[Two cases of advanced colorectal cancer which demonstrated the reversibility of oxaliplatin-mediated increase in splenic volume].

Hepatic sinusoidal injury arises occasionally after oxaliplatin-based chemotherapy. As a result, portal hypertension associated with splenomegaly occurs in some cases. We report two cases of advanced colorectal cancer which showed splenomegaly after administration of oxaliplatin-based chemotherapy. In both cases, mFOLFOX6/bevacizumab was administered as a firstline chemotherapy. Splenic volume was determined by loading the CT images onto a commercially available workstation. In case 1, initial splenic volume was 137.82mL. Two months later, it increased to 160.96mL. After six cycles of chemotherapy, we removed oxaliplatin due to peripheral neuropathy. Consequently, the splenic volume decreased to 151.58mL. Subsequent to the reintroduction of oxaliplatin, the splenic volume increased to 177.48mL. Following two cycles of mFOLFOX6/bevacizumab, oxaliplatin was removed again. In a similar way, splenic volume decreased to 158.52mL. In case 2, initial splenic volume was 105.84mL. Ten months later, it increased to 228.54mL. After administration of mFOLFOX6/bevacizumab, we continued chemotherapy with sLV5FU2/bevacizumab and irinotecan. The splenic volume decreased to 197. 06mL. In conclusion, oxaliplatin- based chemotherapy induces an increase in splenic volume, however, it may be reversible after discontinuation of oxaliplatin.

[Two cases of colorectal cancer presenting with periodic, transient elevation of serum iron after chemotherapy including irinotecan].

It is known that the serum iron level shows a transient elevation after chemotherapy in some cases; however, the cause of this phenomenon has not been clearly described. We report two cases of colorectal cancer whose serum iron level demonstrated recurrent elevation after administration of irinotecan as a second-line chemotherapy. The transferrin saturation rate showed marked elevation together with serum iron. This fact indicates that the release of non-transferrin bound iron (NTBI) occurs and then, NTBI binds with transferrin immediately thereafter. Additionally, elevation of indirect bilirubin in case 1, and mild anemia in case 2 were observed after every course of chemotherapy. All these phenomena were synchronized with the fluctuation of the serum iron level. These observations suggest that the transient elevation of the serum iron was related with the release of the NTBI from red blood cells after chemotherapy including irinotecan.

[A case of mucosa-associated lymphoid tissue lymphoma with penicillin allergy successfully treated with levofloxacin, minomycin and rabeprazole].

A 52-year-old Japanese woman was referred to our Institute because of Helicobacter pylori(H. pylori)-positive gastric mucosa-associated lymphoid tissue(MALT)lymphoma. Since she had a penicillin allergy, we could not eradicate H. pylori using the standard triple therapy including amoxicillin. Additionally, H. pylori was resistant to both clarithromycin and metronidazole. So she was treated with minomycin (MINO), levofloxacin (LVFX), and rabeprazole (RPZ) based on a drug sensitivity test. MINO+LVFX+RPZ appear to be a promising, appropriate, and well-tolerated eradication regimen for H. pylori demonstrating resistance to both clarithromycin and metronidazole, and for patients who are allergic to penicillin.

[Two cases of colorectal cancer presenting with periodic, transient elevation of serum iron due to hemolysis after chemotherapy including 5-FU].

The serum iron level reportedly shows transient elevation after chemotherapy in some cases. However, the cause of this phenomenon has not been clearly described. We report two cases of colorectal cancer whose serum iron level demonstrated recurrent elevation after chemotherapy. Both were advanced colorectal cancer cases with liver metastases, so we started chemotherapy with modified FOLFOX6+bevacizumab. After several courses, we changed the regimen to simplified LV5FU2+ bevacizumab in both cases. The serum iron level showed transient, periodical elevation irrespective of the therapeutic regimen. Additionally, indirect bilirubin also showed transient elevation, which was completely synchronized with the fluctuation of the serum iron level. These observations suggest that hemolysis is the main cause of periodic, transient elevation of serum iron level after chemotherapy including 5-FU.

Mitochondrial signal lacking manganese superoxide dismutase failed to prevent cell death by reoxygenation following hypoxia in a human pancreatic cancer cell line, KP4.

One of the major characteristics of tumor is the presence of a hypoxic cell population, which is caused by abnormal distribution of blood vessels. Manganese superoxide dismutase (MnSOD) is a nuclear-encoded mitochondrial enzyme, which scavenges superoxide generated from the electron-transport chain in mitochondria. We examined whether MnSOD protects against hypoxia/reoxygenation (H/R)-induced oxidative stress using a human pancreas carcinoma-originated cell line, KP4. We also examined whether MnSOD is necessarily present in mitochondria to have a function. Normal human MnSOD and MnSOD without a mitochondrial targeting signal were transfected to KP4 cells, and reactive oxygen species, nitric oxide, lipid peroxidation, and apoptosis were examined as a function of time in air following 1 day of hypoxia as a H/R model. Our results showed H/R caused no increase in nitric oxide, but resulted in increases in reactive oxygen species, 4-hydroxy-2-nonenal protein adducts, and apoptosis. Authentic MnSOD protected against these processes and cell death, but MnSOD lacking a mitochondrial targeting signal could not. These results suggest that only when MnSOD is located in mitochondria is it efficient in protecting against cellular injuries by H/R, and they also indicate that mitochondria are primary sites of H/R-induced cellular oxidative injuries.