Molecular analysis of fungal populations in patients with oral candidiasis using internal transcribed spacer region

Oral candidiasis is closely associated with changes in the oral fungal flora and is caused primarily by Candida albicans. Conventional methods of fungal culture are time-consuming and not always conclusive. However, molecular genetic analysis of internal transcribed spacer (ITS) regions of fungal rRNA is rapid, reproducible and simple to perform. In this study we examined the fungal flora in patients with oral candidiasis and investigated changes in the flora after antifungal treatment using length heterogeneity-polymerization chain reaction (LH-PCR) analysis of ITS regions. Fifty-two patients with pseudomembranous oral candidiasis (POC) and 30 healthy controls were included in the study. Fungal DNA from oral rinse was examined for fungal species diversity by LH-PCR. Fungal populations were quantified by real-time PCR and previously-unidentified signals were confirmed by nucleotide sequencing. Relationships between the oral fungal flora and treatment-resistant factors were also examined. POC patients showed significantly more fungal species and a greater density of fungi than control individuals. Sixteen fungi were newly identified. The fungal populations from both groups were composed predominantly of C. albicans, though the ratio of C. dubliniensis was significantly higher in POC patients than in controls. The diversity and density of fungi were significantly reduced after treatment. Furthermore, fungal diversity and the proportion of C. dubliniensis were positively correlated with treatment duration. These results suggest that C. dubliniensis and high fungal flora diversity might be involved in the pathogenesis of oral candidiasis. We therefore conclude that LH-PCR is a useful technique for diagnosing and assessing the severity of oral candidal infection.

Clinical relevance of Küttner tumour and IgG4-related dacryoadenitis and sialoadenitis

Objectives

Küttner tumour (KT), so-called chronic sclerosing sialoadenitis, is characterised by concomitant swelling of the submandibular glands secondary to strong lymphocytic infiltration and fibrosis independent of sialolith formation. However, recent studies have indicated that some patients with KT develop high serum levels of IgG4 and infiltration of IgG4-positive plasma cells, namely IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS), so-called Mikulicz's disease. The aim of this study was to clarify the clinical and pathological associations between KT and IgG4-DS.

Materials and Methods

Fifty-four patients pathologically diagnosed with KT or chronic sialoadenitis were divided into two groups according to the presence or absence of sialolith (KT-S (+) or KT-S (−), respectively).

Results

There were no significant differences in the clinical findings, including the mean age, sex and disease duration, between the two groups. All patients in the KT-S (+) group showed unilateral swelling without infiltration of IgG4-positive plasma cells or a history of other IgG4-related diseases (IgG4-RD), while those in the KT-S (−) group showed bilateral swelling (37.5%), strong infiltration of IgG4-positive plasma cells (87.5%) and a history of other IgG4-RD (12.5%).

Conclusions

These results suggest an association between the pathogeneses of KT-S (−) and IgG4-DS, but not KT-S (+).

Difficulties in removal of the titanium locking plate in Japan

OBJECTIVE

This study was designed to evaluate the frequency of intraoperative complications associated with titanium locking compression plate (LCP) removal.

DESIGN

Retrospective study.

METHODS

Medical records were reviewed for surgical technique, plate types used, position and number of screws, time from internal fixation to plate removal, and intraoperative complications. Radiographs were reviewed to evaluate the position of the plates and screws and the accuracy of the screw direction. Mann-Whitney and Yates Chi-square tests were calculated with the level of significance at P < 0.05.

RESULTS

All LCPs could be removed. Of the 342 locking head screws (LHSs), a total of 21 (6.1%) screws, 3 (2.0%) 5.0 mm screws (3/153) and 18 (10.7%) 3.5 mm screws (18/169), were difficult to remove. The frequency of difficulty associated with the 3.5 mm LHSs was significantly higher than that of the 5.0 mm LHSs (P < 0.01). The frequency of difficulty associated with the removal of LHSs at the diaphysis was higher than that of LHSs at the epiphysis (P < 0.01), especially with 3.5 mm LHSs. The mean age was significantly lower in the patients in whom removal was difficult (P < 0.05). Our analysis revealed that the frequency of removal difficulty was high when a 3.5 mm LHS was inserted into the diaphysis of young patients.

CONCLUSIONS

We should recognize that the removal of LCPs can involve numerous problems and great care should be exercised, especially in cases involving 3.5 mm LHSs.

Clinical characteristics of Mikulicz's disease as an IgG4-related disease

OBJECTIVES

Mikulicz's disease (MD) was considered to be a subtype of Sjögren's syndrome (SS), based on histopathological similarities. However, recent studies have indicated that patients with MD show high serum IgG4 concentration, and suggested that MD is one of "IgG4-related disease" and distinguishable from SS. Therefore, we clinically and histopathologically examined the disease states of MD and SS in detail.

MATERIALS AND METHODS

Twenty patients with Mikulicz's disease and 18 with SS were comparatively studied to determine clinical characteristics in MD patients.

RESULTS

Sialography in MD patients did not show the "apple-tree sign" typically seen in SS. Serologically, high serum IgG4 levels but not anti-SS-A or anti-SS-B antibodies were observed in MD. SS showed lymphocytic infiltration of various subsets with atrophy or severe destruction of the acini, while MD showed selective infiltration of IgG4+ plasma cells with hyperplastic germinal centers and mild acini destruction. Corticosteroid treatment of MD reduced IgG and IgG4 levels and improved salivary function. A negative correlation between disease duration and increasing rate of salivary flow was observed in MD.

CONCLUSIONS

These results suggested that the pathogenesis of MD might be different from those of SS.

CLINICAL RELEVANCE

early diagnosis and treatment of MD is important for the improvement of salivary function.

Selective localization of T helper subsets in labial salivary glands from primary Sjögren's syndrome patients

The aim of this study was to investigate the initiation and progression of autoimmune damage in the lesions of labial salivary glands (LSGs) from primary Sjögren's syndrome (SS) patients by examining the selective localization of T helper (Th) subsets such as Th1, Th2, Th17 regulatory T cells (T_regs) and follicular T helper cells (Tfh). The expression of cytokines and transcription factors associated with these Th subsets in the LSGs from 54 SS patients and 16 healthy controls was examined using real-time polymerase chain reaction (PCR) and immunostaining. Additionally, infiltrating lymphocytes without germinal centre (GC^-) and with GC (GC⁺) in the LSGs specimens from eight SS patients were extracted selectively by laser capture microdissection (LCM). The mRNA expression of these molecules was compared between the two sample groups of GC^- and GC⁺ by real-time PCR. The mRNA expression of cytokines and transcription factors of all T helper (Th) subsets in the LSGs from the SS patients was increased significantly in comparison with controls. In LSGs from the SS patients, Th2 and Tfh was associated closely with strong lymphocytic infiltration; however, Th1, Th17 and T_regs was not. In the selectively extracted lesions of LSGs, Th1 and Th17-related molecules were detected strongly in the GC^-, while Th2 and Tfh-related molecules were detected in the GC⁺. In contrast, no significant association with strong lymphocytic infiltration was observed in T_reg-related molecules. These results indicate that SS has selective localization of Th subsets such as Th1, Th2, Th17 and Tfh in the LSGs, which is associated closely with disease severity and/or status. SS might be initiated by Th1 and Th17 cells, and then progressed by Th2 and Tfh cells via GC formation.

Cytokine/chemokine profiles contribute to understanding the pathogenesis and diagnosis of primary Sjögren's syndrome

To investigate the pathogenesis of localized autoimmune damage in Sjögren's syndrome (SS) by examining the expression patterns of cytokines, chemokines and chemokine receptors at sites of autoimmune damage. mRNA expression of these molecules in the labial salivary glands (LSGs) and peripheral blood mononuclear cells (PBMCs) from 36 SS patients was examined using a real-time polymerase chain reaction-based method. Subsets of the infiltrating lymphocytes and chemokines/chemokine receptors expression in the LSG specimens were examined by immunohistochemistry. Cytokines/chemokine concentrations in the saliva were analysed using flow cytometry or enzyme-linked immunosorbent assay. mRNA expression of T helper type 1 (Th1) cytokines, chemokines and chemokine receptors was higher in LSGs than in PBMCs. In contrast, mRNA expression of Th2 cytokines, chemokines [thymus and activation-regulated chemokine (TARC/CCL17), macrophage-derived chemokine (MDC/CCL22)] and chemokine receptor (CCR4) was associated closely with strong lymphocytic accumulation in LSGs. Furthermore, TARC and MDC were detected immunohistochemically in/around the ductal epithelial cells in LSGs, whereas CCR4 was detected on infiltrating lymphocytes. The concentrations of these cytokines/chemokines were significantly higher in the saliva from SS patients than those from controls, and the concentrations of Th2 cytokines/chemokines were associated closely with strong lymphocytic accumulation in LSGs. These results suggest that SS might be initiated and/or maintained by Th1 and Th17 cells and progress in association with Th2 cells via the interaction between particular chemokines/chemokine receptors. Furthermore, the measurement of cytokines/chemokines in saliva is suggested to be useful for diagnosis and also to reveal disease status.

Interleukin-21 contributes to germinal centre formation and immunoglobulin G4 production in IgG4-related dacryoadenitis and sialoadenitis, so-called Mikulicz's disease

OBJECTIVES

Interleukin (IL)-21 is mainly produced by CD4 T helper (Th) cells including Th2, Th17 and follicular helper T (Tfh) cells. Recent studies have reported that IL-21 is involved in the formation of germinal centres (GCs) and class switching of IgG4. It has been suggested that IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS), so-called Mikulicz's disease (MD), is distinct from Sjögren's syndrome (SS) and shows a high frequency of GC formation in salivary glands. In this study the expression of IL-21 in IgG4-DS and SS patients was examined.

METHODS

Twelve patients with IgG4-DS, 15 with SS and 15 healthy subjects were screened for (1) ectopic GC formation in formalin-fixed labial salivary gland (LSG) biopsy samples; (2) expression of IL-21, Th2-, Th17- and Tfh-related molecules (cytokines, chemokine receptors and transcription factors) in LSGs; (3) relationship between IgG4/IgG ratio and mRNA expression of IL-21 in LSGs.

RESULTS

mRNA expression of IL-21 and Bcl-6 in LSGs from patients with IgG4-DS was significantly higher than in patients with SS and controls. IL-21 and CXCR5 were detected by immunohistochemistry in or around GC in patients with SS and those with IgG4-DS. IL-21 was detected in infiltrating lymphocytes outside GC only in patients with IgG4-DS. Expression of IL-21 was consistent with that of Th2-related molecules while IL-17 was rarely seen in IgG4-DS. Furthermore, the expression of IL-21 in LSGs was correlated with the number of GC formations and the IgG4/IgG ratio in patients with IgG4-DS.

CONCLUSIONS

These results suggest that overexpression of IL-21 by Th2 cells might play a key role in GC formation and IgG4 production in IgG4-DS.

C2 lamina reconstruction using locking miniplate for the intradural tumor of the craniocervical junction (two case reports)

OBJECTIVE

To describe a technique for C2 lamina reconstruction using locking miniplates for the extirpation of spinal tumors in the craniocervical junction. Many spinal surgery cases in which lamina reconstructions have been performed using non-locking miniplates have been reported. However, there is only one report of the use of locking miniplates for lamina reconstruction in spinal tumor cases.

METHODS

We performed C2 lamina reconstructions using locking miniplates in a patient with a spinal tumor and another with a cystic lesion. The clinical and radiologic features of both cases are reported, and the surgical technique is described.

RESULTS

A 62-year-old female and a 30-year-old male were diagnosed with meningioma and a neurenteric cyst, respectively, in the craniocervical junction. Extirpation of these lesions was performed in combination with C2 lamina reconstruction and reattachment of the paraspinous muscle to the C2 spinous process. A follow-up examination at 1 year postoperatively demonstrated no significant change in the sagittal alignment of the cervical spine and a good postoperative course in both cases. Bony fusion was detected in both cases, and no implant failure occurred in either case.

CONCLUSIONS

This procedure results in rigid fixation of the reimplanted C2 lamina and helps to restore the paraspinous muscles. For these reasons, it appears to be a useful surgical procedure for spinal tumors requiring C2 laminectomy and does not cause postoperative kyphosis of the cervical spine.

Th2 and regulatory immune reactions contribute to IgG4 production and the initiation of Mikulicz disease

OBJECTIVE

Mikulicz disease has been considered to be a subtype of Sjögren's syndrome (SS). However, recent studies have suggested that Mikulicz disease is an IgG4-related disease and is distinguishable from SS. In addition, it has been reported that both interleukin-4 (IL-4) and IL-10 induce IgG4 production and inhibit IgE. This study was undertaken to examine the expression of these cytokines in patients with Mikulicz disease and patients with SS.

METHODS

Labial salivary gland (LSG) sections from 15 patients with Mikulicz disease and 18 patients with SS were examined for subsets of the infiltrating lymphocytes, expression patterns of messenger RNA (mRNA) for cytokines/chemokines, and relationships between the IgG4:IgG ratio and the expression of mRNA for IL-4 or IL-10.

RESULTS

Immunohistochemical analysis showed lymphocyte infiltration of various subsets in the LSGs of SS patients, and the selective infiltration of IgG4-positive plasma cells and Treg cells in the LSGs of Mikulicz disease patients. The levels of mRNA for both Th1 and Th2 cytokines and chemokines in LSGs from patients with SS were significantly higher than in controls, while the expression of both Th2 and Treg cells was significantly higher in the patients with Mikulicz disease than in controls. Furthermore, the expression of IL-4 or IL-10 in the LSGs was correlated with the IgG4:IgG ratio.

CONCLUSION

These results suggest that the pathogenesis of Mikulicz disease is different from that of SS. Mikulicz disease is a unique inflammatory disorder characterized by Th2 and regulatory immune reactions that might play key roles in IgG4 production.

Effects of an immuno-enhanced diet containing antioxidants in esophageal cancer surgery following neoadjuvant therapy

Neoadjuvant therapy-induced immunological deterioration may be a key factor in postoperative morbidity in patients with esophageal cancer. This study aimed to determine the effects of perioperative feeding with an immuno-enhanced diet on immune competence in patients treated with neoadjuvant therapy followed by surgery. Because an immuno-enhanced diet that contained several antioxidants was used, perioperative oxidative stress and the effects of the immuno-enhanced diet on this stress were also investigated. Of 39 patients with esophageal cancer who underwent similar surgical procedures, 26 patients who received chemotherapy or chemoradiation therapy before surgery were randomly divided into two groups: group 1 (n= 14) was given an immuno-enhanced diet for 5 days before surgery, and group 2 (n= 12) received no enteral feeding products before surgery. Group 3 (n= 13) consisted of patients that did not receive neoadjuvant therapy and received no enteral feeding products before surgery. Several markers for coagulation and fibrinolysis were determined and immunological assessments were performed for each patient. To measure reactive oxygen metabolites and the total antioxidant capacity, diacron-reactive oxygen metabolites (d-ROMs) and OXY-adsorbent tests were performed using a free radical elective evaluator. Significant depression in lymphocyte numbers was observed in groups 1 and 2 before and early after surgery as compared to group 3. Numbers of B cells, CD4/CD8 ratio, and phytohemagglutinin-induced lymphocyte transformation tests were also significantly decreased in groups 1 and 2 on postoperative day 1. Fibrin and fibrinogen degradation products were significantly elevated in group 2 compared to group 1. d-ROMs and OXY-adsorbent test values were elevated before surgery and were decreased transiently early after surgery. Compared to groups 2 and 3, d-ROMs values were significantly lower in group 1 patients throughout the postoperative period, while OXY-adsorbent test values were significantly higher in group 2 patients. Oxidative index was significantly suppressed in group 1 compared to group 3. No significant intergroup differences were observed with regard to morbidity after surgery. Although the baseline levels of immunological function might have been different because of less-advanced cancer stages in group 3, neoadjuvant therapy significantly affected several immunological parameters. Preoperative administration of an immuno-enhanced diet did not significantly prevent neoadjuvant therapy-induced immunological deterioration prior to esophageal cancer surgery. Patients with esophageal cancer had elevated levels of oxidant and antioxidant activities before surgery, which were transiently decreased early after surgery. Although the underlying mechanisms for these perioperative changes are unclear, this study showed that an immuno-enhanced diet containing several antioxidants may reduce oxidative stress following esophageal cancer surgery. After these mechanisms are studied further, oxidative stress control may become another tool for perioperative management to reduce morbidity after esophageal cancer surgery.

[Surgical treatment and outcome of multiple primary lung cancers]

We assessed the selection of the type of pulmonary resection, operative morbidity, mortality and the outcome of our 14 cases who underwent surgical treatment for multiple primary lung cancer. Eleven cases underwent lobectomy with limited surgery, 3 cases underwent combination of limited surgery. Only 1 case had prolonged air leakage after surgery, but other cases had no postoperative complication and there was no operative death. The survival rate was higher than that of T4 (metastasis to the same lung lobe) cases and M1 (metastasis to another lung lobes) cases. With this result, we consider that postoperative good survival can be expected by the aggressive surgical approach for cases of multiple primary lung cancer, despite it is difficult to distinguish multiple primary lung cancers and metastatic cancers preoperatively. On the other hand, the opportunity to treat early-stage lung cancer is possibly increase with the spread of medical checkup using computed tomography (CT), it will be necessary to introduce limited surgery at 1st operation to keep post-operative pulmonary function, considering another surgery for the 2nd primary lung cancer.

Experimental evaluation of photocrosslinkable chitosan hydrogel as injection solution for endoscopic resection

BACKGROUND AND STUDY AIMS

Saline as an injection solution for endoscopic resection techniques has several disadvantages such as a short-lasting effect leading to a potentially higher risk of bleeding and perforation. The new substance of photocrosslinkable chitosan hydrogel in a DMEM/F12 medium (PCH) can be converted into an insoluble hydrogel by ultraviolet irradiation for 30 s, and was evaluated in two sets of animal experiments.

METHODS

18 pigs were used in the two parts of the study. First, mucosal resections were done with either PCH or hypertonic saline; the effects of both agents on wound healing were examined endoscopically and histologically. Second, in vivo degradation of PCH was examined using six pig stomachs.

RESULT

PCH injection led to a longer-lasting elevation with clearer margins, compared with hypertonic saline, thus enabling precise endoscopic submucosal dissection (ESD) along the margins of the elevated mucosa. The endoscopic appearance after ESD was similar in both groups. PCH biodegradation was completed within 8 weeks according to endoscopic and histologic analyses.

CONCLUSION

PCH is a promising agent for submucosal injection prior to various techniques of endoresection. It should be evaluated in clinical trials after biocompatibility testing for PCH is completed.

Submucosal injection, for endoscopic mucosal resection, of photocrosslinkable chitosan hydrogel in DMEM/F12 medium

BACKGROUND AND STUDY AIMS

We studied the ability of a photocrosslinkable chitosan in DMEM/F12 medium to maintain submucosal thickness and to reduce bleeding after mucosal resection. We also investigated the behavior of chitosan hydrogels with regard to wound healing.

METHODS

The gastric submucosal layer of heparinized rats was injected with the photocrosslinkable chitosan in medium (which was then irradiated with ultraviolet light to form a hydrogel), or with sodium hyaluronate, or hypertonic saline, and three investigations were done, using three different sets of rats. The first and second were measurement of the thickness of the layer, and of the amount of bleeding induced by mucosal resection, respectively. Thirdly, the effects of the chitosan hydrogel on wound healing were examined histologically.

RESULTS

Gastric submucosal layers of chitosan hydrogel-treated animals remained significantly thicker than those of other groups for at least 6 h after injection. The total amount of bleeding 20 min after mechanical mucosal resection was 170.0 +/- 20.0 mg, 678.3 +/- 226.3 mg, and 1020.0 +/- 104.1 mg in the chitosan hydrogel, sodium hyaluronate, and hypertonic saline groups, respectively. Histological study revealed that the focus of bleeding was surrounded by chitosan hydrogel and that almost all the hydrogel was biodegraded within 4 weeks. Furthermore, a discernible, but not statistically significant effect of the chitosan hydrogel on wound healing was observed.

CONCLUSIONS

The chitosan hydrogel produced mucosal elevation after submucosal injection with ultraviolet irradiation, and it significantly reduced bleeding after mucosal resection. Our newly developed chitosan hydrogel in medium might be a promising submucosal agent for endoscopic mucosal resection.

Reduction rate of lymph node metastasis as a significant prognostic factor in esophageal cancer patients treated with neoadjuvant chemoradiation therapy

Tumor regression is used widely as a measure of tumor response following radiation therapy or chemoradiation therapy (CRT). In cases of esophageal cancer, a different pattern of tumor shrinkage is often observed between primary tumors and metastatic lymph nodes (MLNs). Regression of MLNs surrounded by normal tissue may be a more direct measure of the response to CRT than regression of a primary tumor as exfoliative mechanical clearance does not participate in shrinkage of MLNs. In this study we evaluated the significance of the reduction rate (RR) of MLNs as a prognostic factor in esophageal cancer patients treated with neoadjuvant CRT. Forty-two patients with marked MLNs were selected from 93 patients with esophageal carcinoma who had received neoadjuvant CRT. The RRs of the primary tumor and the MLNs were calculated from computed tomography scans. In 20 patients, surgical resection was carried out following CRT. Univariate analysis was used to determine which of the following variables were related to survival: size of the primary tumor and MLNs; RRs of both lesions; degree of lymph node (LN) metastasis; clinical stage; and surgical resection. Multivariate analysis was then performed to assess the prognostic relevance of each variable. The primary tumor was larger than the MLNs in 69% of patients before CRT and in 40% of patients after CRT. In 79% of the patients, the RR of the primary tumor was greater than the RR of the MLNs. The results of the univariate analyses showed that a high RR of the MLNs and surgical resection after CRT were associated with significantly improved survival. The multivariate analysis demonstrated that the RR of MLNs had the strongest influence on survival. The RR of LN metastasis should be evaluated as an important prognostic predictor in patients with marked LN metastasis of esophageal cancer treated with CRT.

[Castleman's disease in the interlobar fissure resected by video-assisted thoracoscopic surgery; report of a case]

An abnormal shadow was detected on the chest X-ray of a 33-year-old man in a medical check-up. Chest computed tomography (CT) showed a 2 x 2 x 3 cm tumor which was enhanced, round, homogeneous, and adjacent to the pulmonary artery in the right interlobar fissure. Video-assisted thoracoscopic surgery was performed in August 2002 for diagnosis and treatment. The tumor was surgically removed and grossly round, elastic and hard. The histopathological diagnosis was hyaline vascular type of Castleman's disease. Postoperative course was uneventful, and the patient was discharged on the third postoperative day. Interlobar Castleman's disease successfully resected by video-assisted thoracoscopic surgery is rare.

Staple line coverage with absorbable mesh after thoracoscopic bullectomy for spontaneous pneumothorax

BACKGROUND

Thoracoscopic simple bullectomy for primary spontaneous pneumothorax (PSP) has a relatively high postoperative recurrence rate and sometimes results in postoperative air leakage. One of the reasons for postoperative recurrence is the regrowth of bullae around the staple line. Therefore, reinforcement of the visceral pleura around the staple line is a reasonable way to prevent postoperative air leaks and recurrence. This study was done to determine the efficacy in preventing postoperative air leak and recurrent pneumothorax of widely covering the staple line with absorbable mesh after thoracoscopic bullectomy.

METHODS

Wide coverage of the staple line with absorbable mesh was performed on 114 patients with PSP. These patients were retrospectively compared with 126 patients who underwent thoracoscopic simple bullectomy alone.

RESULTS

The postoperative duration of chest drainage in the coverage group (mean, 1 day; range, 0-5) was significantly shorter than that in the simple bullectomy group (mean, 3 days; range 0-20). A prolonged air leak (>7 days) occurred in six patients in the simple bullectomy group, but there were no such leaks in the coverage group. Recurrent pneumothorax occurred in three patients (2.6%) in the coverage group and 12 patients (9.5%) in the simple bullectomy group.

CONCLUSION

Wide coverage of the staple line with absorbable mesh is effective in preventing postoperative air leak and in decreasing the recurrence rates of PSP.

Spontaneous subacute intratumoral hemorrhage of hepatic cavernous hemangioma

We report a case of giant hepatic cavernous hemangioma associated with spontaneous subacute intratumoral hemorrhage. Magnetic resonance imaging showed an oval, homogeneous, high-intensity lesion with a low-intensity rim in the original high-intensity tumor on T2-weighted images. On T1-weighted images, this oval lesion showed heterogeneous high intensity with peripheral higher intensity. The histologic specimen confirmed hepatic hemangioma with intratumoral hemorrhage.

Management of branch duct-type intraductal papillary mucinous tumor of the pancreas based on magnetic resonance imaging

BACKGROUND

We assessed the usefulness of magnetic resonance imaging (MRI) in identifying nonmalignant intraductal papillary mucinous tumors (IPMTs) of the pancreas.

METHODS

Thirty-three patients with branch duct-type IPMT diagnosed by endoscopic retrograde cholangiopancreatography were prospectively examined with magnetic resonance cholangiopancreatography followed by dynamic gadolinium-enhanced MRI examinations, and patients with no findings suggestive of malignancy, including a solid mass, mural nodules, a main pancreatic duct wider than 5 mm in diameter, and stenosis of the main pancreatic duct, were prospectively followed up with sequential MRI examinations once or twice a year.

RESULTS

Twenty-six (79%) patients showed no findings suggestive of malignancy in the initial MRI examination. The diameter (mean +/- standard error) of the main pancreatic duct was 3.9 +/- 0.7 mm and that of the ectatic branch pancreatic duct was 36.0 +/- 9.1 mm. Twenty-three patients were prospectively followed for more than 36 months and 22 of them showed no findings suggestive of malignancy during follow-up periods ranging from 39 to 77 months (mean = 55 months).

CONCLUSION

MRI was useful to identify nonmalignant IPMTs of the branch duct type, and close follow-up observation with serial MRI examinations may be appropriate in the management of such patients.

[Intraoperative conversion and postoperative complication of video-assisted thoracoscopic surgery lobectomy for primary lung cancer]

By 2002, we had attempted video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy for 140 primary lung cancer cases. Four cases (2.9%) were converted to standard posterolateral thoracotomy for oncologic reasons and aortic injury, and 7 cases (5%) were converted to minithoracotomy with a 10 cm incision due to almost injuring the vascular system. Average blood loss in these cases was 379 ml, and there was no blood transfusion required. Seven of these 11 cases had true pleural symphysis in the thoracic cavity. The remaining 129 cases, consisted of 93 lobectomies and 34 segmentectomies, performed with a minithoracotomy of 5 cm using 2 ports. Average surgical duration was 227 minutes, and blood loss was 100 ml. Postoperative complication occurred in 15 patients (11.6%). Major complications included 1 broncho-pleural fistula, 1 pulmonary infarction, 1 cerebral infarction and 1 respiratory failure needed for mechanical ventilation. However, there were no hospital deaths. The mean postoperative hospital stay was 12 days. We recommend that surgeons should pay attention to hilar dissection, particularly in the presences of adhesion and carefully judge whether to convert to thoracotomy at the time of hemorrhage. The VATS procedure has a low mortality and morbidity for lung cancer, but particulaly in high risk patients, requires care and management the same as an open thoracotomy.

Comparison of 99mTc-MIBI uptakes on planar images with those in excised rats organs

The precision with which images reflect tracer uptake in the myocardium has been studied. Additionally, the degree to which Tc methoxyisobutylisonitrile (99mTc-MIBI) in the liver gave the effect to a myocardial image has been examined. After administering Tc-MIBI to normal male rats, we compared the myocardial uptakes obtained using a gamma camera with the actual uptakes in the excised organs. Twenty-nine rats were used. Following imaging, the anterior view at 5, 10, 15, 30, 45, 60, 90 and 120 min after administration of the tracer, uptakes in the heart, lung, liver and blood were estimated with a well-type scintillation counter (WC) and represented as the percentage of the injected dose per gram of tissue (%ID/g). The regions of interest (ROIs) were placed on planar images (PI) and the uptake in each organ was estimated as the percentage of the injected dose per pixel (%ID/pixel). The ratios of PI-to-WC and heart-to-organ were also evaluated. Cardiac uptake with WC was maximum (1.581%+/-1.893%) at 10 min post-injection. On the other hand, that with PI was maximum (1.493%+/-0.598%) at 45 min post-injection, but there were significant differences between both measurements (PI/WC ratio: about 1.0 time). Pulmonary uptake with WC was the maximum at 5 min (0.808%+/-0.015%) post-injection, and decreased gradually. PI measurement showed the maximum value at 45 min (0.760%+/-0.012%). Hepatic uptake with WC was the maximum at 30 min (0.594%+/-0.254%). On the other hand, PI measurement showed the same pattern with WC, but these values were higher value than WC as the whole. PI measurement showed higher uptakes in each organ than WC measurement. It was concluded that uptakes or the heart-to-organ ratio obtained clinically with PI might not represent a value that is always accurate.

The relationship between the visually evoked P300 event-related potential and gamma band oscillation in the human medial and basal temporal lobes: an electrocorticographic study

We have recorded electrocorticographic activities (ECoG) from subdural electrodes on the human medial temporal lobe (MTL) and basal temporal lobe (BTL) in epileptic patients during cognitive visual tasks designed to evoke the P300 event related potential (ERP). From those recordings we examined the event related gamma band oscillation (ERGBO) and P300 ERP. While P300 was predominantly observed in the MTL, ERGBO was observed in both MTL and BTL. Resembling to P300, ERGBO responses were more often observed following rare stimuli than frequent stimuli. In average responses the ERGBO to rare stimuli followed P300, beginning at 440.5 ms and continuing for about 100 ms. Past studies suggest P300 ERP component reflects a role in cognitive function. Since ERGBO in the present study appeared in different regions and at a different latency from P300, ERGBO may reflect a different physiological role in the cognitive process.

Periodate-treated, non-anticoagulant heparin-carrying polystyrene (NAC-HCPS) affects angiogenesis and inhibits subcutaneous induced tumour growth and metastasis to the lung

Periodate-treated, non-anticoagulant heparin-carrying polystyrene consists of about ten periodate-oxidized, alkaline-degraded low molecular weight-heparin chains linked to a polystyrene core and has a markedly lower anti-coagulant activity than heparin. In this study, we evaluated the effect of non-anticoagulant heparin-carrying polystyrene on tumour growth and metastasis. Non-anticoagulant heparin-carrying polystyrene has a higher activity to inhibit vascular endothelial growth factor-165-, fibroblast growth factor-2- or hepatocyte growth factor-induced human microvascular endothelial cell growth than heparin, ten periodate-oxidized-heparin and ten periodate-oxidized-low molecular weight-heparin, which is probably due to the heparin-clustering effect of non-anticoagulant heparin-carrying polystyrene. Non-anticoagulant heparin-carrying polystyrene inhibited human microvascular endothelial cell, B16 melanoma and Lewis lung cancer cell adhesion to Matrigel-coated plates. Non-anticoagulant heparin-carrying polystyrene also showed strong inhibitory activities in the tubular formation of endothelial cells on Matrigel and B16-melanoma and Lewis lung cancer cell invasion in a Matrigel-coated chamber assay. In vivo studies showed that growth of subcutaneous induced tumours and lung metastasis of B16-melanoma and Lewis lung cancer cells were more effectively inhibited by non-anticoagulant heparin-carrying polystyrene than ten periodate-oxidized-heparin and ten periodate-oxidized-low molecular weight-heparin. Furthermore, non-anticoagulant heparin-carrying polystyrene markedly reduced the number of CD34-positive vessels in subcutaneous Lewis lung cancer tumours, indicating a strong inhibition of angiogenesis. These results suggest that non-anticoagulant heparin-carrying polystyrene has an inhibitory activity on angiogenesis and tumour invasion and may be very useful in cancer therapy.

Usefulness of Multidetector 3D-CT Angiography in the Evaluation of Infantile Perimedullary Spinal Arteriovenous Fistula

SUMMARY

We report an infantile huge perimedullary spinal arteriovenous fistula (SAVF) associated with Hereditary-Hemorrhagic-Telangiectasia (HHT), which was treated by glue embolization in one session. Three-dimensional Multidetector Computed Tomography Angiography (3D-MCTA) was useful in pre- and post-endovascular intervention.

Beneficial effects of immediate enteral nutrition after esophageal cancer surgery

This study was conducted to determine the effects of immediate enteral nutrition (EN) on nutritional status, immunological competence, and the suppression of excessive inflammatory responses in patients following esophageal cancer surgery. Twenty-four patients who underwent the same elective operation for thoracic esophageal carcinoma were randomized into an immediate enteral nutrition (IEN) group who received EN from postoperative day (POD) 1 and a parenteral nutrition (PAN) group. Both groups received comparable volumes and calories on the same POD. Laboratory studies were carried out preoperatively and on PODs 1-7. Other nutritional and immunological assessments were repeated on PODs 1 and 7. Plasma concentrations of nitrate and nitrite were also measured. All of the patients in the IEN group tolerated enteral feeding well. There were no significant differences in the results of nutritional assessments, lymphocyte function, or plasma nitrate and nitrite levels between the two groups. The IEN group showed a significantly earlier recovery of the total lymphocyte count. The serum levels of total bilirubin and C-reactive protein were significantly attenuated in the IEN group. These results indicate that immediate EN may have beneficial effects on immunological competence and the suppression of excessive inflammatory responses in patients following esophagectomy. Patients undergoing radical esophageal surgery who are subjected to severe surgical stress might benefit the most from early EN.

Surgical treatment of early-infantile epileptic encephalopathy with suppression-bursts associated with focal cortical dysplasia

A surgically treated case of early-infantile epileptic encephalopathy (EIEE) with suppression-bursts associated with focal cortical dysplasia is reported. Tonic-clonic seizures followed by a series of spasms occurred at age of a few days. Interictal electroencephalogram (EEG) revealed a suppression-burst pattern and magnetic resonance imaging suggested focal cortical dysplasia in the left prefrontal area. Combination therapies of antiepileptic treatments showed only partial efficacy. The patient underwent lesionectomy at 4 months of age and the spasms decreased to zero to two series daily. At age 2 years, his seizures increased in number and EEG showed that residual left hemisphere was the main epileptogenic focus. Modified functional hemispherectomy of the left hemisphere was applied at age 3 years. The patient, now 5 years old, is free from seizure and gaining psychomotor development gradually. In cases of EIEE with focal cortical dysplasia, surgical treatment may have beneficial effects on both psychomotor development and seizure control.

Papillonodular type of cystic partially differentiated nephroblastoma: a case report

We report a case of the papillonodular type of cystic partially differentiated nephroblastoma (CPDN), an extremely rare renal neoplasm that occurs in newborns and infants. The papillonodular type of CPDN is a variant of the conventional form of CPDN. MRI clearly demonstrated the gross pathologic features, distinguishing it from other renal multilocular cystic tumors.

X chromosome methylation-based chimerism assay for sex-mismatched hematopoietic stem cell transplantation

Analysis of hematopoietic chimerism is important for monitoring engraftment, graft failure, and disease recurrence. Although several techniques are now available, their sensitivity is unsatisfactory. In sex-mismatched stem cell transplantation (SCT) with a female donor, Y chromosome-specific sequences have proven the most sensitive marker. However, in the case of a male donor, no such reliable marker has been available to date. In this study, we report a novel method we developed to detect microchimerism in female recipients who receive SCT from male donors. The X-linked human androgen receptor gene (HUMARA) contains a highly polymorphic CAG trinucleotide repeat. Near this polymorphic site are methyl-sensitive HpaII restriction enzyme sites. After HpaII digestion, unmethylated male HUMARA sequences are completely digested, while methylated female ones remain intact among the male origin cells. This allows a highly efficient detection of a small number of female cells. Combined with the nested PCR technique, the X chromosome methylation-based chimerism assay could attain a 10(-4) level of sensitivity, which is 1000-fold higher than that of conventional assays. The applicability of the method was confirmed in two transplant cases. This highly sensitive method can also be applied to detect minimal residual disease or microchimerism in conditions other than hematopoietic SCT.

Experimental evaluation of photocrosslinkable chitosan as a biologic adhesive with surgical applications

BACKGROUND

In various surgical cases, effective tissue adhesives are required for both hemostasis (eg, intraoperative bleeding) and air sealing (eg, thoracic surgery). We have designed a chitosan molecule (Az-CH-LA) that can be photocrosslinked by ultraviolet (UV) light irradiation, thereby forming a hydrogel. The purpose of this work was to evaluate the effectiveness and safety of the photocrosslinkable chitosan hydrogel as an adhesive with surgical applications.

METHODS

The sealing ability of the chitosan hydrogel, determined as a bursting pressure, was assessed with removed thoracic aorta, trachea, and lung of farm pigs and in a rabbit model. The carotid artery and lung of rabbits were punctured with a needle, and the chitosan hydrogel was applied to, respectively, stop the bleeding and the air leakage. In vivo chitosan degradability and biologic responses were histologically assessed in animal models.

RESULTS

The bursting pressure of chitosan hydrogel (30 mg/mL) and fibrin glue, respectively, was 225 +/- 25 mm Hg (mean +/- SD) and 80 +/- 20 mm Hg in the thoracic aorta; 77 +/- 29 mm Hg and 48 +/- 21 mm Hg in the trachea; and in the lung, 51 +/- 11 mm Hg (chitosan hydrogel), 62 +/- 4 mm Hg (fibrin glue, rubbing method), and 12 +/- 2 mm Hg (fibrin glue, layer method). The sealing ability of the chitosan hydrogel was stronger than that of fibrin glue. All rabbits with a carotid artery (n = 8) or lung (n = 8) that was punctured with a needle and then sealed with chitosan hydrogel survived the 1-month observation period without any bleeding or air leakage from the puncture sites. Histologic examinations demonstrated that 30 days after application, a fraction of the chitosan hydrogel was phagocytosed by macrophages, had partially degraded, and had induced the formation of fibrous tissues around the hydrogel.

CONCLUSIONS

A newly developed photocrosslinkable chitosan has demonstrated strong sealing ability and a great potential for use as an adhesive in surgical operations.

Analysis of the distribution of CAG repeats and X-chromosome inactivation status of HUMARA gene in healthy female subjects using improved fluorescence-based assay

We investigated the polymorphic CAG-repeat distribution and the X-inactivation status of the human androgen receptor (HUMARA) gene in 58 female Japanese volunteers. Polymerase chain reaction amplification was performed using a fluorescent-dye-labeled primer under conditions specific for GC-rich targets, and fragments were analyzed. To estimate the length of these fragments, FAM-labeled (blue fluorescent) products were simultaneously compared with ROM-labeled size markers (red) that were created by sequencing various HUMARA fragments. The number of polymorphic CAG repeats of HUMARA in 116 alleles from 58 female subjects ranged from 15 to 28. Of the 58 volunteers, 51 (88.0%) were heterozygous. In 96% of the heterozygous female subjects, the allelic differences were no greater than 6 repeats. X-chromosome inactivation was calculated as the ratio of the area of the smaller peak to the sum of the areas of the smaller and larger peaks. The average ratio was 0.38 (range, 0.09-0.50). Preferential use of 1 allele, by more than 75% (ratio. <0.25). was observed in 5 volunteers (10.9%). The clonal nature of a patient with chronic myelogenous leukemia was easily identified. This method is sensitive enough to discriminate a difference of 1 triplet repeat.

DNA topology on an increase in positive writhing number of DNA: conformation changes in the time course of cis-diamminedichloroplatinum(II)-DNA adducts

We show that the topological significance of the gel mobility of cis-diamminedichloroplatinum(II) (DDP)-closed circular DNA (ccDNA) adducts decreases with reaction time, until a point at which it joins relaxed DNA, and that the mobility of the adducts increases again. There is no relationship between the relative length of the adducts and the gel mobility. Although the significance of the decrease of gel mobility is due to the unwinding of cis-DDP-DNA (or trans-DDP-DNA) adducts, the conformational significance of the subsequent increase in mobility is unclear. To elucidate the conformational significance for unwinding of the adducts, we measured the writhing number (Wk) of the adducts using electron microscopy and analyzed the topological states of cis-DDP (or trans-DDP) adducts based on the White rule, Lk=Wk+Tk. Where, Lk and Tk represent the linking and twisting number in the ring, respectively. From the data, we found that the Wk of cis-DDP-ccDNA adducts in comparison with trans-DDP-ccDNA adducts increases from a negative to a positive number with time. This suggests that cis-DDP plays a role in the change of the topological state of ccDNA. In the abstraction of platinum from the adducts with CN- ion, the differences in both topological states may explain why Pt in trans-DDP is abstracted more easily than in cis-DDP. To explain the abstraction of Pt ion, we also discuss the findings based on the thermodynamic cycle in a intermolecular crosslink model Pt(NH3)2(guanine)2(2+)-->Pt(CN)4(2-) using the Pt parametrized PM3 method.

Molecular detection of tumor cells at diagnosis invading the bone marrow and peripheral blood of patients with aggressive or indolent lymphomas

We studied tumor cell invasions of bone marrow and peripheral blood in patients with various types of advanced non-Hodgkin's lymphoma by amplifying complementarity determining region III using the polymerase chain reaction (PCR) method and developing patient-specific probes. After molecular engineering, we could detect tumor cells in bone marrow from seven of 11 cases and in peripheral blood from six of 11 cases, despite negative results in four cases studied morphologically. Indolent cases were more likely to yield positive results than aggressive cases. The reason may be different biological behaviors among the histological types.

Successful transarterial glue embolisation by wedged technique for a tentorial dural arteriovenous fistula presenting with a conjunctival injection

Many tentorial dural arteriovenous fistulae (TDAVF) present with intracranial haemorrhage. We report a patient who presented with conjunctival injection. Transarterial embolisation of the TDAVF was undertaken with a wedged injection of a low concentration of N-butyl cyanoacrylate, arresting the flow next to the proximal segment of the venous outlet. After three sessions, a complete cure was achieved. We present a useful method which has not been reported previously.

Apoptosis of Neuro2a cells induced by lysosphingolipids with naturally occurring stereochemical configurations

Lysosphingolipids, which lack the fatty acid moiety of sphingolipids, are known to be accumulated in some variants of sphingolipid storage diseases. Here, we report that lysosphingolipids with naturally occurring stereochemical configurations induce apoptosis in mouse neuroblastoma Neuro2a cells. The intracellular dehydrogenase activity and [3H]thymidine incorporation of Neuro2a cells were strongly suppressed by the addition of lysosphingolipids in a dose-dependent manner, whereas the parental sphingolipids had no effect. Intranucleosomal DNA fragmentation, chromatin condensation, and phosphatidylserine externalization, which are typical features of apoptosis, were observed when the cells were cultured with 40-80 microM of lysosphingolipids for 24-48 h in the presence of 5% fetal calf serum. Activation of caspase-3-like enzyme occurred after addition of lysosphingolipids followed by incubation at 37 degrees C for 24 h. The addition of an inhibitor of caspases, ZVAD-fmk, to the Neuro2a cell culture completely inhibited the elevation of caspase-3 activity but not the DNA fragmentation. These results may indicate that a caspase-3 independent signaling pathway is involved in the lysosphingolipid-induced apoptosis and suggest that accumulation of lysosphingolipids, but not parental sphingolipids, triggers the apoptotic cascade in neuronal cells of patients with sphingolipidoses.

Effect of multiple subpial transection on motor cortical excitability in cortical dysgenesis

We report here a 12-year-old patient with unilateral cortical dysgenesis and intractable simple partial seizure in his left arm, who underwent multiple subpial transection (MST) in the right cerebral cortex including the primary motor cortex. We investigated motor cortical excitability using multimodal transcranial magnetic stimulation (TMS) before and 1 month after MST, in which surgical cortical incisions were made with strokes 5 mm apart and 4 mm deep. Preoperative TMS studies showed hyperexcitability in the affected motor cortex as abnormally prolonged muscle responses to TMS with a wide cortical motor map, which were markedly reduced following the operation. The preoperative motor evoked potentials were large and polyphasic, and consisted of early and late components. The late component was completely abolished after MST, suggesting that this component might be due to activation of the corticospinal tract neurones by long recurrent axon branches of dysplastic excitatory pyramidal neurones, which were cut by MST, or by delayed, polysynaptic intracortical conduction with marked temporal dispersion. Intracortical inhibition in the affected motor cortex was also disrupted preoperatively and improved after MST. Postoperative recruitment order of muscle responses to TMS was bilaterally symmetrical, indicating that MST did not interfere with the function of the corticospinal tract neurones. The patient showed fair motor recovery and good seizure control after the operation. These results of TMS studies demonstrated the remarkable effectiveness of MST not only on intractable seizure but also on abnormal motor cortical organization and hyperexcitability in cortical dysgenesis.

Long-term survival after gastric cancer and liver and paraaortic lymph node metastases: report of a case

We report the case of a 46-year-old man in whom successful resection of carcinoma of the stomach with liver and paraaortic lymph node metastases was carried out. The carcinoma was removed completely with combined resection of the lower esophagus, total stomach, distal pancreas, spleen, two metastatic liver nodes, and groups 1 and 2 and abdominal paraaortic lymph nodes. Adjuvant chemotherapy was administered postoperatively. The patient is currently well with a grade 1 performance status and no signs of recurrence 12 years after his operation. This experience suggests that even the presence of metastatic paraaortic lymph nodes and liver metastases is not necessarily a contraindication to surgery when the carcinoma can be resected curatively and safely.

Port-access cardiac surgery. Experience with 34 cases at Keio University Hospital

OBJECTIVES

We reviewed our experience with port-access cardiac surgery and evaluated the medical effects and benefits of this technique in view of postoperative quality of life and medical expenses incurred during hospitalization.

METHODS

From June 1998 to August 2000, port-access cardiac surgery was conducted on 34 patients--22 with atrial septal defect, 6 with mitral regurgitation, 2 with coronary artery disease, 2 with partial endocardial cushion defect, 1 with ventricular septal defect, and 1 with atrial and ventricular septal defects. Two types of endoaortic-balloon catheters were used to execute aortic cross-clamping. Skin incisions were 5 cm long.

RESULTS

No hospital or late deaths were observed. Patients with atrial septal defect were discharged on postoperative day 3.7, patients of mitral regurgitation on postoperative day 4.2, and patient of ventricular septal defect on postoperative day 4.0 on the average. None were readmitted. Patients appeared undisturbed by early discharge and were able to resume physical work on day 22 on the average after discharge.

CONCLUSION

Patients undergoing port-access cardiac surgery recovered quickly from surgery and resumed work quickly. This technique thus proved satisfactory both physically and mentally to patients and improved their quality of life. Medically and economically this technique proved extremely beneficial. We confirmed it to constitute a viable approach and option for cardiac surgery in selected patients.

Neuronal disconnection for the surgical treatment of pediatric epilepsy

The surgical methods and results of disconnective surgery for pediatric epilepsy were retrospectively analyzed. The techniques of neuronal disconnection included multiple subpial resection (MST), corpus callosotomy. and functional hemispherectomy by disconnection. Of 158 total pediatric operations, disconnective techniques were employed in more than 60% of the cases. MST was applied when the epileptic focus was located in unresectable cortices such as speech or motor areas. MST was also instrumental when the epileptogenic zone was extensive and was widely disseminated, as is often observed in cases of neocortical epilepsy. Of 25 patients who underwent MST, surgical outcomes after > 1 year follow-up showed Engel Class I or II in 10 cases, Class III in 12, and Class IV in 3. No mortality or morbidity was encountered during surgery or postoperatively. Corpus callosotomy was applied to cases of disabling generalized seizures and showed a marked effect in alleviating potentially injurious drop attacks. Of 34 patients with drop attacks, 29 became free from this type of seizure, 4 had infrequent attacks, and only 1 showed no beneficial effect. Postoperative improvement of cognition and speech was recognized in 77% of the cases. We developed a new method of functional hemispherectomy by fiber disconnection and applied this less invasive technique to 23 cases of hemispheric lesions. Of the 17 cases with > 1 year follow-up, 13 were in Class I or II, and 3 in Class III, and 2 in Class IV. Development partially normalized in infants with good seizure outcomes.

Adult Still's disease as a paraneoplastic manifestation of breast cancer

We treated a patient who developed symptoms and findings indistinguishable from those of adult Still's disease as a manifestation of metastatic breast cancer 7 years after treatment for a stage 1 tumor. Although clinical features fulfilled diagnostic criteria for adult Still's disease, examination of a bone marrow biopsy specimen indicated that the apparent adult Still's disease was a paraneoplastic manifestation associated with diffuse marrow infiltration by breast cancer. The fever and polyarthralgia resolved with administration of prednisolone, and antiestrogen therapy with tamoxifen citrate was also started.

Cortical oscillations in human medial temporal lobe during wakefulness and all-night sleep

We have recorded human medial temporal lobe electrocorticogram during wakefulness and natural sleep in epileptic patients with subdural electrodes. From these recordings, we have found gamma (30-150 Hz) [Neuroscience 90 (1999) 1149] and beta-1 (10-20 Hz) [NeuroReport 10 (1999) 3055] activities during wakefulness in human medial temporal lobe. In this paper, we will report changes of these frequencies across wake and natural sleep. Electrocorticograms during wake, slow wave sleep and rapid eye movement (REM) sleep were subjected to fast Fourier transformation analysis. During wake two spectral enhancements, beta-1 and gamma, were consistently observed across subjects. In the raw signal, beta-1 was observed as a regular rhythmic oscillation. In slow wave sleep, the beta-1 peak disappeared but gamma remained, although slightly reduced in power. During REM sleep, beta-1 appeared again, but the peak frequency was significantly lower than during wake (mean frequency: wake=16.6, REM=12.8 Hz). The gamma peak was also present in REM sleep. It has been known that the rhythmic slow activity (RSA) or theta is observed in some animals. However, it is unclear whether the human hippocampus displays similar activity. Since human beta-1 appears during wake and REM sleep when RSA is observed in other species, and since beta-1 is also a regular rhythmic oscillation, we propose that beta-1 may be the functional equivalent of hippocampal RSA (theta) observed in some animals. Functional significances of the gamma activity should be further investigated.