Downregulation of ferritin heavy chain increases labile iron pool, oxidative stress and cell death in cardiomyocytes

Ferritin heavy chain (FHC) protein was significantly reduced in murine failing hearts following left coronary ligation or thoracic transverse aortic constriction. The mRNA expression of FHC was not significantly altered in failing hearts, compared to that in control sham-operated hearts. Prussian blue staining revealed spotty iron depositions in myocardial infarct failing hearts. Oxidative stress was enhanced in the myocardial infarct failing hearts, as evidenced by increases in 4-hydroxy-2-nonenal and 8-hydroxy-2′-deoxyguanosine immunoreactivity. To clarify the functional significance of FHC downregulation in hearts, we infected rat neonatal cardiomyocytes with adenoviral vector expressing short hairpin RNA targeted to FHC (Ad-FHC-RNAi). The downregulation of FHC induced a reduction in the viability of cardiomyocytes. The relative number of iron deposition-, 4-hydroxy-2-nonenal- or 8-hydroxy-2′-deoxyguanosine-positive cardiomyocytes was significantly higher in Ad-FHC-RNAi-infected cardiomyocytes than in control vector-infected cardiomyocytes. Treatment of Ad-FHC-RNAi-infected cardiomyocytes with desferrioxamine, an iron chelator, significantly reduced the number of iron, 4-hydroxy-2-nonenal or 8-hydroxy-2′-deoxyguanosine-positive cells, and increased viability. In addition, treatment with N-acetyl cysteine, an antioxidant, significantly reduced the number of 4-hydroxy-2-nonenal- or 8-hydroxy-2′-deoxyguanosine-positive cells. Reduced viability in Ad-FHC-RNAi-infected cardiomyocytes was significantly improved with N-acetyl cysteine treatment. These findings indicate that excessive free iron and the resultant enhanced oxidative stress caused by downregulation of FHC lead to cardiomyocyte death. The decrease in FHC expression in failing hearts may play an important role in the pathogenesis of heart failure.     

Diffuse intrahepatic recurrence after percutaneous radiofrequency ablation for solitary and small hepatocellular carcinoma

Two patients developed segmental, diffuse intrahepatic recurrence after percutaneous radiofrequency ablation (RFA) to treat a primary, solitary, and small (2.5 cm) hepatocellular carcinoma (HCC). Despite the size of the HCC, levels of the tumor markers (α-fetoprotein, α-fetoprotein-L3%, and des-γ-carboxyprothrombin) were all elevated before RFA, and tumors in both patients were contiguous with a major branch of the portal vein. Tumor biopsies of both patients revealed moderately differentiated HCC but diagnostic imaging showed an area of reduced tumor blood flow, suggesting a poorly differentiated component. Since early detection of post-RFA malignancies by standard ultrasonography and contrast-enhanced computed tomography was difficult, the most sensitive indicator of recurrence in these two patients was the elevated tumor markers. The diffuse intrahepatic recurrence was thought to be caused by increased intratumoral pressure during RFA, resulting in the dissemination of cancer cells through the contiguous portal vein. The clinical course of these tumors indicate that the choice of RFA should be carefully considered when treating specific subtype of HCC that is adjacent to main portal vein branch and involves a possible poorly differentiated component and that surgical resection or combinations of RFA with other treatment modalities such as transcatheter arterial chemoembolization should be considered as alternative treatment strategies.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR ESOPHAGEAL SQUAMOUS CELL NEOPLASMS

Endoscopic submucosal dissection (ESD) has gradually gained acceptance as one of the standard treatments for early esophageal cancer, as well as for early gastric cancer in Japan, but standardization of the knowledge is still incomplete. The final goal to perform ESD is not to resect the lesion in an en bloc fashion, but to save the patient from esophageal cancer‐related death. Thus, the indications should be considered based on the entire patient, not just the target lesion itself, and pre‐, peri‐ and postoperative management of the patient is also very important, as well as technical aspects of ESD. In terms of the techniques of ESD, owing to refinement of the procedural strategy, invention of the devices, and the learning curve, acceptable safety and favorable middle‐term efficacy have been obtained. We believe that ESD will become a standard treatment for early esophageal cancer not only in Japan but also worldwide in the near future.     

Repeated social defeat stress induces chronic hyperthermia in rats

Psychological stressors are known to increase core body temperature (T_c) in laboratory animals. Such single stress-induced hyperthermic responses are typically monophasic, as T_c returns to baseline within several hours. However, studies on the effects of repeated psychological stress on T_c are limited. Therefore, we measured T_c changes in male Wistar rats after they were subjected to 4 social defeat periods (each period consisting of 7 daily 1 h stress exposures during the light cycle followed by a stress-free day). We also assessed affective-like behavioral changes by elevated plus maze and forced swim tests.In the stressed rats, the first social defeat experience induced a robust increase in T_c (+ 1.3 °C). However, the T_c of these rats was not different from control animals during the subsequent dark period. In comparison, after 4 periods of social defeat, stressed rats showed a small but significantly higher (+ 0.2-0.3 °C) T_c versus control rats during both light and dark periods. Stressed rats did not show increased anxiety-like behavior versus control rats as assessed by the elevated plus maze test. However, in the forced swim test, the immobility time of stressed rats was significantly longer versus control rats, suggesting an increase in depression-like behavior. Furthermore, hyperthermia and depression-like behavior were still observed 8 days after cessation of the final social defeat session. These results suggest that repeated social defeat stress induces a chronic hyperthermia in rats that is associated with behavior resembling depression but not anxiety.     

Adaptations to the incidental cases encountered at the division of clinical laboratory

We analyzed 4 cases that were not determined as incidents and another 7 cases determined as incidents, found at the department of clinical laboratory of us from April 2009 to March 2010. The former cases were, excess values of LD, and Cl, and glucose leveled as 0 mg/dl incorrectly, and misdirected blood samples at the ER. Our routine equipment and sample flow did not detect these false values. Resetting for auto dilution system and secondary check by every worker were reconsidered for these measurements. Antiseptic drug usage was notified by clinicians, and actually affected to the excessive Cl value. Real incidents were, two unprocessed samples, leakage of a sample, missing processes that caused delay of clinical practice, mixed up sample labels, a lost narcotic patch during cardiac ultrasonography. A lack of checking, carelessness, and accidental mistakes were reevaluated and reminded for workers on the duties. Also inadequate pharmaceutical knowledge and responsibilities of this section might severely affect on these lessons. Efforts were taken so that all workers shared the accurate information. Code blue cases are defined here as those of life-threatening events and sudden vital changes occurred in highest emergency, involve all health care workers, patients, and families. It is very important here to keep regular trainings for workers to cope with such events as well as preemptive assessments on environment and underlying risks in our laboratory. In line with the continuous advances in clinical medicine, medical safety managements are growing issues. To achieve safer environment and minimize various type of risks in the hospital, these incidents are to be assessed and reported regularly.     

Osteosarcoma arising in the breast

We report on a 49-year-old woman with osteosarcoma arising in the breast. She had undergone two consecutive excision biopsies for right breast tumors at ages 40 and 42 years. The tumors were diagnosed as a fibroadenoma and a benign phyllodes tumor, respectively. At age 46 years, she noticed a gradually enlarging mass in the same breast. After 3 years, at age 49 years, total mastectomy was performed. The tumor occupied the entire breast and measured 12x9x8.5 cm. The tumor cells were spindle-shaped and pleomorphic, with large, irregular nuclei and distinct nucleoli. Many tumor cells had characteristics of osteoblastic and chondroblastic elements producing osteoid, osseous, and cartilaginous intracellular substances. Pathologic mitoses and apoptotic cells were frequent. Neoplastic cells had infiltrated the skin. Blood and lymph vessel invasion was present. Tumor cells expressed vimentin, osteopontin, vascular endothelial growth factor, CD10, and alkaline phosphatase, but did not express keratin. Chemotherapy was not effective. The patient died of multiple pulmonary metastases 9 months after mastectomy.