[A rare cause of variceal bleeding]

BACKGROUND

Agnogenic myeloid metaplasia (AMM) is a clonal stem cell disease, which is characterized by myelofibrosis, osteosclerosis and pancytopenia. Affected patients frequently develop portal hypertension secondary to extramedullary hematopoiesis, which rarely becomes clinically relevant.

CASE REPORT

We here report on a 63-year-old patient with a first presentation of variceal bleeding. The patient was diagnosed with portal hypertension and due to marked splenomegaly, liver cirrhosis was suspected. Subsequently, an extramedullary hematopoiesis and AMM could be diagnosed. The variceal bleeding was initially treated endoscopically. The patient has received cytoreductive therapy and a splenorenal shunt, which has led to remission and long-term survival.

CONCLUSION

Agnogenic myeloid metaplasia is a rare cause of portal hypertension and may present with variceal bleeding. Clinicians should be aware of this rare cause of portal hypertension, as treatment of the underlying disease with cytoreductive therapy and appropriate management of portal hypertension may lead to long-term survival.

Oxidative stress-induced apoptosis in dividing fibroblasts involves activation of p38 MAP kinase and over-expression of Bax: resistance of quiescent cells to oxidative stress

Oxidative stress has been postulated to be involved in aging and age-related degenerative diseases. Cell death as a result of oxidative stress plays an important role in the age related diseases. Using human diploid fibroblasts (HDF) as model to study the mechanism of cell death induced by oxidative stress, a condition was standardized to induce apoptosis in the early passage sub-confluent HDFs by a brief exposure of cells to 250 microM hydrogen peroxide. It was observed that p38 MAP kinase (MAPK) was activated soon after the treatment followed by over-expression of Bax protein in cells undergoing apoptosis. An interesting finding of the present study is that the confluent, quiescent HDFs were resistant to cell death under identical condition of oxidative stress. The contact-inhibited quiescent HDFs exhibited increased glutathione level following H(2)O(2)-treatment, did not activate p38 MAP kinase, or over-express Bax, and were resistant to cell death. These findings indicated that there was a correlation between the cell cycle and sensitivity to oxidative stress. This is the first report to our knowledge that describes a relationship between the quiescence state and anti-oxidative defense. Furthermore, our results also suggest that the p38MAPK activation-Bax expression pathway might be involved in apoptosis induced by oxidative stress.