[Analysis of Device-Related Infection after Deep Brain Stimulation Surgery].

BACKGROUND: Device-related infection frequently becomes a serious problem after deep brain stimulation(DBS)surgery and DBS device removal is usually the only effective treatment option. In this study, we examined risk factors for infection related to DBS devices at our institution. METHODS: We retrospectively investigated 80 DBS surgeries performed between March 2009 and September 2017 at our institution. We examined the relationship between DBS device-related infection and the following items:duration of electrode placement surgery, total number of tracks of microelectrode recordings(MER), period between surgeries, highest body temperature until implantable pulse generator(IPG)implantation, and patient background characteristics. RESULTS: Four(5.0%)patients developed device-related infection after DBS surgery. Three of them required device removal, whereas one improved following antibiotic treatment alone. We did not identify any specific trend or risk factor for infection. DISCUSSION: We perform DBS surgery in two stages. Patients were implanted with an IPG 2-3 days after electrode placement until August 2016, and at 6-8 days starting in September 2016. All cases of infection developed before September 2016, and no cases of infection have occurred since September 2016. We believe that lengthy surgical electrode placement affects the general status of patients and performing surgery before stabilization might confer a risk of infection. CONCLUSION: Device-related infection after DBS surgery does not seem to be associated with any risk factors. However, a shorter period between two-staged surgeries might affect infection rates.

[Successful use of danaparoid in the treatment of portal vein thrombosis that developed in a warfarin-administered hepatitis C virus-related cirrhosis patient].

An 84-year-old woman with hepatitis C virus-related cirrhosis, hepatocellular carcinoma and atrial fibrillation, who presented with hematemesis, was initially treated with endoscopic variceal ligation (EVL) for an esophageal varix hemorrhage. However, computed tomography (CT) upon admission had revealed portal vein thrombosis, despite having received warfarin for existing atrial fibrillation. We subsequently initiated a 2-week treatment with danaparoid;warfarin being discontinued in order to reduce the risk of re-hemorrhage. A follow-up CT after treatment revealed complete reduction of the portal vein thrombosis. This is the first successful report of danaparoid use in the treatment of portal vein thrombosis that developed in a patient who had received warfarin.

In-situ transmission electron microscopy observation of electromigration in Au thin wires.

Electromigration of thin Au wire is studied by the use of in-situ transmission electron microscopy (TEM) techniques from the viewpoint of nanogap formation. We use a relatively wide Au wire as a starting material because the position-dependent structure change in the wire provides information of the thermal effect caused by the current flow. In-situ TEM observation, in which current measurements of the Au wire are simultaneously performed, reveals the process of the growth of voids and grains. Finally the formation of a nanogap by electromigration is observed doing with current measurements. All the results observed by in-situ TEM indicate the fact that the thermal effects or temperature increase in the wire region take an important role for the structure change caused by electromigration of Au in the wire. It is suggested that the position of the nanogap can roughly be arranged by setting the wire structure and current direction even though a relatively wide wire was used. The detailed observation by in-situ TEM also suggests that the control of heat generation in the wire makes the nanogap sharp because of the well-controlled recrystallization of Au nanowires.

[A case of solitary neurocysticercosis of unknown transmission route].

We report a case of solitary neurocysticercosis of unknown transmission route. A 26-year-old male was taken to our hospital with a history of general convulsions. On admission, physical and neurological findings were normal. On the basis of neuroimaging (computed tomography scan and magnetic resonance imaging), initial diagnosis was brain abscess and the patient was treated with antibiotics. Two months later, the patient, at times, presented a loss of consciousness. The follow-up MRI revealed that the enhanced lesion became enlarged and perifocal edema became evident, so the patient was surgically treated. By histopathological examination, the lesion was diagnosed as a cysticercus. The immunoserologic assay gave a positive result for the disease. Postoperatively, the symptoms improved. Cerebral cysticercosis is the most common parasitic disease of the central nervous system, but rare in Japan. Therefore its diagnosis remains difficult, especially in the case of solitary cerebral cysticercosis, which has been reported only 7 times in Japan. The pathological examination or the immunoserologic assay should be taken into consideration to obtain definitive diagnosis of cerebral cysticercosis.