Search

Your search keyword '"Hazarbassanov, Rossen M."' showing total 19 results
Start Over Author "Hazarbassanov, Rossen M."
19 results on '"Hazarbassanov, Rossen M."'

3. A Hybrid Artificial Intelligence Model for Detecting Keratoconus

Author

Alyasseri, Zaid Abdi Alkareem, primary, Al-Timemy, Ali H., additional, Abasi, Ammar Kamal, additional, Lavric, Alexandru, additional, Mohammed, Husam Jasim, additional, Takahashi, Hidenori, additional, Milhomens Filho, Jose Arthur, additional, Campos, Mauro, additional, Hazarbassanov, Rossen M., additional, and Yousefi, Siamak, additional

Published
2022
Full Text
View/download PDF

9. The effects of riboflavin and ultraviolet light on keratocytes cultured in vitro

Author

Covre, Joyce L., Cristovam, Priscila C., Loureiro, Renata R., Hazarbassanov, Rossen M., Campos, Mauro, Sato, Élcio H., and Gomes, José Álvaro P.

Subjects
Cornea, Córnea, Corneal stroma, Corneal keratocytes, Raios ultravioleta, Apoptose, Ultraviolet rays, Riboflavin, Riboflavina, Apoptosis, Ceratócitos da córnea, Substância própria
Abstract

Purpose: To culture quiescent human keratocytes and evaluate the effects of ultraviolet light and riboflavin on human corneal keratocytes in vitro. Methods: Keratocytes were obtained from remaining corneoscleral ring donor corneas previously used in corneal transplant surgeries and cultured in DMEM/F12 with 2% FBS until confluence. Characterization of cultured cells was performed by immunofluorescence analysis for anti-cytokeratin-3, anti-Thy-1, anti-α-smooth muscle actin, and anti-lumican. Immunofluorescence was performed before and after treatment of cultured cells with either ultraviolet light or riboflavin. Corneal stromal cells were covered with collagen (200 µL or 500 µL) and 0.1% riboflavin, and then exposed to ultraviolet light at 370 nm for 30 minutes. After 24 hours, cytotoxicity was determined using MTT colorimetric assays, whereas cell viability was assessed using Hoechst 33342 and propidium iodide. Results: Cell cultures achieved confluence in approximately 20 days. Expression of the lumican was high, whereas no expression of CK3, Thy-1, and α-SMA was observed. After crosslinking, MTT colorimetric assays demonstrated a low toxicity rate, whereas Hoechst 33342/propidium iodide staining demonstrated a low rate of apoptosis and necrosis, respectively, in all collagen-treatment groups. Conclusion: Keratocytes can be successfully cultured in vitro and characterized by immunofluorescence using lumican. MTT colorimetric assays, and Hoechst 33342, and propidium iodide staining demonstrated a higher rate of cell death in cells cultured without collagen, indicating collagen protects keratocytes from the cytotoxic effects of ultraviolet light. RESUMO Objetivo: Avaliar o efeito da aplicação da luz ultravioleta e riboflavina sobre ceratócitos da córnea humana in vitro. Métodos: Os ceratócitos foram obtidos a partir das rimas corneoesclerais remanescentes da trepanação de córneas previamente utilizadas em cirurgias de transplante de córnea e cultivadas em meio DMEM/F12 com 2% de FBS até atingir confluência. As culturas de células foram caracterizadas por imunofluorescência com os anticorpos K3 (marcador de células epiteliais), Thy-1 (marcador de fibroblasto) SMA (marcador de miofibroblasto) e Lumican (marcador de ceratócitos). Imunofluorescência também foi feita após o tratamento. As células do estroma da córnea foram cobertas com colágeno (200 µL e 500 µL) e 0,1% de riboflavina e exposta a luz UVA a 370 nm por 30 minutos. Após 24 horas, citotoxicidade foi determinada por ensaio de MTT e a viabilidade celular foi feita por Hoechst 33342/Iodeto de propideo. Resultados: As culturas de células atingiram confluência em aproximadamente 20 dias. Imunofluorescência apontou alta expressão para o marcador de ceratócitos (Lumican) e expressão negativa par os marcadores de células epiteliais (K3), fibroblasto (Thy-1) e miofibroblasto (α-SMA). Após o cross linking a análise de MTT mostrou baixa taxa de toxicidade e com a coloração de Hoechst 33342/Iodeto de propideo baixa taxa de apoptose e necrose respectivamente em todos os grupos que continham colágeno. Conclusão: As culturas de ceratócitos foram obtidas e caracterizadas por imunofluorescência através do marcador Lumican com sucesso. O ensaio de MTT e a coloração por Hoechst 33342 e iodeto de propídio, apresentaram maior índice de morte celular nos grupos que não continham colágeno, provando que protege as células contra os efeitos da luz UVA.

Published
2016

15. Conjunctival Epithelial Cells Cultivated Ex Vivofrom Patients with Total Limbal Stem Cell Deficiency

Author

Silber, Paulo C., Ricardo, José R.S., Cristovam, Priscila C., Hazarbassanov, Rossen M., Dreyfuss, Juliana L., and Gomes, José A.P.

Abstract

Purpose Reconstruction of the ocular surface is challenging. As an alternative to mucosal and limbal epithelial, we study the feasibility of cultivated human conjunctival epithelial (HCjE) cells of patients with total limbal stem cell deficiency (LSCD).Methods We studied superior forniceal conjunctival biopsies harvested from 9 living donors with total LSCD of several etiologies who underwent surgery for ocular surface reconstruction. The conjunctival explants were cultivated on serum and growth factor supplemented DMEM/F12 under submerged conditions on denuded human amniotic membrane and tissue culture dishes. The area of cell growth was assessed. Cell morphology was analyzed by light microscopy, impression cytology, and transmission electron microscopy. Cultures were evaluated for epithelial cytokeratins (CK3, CK19), proliferation marker (Ki-67), and putative stem cells markers (ABCG2 and p63). Confocal immunofluorescence was also performed to assess CK3, CK19, Ki-67, ABCG2, and p63.Results The HCjE cells cultivated ex vivowere successfully expanded on denuded amniotic membrane but with a slower growth than in the tissue culture dish. Transmission electron microscopy showed stratified epithelium with microvilli, desmosomes, and hemidesmosomes. Impression cytology showed PAS+ cells that resembled goblet cells. Immunocytochemical analysis showed positivity for CK3, CK19, Ki-67, ABCG2, and p63. Confocal immunofluorescence was positive for CK3, CK19, Ki-67, ABCG2, and p63.Conclusions Our results showed that it is possible to cultivate HCjE cells ex vivoof patients with ocular surface diseases. This method is important for ocular surface reconstruction in patients with bilateral total LSCD.

Published
2015
Full Text
View/download PDF

16. Minor salivary glands and labial mucous membrane graft in the treatment of severe symblepharon and dry eye in patients with StevenseJohnson syndrome.

Author

Sant'Anna, Ana Estela B. P. P., Hazarbassanov, Rossen M., Freitas, Denise de, and Gomes, José Álvaro P

Abstract

Objective To evaluate minor salivary glands and labial mucous membrane graft in patients with severe symblepharon and dry eye secondary to StevenseJohnson syndrome (SJS). Methods A prospective, non-comparative, interventional case series of 19 patients with severe symblepharon and dry eye secondary to SJS who underwent labial mucous membrane and minor salivary glands transplantation. A complete ophthalmic examination including the Schirmer I test was performed prior to and following surgery. All patients had a preoperative Schirmer I test value of zero. Results Nineteen patients with severe symblepharon and dry eye secondary to SJS were included in the study. There was a statistically significant improvement in the best spectacle-corrected visual acuity in eight patients (t test; p=0.0070). Values obtained in the Schirmer I test improved significantly in 14 eyes (73.7%) 6 months following surgery (x2 test; p=0.0094). A statistically significant increase in tear production (Schirmer I test) was found in eyes that received more than 10 glands per graft compared with eyes that received fewer glands (x2 test; p=0.0096). Corneal transparency improved significantly in 11 (72.2%) eyes and corneal neovascularisation improved significantly in five eyes (29.4%) (McNemar test; p=0.001 and p=0.0005). The symptoms questionnaire revealed improvement in foreign body sensation in 53.6% of the patients, in photophobia in 50.2% and in pain in 54.8% (KruskaleWallis test; p=0.0167). Conclusion Labial mucous membrane and minor salivary glands transplantation were found to constitute a good option for the treatment of severe symblepharon and dry eye secondary to SJS. This may be considered as a step prior to limbal stem cell and corneal transplantation in these patients. [ABSTRACT FROM AUTHOR]

Published
2012
Full Text
View/download PDF

19. Minor salivary glands and labial mucous membrane graft in the treatment of severe symblepharon and dry eye in patients with Stevens-Johnson syndrome.

Author

Sant' Anna AE, Hazarbassanov RM, de Freitas D, and Gomes JÁ

Subjects
Adult, Conjunctival Diseases etiology, Conjunctival Diseases physiopathology, Cornea physiopathology, Dry Eye Syndromes etiology, Dry Eye Syndromes physiopathology, Eyelid Diseases etiology, Eyelid Diseases physiopathology, Female, Humans, Labial Frenum, Male, Prospective Studies, Surveys and Questionnaires, Suture Techniques, Tears physiology, Treatment Outcome, Visual Acuity physiology, Conjunctival Diseases surgery, Dry Eye Syndromes surgery, Eyelid Diseases surgery, Mouth Mucosa transplantation, Salivary Glands, Minor transplantation, Stevens-Johnson Syndrome complications
Abstract

Objective: To evaluate minor salivary glands and labial mucous membrane graft in patients with severe symblepharon and dry eye secondary to Stevens-Johnson syndrome (SJS)., Methods: A prospective, non-comparative, interventional case series of 19 patients with severe symblepharon and dry eye secondary to SJS who underwent labial mucous membrane and minor salivary glands transplantation. A complete ophthalmic examination including the Schirmer I test was performed prior to and following surgery. All patients had a preoperative Schirmer I test value of zero., Results: Nineteen patients with severe symblepharon and dry eye secondary to SJS were included in the study. There was a statistically significant improvement in the best spectacle-corrected visual acuity in eight patients (t test; p=0.0070). Values obtained in the Schirmer I test improved significantly in 14 eyes (73.7%) 6 months following surgery (χ(2) test; p=0.0094). A statistically significant increase in tear production (Schirmer I test) was found in eyes that received more than 10 glands per graft compared with eyes that received fewer glands (χ(2) test; p=0.0096). Corneal transparency improved significantly in 11 (72.2%) eyes and corneal neovascularisation improved significantly in five eyes (29.4%) (McNemar test; p=0.001 and p=0.0005). The symptoms questionnaire revealed improvement in foreign body sensation in 53.6% of the patients, in photophobia in 50.2% and in pain in 54.8% (Kruskal-Wallis test; p=0.0167)., Conclusion: Labial mucous membrane and minor salivary glands transplantation were found to constitute a good option for the treatment of severe symblepharon and dry eye secondary to SJS. This may be considered as a step prior to limbal stem cell and corneal transplantation in these patients.

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results