Melatonin regulates traumatic optic neuropathy via targeting autophagy.

OBJECTIVE: Traumatic optic neuropathy (TON) usually refers to the indirect damage to the optical nerve, which can cause partial or complete blindness. Melatonin (MT) is a kind of indole hormone, and the retina is one of its natural sites of secretion in the human body. This study aims to explore MT in the retina and optic nerve injuries due to TON. MATERIALS AND METHODS: Sprague-Dawley (SD) rats were used for TON model in the study. After operation, rats were treated with MT or phosphate buffered saline (PBS) for 4, 7, 14, 21, and 28 days before sacrifice. The changes in retinal ganglion cells (RGCs) were observed via hematoxylin-eosin (HE) staining. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was applied to observe apoptosis. Immunofluorescence staining was applied to detect caspase-3 and Western blot was used to detect LC3, cleaved caspase-3 and glyceraldehyde phosphate dehydrogenase (GAPDH). RESULTS: The number of RGCs in MT group increased compared to the model group. After MT treatment, the increased number of TUNEL positive cells and the increased number of caspase-3 positive cells in the retina of MT group was alleviated. Moreover, Western blot analysis revealed that the LC3-II/LC3-I ratio in the retinal tissue of MT group was further increased, while the increased cleaved caspase-3 protein level in the retina of MT group was alleviated compared to the model group. CONCLUSIONS: The results of this study revealed that MT therapy affects the apoptosis level of RGCs after TON through alleviating the increased caspase-3 protein level. Its mechanism may be that it further up-regulates the autophagy level of RGCs after TON, ultimately inhibiting the apoptosis of RGCs after TON and playing a neuroprotective role.

[Studies on distribution and behavior of Anopheles minimus and its role of malaria transmission in Hainan Province at present].

Anopheles minimus was once a main malaria vector in Hainan Island and had been eliminated basically through the campaign of indoor residual spraying launched in 1959. It again became an incriminated vector of some focal malaria outbreaks in recent years. The present study was conducted in a selected county-Danxian and a typical hilly area-Feibar in the west part of Danxian county in 1989-1990. An. minimus was found in 50% and 62.5% of the surveyed sites at mountainous and hilly area of Danxian county, but not found in coastal region. An. minimus was found in all 18 sites surveyed in Feibar district, constituting 52% of anopheline composition. Man-biting rate made by human-baited collection was 3.2 before midnight and 38.2 when collected through whole night in some sites. However, the behaviour characteristics of An. minimus has changed. It has become exophilic, exophagic, and has an equal preference for man and cattle. The vectorial capacity of An. minimus estimated by quantitative data was in accord with malaria infection rate in Feibar district, and the malaria infection rate among the inhabitants in three types of residential quarter with different socioeconomic conditions. Malaria infection rates of residential quarter of land-reclamation outcomers, villagers and state farm residents were 10%, 2.9% and 0.5%, respectively during 40 days from July to August, 1990.(ABSTRACT TRUNCATED AT 250 WORDS)