Introduction: During their clinical clerkship (CC), Japanese medical students’ literature searching skills were ambiguous. We conducted a questionnaire survey on students’ search processes to determine whether this skill improved after a lecture on conducting searches.　Method: This study was conducted from May to December 2019. The questionnaire survey was followed by a 90-minute lecture combining information and relevant activities. The questionnaire included students’ self-evaluation of their literature searching abilities, and references from their medical summaries and reports were compared to those of students from a 2018 group who did not attend the lecture.　Results: Sixty-seven students participated in the questionnaire survey and lecture. Questionnaire results demonstrated that the most frequently used search tool was PubMed. Regularly used types of literature were Japanese textbooks medical guidelines issued by the Japanese Medical Society, and English-language medical journal articles. The two major difficulties in conducting searches were the inability to critically appraise the literature and inadequate English reading skills.　The students’ satisfaction level regarding the lecture was found to be acceptable. After attending the lecture, students’ self-evaluation of their literature searching abilities improved significantly. Furthermore, compared to the 2018 group, references in students’ summaries and reports increased. Additionally, the number of English-language medical journal articles cited in reports was higher among students in the 2019 group than the 2018 group.　Conclusions: Although CC students can conduct literature searches, they struggle with critical appraisal and English-language comprehension. Interventions such as lectures may effectively improve their searching skills during CC.

There are few reports of prosthetic valve endocarditis due to Corynebacterium striatum. Here we report a case of prosthetic valve endocarditis after mitral valve replacement. A 77-year-old woman, who underwent mitral valve replacement and tricuspid valve annulo-plasty 4 months previously, was admitted to our hospital because of shock and loss of consciousness. A transthoracic echocardiogram showed severe mitral regurgitation due to dehiscence of the prosthetic mitral valve. We used the percutaneous cardiopulmonary support system for the management of circulatory collapse and, performed emergency mitral valve replacement. We detected C. striatum in preoperative blood and vegetation cultures. Antibiotic therapy was continued for 6 weeks, and the patients recovered without any complications.

A 56-year-old woman was admitted due to a cerebral hemorrhage two years after undergoing aortic valve replacement, mitral valve annuloplasty, and tricuspid valve annuloplasty. During treatment, she developed infective endocarditis. Although this was successfully treated conservatively, a surgical approach was subsequently adopted due to progressive mitral stenosis. Echocardiography revealed gradual proliferation of abnormal tissue overhanging the mitral valve around the prosthetic mitral annularring, as well as increased flow velocity in the artificial aortic valve. The cause of the increased flow velocity could not be determined on echocardiography. However, multidetector computed tomography revealed abnormal subprosthetic tissue that obstructed the opening and closing of the prosthetic aortic valve. Resection of the abnormal tissue and double valve replacement were performed. Prosthetic valve dysfunction due to pannus proliferation is relatively rare (around 1-2%), but it should be considered as a potential long-term postoperative complication. Though turbulent flow has been suggested as a potential cause, the exact etiology remains unknown. Furthermore, the disease course may be fulminant or gradual and symptomatic, leading to difficulties with diagnosis. A case of double valve replacement conducted for valve dysfunction due to abnormal tissue proliferation occurring two years after aortic valve replacement, mitral valve annuloplasty, and tricuspid valve annuloplasty followed by infective endocarditis is reported, along with a review of the related literature.

We report a case of quadricuspid aortic valve concomitant with infective endocarditis. A 73-year-old woman was admitted to our hospital because of general fatigue, loss of body weight and high fever. Transthoracic echocardiography showed moderate aortic regurgitation and left ventricle-right atrium fistulae with vegetation. Infectious endocarditis was diagnosed. Since her fever and hemolytic anemia were not controlled by antibiotics, we operated and the aortic valve had four cusps and there were vegetations on the aortic valve and left ventricle outflow tract. Perforation of the membranous septum was observed. Complete debridement and aortic valve replacement with patch repair of a left ventricle-right atrium (LV-RA) fistula was performed. Although she needed a permanent pacemaker due to complete AV block, her postoperative course was uneventful.

BACKGROUNDThe earthworm fibrinolytic enzyme (EFE) is a complex protein enzyme that is widely distributed in the earthworm's digestive cavity. Possessing strong protein hydrolysis activity, EFE not only has a direct effect on fibrin, but also can activate plasminogen. Its therapeutic and preventative effects on thrombosis-related disease have been confirmed clinically. Recently, there has been increased interest in the anti-tumor activity of EFE. In this study, the anti-tumor activity of EFE, isolated from Eisenia foetida, on human hepatoma cells was evaluated in vitro and in vivo. The potential mechanisms involved were also studied.

METHODSIn vitro experiments were performed in four human hepatoma cell lines: HLE, Huh7, PLC/PRF/5 and HepG2. After treatment with EFE in various concentrations, the inhibition of the rate of cell proliferation was measured. For the in vivo studies, tumor-bearing models xenografted with Huh7 cells were developed in nude mice, and then the mice were fed with EFE once a day for 4 weeks, and the control group received only saline. An inhibitory effect on tumor growth was observed. Also, apoptosis was observed with flow cytometric assay and fluorescent dye staining with acridine orange and ethidium bromide (AO/EB). The expression of matrix metalloproteinase 2 (MMP-2) were detected by Western blotting assay.

RESULTSAfter treatment with various concentrations of EFE, the proliferation of all hepatoma cell lines was suppressed to varying degrees in vitro. The IC(50) for HLE, Huh7, PLC/PCF/5 and HepG2 were 2.11, 5.87, 25.29 and 17.30 uku/ml, respectively. After administration of EFE orally for 4 weeks, the growth of tumor xenograft of Huh7 cells in nude mice was significantly inhibited in vivo. The tumor inhibitory rates in the EFE 500 uku/(kgxd) and 1000 uku/(kgxd) groups were 46.08% (compared with control group, P = 0.026) and 57.52% (compared with control group, P = 0.002) respectively. Meanwhile, the average weight of body, spleen or thymus did not show any remarkable differences among the various groups. The population in sub-G(1) stage was more in the EFE treated groups than in the control group according to flow cytometric assay. After treatment with EFE 0, 5, 10 uku/ml for 72 hours, the apoptotic rates were 3.5%, 10.9% and 12.3% in HLE cells, and 5.0%, 24.7% and 34.5% in Huh7 cells respectively. Under fluorescent staining with AO/EB, the apoptotic morphological changes could be detected more significantly in the EFE treated groups than in the untreated groups. After treatment with EFE in doses of 0, 5, 10 uku/ml for 72 hours, the apoptotic rates were 3.02%, 8.76%, 10.54% in HLE cells, and 3.95%, 18.27%, 30.89% in Huh7 cells respectively. The apoptosis-inducing effects of EFE occurred in a dose dependent manner. Western blotting assay showed that, after treatment with EFE, the secretions of MMP-2 were significantly inhibited in HLE and Huh7 cells.

CONCLUSIONSEFE showed significant anti-tumor activity in hepatoma cells both in vitro and in vivo, which may be because EFE could induce apoptosis of hepatoma cells and inhibit the expression of MMP-2. This suggests that EFE has a potential role in the treatment of hepatoma.

Animals ; Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Fibrinolytic Agents ; pharmacology ; Flow Cytometry ; Humans ; Liver Neoplasms, Experimental ; drug therapy ; pathology ; Male ; Matrix Metalloproteinase 2 ; analysis ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Oligochaeta ; enzymology ; Transplantation, Heterologous

We report a rare case of acute type A aortic dissection with paraplegia which was reversed using cerebrospinal fluid drainage (CFD). The patient was a 80-year-old man who was admitted with acute back pain and paraplegia. Computed tomographic scans showed an acute type A aortic dissection. Four hours after onset of paraplegia, CFD was initiated by inserting an intrathecal catheter at L3-L4. Cerebrospinal fluid was drained freely by gravity whenever the pressure exceeded 10cmH₂O. After 32h, the neurological deficit was completely resolved. CFD can be considered a useful treatment in patients with paraplegia after acute aortic dissection.

A 74-year-old man with renal failure had been treated with maintenance hemodialysis for 1.5 years at another hospital. The patient had an abdominal aortic aneurysm, bilateral iliac artery occlusion and coronary artery stenosis with a lesion in the left main trunk, but had been under observation because of the high risk of surgery. The patient elected to have surgery and was admitted to our hospital. We performed simultaneous surgery for severe coronary artery stenosis and abdominal aortic aneurysm with a maximum diameter of 85mm. The postoperative course was generally uneventful, but the patient required treatment of arrhythmia. We conclude that simultaneous surgery for angina pectoris and abdominal aortic aneurysm is feasible even in hemodialysis patients. It is important to pay attention to arrhythmia in the management of such patients, especially those with decreased cardiac function.

A 60-year-old male who had a history of Buerger's disease was admitted due to chest pain on exertion. Coronary angiography showed severe double vessel disease (the left anterior descending artery and the right coronary artery). Carotid angiography showed severe stenosis of the left internal carotid artery associated with brain ischemia. In addition, angiography of the lower extremities showed segmental occlusion and collateral arteries resembly a “corkscrew” appearance. We implanted a stent in the carotid artery followed by revascularization surgery of the left lower leg and simultaneous coronary artery bypass surgery. The postoperative course was excellent.

We evaluated the relation of changes in skin temperature, measured by thermography, to clinical symptoms and findings in patients who underwent coronary artery bypass surgery using the radial artery. All had a negative Allen test before operation. Ten consecutive patients who underwent surgery at least 3 months prior to the study were selected. Left radial artery grafts were harvested in all patients. Skin temperature was measured twice, before and after exercise. Two patients had a cold sensation at the arterial harvest site at rest. Three, including these two, complained of pain along the harvest site after exercise. No differences in temperature were observed before and after exercise in the ulnar aspects of the palm or forearm on either the left or right side. On the other hand, the increase in radial aspect temperature on the left side was smaller than that on the right. Skin temperature was clearly decreased after loaded exercise in 3 patients. We believe that the indications of grafting should be carefully considered because patients can show findings associated with circulatory disturbance at arterial harvest sites.