Macular hole formation after macular haemorrhage associated with rupture of retinal arterial macroaneurysm.

AIM: To investigate the frequency and risk factors of macular hole (MH) formation after rupture of a retinal arterial macroaneurysm. METHODS: Fifty-six eyes from 56 patients with rupture of a retinal arterial macroaneurysm with or without an MH (MH and non-MH groups, respectively) were reviewed. Frequency and risk factors related to MH formation were assessed, with risk factors including age; sex; distance from the macroaneurysm to the fovea; incidence of haemorrhages involving the macula such as preretinal, subinternal limiting membrane (sub-ILM), subretinal and vitreous; and vitreous surgery. MH formation in these patients was recorded and analysed. RESULTS: Of the 56 eyes reviewed, seven (12.5%) had an MH after rupture of the retinal arterial macroaneurysm. The incidence of subretinal and sub-ILM haemorrhages involving the macula was significantly greater in the MH group than in the non-MH group (p = 0.037 and 0.045, respectively). CONCLUSION: These results suggest that the presence of subretinal and sub-ILM haemorrhages after rupture of a retinal arterial macroaneurysm may contribute to formation of an MH.

Expression of citrulline-nitric oxide cycle in lipopolysaccharide and cytokine-stimulated rat astroglioma C6 cells.

Nitric oxide (NO) is involved in many physiological and pathological processes in the brain. NO is synthesized from arginine by nitric oxide synthase (NOS), with citrulline generated as a by-product of the reaction. Thus, citrulline can by recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL) via the citrulline-NO cycle. Rat astroglioma C6 cells were treated with bacterial lipopolysaccharide (LPS), interferon-gamma (IFNgamma) and tumor necrosis factor-alpha, and the expression of the enzymes of the citrulline-NO cycle was investigated by RNA blot and immunoblot analyses. NO production from arginine and citrulline was also assessed. iNOS mRNA and protein were induced 6-12 h after stimulation with LPS and cytokines and decreased at 24 h. AS mRNA increased up to 12 h and decreased at 24 h. AS protein increased gradually up to 48 h. On the other hand, AL mRNA remained unchanged by stimulation. NO production from arginine was enhanced by the treatment with LPS and cytokines. NO production was also observed when arginine was replaced by citrulline. These results indicate that NO production is enhanced in LPS- and cytokine-stimulated C6 cells due to induction of iNOS and that the citrulline-arginine recycling is important for NO production.

[Pharmacological studies of FUT-175, nafamstat mesilate. III. Anti-inflammatory activities of FUT-175].

Anti-inflammatory effects of FUT-175 (nafamstat mesilate), a new synthetic serine protease inhibitor, on various types of experimental inflammation were investigated in vivo and in vitro, in comparison with non-steroidal anti-inflammatory drugs (NSAID). The in vivo studies showed that FUT-175 has the abilities to inhibit almost all types of inflammatory reactions employed in the present study. In particular, being evaluated on the basis of the effect of indomethacin, FUT-175 exhibited relatively higher potencies against some reactions such as zymosan-induced increase of vascular permeability, scald paw edema, zymosan-induced granuloma-pouch, the Arthus reaction and acetic acid-induced writhing in which the complement system or the kallikrein-kinin system are considered to play an important role. The in vitro studies showed that FUT-175 is quite different from NSAID, that is, FUT-175 had no effects on heat-induced erythrocyte-lysis and heat-induced denaturation of bovine serum albumin. FUT-175 also had no effect on chemotaxis of polymorphonuclear leucocytes, but inhibited the production of chemotactic factor by antigen-antibody reaction. These above results suggested that FUT-175 has a different mode of action from NSAID and that serine protease inhibiting activities of this compound might play an important role in its anti-inflammatory effect.