These results suggest that a GIMAP cluster is a novel susceptibility locus for BD, which is involved in T-cell survival, and T-cell aberration can contribute to the development of BD.

No abstract

The ability to identify individuals at risk of ocular disease, or to determine the potential severity of disease or response to therapy is the current focus of much research. These studies are being led by genetic analysis of individuals to determine associations with alterations in gens that may explain manifestations of particular diseases. In this review we consider the basic principles behind genetic studies in general and of ocular disease in particular. We address the methodologies being utilised, and the results derived so far. The potential and pitfalls of such studies are relevant to the concept of personalised medicine and better defined clinical trials.

Time-dependent changes in the cell death mode from apoptosis to necrosis were studied in cultured 143B cells treated with menadione, an anti-cancerous drug, excluding a possible involvement of "secondary necrosis." The population of apoptotic cells judged by FITC-Annexin V and propidium iodide (PI) double staining reached its maximum at 6 hours after 100 microM menadione treatment followed by an abrupt decrease thereafter, while that of necrotic cells continuously increased reaching 90% at 24 hours. Electron microscopically, cells attached to the culture dish at 6 hours after the treatment consisted of two different types of cells: cells with typical apoptotic features occupying the major population and those with condensed nuclei and swollen cytoplasm. Cells attached to the culture dish at 8 hours after the treatment consisted exclusively of those with condensed nuclei and swollen cytoplasm. Mitochondria in these cells showed various structural changes: those swollen to various degrees with deposition of flocculent densities, or those with highly condensed matrix. Distinct decreases both in intracellular levels of ATP and caspase-3-like activities and remarkable elevations of intracellular levels of superoxide, which were partly suppressed by NAD(P)H oxidase inhibitors, occurred at 6 hours after the treatment. These results may suggest that distinct increases of the intracellular level of superoxide derived from plasma membrane NAD(P)H oxidase besides that from mitochondria have triggered the transition of cell death mode from apoptosis to necrosis. Transition of highly condensed mitochondria to extremely swollen ones may reflect necrotic processes in menadione-treated cells. The present study strongly suggests that time-dependent study is essential using the electron microscopic technique to analyze detailed processes in the changes of the cell death mode.

Detailed mechanisms of the switch of the cell death mode from apoptosis to necrosis remain to be solved, although the intracellular level of ATP and that of free radicals have been postulated to be the major factors involved in the mechanisms. In the present study menadione (MEN)-induced cell injury processes were studied using rho0 cells derived from human osteosarcoma 143B cells and parental rho+ cells co-treated with inhibitors of electron transfer chain of mitochondria or oligomycin, an inhibitor of ATP synthesis. Treatment of rho+ cells with 100 microM MEN induced apoptosis, which reached the maximum at 6 h, and was followed by an abrupt decrease thereafter, while necrotic cells (NC) increased continuously when they were judged by Annexin V and PI double staining. On the other hand, MEN induced apoptotic and necrotic changes much faster in rho0 cells compared to rho+ cells. The frequency to find apoptotic cells (AP) in the former cells was distinctly smaller than that to find NC judged by Annexin V and PI double staining. Electron microscopically, a major population of rho0 cells treated with MEN for 6 h consisted of intermediate cells, and a small number of AP co-existed. At 9 h of the treatment intermediate cells were exclusively seen, and AP were hardly detected. When parental rho+ cells were treated with MEN in the presence of oligomycin or oligomycin plus antimycin A both apoptotic and necrotic changes of the cells were distinctly accelerated. The intracellular level of superoxide in rho0 cells continuously increased after the MEN treatment, whereas that of ATP remained distinctly low before and after the MEN treatment compared to that in rho+ cells. These data suggest that the intracellular level of superoxide may be a key factor controlling the switch from apoptosis to necrosis.