Objective To study H2O2-induced single strand breaks(SSB) formation in DNA and the reparation in NIH3T3 mouse fibroblasts by single cell gel electrophoresis technique(SCGE,Comet Assay) and to introduce SCGE.Methods The NIH3T3 mouse fibroblasts were incubated,and cell damage was induced by H2O2 and determined by SCGE.Results ① H2O2-induced damage class graph of the DNA Comet in the NIH3T3 mouse fibroblasts was established.② H2O2-induced SSB was H2O2 dose-dependent.③ The reparation of the damaged DNA was time-dependent and could be achieved 15min after incubation.The data indicated that most reparations were completed within 1 hour,but a few might take longer time.Conclusion Single cell gel electrophoresis technique is a simple and sensitive method to determine oxidation-induced single strand breaks(SSB) formation in DNA.

Some fragments of gravid proglottids of diphyllobothriid cestodes were evacuatedspontaneously, and complete strobila with scolex was expelled after the treatment with bithionol from a 35-year-old man in Ehime Prefecture, Where diphyllobothriasis has scarcely been recorded. The cestodes was identified as Diphyllobothrium latum by the following morphological characters: thin, weakly muscled strobila, with clavate scolex: distal end of uterus extending posteromediad to uterin pore, forming an acute angle with ventral surface of segment, genital pore and uterine pore widely separated; vagina turning abruptly ventrad just ventral to seminal vesicle, forming an angle of near 60°; there is a constriction between segments and often an area without testes and vitellaria; ovary with no anterior horns seen; the smooth surface of the egg-shell with shallow and widely spaced pits (scanning electron micrograph)

Introduction: We report a case of severe headache caused by lung cancer metastasis to the base of the skull that was difficult to diagnose due to a lack of imaging evidence. Case: A 70-year-old man diagnosed with advanced lung cancer experienced sudden, severe headache. He was diagnosed as having a tension-type headache because magnetic resonance imaging of his head failed to detect any pathology. He was prescribed various drugs, which except for strong opioids failed to treat his headache. He referred to our palliative care unit to treat the pain. Re-evaluation of his head CT revealed metastasis to the clivas. His pain was treated with rapid titration of subcutaneous oxycodone injection. Conclusion: Even if radiographic investigations fail to identify the metastasis, the patient should be re-evaluated if the headache worsens and/or is accompanied with cranial nerve dysfunction.

We evaluated the surgical strategy for thoracic aortic aneurysm associated with abdominal aortic aneurysm. From January 1982 to March 1999, 24 consecutive patients underwent surgical treatment for thoracic aortic aneurysm with abdominal aortic aneurysm. Staged operation was performed if one was only slightly dilated, but extensive operation was needed if the size of both aneurysms was greater than 6cm. In cases of thoracic aortic aneurysm with abdominal aortic aneurysm up to 4cm in size, surgical treatment was performed only for the thoracic aortic aneurysm. Circulatory support during operation was established from the ascending aorta, and circulatory arrest with deep hypothermia and retrograde cerebral perfusion were used for brain protection during surgery for thoracic aortic arch aneurysm. Hospital mortality was 12.5% (3/24 cases). The causes of death were cerebral infarction and respiratory failure. Antegrade systemic perfusion and aortic no-touch technique were an effective method of surgery for thoracic aortic aneurysm with abdominal aortic aneurysm to avoid perioperative embolism and major complications. We successfully performed staged operation, but regular radiographic follow-up was needed.

Although sequential bypass with in situ arterial conduits (the left and right internal thoracic arteries; LITA and RITA, the right gastroepiploic artery; GEA) in coronary artery bypass grafting (CABG) is technically demanding, it is one of the most important procedures using a limited number of in situ arterial conduits to revascularize a wide area. In this report, we retrospectively investigated the clinical outcome of CABG with 4 or more distal anastomoses using only in situ arterial conduits. From December 1990 to May 1999, 62 patients underwent CABG with in situ arterial conduits, with at least one sequential bypass. There were 59 men and 3 women patients with mean age of 59.6 years (41 to 82 years). Mean postoperative follow-up period was 32 months (1 to 101 months). The total number of distal anastomoses was 4 (1 sequential bypass) in 54 patients, 4 (2 sequential bypasses) in 6 patients, 5 (1 sequential bypass) in 1 patient and 6 (3 sequential bypasses) in 1 patient. There were 5 emergency operations (8%), 37 patients (60%) had a history of myocardial infarction, 30 patients (48%) had diabetes mellitus and 6 patients (10%) had chronic renal failure and were on hemodialysis. Left ventricular ejection fraction was 40% or less in 15 patients (24%). There were no early deaths. Angiographic patency was satisfactory for each graft (sequential: individual, LITA 96.7%: 100%, RITA 100%: 100%, GEA 89.5%: 97.4%). Patency of a distal anastomoses of GEA was rather poorer than that of proximal (p=0.03). Three patients died during the follow-up period (all of them due to malignancy). The 5-year actuarial survival and cardiac event-free rate was 94.6% and 87.2%, respectively. In conclusion, although an indication of GEA sequential grafting needs further study, in situ arterial grafting with at least one sequential arterial conduit was associated with excellent results and achieved more complete revascularization with exclusive use of in situ arterial conduits in patients with diffuse coronary artery disease.

After bleeding is controlled with hemostats during surgery, the residual material should be resorbed without adverse effects such as inflammation, infection or scar formation. To evaluate the biocompatibility of hemostats, three kinds of commercially available collagen hemostats, cotton type (Integran^®), microfibrillar type (Avitene^®), and sheet type (TachoComb^®), were examined. A rabbit ear chamber (REC), a system for viewing materials in vivo, was applied to the auricle of male Japanese white rabbits. The REC was designed to leave a 50-μm-thick and 6.4mm-diameter chamber, and 0.5mg of each specimen (Integran; n=8, Avitene; n=6, TachoComb; n=6) was placed in the chamber. Macroscopic and microscopic observations were performed every week up to 5 weeks without anesthetizing or stressing the animal. In the Integran group, capillaries infiltrated between the collagen fibers, and the vasculature in the REC field was complete in 6 out of 8 animals at 5 weeks. Cotton type collagen fibers of Integran became thinner every week without effusion. In the TachoComb group, capillaries were directed toward the effusion at 2 weeks, while in the Avitene group, a similar phenomenon was not observed. The vasculature was incomplete, with either effusion or infection at 5 weeks in the Avitene and TachoComb groups. Material was recognized up to 4 weeks in the TachoComb group, whereas the space occupied by material remained vacant without vasculature in the Avitene group. Our results suggest that cotton type configuration is excellent as a collagen hemostat, with smooth capillary infiltration, rapid resorption of material and promotion of the healing process.

When local hemostatic agents are used in surgery, rapid dissolution followed by prompt absorption without adverse effect after successful hemostasis are essential qualities. Residual hemostatic materials greatly influence host cells during the wound healing process. Biocompatibility of material is also essential. Furthermore, hemostatic agents also should be free of cytotoxicity that may block mitosis and migration of host cells, so that wound healing can proceed smoothly. For the evaluation of biocompatibility and cytotoxicity, 4 commercially available hemostatic agents; oxidized regenerated cellulose (Surgicel^®), gelatin sponge (Spongel^®), microfibrillar collagen (Avitene^®) and cotton type collagen (Integran^®) were tested in vitro and in vivo. The hydrogen ion concentration (pH) of culture medium containing hemostatic agents was measured. Fibroblasts were cultured with the hemostatic agents in petri dishes for 5 days. A rabbit ear chamber (REC) model was used to evaluate tissue compatibility and the healing process. Each hemostatic agent was placed in the REC and evaluated macroscopically once a week up to 5 weeks. At 72h, the pH of the culture medium containing Surgicel was low at 7.2, while they stayed between 7.7-7.8 with the other agents. In the fibroblast culture containing Surgicel, cell detachment occurred and the cell numbers decreased, while no particular changes occurred with other hemostatic agents. In the REC model, after 5 weeks Surgicel was dissolved and remained in the effusion, and the healing process was disturbed by inflammation. Spongel was dissolved and absorbed, with normal vasculature. Avitene was dissolved and remained in the effusion, but did not induce strong inflammation. With Integran, the healing process was prompt but the material was still recognizable at 5 weeks. The 4 hemostatic materials tested showed differences in biocompatibility and cytotoxicity. The ability of hemostasis is important; however, after hemostasis is achieved, unused hemostatic material should be eliminated, leaving as little hemostatic agent as possible to avoid postoperative complications.