Documentation of acute increase in ventricular capture threshold after direct current cardioversion with AutoCapture threshold record

This report describes acute and persistent increase in ventricular capture threshold after direct current cardioversion by using AutoCapture threshold record. Careful follow-up is required to be sure that the system continues to function according to its design specifications.     

Delayed-onset temporary auditory threshold shift following head blow in guinea pigs

This study attempts to investigate the development of sensorineural hearing loss following a head blow without skull fracture in association with physiological and histopathologic changes in an experimental animal model. With the head in a freely movable position, albino guinea pigs were given a single blow to the occipital region by a head blow device. At 1, 7, and 14 days after the blow, the animals' auditory brainstem response (ABR) and cochlear microphonics (CM) were examined, and both the temporal bone and brain stem were observed by light and electron microscopy. The ABR threshold was unchanged at day 1, was significantly increased at day 7, and was fully recovered at day 14. The I-V and I-II interpeak latencies were significantly prolonged at days 1 and 7, and wave I latency was significantly prolonged at day 7 only. These latencies were recovered to normal limits at day 14. On the other hand, no significant change in CM versus the control group was observed at any point in the measurements. Histopathologically, no abnormal finding was seen at the light microscopic level. However, at the electron microscopic level, there were some injuries to the eighth nerve. At day 1, the lamellar structure of the myelin sheath was irregular, and the periaxonal space was expanded; at day 7, the myelin sheath was disintegrated. At day 14, however, these changes were partially reversed. These results suggest that sensorineural hearing loss following a head blow in this model is attributed to dysfunction of the eighth nerve rather than to cochlear impairment.     

Apparent diffusion coefficient of human brain tumors at MR imaging

PURPOSE: To determine if apparent diffusion coefficient (ADC) can be used to differentiate brain tumors at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Institutional review board approval or informed patient consent was not required. MR images were reviewed retrospectively in 275 patients with brain tumors: 147 males and 128 females 1-81 years old, treated between September 1997 and July 2003. Regions of interest were placed manually in tumor regions on MR images, and ADC was calculated with a five-point regression method at b values of 0, 250, 500, 750, and 1000 sec/mm2. ADC values were average values in tumor. All brain tumor subgroups were analyzed. Logistic discriminant analysis was performed by using ADC, age, and patient sex as independent variables to discriminate among tumor groups. RESULTS: A significant negative correlation existed between ADC and astrocytic tumors of World Health Organization grades 2-4 (grade 2 vs grades 3 and 4, accuracy of 91.3% [P < .01]; grade 3 vs 4, accuracy of 82.4% [P < .01]). ADC of dysembryoplastic neuroepithelial tumors (DNTs) was higher than that of astrocytic grade 2 tumors (accuracy, 100%) and other glioneuronal tumors. ADC of malignant lymphomas was lower than that of glioblastomas and metastatic tumors (accuracy, 83.6%; P < .01). ADC of primitive neuroectodermal tumors (PNETs) was lower than that of ependymomas (accuracy, 100%). ADC of meningiomas was lower than that of schwannomas (accuracy, 92.4%; P < .01). ADC of craniopharyngiomas was higher than that of pituitary adenomas (accuracy, 85.2%; P < .05). ADC of epidermoid tumors was lower than that of chordomas (accuracy, 100%). In meningiomas, ADC was not indicative of malignancy grade or histologic subtype. CONCLUSION: ADC is useful for differentiation of some human brain tumors, particularly DNT, malignant lymphomas versus glioblastomas and metastatic tumors, and ependymomas versus PNETs.     

Transplacental transmission of maternal B-cell lymphoma

We report a case of maternal malignant lymphoma transferred to the fetus during pregnancy. A 29-year-old woman developed lymphoma at 29 weeks' gestation, and her infant developed malignant lymphoma at 8 months. Immunohistochemical examinations revealed lymphoid cells of similar characteristics in the maternal, placental, and infant tissues.     

Spontaneous regression of Langerhans cell histiocytosis: a case report

BACKGROUND: Spontaneous regression of Langerhans cell histiocytosis (LCH) has been reported in skin, bone, and pulmonary lesions. However, such phenomena in the central nervous system (CNS) have not been described previously. CASE DESCRIPTION: A case of LCH in the CNS with spontaneous regression is reported. A 2-year-old boy presented with general convulsion followed by frequent vomiting and diabetes insipidus. Magnetic resonance imaging (MRI) scan revealed numerous multifocal nodules predominantly in the left frontal lobe. The patient underwent surgery to remove part of the frontal lesion. Subsequent to surgery, residual lesions showed regression without any additional treatment, and clinical symptoms also subsided. The multiple lesions disappeared completely and did not relapse during 5-year observation. CONCLUSION: Surgical resection and/or adjuvant therapy such as radiation and chemotherapy has been performed for the treatment of LCH in the CNS. However, there may be a subgroup of patients with multifocal brain LCH that regress spontaneously. Further clinical study is required to establish the natural course and prognostic factors of this disease.     

Biological reactions resulting from endotoxin adsorbed on dialysis membrane: an in vitro study

Some types of dialysis membrane are known to adsorb endotoxin (ET). It is suggested that the biocompatibility of dialysis membrane is enhanced by adsorption and inhibition of ET. This study attempts to clarify the membrane-mediated biological reaction of the ET that is adsorbed to a dialysis membrane. After a dialysis circuit was prepared, contaminated dialysate was introduced on the dialysate side of a polyether polymer alloy (PEPA) membrane that adsorbs ET while saline solution or blood were introduced on the blood side, and the difference in ET adsorption between the two set-ups was measured. Further, the side filled with blood was left standing for 2 h, after which the changes in the amount of interleukin 1 receptor antagonist (IL-1Ra) produced from the whole blood were also assayed. Significantly more ET was adsorbed to the dialysis membrane when blood rather than saline was on the other side. In addition, the IL-1Ra production from the dialysis membrane that adsorbed ET was significantly higher. The ET adsorbed to the dialysis membrane may influence a living body even if it does not pass through the membrane. Accordingly, it is difficult to assume that the adsorption of ET to the membrane enhances its biocompatibility.     

Large Perigraft Seroma After Aortoiliac Bypass with an Expanded Polytetrafluoroethylene Graft: Report of a Case

A 63-year-old man who had undergone aortoiliac bypass with an expanded polytetrafluoroethylene (PTFE) graft was referred to our hospital for investigation and treatment of a possible pseudoaneurysm of the abdominal aorta. A tender, pulsatile, and bulging mass, about the size of an adult fist, was palpated around the navel. Enhanced computed tomography (CT) showed a large low-density area around the abdominal aorta and PTFE graft, and aortography showed a patent graft with no anastomotic leakage. Operative inspection revealed that the pulsatile mass was a large perigraft seroma, and we replaced the PTFE graft with a new woven Dacron graft. The patient has been well with no sign of recurrence for 1 year, although close long-term follow-up is mandatory.     

Chest wall schwannoma associated with neurofibromatosis 2--a case report

We report a rare case of neurofibromatosis type-2 (NF-2) associated with a chest wall schwannoma that was initially suspected of being a breast tumor. The patient was a 28-year-old female who was diagnosed as having NF-2 at 19 years old. At that time, she noticed a mass in the upper lateral region of her left breast but did not have it examined. The mass grew and became painful, and she was therefore referred to our department. Results of the initial examination indicated the possibility of a breast tumor, but a diagnosis of extramammary tumor of the major pectoralis major muscle was made on the basis of the results of ultrasonography and 3-dimensional computed tomography (3D-CT). An endoscope-assisted extirpation of the tumor was performed. Histologically, the tumor was an Antoni type A and B neurilemoma and was diagnosed as a schwannoma.