29 research outputs found
Scotopic contrast sensitivity and glare after accelerated corneal cross-linking
Background: The aim was to assess one-year changes in uncorrected and corrected contrast sensitivity (CS) and glare under scotopic conditions after accelerated cross-linking (CXL) using the 18 mW/cm2 protocol for the treatment of progressive keratoconus and compare results with unoperated controls. Methods: In this non-randomised clinical trial, 30 eyes were enrolled in the CXL group and 30 were assigned to the control group. Scotopic CS at spatial frequencies (SFs) of 0.5, 1.1, 2.2, 3.4, 7.1 and 15 cycles per degree (cpd) were assessed using the MonCv3System (Metrovision, Pérenchies, France) under scotopic conditions (0.5 lux) at baseline and at six and 12 months. Results: The mean ages of the participants in the CXL and control groups were 24.32 ± 5.17 and 30.93 ± 7.43 years, respectively (p < 0.001). After adjusting for age, changes in uncorrected and corrected CS and glare were similar in the two groups (all p > 0.05) except for corrected CS at SF 7.1 cpd (1.45 ± 4.31 versus 3.21 ± 4.69 dB, p = 0.010) and 15 cpd (1.12 ± 4.63 versus 3.03 ± 5.48 dB, p = 0.007), which were reduced as an effect of CXL. Based on covariate analyses, among corrected CS indices, corrected CS7.1 and CS15 were related to CXL and their baseline values (all p < 0.050). Uncorrected CS in all SFs and uncorrected and corrected glare were related to their pre-operative values (all p < 0.001). Conclusion: Accelerated CXL can reduce scotopic corrected CS at SFs higher than 7.0 cpd in cases with better baseline values of these parameters. Changes in uncorrected CS and glare are only a factor of baseline values and the indices reduce in cases with better baseline values after one year. © 2017 Optometry Australi
Maxadilan Prevents Apoptosis in iPS Cells and Shows No Effects on the Pluripotent State or Karyotype
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a structurally endogenous peptide with many biological roles. Maxadilan, a 61-amino acid vasodilatory peptide, specifically activates the PACAP type I receptor (PAC1). Although PAC1 has been identified in embryonic stem cells, little is known about its presence or effects in human induced pluripotent stem (iPS) cells. In the present study, we investigated the expression of PAC1 in human iPS cells by reverse transcriptase polymerase chain reaction (RT-PCR) and western blot analysis. To study the physiological effects mediated by PAC1, we evaluated the role of maxadilan in preventing apoptotic cell death induced by ultraviolet C (UVC). After exposure to UVC, the iPS cells showed a marked reduction in cell viability and a parallel increase of apoptotic cells, as demonstrated by WST-8 analysis, annexin V/propidium iodide (PI) analysis and the terminal transferase dUTP nick end labeling (TUNEL) assay. The addition of 30 nM of maxadilan dramatically increased iPS cell viability and reduced the percentage of apoptotic cells. The anti-apoptotic effects of maxadilan were correlated to the downregulation of caspase-3 and caspase-9. Concomitantly, immunofluorescence, western blot analysis, real-time quantitative polymerase chain reaction (RT-qPCR) analysis and in vitro differentiation results showed that maxadilan did not affect the pluripotent state of iPS cells. Moreover, karyotype analysis showed that maxadilan did not affect the karyotype of iPS cells. In summary, these results demonstrate that PAC1 is present in iPS cells and that maxadilan effectively protects iPS cells against UVC-induced apoptotic cell death while not affecting the pluripotent state or karyotype
Histone H1 Depletion Impairs Embryonic Stem Cell Differentiation
Pluripotent embryonic stem cells (ESCs) are known to possess a relatively open chromatin structure; yet, despite efforts to characterize the chromatin signatures of ESCs, the role of chromatin compaction in stem cell fate and function remains elusive. Linker histone H1 is important for higher-order chromatin folding and is essential for mammalian embryogenesis. To investigate the role of H1 and chromatin compaction in stem cell pluripotency and differentiation, we examine the differentiation of embryonic stem cells that are depleted of multiple H1 subtypes. H1c/H1d/H1e triple null ESCs are more resistant to spontaneous differentiation in adherent monolayer culture upon removal of leukemia inhibitory factor. Similarly, the majority of the triple-H1 null embryoid bodies (EBs) lack morphological structures representing the three germ layers and retain gene expression signatures characteristic of undifferentiated ESCs. Furthermore, upon neural differentiation of EBs, triple-H1 null cell cultures are deficient in neurite outgrowth and lack efficient activation of neural markers. Finally, we discover that triple-H1 null embryos and EBs fail to fully repress the expression of the pluripotency genes in comparison with wild-type controls and that H1 depletion impairs DNA methylation and changes of histone marks at promoter regions necessary for efficiently silencing pluripotency gene Oct4 during stem cell differentiation and embryogenesis. In summary, we demonstrate that H1 plays a critical role in pluripotent stem cell differentiation, and our results suggest that H1 and chromatin compaction may mediate pluripotent stem cell differentiation through epigenetic repression of the pluripotency genes
Determination of dose enhancement caused by AuNPs with Xoft® Axxent® Electronic (eBx™) and conventional brachytherapy: in vitro study
Elham Shahhoseini,1 Prabhakar Ramachandran,1,2 William Roy Patterson,3 Moshi Geso1 1Discipline of Medical Radiation, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia; 2Department of Physical Sciences, Peter Mac Callum Cancer Centre, Melbourne, VIC, Australia; 3Andrew Love Cancer Centre, Geelong Hospital, Geelong, VIC, Australia Purpose: The purpose of this study was to determine dose enhancement (DE) and the possible clinical benefits associated with the inclusion of gold nanoparticles (AuNPs) in cancer cells irradiated by either an 192Ir brachytherapy source or a Xoft® Axxent® Electronic (eBx™) Brachytherapy. Patients and methods: Brachytherapy DE caused by AuNPs is investigated using two methods, namely 192Ir and eBx™ Brachytherapy. The second method, which was recently introduced clinically, operates at ~50 kV, which is also the optimal beam energy for DE. In this in vitro study, two cancer cell lines, lung (A549) and prostate (DU145), were used. Cells were incubated with 1 mM (2% w/w) concentration of AuNPs of ~15 nm in size. The control groups were exposed to a range of doses from 0 (control) to 6 Gy, with eBx™ and 192Ir sources separately. A clonogenic assay was conducted to determine cell survival curves. Results: High dose enhancement factor (DEF) values were achieved in treated groups with low concentration of AuNPs with the 50 kV energy associated with the eBx™. The DE levels in eBx™ for Du145 and A549 cells were found to be 2.90 and 2.06, respectively. The results showed DEFs measured for the same cell lines using 192Ir brachytherapy to be 1.67 and 1.54 for Du145 and A549 cancer cells, respectively. This clearly indicates that much higher DE values are obtained in the case of eBx™ X-ray brachytherapy compared to 192Ir gamma brachytherapy. Conclusion: The higher DE values obtained with eBx™ compared to 192Ir brachytherapy can be attributed to the lower average energy of the former and being closer to the optimal energy for DE. This could potentially be utilized by medical practitioners and clinicians to achieve the same tumor control with a significantly lower dose from the eBx™ compared to the 192Ir brachytherapy treatment, thus bringing huge benefits to the brachytherapy-treated patients. Keywords: gold nanoparticles, prostate cancer cells, lung cancer cells, Xoft® Axxent® Electronic Brachytherapy (eBx™), 192Ir brachytherapy, dose enhancement facto
Determination of dose enhancement caused by AuNPs with Xoft® Axxent® Electronic (eBx TM) and conventional brachytherapy: in vitro study
Purpose: The purpose of this study was to determine dose enhancement (DE) and the possible clinical benefits associated with the inclusion of gold nanoparticles (AuNPs) in cancer cells irradiated by either an Ir-192 brachytherapy source or a Xoft (R) Axxent (R) Electronic (eBx (TM)) Brachytherapy. Patients and methods: Brachytherapy DE caused by AuNPs is investigated using two methods, namely Ir-192 and eBx (TM) Brachytherapy. The second method, which was recently introduced clinically, operates at similar to 50 kV, which is also the optimal beam energy for DE. In this in vitro study, two cancer cell lines, lung (A549) and prostate (DU145), were used. Cells were incubated with 1 mM (2% w/w) concentration of AuNPs of similar to 15 nm in size. The control groups were exposed to a range of doses from 0 (control) to 6 Gy, with eBx (TM) and Ir-192 sources separately. A clonogenic assay was conducted to determine cell survival curves. Results: High dose enhancement factor (DEF) values were achieved in treated groups with low concentration of AuNPs with the 50 kV energy associated with the eBx (TM). The DE levels in eBx (TM) for Du145 and A549 cells were found to be 2.90 and 2.06, respectively. The results showed DEFs measured for the same cell lines using Ir-192 brachytherapy to be 1.67 and 1.54 for Du145 and A549 cancer cells, respectively. This clearly indicates that much higher DE values are obtained in the case of eBx (TM) X-ray brachytherapy compared to Ir-192 gamma brachytherapy. Conclusion: The higher DE values obtained with eBx (TM) compared to Ir-192 brachytherapy can be attributed to the lower average energy of the former and being closer to the optimal energy for DE. This could potentially be utilized by medical practitioners and clinicians to achieve the same tumor control with a significantly lower dose from the eBx (TM) compared to the Ir-192 brachytherapy treatment, thus bringing huge benefits to the brachytherapy-treated patients
Determination of dose enhancement caused by AuNPs with Xoft® Axxent® Electronic (eBx TM) and conventional brachytherapy: in vitro study
Purpose: The purpose of this study was to determine dose enhancement (DE) and the possible clinical benefits associated with the inclusion of gold nanoparticles (AuNPs) in cancer cells irradiated by either an Ir-192 brachytherapy source or a Xoft (R) Axxent (R) Electronic (eBx (TM)) Brachytherapy. Patients and methods: Brachytherapy DE caused by AuNPs is investigated using two methods, namely Ir-192 and eBx (TM) Brachytherapy. The second method, which was recently introduced clinically, operates at similar to 50 kV, which is also the optimal beam energy for DE. In this in vitro study, two cancer cell lines, lung (A549) and prostate (DU145), were used. Cells were incubated with 1 mM (2% w/w) concentration of AuNPs of similar to 15 nm in size. The control groups were exposed to a range of doses from 0 (control) to 6 Gy, with eBx (TM) and Ir-192 sources separately. A clonogenic assay was conducted to determine cell survival curves. Results: High dose enhancement factor (DEF) values were achieved in treated groups with low concentration of AuNPs with the 50 kV energy associated with the eBx (TM). The DE levels in eBx (TM) for Du145 and A549 cells were found to be 2.90 and 2.06, respectively. The results showed DEFs measured for the same cell lines using Ir-192 brachytherapy to be 1.67 and 1.54 for Du145 and A549 cancer cells, respectively. This clearly indicates that much higher DE values are obtained in the case of eBx (TM) X-ray brachytherapy compared to Ir-192 gamma brachytherapy. Conclusion: The higher DE values obtained with eBx (TM) compared to Ir-192 brachytherapy can be attributed to the lower average energy of the former and being closer to the optimal energy for DE. This could potentially be utilized by medical practitioners and clinicians to achieve the same tumor control with a significantly lower dose from the eBx (TM) compared to the Ir-192 brachytherapy treatment, thus bringing huge benefits to the brachytherapy-treated patients
Combined Effects of Gold Nanoparticles and Ionizing Radiation on Human Prostate and Lung Cancer Cell Migration
The effect of 15 nm-sized gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the migration and adhesion of human prostate (DU145) and lung (A549) cancer cell lines was investigated. Cell migration was measured by observing the closing of a gap created by a pipette tip on cell monolayers grown in 6-well plates. The ratio of the gap areas at 0 h and 24 h were used to calculate the relative migration. The relative migration of cells irradiated with 5 Gy was found to be 89% and 86% for DU145 and A549 cells respectively. When the cells were treated with 1 mM AuNPs this fell to ~75% for both cell lines. However, when the cells were treated with both AuNPs and IR an additive effect was seen, as the relative migration rate fell to ~60%. Of interest was that when the cells were exposed to either 2 or 5 Gy IR, their ability to adhere to the surface of a polystyrene culture plate was significantly enhanced, unlike that seen for AuNPs. The delays in gap filling (cell migration) in cells treated with IR and/or AuNPs can be attributed to cellular changes which also may have altered cell motility. In addition, changes in the cytoskeleton of the cancer cells may have also affected adhesiveness and thus the cancer cell's motility response to IR
Epigenetic alterations of CYP19A1 gene in Cumulus cells and its relevance to infertility in endometriosis
Purpose: The purpose of the present study was to investigate the epigenetic mechanisms responsible for the aberrant aromatase expression (CYP19A1) in Cumulus Cells (CCs) of infertile endometriosis patients. Method: Cumulus cells were obtained from 24 infertile patients with and without endometriosis who underwent ovarian stimulation for intracytoplasmic sperm injection. Expression of CYP19A1 gene was quantified using Reverse Transcription Q-PCR. DNA methylation, histone modifications, and binding of Estrogen Receptor, ERβ to regulatory DNA sequences of CYP19A1 gene were evaluated by Chromatin ImmunoPrecipitation (ChIP) assay. Results: CYP19A1 gene expression in CCs of endometriosis patients was significantly lower than the control group (P = 0.04). Higher incorporation of MeCP2 (as a marker of DNA methylation) on PII and PI.4 promoters, and hypoacetylation at H3K9 in PII and hypermethylation at H3K9 in PI.4 were observed in CYP19A1 gene in endometriosis patients (P < 0.05). Moreover, a decreased level of ERβ binding to PII and an increased level of its binding to PI.3 and PI.4 promoters of CYP19A1 were observed in endometriosis patients when compared to control. Conclusion: Significant reduction of CYP19A1 gene expression in CCs of endometriosis patients may be the result of epigenetic alterations in its regulatory regions, either by DNA methylation or histone modifications. These epigenetic changes along with differential binding of ERβ (as a transcription factor) in CYP19A1 promoters may impair follicular steroidogenesis, leading to poor Oocyte and embryo condition in endometriosis patients. © 2016, Springer Science+Business Media New York
Scotopic contrast sensitivity and glare after accelerated corneal cross-linking
Background: The aim was to assess one-year changes in uncorrected and corrected contrast sensitivity (CS) and glare under scotopic conditions after accelerated cross-linking (CXL) using the 18 mW/cm2 protocol for the treatment of progressive keratoconus and compare results with unoperated controls. Methods: In this non-randomised clinical trial, 30 eyes were enrolled in the CXL group and 30 were assigned to the control group. Scotopic CS at spatial frequencies (SFs) of 0.5, 1.1, 2.2, 3.4, 7.1 and 15 cycles per degree (cpd) were assessed using the MonCv3System (Metrovision, Pérenchies, France) under scotopic conditions (0.5 lux) at baseline and at six and 12 months. Results: The mean ages of the participants in the CXL and control groups were 24.32 ± 5.17 and 30.93 ± 7.43 years, respectively (p < 0.001). After adjusting for age, changes in uncorrected and corrected CS and glare were similar in the two groups (all p > 0.05) except for corrected CS at SF 7.1 cpd (1.45 ± 4.31 versus 3.21 ± 4.69 dB, p = 0.010) and 15 cpd (1.12 ± 4.63 versus 3.03 ± 5.48 dB, p = 0.007), which were reduced as an effect of CXL. Based on covariate analyses, among corrected CS indices, corrected CS7.1 and CS15 were related to CXL and their baseline values (all p < 0.050). Uncorrected CS in all SFs and uncorrected and corrected glare were related to their pre-operative values (all p < 0.001). Conclusion: Accelerated CXL can reduce scotopic corrected CS at SFs higher than 7.0 cpd in cases with better baseline values of these parameters. Changes in uncorrected CS and glare are only a factor of baseline values and the indices reduce in cases with better baseline values after one year. © 2017 Optometry Australi
Evaluation of Toll-like receptor 3 (TLR3) signaling pathway genes and its genetic polymorphisms in ectopic and eutopic endometrium of women with endometriosis
Objective: Toll-like receptors (TLRs, as members of the innate immune system) are expressed in the human endometrium and their aberrant regulation and expression are involved in the pathogenesis of endometrial diseases. This study is aimed at evaluation of TLR3 signaling pathway genes and its genetic changes in endometriosis patients. Materials and methods: Blood samples were collected from 83 endometriosis patients and 93 healthy fertile women and PCR was performed in blood-derived DNA for detection of SNP of TLR3. Also, ectopic (EC) and eutopic (EU) endometrial biopsies were obtained from endometriosis patients (n = 20), as well as endometrium from healthy women (n = 16, CE). Q-PCR was performed for determination of mRNA expression level of TLR3 signaling pathway genes (TLR3, TICAM, NF-kB1A, CXCL10, IRF3, IFN-B1, IL-6 and IL-8). Also, serum protein levels of TLR3, IFN-β, IL-6 and IL-8 were determined using ELISA. Results: The mRNA expression levels of TLR3, NF-kB1A, IFN-B1, IRF3, TICAM1, IL-6 and IL-8 were significantly higher in EU compared to ectopic ones and also compared to CE. SNPs frequency (rs3775291 and rs3775290) was not significantly different between patients and controls. Serum protein levels of TLR3, IFN-β, IL-6 and IL-8 were significantly increased in endometriosis patients. Conclusion: Significant changes were observed in the expression of IL-6 and IL-8 cytokines and other genes in TLR3 cascade in diseased EU, demonstrating that EU similarly to EC is in an intensive inflammatory state. These fundamental alterations in the concept of immune response in EU may lead to its activation, escapes from apoptosis, and displaced implantation of the endometrium. © 2021 Elsevier Masson SA