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PURPOSE: The purpose of this study was to assess the pull-out bond strength (PBS) of endodontically treated anterior teeth that had been restored with monolithic zirconia endocrowns using different extension depths (EDs) and post-and-core crowns after chewing simulation. METHODS: Thirty-six maxillary central teeth were used (n = 12). Group I: Glass fiber post-and-core crown, Group II: Endocrown with 3-mm EDs, Group III: Endocrown with 5-mm EDs. Restorations were fabricated from monolithic zirconia blocks using a CAM (computer-aided manufacturing) device. For cementation, conventional resin luting agent (Multilink N) was used. All samples were aged with a chewing simulator and PBS tests were conducted at a speed of 1 mm/min using an electromechanical servo universal testing machine. The values were recorded in MPa by dividing the failure load by the bonding area. One-way ANOVA and the post-hoc Tukey test were used for statistical analysis (P = 0.05). RESULTS: Group III demonstrated significantly greater PBS values than Groups I and II (P = 0.001). No significant difference was found between Groups I and II (P = 0.072). CONCLUSION: Increasing the ED of an endocrown influences the PBS of endodontically treated anterior teeth restored with monolithic zirconia endocrowns.
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Coronas , Circonio , Ensayo de Materiales , Diente Molar , Análisis del Estrés Dental , Porcelana Dental , Cerámica/químicaRESUMEN
PURPOSE: To evaluate the effect of different surface treatments, ferrule heights, and luting agents on the pull-out bond strength (PBS) of computer-aided design/computer-aided manufacturing (CAD-CAM) monolithic endocrowns. METHODS: After endodontic treatment and preparation for two endocrown designs (ferrule height 0 mm or 2 mm), CAD-CAM monolithic zirconia endocrowns were fabricated for 80 mandibular molars. Each endocrown design group was then divided on the basis of surface treatment into two groups: half were air-abraded and half were air-abraded/laser-irradiated. Then, all treated groups were further divided into two subgroups (n = 10) and cemented to teeth with either a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing resin luting agent (Panavia SA) or a combination of MDP-containing primer and MDP-free resin luting agent (Monobond Plus/Multilink Automix). PBS was measured with a universal test machine after simulated chewing and thermocycling. Three-way ANOVA and the post-hoc Bonferroni test were used for statistical analysis. RESULTS: PBS was significantly associated with type of surface treatment, type of luting agent, and ferrule height. Air-abraded/laser-irradiated endocrowns with a 2-mm ferrule that were cemented with Monobond Plus/Multilink Automix had the highest PBS (P < 0.05). CONCLUSION: Surface treatment with air abrasion/laser irradiation, presence of a ferrule, and priming with an MDP-containing primer increased the PBS of monolithic zirconia endocrowns.
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Recubrimiento Dental Adhesivo , Cementos Dentales , Abrasión Dental por Aire , Análisis del Estrés Dental , Ensayo de Materiales , Metacrilatos , Cementos de Resina/química , Propiedades de Superficie , Circonio/químicaRESUMEN
BACKGROUND: The violence experienced by a woman during her pregnancy period has a direct impact on both mother and child, and it generally harms the development of the family and society. AIM: This study was conducted to determine spouse violence experiences of married women aged 15 years and older during their pregnancy period who live in a province in eastern Turkey. MATERIALS AND METHODS: This descriptive study was carried out with 712 married women living in a city center in Turkey. Participants were selected by systematic sampling from the records by reaching to all family health centers in the city. The field study was conducted between April and June 2015. The questionnaire was prepared by the researchers. The findings of the study were evaluated in "SPAS version 22 software package." Chi-square test and multidimensional logistic regression analysis were used in the analysis. P < 0.05 was considered statistically significant in the comparisons. RESULTS: In our study, having a kinship relationship with her husband, lack of education of herself and her husband, and lack of employment by the woman were found to be the risk factors for violence during pregnancy period (P < 0.05). The fact that she was exposed to physical violence from her husband during her no pregnancy period, and that the woman was beaten by her father during her childhood period increased the risk of violence during pregnancy period (P < 0.05). CONCLUSION: The rate of exposure to physical violence by her spouse during pregnancy period is high. The provision of education and employment can increase a woman's social networks and improve her status within the family.
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Maltrato Conyugal , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Embarazo , Factores de Riesgo , Factores Socioeconómicos , Turquía/epidemiología , ViolenciaRESUMEN
The purposes of this study are to examine how social learning processes and social structure correlate with delinquency among Turkish adolescents and to articulate to what extent Akers's social structure and social learning (SSSL) theory explains delinquency in Turkey, which is a different cultural context from Western countries in terms of family structure, level of collectivism or individualism, religion, belief systems, and norms. This study contributes to the existing body of knowledge by providing the first study testing Akers's theory in the Turkish context. Analyses, relying on a structural equation modeling (SEM) framework, showed that the social learning process accounted for a substantial amount of variation in explaining adolescent delinquency. We also found that social learning process somewhat mediates social structural effects on delinquency.
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Conducta del Adolescente/psicología , Condicionamiento Psicológico , Delincuencia Juvenil/psicología , Aprendizaje Social , Adolescente , Niño , Femenino , Humanos , Análisis de Clases Latentes , Masculino , Controles Informales de la Sociedad , TurquíaRESUMEN
INTRODUCTION: Anatomical changes after surgery and fibrotic adhesions increase the organ laceration risk, including that of the ureter, in recurrent cases and secondary operations. The aim of this study was to investigate the changes in the anatomical localisations of the ureters via computed tomography urography in patients undergoing rectal cancer surgery. MATERIAL AND METHODS: The study involved prospectively collected data on the changes of ureteral location preoperatively and postoperatively in patients with operated rectal cancer. Distances (mm) of ureters determined midline in the computed tomography urogram phase. RESULTS: A total of 18 patients were included. The mean distances between the right (R1 ) and left (L1 ) ureters and the mid-vertebral line before the surgery were 30.9 ±5.4 mm and 34.5 ±9.9 mm, respectively. The postoperative distances between them (R2 and L2 ) were 26.4 ±9.1 mm and 29.5 ±9.9 mm, respectively. The R2 measurement showed that 83.3% (15/18) of the right ureters had deviated medially, whereas 16.7% (3/18) of them had deviated laterally. The L2 measurements showed that 88.8% (16/18) of the left ureters had deviated medially, whereas 11.2% (2/18) of them had deviated laterally. The differences between the preoperative and postoperative measurements of the right and left ureter positions were 4.5 ±9.2 mm and 4.9 ±4.6 mm, respectively, with the displacement in the left ureter being statistically significant (p ≤ 0.001). CONCLUSIONS: Rectal cancer surgery causes medially deviated changes in the positions of the ureters.
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PurposeFibromyalgia (FM) is a chronic pain disorder associated with pain and hypersensitivity in various parts of the body. The aim of this study was to understand whether changes in corneal sensitivity were associated with the subjective complaints of these patients.Patients and methodsIn this study, we included 36 patients with FM (30 female, 6 male, mean age: 46.7±9.2 years) and 39 healthy control subjects (33 females, 6 males, mean age: 44.3±7.6 years). We performed a detailed ophthalmological examination, measured tear film breakup time (TBUT), and performed Schirmer I test without anesthetic (SIT). Only patients that did not have any eye disease were included in this study. Subjective complaints of the patients were evaluated with ocular surface disease index (OSDI) scores and the corneal sensation was evaluated with Cochet-Bonnet esthesiometer.ResultsThere was no significant difference between the groups for age, sex, and visual acuity. Both SIT (16.1 mm vs 15.3 mm, P=0.36) and TBUT results (17.8 s vs 18.8 s, P=0.40) were similar in FM group and the controls subjects. However, corneal sensations in central (60.0 mm vs 55.0 mm, P=0.03), superior (57.5 mm vs 50.0 mm, P=0.005), and inferior (53.89 mm vs 46.03 mm, P<0.001) regions were significantly increased in FM patients. There was a significant positive correlation between corneal sensation and OSDI scores.ConclusionIn this study, we have demonstrated that the patients with FM have increased corneal sensitivity and have related ocular surface complaints similar to dry eye disease in the absence of it.
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Córnea/fisiología , Síndromes de Ojo Seco/etiología , Dolor Ocular/etiología , Fibromialgia/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lágrimas/metabolismo , Agudeza VisualRESUMEN
AIM OF THE STUDY: Examination of esophagojejunal (EJ) anastomosis with aqueous contrast swallow after total gastrectomy is still routinely conducted by many centres. The present study aimed to answer the question: Is it necessary to evaluate EJ anastomosis in terms of leakage by having every patient drink oral contrast agent before initiation of oral food intake after total gastrectomy (TG) performed due to gastric cancer? MATERIAL AND METHODS: Clinical and radiological results of patients on whom total gastrectomy was performed due to gastric cancer between January 2013 and December 2016 were retrospectively reviewed. Diagnostic method used for patients in whom leak developed and therapeutic interventions were assessed. Evaluation results from aqueous contrast agent and clinical, laboratory, and tomographic findings were studied. RESULTS: Sixty of the 69 patients who underwent total gastrectomy with a diagnosis of gastric adenocarcinoma swallowed aqueous contrast agent on postoperative day 7 ±2 days and were evaluated in terms of anastomotic leak. Leak developed in 14 patients (20.2 %), 10 of whom ingested contrast agent. Leak was identified in 6 of those patients; however, diagnosis was made with multislice computed tomography (CT) in four patients (40%). The sensitivity of the examination with aqueous contrast agent was 60%. CONCLUSIONS: Evaluating anastomotic leak with aqueous contrast agent after TG has low sensitivity, and it would be wise to resort to this procedure in cases with clinical suspicion, rather than routinely performing it in every patient.
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The aim of this study is to evaluate the effect of 18FDG PET on preoperative staging and clinical management of pancreatic cancer. Between December 2011 and February 2015, 28 consecutive patients with borderline resectable pancreatic cancer were evaluated with both 18FDG PET scans and conventional preoperative imaging studies. Medical records of all patients were noted prospectively. 18FDG PET findings were compared with conventional imaging studies and over-staging or down-staging rates with changes in clinical management were evaluated. The correlation of 18FDG PET with conventional imaging studies was evaluated with a kappa agreement coefficient. A number of 22 (78.5%) patients had pancreatic head cancer and 6 (21.4%) patients had pancreatic body and tail cancers. Based on 18FDG PET, additional lesions were found in 4 (14.28%) of the patients which were lung and peritoneal lesions as metastasis. No hepatic metastasis or supraclavicular lymph node involvement was confirmed in patients. Routine use of 18FDG PET for preoperative staging has not an effect on cancer management in 96.8% of our patients. In conclusion, 18FDG PET has additional value over conventional radiologic techniques for monitoring the treatment response in locally advanced pancreatic cancer patients. It is feasible to predict early metastasis and patient outcome early (after one course of IC) during therapy.
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Fluorodesoxiglucosa F18 , Neoplasias Pancreáticas/diagnóstico por imagen , Radiofármacos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tomografía de Emisión de PositronesRESUMEN
Many reports led to the consensus on the use of progesterone (P) for luteal-phase support. Vaginal P application is the method of choice due to its simplicity and high patient convenience but is hampered by application difficulties and personal or cultural aversions. Inappropriate vaginal P use may alter successful implantation, leading physicians to consider alternate P application routes. A worldwide survey revealed that intramuscular plus vaginal P (combined P) is the method used in nearly one-third of in vitro fertilization (IVF) cycles, particularly in Asia and North America; unfortunately, the outcomes of this approach have not been clearly elucidated. In the current analysis, we evaluated any additional benefit of short course parenteral P in addition to vaginal P capsules during a specific period in terms of implantation, pregnancy rates, miscarriages and ectopic pregnancies in cleavage stage embryo transfer (ET) cycles of good-prognosis patients. Despite significantly higher implantation rates in the combined arm, clinical and ongoing pregnancies were comparable in both groups, whereas a trend toward increased pregnancy rates was observed with combined support. The available data are too limited to draw conclusions.
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Transferencia de Embrión/métodos , Fase Luteínica/efectos de los fármacos , Inducción de la Ovulación/métodos , Progesterona/uso terapéutico , Administración Intravaginal , Adulto , Femenino , Humanos , Inyecciones Intramusculares , Embarazo , Índice de Embarazo , Progesterona/administración & dosificación , Pronóstico , Resultado del TratamientoRESUMEN
BACKGROUND: Essential thrombocythemia (ET) is a clonal disease in which thrombotic and hemorrhagic complications are common. Our aim in this study was to investigate whether oxidative stress in ET patients increased compared to healthy volunteers and to investigate whether there is a relationship between vascular events and oxidative status parameters in ET patients. PATIENTS AND METHODS: We determined the serum levels of oxidative status parameters, such as total oxidative status (TOS), total antioxidant status (TAS), oxidative stress index (OSI) and malondialdehyde (MDA) in ET patients. Forty-three ET patients (20 males, 23 females) and 20 healthy volunteers were enrolled. Oxidative status parameters of the patients were compared with those of the controls at time of diagnosis and at 6th-month follow-up. Additionally, oxidative status parameters of patients with ET with a history of vascular event were compared with patients without a vascular event history during diagnosis. RESULTS: Rises in TOS, OSI, and MDA were statistically significant in the patients group; however, the TAS value was significantly lower compared to the control group. Furthermore, TOS was significantly higher in patients with history of vascular event compared to the patients without such a history. Following therapy, OSI and MDA values were significantly reduced in the patient group compared to the pre-treatment values. CONCLUSIONS: Our findings reveal that although oxidative stress parameters were increased, compensative total antioxidant status was significantly reduced in ET patients. Furthermore, TOS values were significantly high in patients with a history of vascular event.
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Antioxidantes/metabolismo , Malondialdehído/metabolismo , Estrés Oxidativo , Trombocitosis/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana EdadRESUMEN
This experiment was designed to investigate the effect of sildenafil citrate on testicular injury after unilateral testicular torsion/detorsion (T/D). Thirty-seven adult male Wistar albino rats were divided into four groups: sham operated group (group 1), T/D+ saline (group 2), T/D+ 0.7 mg sildenafil citrate (group 3) and T/D+ 1.4 mg sildenafil citrate (group 4). Testicular torsion was created by rotating the right testis 720° in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. The level of GSH (P < 0.05) in the testis in the group 2 were significantly lower (P < 0.05) and the levels of MDA and NO (P < 0.01 for both) in the testis were significantly higher when compared with those of the group 1. Administration of low dose sildenafil citrate prevented the increases in MDA and NO levels and decreases in GSH values induced by testicular torsion. However, administration of high dose sildenafil citrate did not have any effect on these testicular tissue parameters (P > 0.05). Also, mean values of seminiferous tubules diameters, germinal cell layer thicknesses and mean testicular biopsy score were significantly better in group 3 than groups 2 and 4. These results suggest that T/D injury occurred in testis after unilateral testicular T/D and that administration of low dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular torsion. Sildenafil citrate probably acts through reduction of reactive oxygen species and support antioxidant enzyme systems.
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Inhibidores de Fosfodiesterasa/uso terapéutico , Piperazinas/uso terapéutico , Torsión del Cordón Espermático/complicaciones , Sulfonas/uso terapéutico , Testículo/lesiones , Animales , Relación Dosis-Respuesta a Droga , Glutatión/metabolismo , Peroxidación de Lípido , Masculino , Malondialdehído/metabolismo , Óxido Nítrico/metabolismo , Purinas/uso terapéutico , Ratas , Ratas Wistar , Citrato de Sildenafil , Testículo/patologíaRESUMEN
AIM: To determine the impact of rectus fascial sling suspension at the time of radical retropubic prostatectomy (RRP) on postoperative continence status. PATIENTS AND METHODS: A total of 86 patients underwent RRP for clinically localized prostate cancer. Out of 86 patients, a rectus fascial sling procedure was incorporated into RRP in 40 randomly selected patients (group 1). The remaining 46 patients underwent standard RRP without any suspension operation (group 2). RESULTS: The incontinence rates were 17.5 and 43.5% for groups 1 and 2, respectively (p = 0.010). Incontinence degrees for each group were statistically significant (p = 0.03). The mean time to achieve full continence was 1.4 +/- 2.2 (0-11) and 3.8 +/- 3.8 (0-12) months for groups 1 and 2, respectively (p = 0.026). CONCLUSION: Our results showed that incorporation of an anterior rectus fascial sling into RRP is a reasonable and efficient way of achieving improved rates of postoperative continence.
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Fasciotomía , Prostatectomía/métodos , Cabestrillo Suburetral , Incontinencia Urinaria/prevención & control , Adulto , Anciano , Humanos , Masculino , Persona de Mediana Edad , Prostatectomía/efectos adversos , Incontinencia Urinaria/etiologíaRESUMEN
We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the standard model with a generalized supersymmetry breaking sector. If the superpotential neutrino Yukawa terms are forbidden by the gauge symmetry [such as a U(1)'], sub-eV scale effective Dirac mass terms can arise at tree level from hard supersymmetry breaking Yukawa couplings, or at one loop due to nonanalytic soft supersymmetry breaking trilinear scalar couplings. The radiative neutrino magnetic and electric dipole moments vanish at one-loop order.
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An implant from hydroxyapatite and polyethylene (HA+PE) composite was investigated for the usability in large bone defects. With this aim, the implants were manufactured in blocks by hot compacting the mixture of 80% HA and 20% PE weight ratio. Powders were machined in a lathe in the dimensions of diaphysis of the radius of the mongrel dogs. Then a defect, 1.5 cm in length, was made in the diaphysis of the radius with an operation performed under general anaesthesia in 16 healthy mongrel dogs. The defects were filled with implant as a block. The dogs were observed radiologically in 15-day intervals and examined clinically in certain intervals. The bone samples were taken out from four dogs for the histopatological examinations at the end of the 2nd, 4th, 6th and 12th months, respectively. Clinical examinations indicated the occurrence of slight lameness in all cases at the first month of experiment, but lameness completely disappeared in a further examination. Progressive resorption and new bone formation began in the implants from the first month, but complete resorption was not observed in any case at the end of 12-month period. SEM and optical microscope examinations revealed fibroblast cell with its clear cytoplasmic extensions and osteoblast cells in endosteum in the inner region. Bone formation increasing and extending to the pores of implant in time and blood vessels with lamellar structure and Haversian system were observed. As a result, it was indicated that HA+PE composite implants could be applied with confidence and are useful in treatment of large bone defects in long bone of dogs.
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Sustitutos de Huesos/uso terapéutico , Durapatita/química , Fijación Interna de Fracturas/instrumentación , Polietileno/química , Prótesis e Implantes , Fracturas del Radio/patología , Fracturas del Radio/cirugía , Animales , Materiales Biocompatibles/uso terapéutico , Perros , Análisis de Falla de Equipo , Fijación Interna de Fracturas/métodos , Diseño de Prótesis , Resultado del TratamientoRESUMEN
Angiotensin-converting enzyme inhibitors (ACEIs) were accepted as a potential cause of inadequate epoetin response in chronic kidney disease (CKD) patients. We aimed to determine the effects of valsartan, an angiotensin receptor blocker (ARB), on serum ertyhropoietin levels and on certain biochemical and haematological parameters in hypertensive CKD patients. Twenty-two stage III-IV CKD patients (mean age; 56.8 +/- 8.9 years, 12 male 10 female) were included in the study. Before initiating the treatment, current anti-hypertensive treatments (if any) were discontinued, and blood samples were collected after a washout period of 3 weeks. Valsartan 80 mg/day was started, and additional anti-hypertensive agents were given according to study protocol if needed. One way Anova and paired t-tests were used for statistical comparisons. Serum blood urea nitrogen (BUN), creatinine, uric acid, potassium, haemoglobin and erythropoietin values were measured, and glomerular filtration rates were calculated before and 3, 6 and 90 days after valsartan treatment, a significant reduction in EPO level was observed at 3rd (19.6 +/- 24.0 vs. 13.8 +/- 8.5, p = 0.010), 6th (12.1 +/- 7.6, p = 0.009), and 90th days (8.3 +/- 5.4, p = 0.007). When pre-treatment values were compared with 90th day results, no significant change was observed in terms of hgb, htc, serum BUN, creatinine, uric acid, potassium, and GFR values. In conclusion, valsartan, an ARB, did not decrease haemoglobin levels in stage III-IV CKD patients despite significant reduction in serum erythropoietinlevels, so ARBs may be preferred to ACEIs in CKD patients when indicated.
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Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Eritropoyetina/análisis , Hemoglobinas/análisis , Fallo Renal Crónico/sangre , Fallo Renal Crónico/tratamiento farmacológico , Tetrazoles/uso terapéutico , Valina/análogos & derivados , Análisis de Varianza , Antihipertensivos/uso terapéutico , Nitrógeno de la Urea Sanguínea , Creatinina/sangre , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Potasio/sangre , Ácido Úrico/sangre , Valina/uso terapéutico , ValsartánRESUMEN
Hypothyroidism is associated with a number of functional renal disorders primarily affecting water and salt handling. In this study, we aim to investigate functional renal disorders in overt and subclinical hypothyroidism. We utilised urinary beta-2 microglobulin (beta2M) as a sensitive marker of tubular dysfunction. Urinary beta2M excretion and tests for renal functions were repeated before and after T4 replacement therapy. Forty-four patients (28 with overt disease, 16 with subclinical disease) and 31 healthy control subjects were involved in the study. There was a significant increase in urinary beta2M in both overt and subclinical hypothyroidism (p < 0.05 in both). TSH levels were correlated with beta2M excretion. Effects of hypothyroidism on renal functions were readily reversible by 3 weeks of thyroid hormone replacement therapy. Urinary beta2M was a sensitive marker of renal tubular dysfunction associated with overt and subclinical hypothyroidism.
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Hipotiroidismo/complicaciones , Enfermedades Renales/etiología , Microglobulina beta-2/orina , Biomarcadores/orina , Femenino , Humanos , Hipotiroidismo/orina , Enfermedades Renales/diagnóstico , MasculinoRESUMEN
AIM: To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium. METHODS: A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps (numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests. RESULTS: Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10+/-2.34 D, t=3.40, P=0.027) and dried eyes (2.12+/-1.01 D, t=4.74, P=0.001) according to the first baseline measurement (4.31+/-1.91 D) of the total mean corneal refractive power was found to be 43.45+/-1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54+/-1.06 D, P>0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26+/-0.93 D, t=34.92, P<0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric. CONCLUSION: We conclude that the pooling of tears at the pterygium apex plays an important role, but fibrovascular traction has no effect on the corneal topographical changes induced by pterygium.
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Córnea/patología , Pterigion/patología , Lágrimas , Adulto , Anciano , Astigmatismo/etiología , Astigmatismo/fisiopatología , Córnea/fisiopatología , Topografía de la Córnea/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pterigion/complicaciones , Pterigion/fisiopatología , Refracción Ocular , Estrés MecánicoRESUMEN
The sequence of cDNA fragments of two isozymes of the purple acid phosphatase from sweet potato (spPAP1 and spPAP2) has been determined by 5' and 3' rapid amplification of cDNA ends protocols using oligonucleotide primers based on amino acid information. The encoded amino acid sequences of these two isozymes show an equidistance of 72-77% not only to each other, but also to the primary structure of the purple acid phosphatase from red kidney bean (kbPAP). A three-dimensional model of the active site has been constructed for spPAP2 on the basis of the kbPAP crystallographic structure that helps to explain the reported differences in the visible and EPR spectra of spPAP2 and kbPAP.
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Fosfatasa Ácida/genética , Glicoproteínas/genética , Proteínas de Plantas/genética , Solanum tuberosum/enzimología , Fosfatasa Ácida/química , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario/química , Glicoproteínas/química , Isoenzimas/genética , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas de Plantas/química , ARN/química , ARN/aislamiento & purificación , Alineación de SecuenciaRESUMEN
Purple acid phosphatase from sweet potatoes Ipomoea batatas (spPAP) has been purified to homogeneity and characterized using spectroscopic investigations. Matrix-assisted laser desorption/ionization mass spectrometry analysis revealed a molecular mass of approximately 112 kDa. The metal content was determined by X-ray fluorescence using synchrotron radiation. In contrast to previous studies it is shown that spPAP contains a Fe(III)-Zn(II) center in the active site as previously determined for the purple acid phosphatase from red kidney bean (kbPAP). Moreover, an alignment of the amino acid sequences suggests that the residues involved in metal-binding are identical in both plant PAPs. Tyrosine functions as one of the ligands for the chromophoric Fe(III). Low temperature EPR spectra of spPAP show a signal near g = 4.3, characteristic for high-spin Fe(III) in a rhombic environment. The Tyr-Fe(III) charge transfer transition and the EPR signal are both very sensitive to changes in pH. The pH dependency strongly suggests the presence of an ionizable group with a pKa of 4.7, arising from an aquo ligand coordinated to Fe(III). EPR and UV/visible studies of spPAP in the presence of the inhibitors phosphate or arsenate suggest that both anions bind to Fe(III) in the binuclear center replacing the coordinated water or hydroxide ligand necessary for hydrolysis. The conserved histidine residues of spPAP corresponding to His202 and His296 in kbPAP probably interact in catalysis.