Statistical Modeling of Subjective Sleep Quality.

Effective maintenance/improvement of sleep quality requires knowledge of how sleep quality is connected to quantitative features of sleep and arbitrarily selected habitual lifestyles, which naturally depend on the demographic characteristics of individuals. To fulfill these needs, a regression model of subjective sleep quality was constructed, whereby one might be able to design a practical strategy for achieving comfortable sleep adapted to individual conditions. Based on data obtained from our previous study, fundamental correlation profiles between day-to-day subjective and quantitative features of sleep were estimated. Obtained correlation profiles involving SRSs, quantitative features of sleep, and sleep habits across a week such as bedtime preference (chronotype), discrepancy between chronotype and social time cue (social jetlag), and habitual sleep-wake pattern (HSWP) were characterized specifically for each self-ratings of sleep quality (SRS) category through backward stepwise Linear Mixed Effect (LME) modeling. The LME model represented SRSs with acceptable accuracy, allowing identification of determinant factors for each category of SRS. The SRS is one possible option to clarify sleep status. In this study, we proposed a possible framework including model-based predictors of SRS in which self-awareness of sleep quality could be improved to facilitate healthy sleep practices.

Relationship between Dynamics of Physiological Signals and Subjective Quality of Life and Its Lifestyle Dependency.

In terms of preventive healthcare, how adopted lifestyle maintains healthy states or leads to pathological states is an essential issue. In this study, for the healthy subjects, their daily patterns of heart rate variability (HRV) and behavioral activity dynamics were analyzed in association with subjective quality of life (QOL), and how the relationship between the physiological signal dynamics and QOL is differentiated by the chronotype (sleep-wake pattern) was investigated. As a result, the morning type subjects were found to show higher sequential variation in R-R interval (rMSSD) and behavioral activity, and to have higher sleep quality and non-depressive tendency. Even the evening type subjects could have higher sleep quality under the condition that rMSSD shows a dip around early afternoon and keep a higher level of activity during the daytime, which may be due to realization of steady entrainment to the circadian time cues. Through this study, fundamental knowledge for preventive healthcare was obtained for us to help people's choice of an appropriate lifestyle for their health.

Modeling of segmentation clock mechanism in presomitic mesoderm.

Somite is sequentially generated in a head-to-tail order by segmentation of the mesenchymal tissue called presomitic mesoderm (PSM). The segmentation occurs periodically at the anterior end of the PSM, and this periodic segmentation has been suggested to be regulated by a molecular clock. In mouse PSM, the segmentation-related genes change their expression every 120 minutes, and this cyclic expression is essential for regular somite segmentation. In this study, a molecular mechanism of segmentation clock involving Wnt and Delta-Notch signaling pathways is modeled, and reality of the model structure is investigated through simulating biological findings. One dimensional array of the cellular clock models is constructed to simulate spatio-temporal dynamics of the gene-expressions in the PSM. The simulation result suggests that the Wnt gradient across the PSM is involved in the dynamics under concern.

Spontaneous chronic head and spinal subdural haematoma.

Spinal chronic subdural haematomas (SSDH) are extremely rare. We report a case of a SSDH combined with intracranial SDH. After tapping the SSDH in addition to the evacuation of SDH, the clinical symptoms dramatically improved. SSDH are considered to have an uncertain prognosis; however, good results can be obtained with an early diagnosis and prompt treatment.

Mathematical models of regulatory mechanisms of sleep-wake rhythms.

Studies of regulatory mechanisms of sleep-wake rhythms have benefited greatly from mathematical modeling. There are two major frameworks of modeling: one integrates homeostatic and circadian regulations and the other consists of multiple interacting oscillators. In this article, model constructions based on these respective frameworks and their characteristics are reviewed. The two-process model and the multioscillator model are explained in detail. An appropriate mathematical abstraction is also shown to provide a viewpoint unifying the model structures, which might seem to be distinct. Recently acquired knowledge of neural regulatory mechanisms of sleep-wake rhythm has prompted modeling at the neural network level. Such a detailed model is also reviewed, and could be used to explore a possible neural mechanism underlying a pathological state of sleep-wake rhythm.

[Surgery for acoustic neurinoma treated by gamma-knife radiosurgery: a case report].

A 52-year-old woman had a history of left hearing loss for 5 years. An acoustic neurinoma with 3.2 cm in diameter was diagnosed and treated with gamma-knife radiosurgery (19 Gy of marginal dose) 1 year and 4 months ago. She developed headache, nausea, and visual disturbance 1 month prior to admission. Slight left facial palsy appeared after radiosurgery. Magnetic resonance imaging demonstrated the tumor with central necrosis in the left cerebellopontine angle cistern, increasing in size to 3.5 cm in diameter, and hydrocephalus. Tumor removal was performed incompletely, because of the fibrous appearance of the tumor and severe adherence with the surrounding cerebellar tissue. Facial palsy did not worsen after surgery. Since the hydrocephalus was not resolved, a right ventriculo-peritoneal shunt was inserted. The clinical course in this case suggests that tumor removal followed by radiosurgery was an approximately effective treatment for large acoustic neurinoma.

Synchronization between hippocampal theta waves and PGO waves during REM sleep.

We investigated the temporal relationship between hippocampal theta waves (referred to as 'theta waves') and ponto-geniculo-occipital (PGO) waves in cats. We measured the time intervals between an occurrence of a PGO wave and the prior and posterior adjacent positive peaks of the theta wave. The unimodal distributions of these intervals suggested a close temporal relationship between PGO and theta waves (i.e. synchronization). In addition, the period of a theta wave during which a PGO wave occurred was not statistically different from that without a PGO wave. This result suggests that the synchronization found here is characterized by phase-locking rather than phase-resetting. Common mechanisms are suggested to underlie the generation of PGO and theta waves.

Clinical effect of intra-arterial tumor necrosis factor-alpha for malignant glioma.

Recombinant human tumor necrosis factor-alpha was administered intra-arterially to treat 20 cases of malignant gliomas, mostly progressive or recurrent. The optimum dosage was determined to be 1 x 10(5) U/sq m/day. Among the 10 evaluable patients treated at this dosage, two responded (one completely and one partially), resulting in a 20% response rate. Side effects were mild and easily controllable. Improvement of neurological symptoms was noted in 47% of the patients a few days after treatment, even when computerized tomography showed no tumor regression. This might have been due to the pleiotypic biological activity of tumor necrosis factor-alpha. Neuroradiographic observations revealed narrowing of the tumor-feeding artery, a decrease in tumor staining ability, and necrosis in the central part of a tumor. The authors suggest that intra-arterial administration of tumor necrosis factor-alpha may be an effective treatment for malignant glioma, including recurrent cases.

Alteration in natural defense activity against NK-susceptible B16 melanoma cells after treatment with Corynebacterium parvum.

We have investigated the effects of administration of C. parvum on host anti-metastatic activity against B16 melanoma H-2L, a natural killer (NK) sensitive clone with a low expression of H-2b. The anti-metastatic activity was estimated by monitoring the following two points. One was the survival ratio at an early stage after an intravenous (iv) inoculation of radiolabeled B16 H-2L cells, the other was the formation of pulmonary metastases after iv injection with the tumor cells. Administration of C. parvum showed a biphasic change in the NK activity of the spleen cells and the peritoneal exudate cells (PEC) in mice. At an early phase (2-3 days) after administration of C. parvum, the NK activity of the spleen cells and PEC was significantly augmented. On the other hand, at a later phase (14 days) after C. parvum administration, the NK activity was deeply depressed. In correlation with NK activity of the mice treated with C. parvum, the anti-metastatic activity of the hosts was augmented in the early phase, whereas a depressed level of anti-metastatic activity was observed in the late phase after administration of C. parvum. These results suggest that the modification of NK activity is a possible basis for modulation of anti-metastatic activity by C. parvum.

Anti-metastatic effect by in vivo administration of concanavalin A through augmentation of T-derived activated killer activity: efficacy to B16 melanoma expressed MHC antigen.

We attempted to investigate if the in vivo administration of concanavalin A (Con A), a potent T cell stimulator, would render anti-metastatic activity in hosts. Assays of activity were performed 20 days after iv inoculation of two clones of the B16 melanoma, B16-H (H-2+, highly metastatic), B16-L (H-2-, low metastatic), or 3LL cells into C57BL mice by enumerating lung colonies. In some experiments, hosts treated with anti-asialo GM1 Ab were used to evaluate effector mechanisms other than NK cells. While the injection of Con A alone had no significant effect on anti-metastatic activity, in nonimmunized hosts the effect by Con A was displayed when the mice were preimmunized with B16-H cells but not in those immunized with B16-L cells. Immunization with B16-H or B16-L cells alone resulted in the generation of killer cells with promiscuous lytic activity and induced an anti-metastatic effect against B16-H, B16-L, and 3LL cells. Con A treatment significantly augmented the killer activity of spleen cells of mice preimmunized with B16-H cells but not of those immunized with B16-L cells. The effectors from mice immunized with B16-H alone or given both Con A and B16-H were mainly of Thy 1+ Lyt2+ asialo GM1- cells, on the other hand, those from mice immunized with B16-L cells expressed asialo GM1 antigen. We showed the efficacy of Con A on the anti-metastatic effect in relation to the host immune response.

Does depression of NK activity cause lymphadenopathy in lpr mice?

B6-lpr/lpr mice develop massive T cell lymphoproliferation, as associated with autoimmune disease. We found a reduced NK activity in the spleen of B6-lpr/lpr mice. Neonatal thymectomy markedly retarded the development of lymphoproliferation and the development of autoantibodies in the B6-lpr/lpr mice. These animals had a higher level of NK activity in the spleen. When the neonatally thymectomized B6-lpr/lpr mice were given anti-asialo GM1 serum (30 microliter) four times at 6-day intervals, initiated at the 8th-10th postnatal week, these mice developed lymphoproliferative disorders and splenomegaly, concomitantly with depression of NK activity. It is therefore tempting to speculate that NK cells are involved in the regulation of the occurrence of lymphoproliferative disorders.

[Coexisting malignant lymphoma and early cancer of the stomach].

A 62-year-old man with malignant lymphoma and early gastric cancer as two independent growths in the stomach was reported. In the resected stomach, malignant lymphoma was observed as a protruding lesion measuring 5.5 X 3.0 X 1.2 cm with four giant folds at the anterior wall of the upper gastric body. There also was a poorly differentiated adenocarcinoma as an early gastric cancer of type IIc + III; it measured 0.9 X 0.7 cm and invaded the submucosal layer at the antral portion. There were no pathological findings, excepting intestinal metaplasia, in the mucosal layer between the two lesions. There was no metastasis from either the malignant lymphoma or the adenocarcinoma to perigastric lymph nodes.