Experimental rationale for using a viscoprotection of the corneal endothelium on the graft formed with a femtosecond laser for the descemet stripping endothelial keratoplasty

Author(s):  
I.S. Tkachenko ◽  
◽  
B.E. Malyugin ◽  
S.A. Borzenok ◽  
D.S. Ostrovskiy ◽  
...  

Purpose. To rationale experimentally the use of a viscoprotection of the corneal endothelium on the graft formed with a femtosecond laser for the descemet stripping endothelial keratoplasty. Material and methods. In our study, we used 12 pig's corneoscleral discs. The preservation time before the experiment averaged 12±4 hours. The corneas were divided into 2 groups. In the operating room, the graft was formed using an LDV Z8 femtosecond laser (Ziemer, Switzerland) from the endothelial side. Before applanation of the donor cornea and femtolaser head, a 1% solution of hydroxypropyl methylcellulose (HPMC) was applied to the endothelium - experimental group. The control group was appraised according to the standard technique, with the application of a few drops of a solution for storing the corneas. Then the applanation was monitored and evaluated by laser optical coherence tomography. Then the graft was separated from the bed and transferred to a conservation medium. Under laboratory conditions, to determine the viability of endothelial cells, the graft was stained with a «vital» dye with the commercial name Life and Dead (Abcam, UK) and placed in a confocal laser scanning microscope. Endothelial cells were counted using the ImageJ software. Results. In the experimental and control groups, the number of living endothelial cells (EC) was 91.06±1.49% and 83.86±2.14%, respectively (p<0.001). The number of dead ECs in the control group was 7.2±0.65% more than in the experimental group and amounted to 16.14±2.14% and 8.94±1.49%, respectively (p<0.001). Conclusion. The study demonstrated that the use of viscoprotection of the corneal graft endothelium for posterior lamellar keratoplasty is quite effective, and significantly reduces the loss of EC at the stage of cutting out the graft with a femtosecond laser. Key words: descemet stripping endothelial keratoplasty, femtosecond laser, vital dyes.

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ting Liu ◽  
Jingjing Zhang ◽  
Dapeng Sun ◽  
Wenjie Sui ◽  
Yangyang Zhang ◽  
...  

Purpose.To find a relatively safe designed stromal bed thickness to avoid endothelial damage for lamellar keratoplasty with an Allegretto Wavelight FS200 femtosecond laser.Methods.Twelve rabbits were randomly divided into 50 μm and 150 μm groups according to the anticipated residue stromal bed thickness preparation with a femtosecond laser. Six rabbits without laser cutting were used as a control group. Central endothelial images were analyzed with in vivo confocal microscopy and scanning electron microscopy. The apoptosis of endothelium was evaluated with Hoechst 33342 staining and a TUNEL assay.Results.The endothelium of the 50 μm group had extensive injuries upon in vivo confocal and scanning electron microscopic observation, and minor injuries were observed in the 150 μm group. Moreover, more apoptotic cells were observed in the 50 μm group.Conclusions.When using a FS200 femtosecond laser assisted anterior lamellar keratoplasty, there was minor endothelium damage with a 150 μm stromal bed, and a more than 150 μm thickness stromal bed design may prevent the damage of corneal endothelium.


2021 ◽  
Vol 17 (1) ◽  
pp. 57-68
Author(s):  
G. A. Boyarinov ◽  
O. D. Solovyova ◽  
E. I. Yakovleva ◽  
L V. Boyarinova ◽  
A. V. Deryugina

The aim of the study was to investigate the effect of ethylmethylhydroxypyridine on the ultrastructural alterations in endothelial cells of liver sinusoidal capillaries (SC) and primary hemostasis in the acute phase of traumatic brain injury (TBI).Materials and methods. Ultrastructural endothelial cell changes were studied in 36 female outbred rats in the acute phase of TBI using electron microscopy, and the platelet count was determined using a blood analyzer. The experimental group (n=18) animals received intraperitoneal injections of ethylmethylhydroxypyridine at the dose of 8.0 mg/kg per day for 12 days, and the control group (n=18) rats were administered with normal saline solution at the same dose.Results. Administration of ethylmethylhydroxypyridine in the early post TBI period reduced microvilli damage in endothelial, hepatic and stellate cells in the Disse space, whereas in the control group a significant decrease of these cells counts was detected. In contrast to the control group, the experimental group animals did not demonstrate thrombocytopenia on the days 1, 3, and 7 after injury. There was a significant increase in the platelet count compared with the baseline values, which was highest on day 12 after injury.Conclusion. Intraperitoneal administration of ethylmethylhydroxypyridine in rats in early post TBI period inhibited the TBI-associated damaging effect of secondary factors on liver sinusoid endothelial cells and platelet consumption.


Author(s):  
I.V. Tsiganenko ◽  
L.K. Ovcharenko

The work considers the causes of the coronary X syndrome development in women by assessing the experimental group and the control group with typical angina pectoris with angiographically altered vessels. Each group included 30 patients. When studingy medical records of the patients in the study group, we found out that in the reproductive period all of them had hyperestrogenemia, confirmed by the laboratory data, with the corresponding consequences in the form of various gynecological diseases, while the patients of the control group had unburdened gynaecological history. In terms of the lipid spectrum, the results turned out to be opposite. In the experimental group, the rates were within the normal range, and the control level of LDL-C significantly exceeded the required values. Despite the fact that estrogens increase the concentration of high density lipoprotein (HDL) in the blood and lower the content of low density lipoprotein (LDL) that are atherogenic, their surplus has a less negative effect than their lack, as the risk of developing atherosclerosis increases with decreasing concentration, and with an increase there is a risk of developing endothelial dysfunction, which provokes the development of coronary syndrome X. These date confirm the development of endothelial dysfunction in the patients of the experimental group with hyperestrogenemia in the history resulted from the impairment of the process of proliferation of endothelial cells with subsequent imbalance of secretion of biologically active substances. Among them, there is nitric oxide, which causes the relaxation of smooth myocytes, thus resulting in vasodilatation, and endothelins, providing the opposite, vasodilating effect. Prostacyclines and thrombomodulins secreted by the vascular endothelium in physiological conditions, counteract platelet aggregation. In the case of damage to the vascular wall, the production of prostacyclin and thrombomodulin is suppressed, but the release of thromboplastin, platelet activation factor and von Willerband factor activates that promote platelet aggregation and blood clotting. Under the participation of other physiologically active substances, selectins, endothelial cells promote adhesion to their surface and further penetration into the site of inflammation of neutrophils, blood acidophils. Selectin is accumulated in the cytoplasm of the endothelial cells in the form of specific electron-cellular inclusions, the so-called bodies of Weibel-Palade. Normally, vascular endothelium is impervious to blood components. However, being affected by a number of factors, and in particular histamine, endothelial cells lose contact with each other and decrease in number. This leads to the release of water and plasma proteins into the intercellular medium causing oedema. Due to the ability of the inner layer of vessels to produce a large number of biologically active substances, such changes can hardly be corrected by therapy.


2002 ◽  
Vol 39 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Takenori Kim ◽  
Hiroyuki Ishikawa ◽  
Soowon Chu ◽  
Asako Handa ◽  
Junichiro Iida ◽  
...  

Objective This study examined the influence of two factors in the constriction of the maxillary dental arch by mucoperiosteal denudation of the palate: (1) inhibition of lateral growth and (2) medial inclination of teeth. Method Thirty-five male 20-day-old Wistar rats were divided into experimental and control groups. The experimental group had bilateral mucoperiosteum excised in the lateral one third of the palate. Methyl methacrylate resin–embedded frontal sections were prepared from both groups after alternate weekly injections of tetracycline and calcein in the dorsal subcutaneous area. The sections were observed and photographed under either a confocal laser scanning microscope, a fluorescence microscope, or both. Chronological changes in lateral palatal growth, maxillary dental arch width, and inclination of the upper first molars were examined up to 8 weeks after the operation. Paraffin-embedded frontal sections were also made and stained with Elastica van Gieson stain. Results The scar tissue formed on the rat palate by the mucoperiosteal denudation was tightly connected to the palatal bone and teeth. The intervals between the labeling lines of the experimental group were less definite during the first 2 weeks after the operation. Increments of palatal and maxillary dental arch widths were smaller in the experimental group than in the control group. The upper first molars in the control group gradually inclined laterally, whereas those in the experimental group inclined medially with age. Conclusion Medial inclination of teeth is a stronger influence than inhibition of lateral growth on constriction of the rat maxillary dental arch.


2008 ◽  
Vol 34 (11) ◽  
pp. 1970-1975 ◽  
Author(s):  
Jodhbir S. Mehta ◽  
Rania Shilbayeh ◽  
Yong-Ming Por ◽  
Howard Cajucom-Uy ◽  
Roger W. Beuerman ◽  
...  

2008 ◽  
pp. 283-288
Author(s):  
I Matějovská ◽  
K Bernášková ◽  
D Krýsl ◽  
J Mareš

Photothrombotic model of ischemia (PT) is based on free radicalmediated endothelial dysfunction followed by thrombosis. Free radicals are also involved in hypoxic preconditioning. We tested the sensitivity of PT to preconditioning with hypobaric hypoxia and to pretreatment with melatonin. In adult Wistar rats, after intravenous application of Rose Bengal, a stereo-tactically defined spot on the denuded skull was irradiated by a laser for 9 min. The first experimental group underwent hypobaric hypoxia three days before irradiation. In the second experimental group, melatonin was applied intraperitoneally one hour before irradiation. Three days after irradiation, animals were sacrificed, the brains perfused, and stained with TTC. Ischemic lesions were divided into grades (I, II, III). In the control group (where no manipulation preceded photothrombosis), most animals displayed deep damage involving the striatum (grade III). The group preexposed to hypoxia showed similar results. Only 28.57 % of the melatonin pretreated animals exhibited grade III lesions, and in 57.14 % no signs of lesions were detected. Pre-exposure to hypoxia was not protective in our model. Pretreatment with melatonin lead to a significant reduction of the number of large ischemic lesions. This result is probably caused by protection of endothelial cells by melatonin.


2020 ◽  
Vol 11 (SPL4) ◽  
pp. 446-449
Author(s):  
Yu-Ri Choi ◽  
Min-Kyung Kang

Candida albicans (C. Albicans) is one of the bacteria that reside in the oral cavity, and the ones living in medical and commercial denture resins, commonly cause diseases. Therefore, this study was conducted to confirm the antibacterial activity of C. Albicans using a denture base resin containing peony extract with antibacterial properties. Contact angle measurements and color change measurements were performed to confirm the physical change of the material added with the antibacterial agent to the denture reline resin. As a result of the antibacterial test, the experimental group exhibited antibacterial activity against C. Albicans. Compared to the optical density results, the results of the experimental group showed a significant difference. As a result of Fluorescent images showing (confocal laser microscope), the control group showed a lot of live bacteria, and no bacteria appeared in the experimental group. All group  did not show any physical changes. As a result of the contact angle measurement, the surface of the experimental group was changed to hydrophilic. In addition, there was no change in the color of the denture reline resin containing peony extract. In conclusion, it was confirmed that the peony extract contained antibacterial activity of the denture resin, and further studies should be conducted on various bacteria for denture base resin disinfection.


Author(s):  
Yu-Ri Choi Et.al

Candida albicans(C. albicans) is one of the bacteria that resides in the oral cavity, and the ones living in medical and commercial denture resins, commonly cause diseases. Therefore, this study was conducted to confirm the antibacterial activity of C. albicans using a denture base resin containing peony extract with antibacterial properties. For the antibacterial effect, optical density and confocal laser microscopy were used. Contact angle measurements and color change measurements were performed to confirm the physical change of the material added with the antibacterial agent to the denture reline resin. As a result of the antibacterial test, the experimental group exhibited antibacterial activity against C. albicans. Compared to the optical density results, the results of the experimental group showed a significant difference. As a result of Fluorescent images showing (confocal laser microscope), the control group showed a lot of live bacteria, no bacteria appeared in the experimental group. All group did not show any physical changes. As a result of the contact angle measurement, the surface of the experimental group was changed to hydrophilic. In addition, there was no change in the color of the denture reline resin containing peony extract. In conclusion, it was confirmed that the peony extract contained antibacterial activity of the denture resin, and further studies should be conducted on various bacteria for denture base resin disinfection.


Cornea ◽  
2007 ◽  
Vol 26 (9) ◽  
pp. 1118-1122 ◽  
Author(s):  
Yanny YY Cheng ◽  
Elisabeth Pels ◽  
Jack PM Cleutjens ◽  
Robert J van Suylen ◽  
Fred Hendrikse ◽  
...  

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