Open Access Pub publishes peer-reviewed, free-to-read open-access articles. Showing
articles matching cell loss — open any to read the full text,
or download the PDF or XML.
Jul 2017 DOI 10.14302/issn.2639-1716.jn-17-1495
J Gonzalez MichaelCorresponding author
University of Puerto Rico Medical Sciences Campus, Schools of Public Health and Pharmacy, San Juan PR.
Diets high in unsaturated fatty acids, especially those containing high levels of linoleic acid, e.g., corn oil, enhance mammary gland tumorigenesis in experimental animals. In contrast, diets high in long-chain polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic (DHA), e.g. menhaden oil, appear to have a suppressive effect on this tumorigenic process. Many mechanisms have been proposed to explain the tumor inhibitory action exerted by menhaden oil and other fish oils, e.g., differences in prostaglandin metabolism, energy efficiency, alterations of the immune system, changes in lipid peroxidation, etc. Fundamental to a mechanistic understanding of this phenomenon, however, is an understanding as to whether or not the tumor inhibitory activities of dietary fish oil is mediated via an inhibition of tumor cell proliferation or mediated via an enhancement of tumor cell loss. Whether the amount of dietary fat or the type of fat effects mammary tumorigenic processes, via an effect on tumor cell proliferation or tumor cell loss, has not been clearly established. In the studies described in this communication, three methods were utilized to study tumor cell proliferation, i.e., H3-thymidine autoradiographic analysis, 5-bromo 2'-deoxyuridine (Brdu) flow cytometric analysis, and proliferative cell nuclear antigen (PCNA) flow cytometric analysis. Two methods were used to study tumor cell loss, i.e., a determination of the I125Urd tumor emission rate and a determination of a cell loss factor from the formulas of Steel and Begg. The tumor examined was the human breast carcinoma cell line MDA- MB231 maintained in athymic nude mouse. No significant difference in cell proliferation between carcinomas of mice fed a high corn oil diet (20% w/w) and a diet high in fish oil (19% menhaden oil, 1% corn oil). In contrast, a significant (p<0.05) increase in the rate of I125Urd emission rate and cell loss factor from the carcinomas in the fish oil fed mice compared to the corn oil fed mice was observed. In summary, the decreased tumor volume in the human breast carcinomas maintained in athymic nude mice fed a fish oil diet as compared to those fed a corn oil diet, appears to be due, at least in part, to an increased rate of carcinoma cell loss rather than a decreased rate of carcinoma cell proliferation.
May 2017 DOI 10.14302/issn.2470-0436.jos-17-1453
Zhang JieCorresponding author
Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, Private bag 92019, Auckland 1142, New Zealand.
Purpose: High intraocular pressure (IOP) is known to result in retinal ganglion cell (RGC) loss, both with chronically raised intraocular pressure (such as with glaucoma) and with acute raises in pressure (due to injury or acute angle closure). Because IOP is often raised during ocular surgery, the purpose of this study was to evaluate the effect of transient moderate IOP on retinal function, RGC survival and the expression of Connexin 43 (Cx43) and glial fibrillary acidic protein (GFAP), ubiquitously expressed central nervous system (CNS) proteins that are known to be elevated during the retinal inflammatory response to injury. Materials and Methods: Wistar rats were exposed to transient IOP at 40 mmHg for 5 or 30 minutes, and 60 mmHg for 5 minutes (via cannulation of the anterior chamber with a saline reservoir raised to a height corresponding to the desired IOP), mimicking potential IOP rises during surgery such as DSAEK and some laser procedures (LASIK and femtosecond laser cataract surgery). Separate groups of animals had IOP maintained at 10 mmHg for 5 or 30 minutes as cannulation controls, or 120 mmHg for 60 minutes as positive controls. Changes in the optic nerve and retina were assessed immunohistochemically for GFAP and Cx43 expression. Retinal function was assessed using electroretinography (ERG) recorded at baseline and 14 days after the IOP rise and compared with RGC counts. Results: Results showed that there was a differential GFAP labelling pattern observed in the anterior optic nerve in the 40 mmHg 30 minute and 60 mmHg 5 minute groups 4 hours after manipulation. Gap junction protein Cx43 was minimally up-regulated in the retina in the short-term. There was, however, minimal long-term effect on retinal function and no RGC loss. Conclusions: n conclusion, elevations of IOP that are short in duration such as those occurring during surgical procedures, do not cause significant changes long-term in retinal function or RGC survival. Key Messages: Cx43 and GFAP are known to be elevated during the retinal inflammatory response to injury. No previous study has explored the effect of moderate and relatively short increases in IOP on the initial inflammatory response. We observed a mild glial inflammatory response in the anterior optic nerve, but only a minimal up-regulation of Cx43. However, transient and moderate IOP rises did not induce long term disruption to RGC function or number as measured by electrophysiology and RGC counts, respectively. This is applicable to clinical practice, as it means the IOP elevations that occur during some surgical procedures are unlikely to be causing long term damage in retinal function or RGC survival.
Sep 2017
Toto LisaCorresponding author
Department of Medicine and Science of Aging
Background: To evaluate cumulative dissipated energy (CDE), laser time, central corneal thickness and endothelial cell loss after two different fragmentation pattern by means of femtosecond laser-assisted cataract surgery (FLACS). Methods: Eighty eyes of 80 patients that underwent FLACS were randomized in two groups: mixed chop and dice lens fragmentation pattern (group 1 with 40 eyes) and mixed chop and cylindrical lens fragmentation pattern (group 2 with 40 eyes). Results: Cumulative dissipated energy was significantly lower in group 1 compared to group 2 (p<0.001). Postoperatively there was a decrement of endothelial cells count at the centre of the cornea in both groups compared with preoperative values with greater decrease in Group 2 (p<0.001). The thickness at the tunnel site showed a greater increase in group 2 compared to group 1 immediately after surgery (p<0.001) The thickness measured at the center of the cornea increased slightly immediately after surgery and showed a similar decrease in both groups. The increase was greater in Group 2 (p<0.001). Conclusions: Both lens fragmentation patterns were effective in nucleus disassembly. Nevertheless dice pattern was related with a lower amount of CDE and induced lower central endothelial cell loss and lower increase of corneal thickness.
Apr 2016 DOI 10.14302/issn.2470-0436.jos-15-763
El-Assal KarimCorresponding author
Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland, UK.
Background: Optic nerve head drusen are acellular hyaline deposits located anterior to the lamina cribrosa, frequently associated with visual field defects. Sometimes rapid worsening of vision may occur due to complications such as acute vascular events, choroidal neovascularization, or serous maculopathy. Case Presentation: Although there are no proven treatments for Optic nerve head drusen associated field loss, we present the case of a patient with Optic nerve head drusen and bilateral rapid progression of visual field loss that has stabilized on intraocular pressure lowering medication. This suggests a role for IOP-mediated retinal ganglion cell loss in this individual. The mechanism of progressive Optic nerve head drusen associated field loss is poorly understood, however experimental glaucoma models and human in vivo imaging studies have shown that structural differences within the optic nerve head are likely to contribute to individual susceptibility to IOP-mediated damage. Conclusion: We propose that eyes with Optic nerve head drusen may be less able to dampen IOP mediated stress, contributing to loss of retinal ganglion cells in some patients.