ABSTRACT
Cataract is one of the major causes of vision loss and even blindness in patients, and surgery is the only effective method to treat it. The pathogenesis and precaution of cataract remain hot issues in ophthalmological research. With the maturation of biotechnology in recent years, modeling methods and species of experimental animals have become more diverse, which are still the mainstay of cataract mechanism research. However, the ideal animal model of cataract has yet to be constructed due to the complexity of human cataract etiology. Herein, the modeling principles, in vivo or in vitro modeling methods, characteristics, and existing problems of animal models of cataract are summarized according to etiology, providing the theoretical foundation for the construction of a comprehensive animal model that more closely resembles the human cataract.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the therapeutic effects of two anastomoses (canaliculus-to-lacrimal sac anastomosis and end-to-end anastomosis) on nasolacrimal laceration for over 7 mm from the broken end to the dacryon.</p><p><b>METHODS</b>A total of 71 patients (44 males and 27 females, aged 16-55 years, mean equal to 34.32 years) with fresh canalicular laceration were treated in our hospital from March 2003 to April 2008. Under a microscope, 37 patients were treated with lacrimal sac anastomosis (the treatment group) and 34 with end-to-end anastomosis (the control group), detaining silicone tubes till 3 months later.</p><p><b>RESULTS</b>The cure rate of the treatment group (89.19%) was significantly higher than that of the control group (55.56%). Class I cure rates were 70.27% in the treatment group and 47.06 % in the control group, and the difference between the two groups was significant (P less than 0.05). Postoperative inflammatory reactions had significant influences on the two kinds of anastomosing methods, but no significant difference was found between the two groups (P larger than 0.05).</p><p><b>CONCLUSIONS</b>When the distance from the broken end to the dacryon is over 7 mm, especially when it is necessary to find the paranasal broken end of the lacrimal canaliculus with dacryocystotomy, canaliculus-to-lacrimal sac anastomosis is a better treatment method than end-to-end anastomosis for laceration of lacrimal canaliculus.</p>
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Anastomosis, Surgical , Lacerations , General Surgery , Lacrimal Apparatus , Wounds and Injuries , General Surgery , Postoperative Complications , Treatment OutcomeABSTRACT
AIM: To explore the relationship between the expression of caspase-2 and caspase-3 and the apoptosis in retinal ischemia/reperfusion (I/R) injury of rats, as well as the therapeutic effects of brain derived neurotrophic factor (BDNF)on the ischemic and reperfused retina.METHODS: This experiment was conducted at the laboratory of Affiliated Hospital of Qingdao University Medical College from February 2007 to July 2007. The models of retinal ischemia/reperfusion injury were made by transiently elevating intraocular pressure. A total of 28 rats were divided into Normal and Operative Groups. Operative group was divided into six subgroups. In each subgroup there were four rats. The left eyes of rats were used for I/R and the right eyes were used for intravitreal injection of brain-derived neurotrophic factor (BDNF) as treatment group. After reperfusion we divided our subgroups according to the reperfusion time as 1, 6, 12, 24, 48, 72 hours. The retinal ganglion cell number was counted by using optic microscope(BX-51,Olympus). Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) method, and the expression of caspase-2,caspase-3 was studied by enzyme linked immunosorbent assay (ELISA) and strept avidin-biotin complex (SABC)immunohistochemistry.RESULTS: No positive apoptotic cells were observed in the normal rats' retinae, but there were a significant number of positive apoptosis cells in 6-24 hours after transient ischemia followed by a decrease at 48 hours. The number of apoptotic cells reached a maximum at 24 hours after ischemia .The expression of caspase-2 gradually increased as early as at 6 hours, reached a peak at 24 hours, then decreased between 48 and 72 hours. Similarly, caspase-3 has the same rule with caspsae-2 in the time courses of expression in retinal tissues.BDNF administered before reperfusion inhibited the expression of apoptosis and ameliorated the retinal tissue damage. It also decreased caspase-2 and caspase-3 expression in ischemic/reperfused retina.CONCLUSION: Retinal ischemia-reperfusion can induce apoptosis of cells in the retina. BDNF rescues retinal ganglion cells (RGCs) from retinal ischemia/reperfusion injury through down-regulation of cell apoptosis and caspase-2 and caspase-3 expression. BDNF have a neuroprotective effect on retina.