46 research outputs found
Relative expression of rRNA transcripts and 45S rDNA promoter methylation status are dysregulated in tumors in comparison with matched-normal tissues in breast cancer
Ribosomal RNA (rRNA) expression, one of the most important factors regulating ribosome production, is primarily controlled by a CG-rich 45S rDNA promoter. However, the DNA methylation state of the 45S rDNA promoter, as well as its effect on rRNA gene expression in types of human cancers is controversial. In the present study we analyzed the methylation status of the rDNA promoter (-380 to +53 bp) as well as associated rRNA expression levels in breast cancer cell lines and breast tumor-normal tissue pairs. We found that the aforementioned regulatory region was extensively methylated (74-96%) in all cell lines and in 68% (13/19 tumor-normal pairs) of the tumors. Expression levels of rRNA transcripts 18S, 28S, 5.8S and 45S external transcribed spacer (45S ETS) greatly varied in the breast cancer cell lines regardless of their methylation status. Analyses of rRNA transcript expression levels in the breast tumor and normal matched tissues showed no significant difference when normalized with TBP. On the other hand, using the geometric mean of the rRNA expression values (GM-rRNA) as reference enabled us to identify significant changes in the relative expression of rRNAs in the tissue samples. We propose GM-rRNA normalization as a novel strategy to analyze expression differences between rRNA transcripts. Accordingly, the 18S rRNA/GM-rRNA ratio was significantly higher whereas the 5.8S rRNA/GM-rRNA ratio was significantly lower in breast tumor samples than this ratio in the matched normal samples. Moreover, the 18S rRNA/GM-rRNA ratio was negatively correlated with the 45S rDNA promoter methylation level in the normal breast tissue samples, yet not in the breast tumors. Significant correlations observed between the expression levels of rRNA transcripts in the normal samples were lost in the tumor samples. We showed that the expression of rRNA transcripts may not be based solely on promoter methylation. Carcinogenesis may cause dysregulation of the correlation between spliced rRNA expression levels, possibly due to changes in rRNA processing, which requires further investigation
Prediction of breast self-examination in a sample of Iranian women: an application of the Health Belief Model
<p>Abstract</p> <p>Background</p> <p>Iranian women, many of whom live in small cities, have limited access to mammography and clinical breast examinations. Thus, breast self examination (BSE) becomes an important and necessary approach to detecting this disease in its early stages in order to limit its resultant morbidity and mortality. This study examined constructs arising from the Health Belief Model as predictors of breast self examination behavior in a sample of women living in Bandar Abbas, Iran.</p> <p>Methods</p> <p>This study was conducted in eight health centers located in Bandar Abbas, Iran. The sample consisted of 240 eligible women who were selected from referrals to the centers. The inclusion criteria were as follows: aged 30 years and over; and able to read and write Farsi. Women with breast cancer, who were pregnant, or breast feeding, were excluded from the study. Data were collected by using a self administered questionnaire which included demographic characteristics and Champion's Health Belief Model Scale. This instrument measures the concepts of disease susceptibility (3 items), seriousness (6 items), benefits (4 items), barriers (8 items) and self-efficacy (10 items).</p> <p>Results</p> <p>The subjects' mean age was 37.2 (SD = 6.1) years. Just under a third of the subjects (31.7%) had performed BSE in the past and 7.1% of them performed it at least monthly. Perceived benefits and perceived self-efficacy of the women who performed BSE were significantly higher compared with women who did not practice BSE (p < 0.03). Furthermore, perceived barriers were lower among those who had performed BSE (p < 0.001). Logistic regression analysis indicated that women who perceived fewer barriers (OR: 0.70, 95% CI: 0.63-0.77, p < 0.001) and had higher self-efficacy (OR: 1.08, 95% CI: 1.02-1.13, p = 0.003) were more likely to perform BSE (R<sup>2 </sup>= 0.52).</p> <p>Conclusion</p> <p>Findings from this study indicated that perceived barriers and perceived self-efficacy could be predictors of BSE behavior among the sample of women. Therefore, BSE training programs that emphasize self-efficacy and address perceived barriers are recommended.</p
High activity redox catalysts synthesized by chemical vapor impregnation
The use of precious metals in heterogeneous catalysis relies on the preparation of small nanoparticles that are stable under reaction conditions. To date, most conventional routes used to prepare noble metal nanoparticles have drawbacks related to surface contamination, particle agglomeration, and reproducibility restraints. We have prepared titania-supported palladium (Pd) and platinum (Pt) catalysts using a simplified vapor deposition technique termed chemical vapor impregnation (CVI) that can be performed in any standard chemical laboratory. These materials, composed of nanoparticles typically below 3 nm in size, show remarkable activity under mild conditions for oxidation and hydrogenation reactions of industrial importance. We demonstrate the preparation of bimetallic Pd–Pt homogeneous alloy nanoparticles by this new CVI method, which show synergistic effects in toluene oxidation. The versatility of our CVI methodology to be able to tailor the composition and morphology of supported nanoparticles in an easily accessible and scalable manner is further demonstrated by the synthesis of Pdshell–Aucore nanoparticles using CVI deposition of Pd onto preformed Au nanoparticles supported on titania (prepared by sol immobilization) in addition to the presence of monometallic Au and Pd nanoparticles
Contrast sensitivity and glare testing in pseudophakia and early cataracts
In order to evaluate the extent of impairment in visual functions in early cataract and to better evaluate visual functions in pseudophakia contrast sensitivity measurements and glare testing were performed and compared with the control group. 70 eyes with early cataracts, 70 pseudophakic eyes and 70 normal eyes were enroiled in the study. Contrast sensitivity scores were significantly lower (p<0.001) and glare was significantly higher (p<0.01) in both study groups when compared with normal subjects. Contrast sensitivity and glare testing reveal useful information about visual impairment in early cataract and they can also explain the subjective symptoms after cataract surgery despite high Snellen visual acuities
A one-handed pars plicata lensectomy-vitrectomy technique for congenital cataracts
Cataract surgery on children's eyes has always been a challenge and a subject of controversy,We present the results of 48 lensectomies performed on 24 infants via a pars plicata approach using an anterior vitrectomy instrument with irrigating/aspirating/cutting functions on the same probe. Surgery involved posterior capsulectomy, removal of the lens material,anterior capsulectomy and anterior vitrectomy. Mean age at surgery was 7.6 months (range 14 days and 18 months). Inadvertent damage to the iris spincter was the only minor intraoperative complication. No major complications were encountered intra-or postoperatively, and the visual axes have remained clear over a mean follow-up period of 13.8 months (range 6 months and 3 years). In conclusion,one-handed pars plicata lensectomy and vitrectomy seems to be easy, simple and without serious complications in infants with congenital cataracts
Effect of Apraclonidine Versus Dorzolamide on Intraocular Pressure After Phacoemulsification
square BACKGROUND AND OBJECTIVE: To investigate the efficacy of 1% apraclonidine hydrochloride and 2% dorzolamide hydrochloride in controlling postoperative intraocular pressure elevation in patients undergoing phacoemulsification
Visual Results and Complications of Posterior Chamber Intraocular Lens Implantation After Capsular Tear During Phacoemulsification
BACKGROUND AND OBJECTIVE: To determine the visual outcome and complications of posterior chamber intraocular lens implantation after capsular tear in patients undergoing phacoemulsification at Istanbul University, Istanbul Faculty of Medicine, Department of Ophthalmology, Istanbul, Turkey
Visual results and complications of posterior chamber intraocular lens implantation after capsular tear during phacoemulsification
BACKGROUND AND OBJECTIVE: To determine the visual outcome and complications of posterior chamber intraocular lens implantation after capsular tear in patients undergoing phacoemulsification at Istanbul University, Istanbul Faculty of Medicine, Department of Ophthalmology, Istanbul, Turkey
Internal ophthalmomyiasis presenting as endophthalmitis associated with an intraocular foreign body.
Ophthalmomyiasis interna infestation by fly larva can present in various forms. A 3-year-old girl with a 15-day history of pain, redness, and tearing of the right eye was referred to our clinic with the diagnosis of enclophthalmitis associated with an intraocular foreign body, based on clinical and ultrasonographic findings. The patient underwent pars plana vitrectomy, during which an 8-mm long larva was encountered within the vitreous cavity. It was removed and identified as a cattle botfly. The patient developed a retinal detachment 1 month postoperatively, but the family refused further treatment and the patient was lost to follow-up. Ophthalmomylasis should be included in the differential diagnosis of endophthalmitis and intraocular foreign bodies in patients from rural areas
Effect of apraclonidine versus dorzolamide on intraocular pressure after phacoemulsification
square BACKGROUND AND OBJECTIVE: To investigate the efficacy of 1% apraclonidine hydrochloride and 2% dorzolamide hydrochloride in controlling postoperative intraocular pressure elevation in patients undergoing phacoemulsification