as a function of age. Altogether, we provide the Cole-Cole parameters for 14 tissue types at three developmental stages.


Subject(s)
Microwaves , Swine , Adolescent , Age Factors , Animals , Child , Electric Impedance , Humans , Models, Biological
11.
Phys Med Biol ; 54(16): 4863-78, 2009 Aug 21.
Article in English | MEDLINE | ID: mdl-19636081

ABSTRACT

A two-pronged approach, review and measurement, has been adopted to characterize the conductivity of tissues at frequencies below 1 MHz. The review covers data published in the last decade and earlier data not included in recent reviews. The measurements were carried out on pig tissue, in vivo, and pig body fluids in vitro. Conductivity data have been obtained for skeletal and myocardial muscle, liver, skull, fat, lung and body fluids (blood, bile, CSF and urine). A critical analysis of the data highlights their usefulness and limitations and enables suggestions to be made for measuring the electrical properties of tissues.


Subject(s)
Electric Conductivity , Organ Specificity , Adipose Tissue , Animals , Body Fluids , Bone and Bones , Brain , Liver , Lung , Muscles , Skin , Swine , Uncertainty
12.
Phys Med Biol ; 54(2): 227-41, 2009 Jan 21.
Article in English | MEDLINE | ID: mdl-19088390

ABSTRACT

In vitro dielectric properties of ageing porcine tissues were measured in the frequency range of 50 MHz-20 GHz, and the total combined uncertainties of the measurements were assessed. The results show statistically significant reduction with age in both permittivity and conductivity of 10 out of 15 measured tissues. At microwave frequencies, the observed variations are mainly due to the reduction in the water content of tissues as an animal ages. The results obtained were then used to calculate the SAR values in children of age 3 and 7 years when they are exposed to RF induced by walkie-talkie devices. No significant differences between the SAR values for the children of either age or for adults were observed.


Subject(s)
Radio Waves/adverse effects , Radio , Adolescent , Adult , Aging/metabolism , Animals , Biophysical Phenomena , Child , Child, Preschool , Electromagnetic Fields , Female , Head , Humans , Male , Microwaves/adverse effects , Organ Specificity , Phantoms, Imaging , Swine
13.
Phys Med Biol ; 52(8): 2229-45, 2007 Apr 21.
Article in English | MEDLINE | ID: mdl-17404466

ABSTRACT

The dielectric properties of pig cerebrospinal tissues were measured in vivo and in vitro, in the frequency range of 50 MHz-20 GHz. The total combined measurement uncertainty was calculated at each frequency point and is reported over representative frequency regions. Comparisons were made for each tissue between the two sets of data and with the literature of the past decade. The in vitro study was extended to include tissue from pigs weighing approximately 10, 50 and 250 kg to re-visit the question of the variation of dielectric properties with age. White matter and spinal chord showed significant variation as function of animal age, no age-related variations were recorded for grey matter.


Subject(s)
Aging/physiology , Brain/physiology , Microwaves , Models, Neurological , Nerve Fibers, Myelinated/physiology , Neurons/physiology , Spinal Cord/physiology , Animals , Computer Simulation , Electric Impedance , Plethysmography, Impedance/methods , Reproducibility of Results , Sensitivity and Specificity , Swine
14.
Bioelectromagnetics ; 28(4): 264-74, 2007 May.
Article in English | MEDLINE | ID: mdl-17203479

ABSTRACT

The complex permittivity of aqueous solutions at 20 degrees C has been measured at concentrations between 0.001 and 5 mol/L and over a frequency range 0.13-20 GHz. The results were combined with literature values to derive empirical equations to predict the dielectric behavior of sodium chloride solutions between 0 and 5 mol/L and 5 degrees C-35 degrees C.


Subject(s)
Microwaves , Sodium Chloride , Electrochemistry , Hypotonic Solutions/chemistry , Models, Chemical , Osmolar Concentration , Saline Solution, Hypertonic/chemistry , Sodium Chloride/chemistry , Temperature
15.
Phys Med Biol ; 51(23): 6033-46, 2006 Dec 07.
Article in English | MEDLINE | ID: mdl-17110768

ABSTRACT

The advantages and limitations of using partial differential analysis to assess the methodological uncertainty associated with the measurement of the dielectric properties of a material are discussed and an alternative pragmatic approach is proposed. It relies on repeat measurements of the dielectric properties of reference liquids and an analysis to estimate random and systematic uncertainties. Examples of measurement uncertainty are provided for well-defined monomolecular materials and for less homogeneous materials at microwave frequencies. All examples relate to measurement with an open-ended coaxial probe but the methodology is not specific to this technique. Examination of the components of uncertainty in the dielectric properties of biological tissue shows that, where the system is free of methodological bias, random fluctuations originating from sampling and natural inhomogeneity dominate the uncertainty budget. In such cases, the mean value of the measured parameter and the standard error of the mean can be taken as a good measure of the true value and its associated uncertainty.


Subject(s)
Electrochemistry/statistics & numerical data , Biometry , Biophysical Phenomena , Biophysics , Dimethyl Sulfoxide/chemistry , Electric Conductivity , Electrochemistry/standards , Ethylene Glycols/chemistry , Formamides/chemistry , Methanol/chemistry , Models, Statistical , Reference Standards , Sodium Chloride/chemistry , Uncertainty
16.
Eur J Ophthalmol ; 16(4): 525-9, 2006.
Article in English | MEDLINE | ID: mdl-16952089

ABSTRACT

PURPOSE: To find a method of calculating intraocular lens (IOL) power that may be independent of preoperative data in eyes that have previously undergone myopic laser in situ keratomileusis (LASIK). METHODS: In 148 eyes of 75 patients, before and 6 months after LASIK, IOL power was calculated with SRK/T formula utilizing the spherical equivalent as the desired target refraction. Assuming that LASIK does not alter the crystalline lens refractive properties, IOL calculation error (CER) was estimated with this formula: CER = [pre-LASIK IOL power]/[post-LASIK IOL power]. Then the authors used postoperative biometry and Orbscan II corneal topography data in multiple regression models to find the best variables to predict the CER. Predicted amount of error which is calculated independent of preoperative data could be used to correct the post-LASIK calculated IOL: [corrected post-LASIK IOL power] = CER x [post-LASIK IOL power]. RESULTS: A regression model with these predictors was found: axial length in millimeters (L), radius of the anterior corneal surface best fitted sphere in millimeters divided by radius of the posterior corneal surface best fitted sphere in millimeters (AntBFS/PostBFS), corneal central 5 millimeters mean power in diopters divided by corneal central 3 millimeters mean power in diopters (mean 5 mm/mean 3 mm), the post-LASIK IOL power, and the post-LASIK simulated K reading. The model R square was 0.88. CONCLUSIONS: There is correlation between post-LASIK biometry values and IOL power correction factor. This study presents a new model for further investigation.


Subject(s)
Keratomileusis, Laser In Situ , Lenses, Intraocular , Models, Biological , Models, Statistical , Myopia/surgery , Refraction, Ocular/physiology , Adult , Astigmatism/surgery , Biometry , Female , Humans , Male , Optics and Photonics , Preoperative Care
17.
Int J Radiat Biol ; 81(12): 869-85, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16524843

ABSTRACT

PURPOSE: This study aimed to determine whether Terrestrial Trunked Radio (TETRA) fields can affect intracellular calcium signalling in excitable cells. MATERIALS AND METHODS: Intracellular calcium concentration ([Ca(2 +) ](i)) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle). [Ca(2 +) ](i) was measured as fura-PE3, fluo-3 or fluo-4 fluorescence by digital image analysis. RESULTS: Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW x kg(-1) showed no significant changes in resting [Ca(2 +) ](i). Increases in [Ca(2 +) ](i) in response to potassium-induced depolarization were significantly different from sham controls in TETRA-exposed cells, but the majority of the difference was attributable to initial biological variation between cell cultures. No difference was found between fura-PE3 (UV excitation) and fluo-3 (visible light excitation) measurements in these cells. Exposure to TETRA (50 or 400 mW x kg(-1)) had no significant effect on either the rate or amplitude of spontaneous Ca(2 +) transients in cardiac myocytes. The cells showed normal responses to salbutamol (50 microM) and acetylcholine (10 microM). CONCLUSIONS: Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca(2 + )](i) in granule cells and cardiac myocytes at any of the SAR tested.


Subject(s)
Calcium Signaling/radiation effects , Cerebellum/radiation effects , Myocytes, Cardiac/radiation effects , Radio Waves/adverse effects , Animals , Calcium/pharmacokinetics , Cerebellum/cytology , Female , Male , Myocytes, Cardiac/physiology , Rats , Rats, Wistar
18.
Bioorg Med Chem Lett ; 11(15): 2011-5, 2001 Aug 06.
Article in English | MEDLINE | ID: mdl-11454469

ABSTRACT

A series of novel, highly potent alpha(v)beta(3) antagonists based on a thiophene scaffold and containing an acylguanidine as an Arg-mimetic is described. A number of structural features, such as cyclic versus open guanidine and a variety of lipophilic side chains, carbamates, sulfonamides and beta-amino acids were explored with respect to inhibition of alpha(v)beta(3) mediated cell adhesion and selectivity versus alpha(IIb)beta(3) binding. In addition, compound 19 was found to be active in the TPTX model of osteoporosis.


Subject(s)
Osteoporosis/prevention & control , Platelet Glycoprotein GPIIb-IIIa Complex/metabolism , Receptors, Vitronectin/antagonists & inhibitors , Animals , Binding Sites/drug effects , Binding Sites/physiology , Carbamates/chemistry , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cells, Cultured , Disease Models, Animal , Dose-Response Relationship, Drug , Guanidine/chemistry , Parathyroidectomy , Platelet Glycoprotein GPIIb-IIIa Complex/chemistry , Rats , Receptors, Vitronectin/metabolism , Sensitivity and Specificity , Sulfonamides/chemistry , Thiophenes/chemical synthesis , Thiophenes/pharmacology , Thyroidectomy
19.
Phys Med Biol ; 46(6): 1617-29, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11419623

ABSTRACT

The dielectric properties of ten rat tissues at six different ages were measured at 37 degrees C in the frequency range of 130 MHz to 10 GHz using an open-ended coaxial probe and a computer controlled network analyser. The results show a general decrease of the dielectric properties with age. The trend is more apparent for brain, skull and skin tissues and less noticeable for abdominal tissues. The variation in the dielectric properties with age is due to the changes in the water content and the organic composition of tissues. The percentage decrease in the dielectric properties of certain tissues in the 30 to 70 day old rats at cellular phone frequencies have been tabulated. These data provide an important input in the provision of rigorous dosimetry in lifetime-exposure animal experiments. The results provide some insight into possible differences in the assessment of exposure for children and adults.


Subject(s)
Electric Conductivity , Microwaves , Age Factors , Animals , Brain/physiology , Brain/radiation effects , Rats , Skin/radiation effects , Skin Physiological Phenomena , Skull/physiology , Skull/radiation effects , Time Factors
20.
Circulation ; 103(8): 1135-41, 2001 Feb 27.
Article in English | MEDLINE | ID: mdl-11222478

ABSTRACT

BACKGROUND: Thrombosis and neointima formation limit the efficacy of coronary angioplasty (PTCA). Clinical trials have implicated the adhesion molecules integrin alpha(IIb)beta(3) and integrin alpha(v)beta(3) in these processes. The roles of these molecules in vascular smooth muscle cell adhesion, platelet aggregation, and the thrombotic and neointimal response to oversize porcine PTCA was investigated by use of a selective alpha(IIb)beta(3) antagonist (lamifiban), a selective alpha(v)beta(3) antagonist (VO514), and a combined alpha(IIb)beta(3)/alpha(v)beta(3) antagonist (G3580). METHODS AND RESULTS: In vitro, both alpha(v)beta(3) inhibitors caused dose-dependent inhibition of porcine vascular smooth muscle cell adhesion to vitronectin but not to collagen type IV, fibronectin, or laminin, whereas selective alpha(IIb)beta(3) inhibition had no effect. Intravenous infusions of either alpha(IIb)beta(3) inhibitor in swine profoundly inhibited ex vivo platelet aggregation to ADP, whereas selective alpha(v)beta(3) inhibition had no effect. In a porcine PTCA model, intravenous infusions of the integrin antagonists were administered for 14 days after oversized balloon angioplasty injury. After PTCA, there was regional upregulation of integrin alpha(v)beta(3) in the developing neointima, as assessed by immunohistochemistry. Six hours after PTCA, obstruction of lumen by thrombus was reduced significantly by alpha(IIb)beta(3) inhibition compared with either control or alpha(v)beta(3) inhibition (mean control, 18.7%; VO514, 18.5%; lamifiban, 6.4%; G3580, 7.9%). Twenty-eight days after PTCA, there was a significant reduction of neointima with inhibitors of either integrin (mean intima/media ratio: control, 3.08; VO514, 1.33; lamifiban, 0.97; G3580, 1.32). CONCLUSIONS: We conclude that both integrin alpha(IIb)beta(3) and integrin alpha(v)beta(3) participate in neointima development after experimental angioplasty.


Subject(s)
Acetates/therapeutic use , Thrombosis/prevention & control , Tyrosine/analogs & derivatives , Tyrosine/therapeutic use , Acetates/pharmacology , Angioplasty, Balloon, Coronary/adverse effects , Animals , Cell Adhesion/drug effects , Disease Models, Animal , Immunohistochemistry , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/physiology , Platelet Aggregation/drug effects , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation Inhibitors/therapeutic use , Platelet Glycoprotein GPIIb-IIIa Complex/antagonists & inhibitors , Platelet Glycoprotein GPIIb-IIIa Complex/biosynthesis , Receptors, Vitronectin/antagonists & inhibitors , Receptors, Vitronectin/biosynthesis , Swine , Thrombosis/etiology , Tunica Intima/drug effects , Tyrosine/pharmacology
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