Anxiety affects the amplitudes of red and green color-elicited flash visual evoked potentials in humans

It has been reported that negative emotional changes and conditions affect the visual faculties of humans at the neural level. On the other hand, the effects of emotion on color perception in particular, which are based on evoked potentials, are unknown. In the present study, we investigated whether different anxiety levels affect the color information processing for each of 3 wavelengths by using flash visual evoked potentials (FVEPs) and State-Trait Anxiety Inventory. In results, significant positive correlations were observed between FVEP amplitudes and state or trait anxiety scores in the long (sensed as red) and middle (sensed as green) wavelengths. On the other hand, short-wavelength-evoked FVEPs were not correlated with anxiety level. Our results suggest that negative emotional conditions may affect color sense processing in humans.

Maternal dietary restriction alters offspring's sleep homeostasis

Nutritional state in the gestation period influences fetal growth and development. We hypothesized that undernutrition during gestation would affect offspring sleep architecture and/or homeostasis. Pregnant female mice were assigned to either control (fed ad libitum; AD) or 50% dietary restriction (DR) groups from gestation day 12 to parturition. After parturition, dams were fed AD chow. After weaning, the pups were also fed AD into adulthood. At adulthood (aged 8-9 weeks), we carried out sleep recordings. Although offspring mice displayed a significantly reduced body weight at birth, their weights recovered three days after birth. Enhancement of electroencephalogram (EEG) slow wave activity (SWA) during non-rapid eye movement (NREM) sleep was observed in the DR mice over a 24-hour period without changing the diurnal pattern or amounts of wake, NREM, or rapid eye movement (REM) sleep. In addition, DR mice also displayed an enhancement of EEG-SWA rebound after a 6-hour sleep deprivation and a higher threshold for waking in the face of external stimuli. DR adult offspring mice exhibited small but significant increases in the expression of hypothalamic peroxisome proliferator-activated receptor α (Pparα) and brain-specific carnitine palmitoyltransferase 1 (Cpt1c) mRNA, two genes involved in lipid metabolism. Undernutrition during pregnancy may influence sleep homeostasis, with offspring exhibiting greater sleep pressure.

The retinoic acid receptor agonist Am80 increases hippocampal ADAM10 in aged SAMP8 mice

The retinoic acid (RA, a vitamin A metabolite) receptor (RAR) is a transcription factor. Vitamin A/RA administration improves the Alzheimer's disease (AD)- and age-related attenuation of memory/learning in mouse models. Recently, a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) was identified as a key molecule in RA-mediated anti-AD mechanisms. We investigated the effect of chronic administration of the RAR agonist Am80 (tamibarotene) on ADAM10 expression in senescence-accelerated mice (SAMP8). Moreover, we estimated changes in the expression of the amyloid precursor protein (APP), amyloid beta (Aβ), and hairy/enhancer of split (Hes), which are mediated by ADAM10. Spatial working memory and the levels of a hippocampal proliferation marker (Ki67) were also assessed in these mice. ADAM10 mRNA and protein expression was significantly reduced in the hippocampus of 13-month-old SAMP8 mice; their expression improved significantly after Am80 administration. Further, after Am80 administration, the expression levels of Hes5 and Ki67 were restored and the deterioration of working memory was suppressed, whereas APP and Aβ levels remained unchanged. Our results suggest that Am80 administration effectively improves dementia by activating the hippocampal ADAM10-Notch-Hes5 proliferative pathway.

[Sleep regulatory mechanisms]

The fact that resting wakefulness does not satisfy the need for sleep suggests that sleep has a critical role for the brain, probably for its maintenance or repair. Neuronal oxidative stress, neuroinflammation, or energy insufficiency in the brain is now considered to be a trigger or cause for sleep induction. And the timing for sleep is controlled by circadian clock which also exists in the brain. Sleep is occurred in the brain, which is regulated by the brain itself. "Why do we sleep ?" Although everyone wants to know the answer for this issue, scientists should still question that "How do we sleep"?

Retinoic acid receptor antagonist LE540 attenuates wakefulness via the dopamine D1 receptor in mice

Vitamin A is a common lipophilic vitamin, and its function is mainly mediated by the binding of its metabolite retinoic acid to retinoic acid receptors (RARs) and retinoid X receptors. Recently, it was reported that the expression of the RARb (an RAR subtype) gene determines the contribution of the delta oscillation in the sleep electroencephalogram (EEG) patterns in mice. We also reported that 4-week dietary deficiency of vitamin A (VAD) causes the attenuation of delta power in sleep and spontaneous activity in mice. However, our previous study could not clarify whether the attenuation of delta power by VAD is attributed to the suppression of RARs. To address this problem, we investigated whether the chronic administration of LE540 (30mg/kg/day), an antagonist of RARs, for 1 or 4weeks attenuated EEG delta power during sleep in mice. Consequently, 4-week LE540 administration induced a significant attenuation of wakefulness and delta power in non-rapid eye movement sleep. Western blot analysis revealed a significant decrease in the expression of dopamine D1 receptor (D1DR) in the striatum and tyrosine hydroxylase in the midbrain of mice that were administered LE540 for 4weeks. High-performance liquid chromatography analysis of striatal tissue revealed a significant decrease in the homovanillic acid/dopamine ratio. Meanwhile, dopamine levels did not change in these mice. Our results suggest that the 4-week antagonism of RARs induces the attenuation of delta power. However, the attenuation of delta power may be elicited indirectly by the decrease of wakefulness followed by the hypo-expression of dopamine receptors especially D1DR.

Refeeding after a 24-hour fasting deepens NREM sleep in a time-dependent manner

Sleep/wake cycle is regulated by a variety of neuropeptides in the hypothalamus, a brain region that also regulates energy homeostasis and feeding behavior. Since circadian rhythms are affected by energy metabolism and feeding condition, we investigated whether changes in feeding regimen would influence sleep/wake parameters and body temperature. We monitored sleep and body temperature across three days of baseline (day 1), fasting (day 2), and refeeding (day 3) conditions under ordinary ambient temperature and employed different refeeding schedules. Refeeding at ZT1 following the 24-h fasting enhanced EEG delta power in NREM sleep. However, when the time of refeeding was set at either ZT7 or ZT12, the enhancement of EEG delta power was attenuated. The amount of NREM sleep was not largely affected by a 24-h fasting started at ZT1, although fasting that started at ZT12 changed the temporal distribution of NREM sleep. Hypothalamic nNOS mRNA level was increased both before and after refeeding at ZT1 compared with control condition, while there was no significant change in mice refed at ZT7. Level of NPY mRNA in the arcuate nucleus was increased before the refeeding only at ZT1. These results suggest that refeeding after a 24-h fasting makes NREM sleep deeper in a time-dependent manner.

Impaired olfactory function in mice with allergic rhinitis

OBJECTIVE

It has been reported that olfactory function is impaired in patients with allergic rhinitis. However, the mechanism of olfactory dysfunction in allergic rhinitis remains poorly understood. Because of difficulties in obtaining and analyzing human olfactory mucosa due to both technical and ethical issues, an animal model needs to be established to clarify the mechanism of olfactory dysfunction in allergic rhinitis. The purpose of this study was to study olfactory function and changes in olfactory mucosa using allergic rhinitis mice.

METHODS

A model of allergic rhinitis mice with olfactory dysfunction was developed by sensitizing with ovalbumin (OVA), and intranasally challenging with the same allergen. Olfactory function of mice with or without allergic rhinitis was assessed by odor detection ability test with cycloheximide and local field potential (LFP) with 1-octanal. We also evaluated histological changes in the olfactory mucosa of allergic rhinitis mice by both light and electron microscopy.

RESULTS

Both of odor detection ability test and LFP showed that olfactory function was impaired in mice with allergic rhinitis, but not in mice without allergic rhinitis. Histopathological findings showed prominent infiltration of eosinophils, plasma cells, neutrophils, mast cells, and macrophages in lamina propria of olfactory mucosa of mice with allergic rhinitis, although infiltration of these cells was not seen in control mice. Allergic rhinitis also increased the number and size of glands in olfactory mucosa, suggesting an elevated amount of mucin in olfactory mucosa.

CONCLUSION

This study showed for the first time that mice with allergic rhinitis have impaired olfactory function, increased size and number of olfactory glands, and infiltration of eosinophils, neutrophils, mast cells, plasma cells, and macrophages in the olfactory mucosa. This suggests that allergic reactions are seen in olfactory mucosa of mice with allergic rhinitis, and that greater olfactory gland activity is associated with olfactory dysfunction. Also, this mouse model could provide an expedient system for analyzing mechanisms of olfactory dysfunction.

The role of limbic-hypothalamic systems in metabolic responses of phenylalanine to repeated cold exposures in rabbits

In this study we examine the effects of lesions to limbic or hypothalamic structures on the metabolic responses of phenylalanine in liver slices prepared from rabbits exposed to cold stress (-20 degrees C) for 12 hours at a fixed time once a day. The results were as follows: 1. The 1st cold exposure (cold exposure on the 1st day) had marked and various effects on phenylalanine metabolism, and the metabolic responses of phenylalanine to cold exposure gradually decreased and then completely disappeared with repetitions of exposure in intact rabbits. 2. The metabolic patterns and responses of phenylalanine to the 1st cold exposure were altered by lesioning the periventricular arcuate nucleus (ARC), ventromedial hypothalamus (VMH), stria terminalis (ST) or dorsal fornix (FX). 3. The complete abolishment of the metabolic responses to cold exposure by its repetition was observed in rabbits with lesions in the ARC or VMH as well. 4. In contrast, metabolic responses of phenylalanine to cold exposure in rabbits with lesions in the ST or FX remained even after six exposures. These results suggest that the ARC, VMH, amygdala (AMYG)-ST system and dorsal hippocampus (HPC)-FX system played a role in the metabolic regulation of phenylalanine and in the metabolic responses of phenylalanine to the 1st cold exposure and that the AMYG-ST and HPC-FX systems, but not the ARC or VMH, participated in the process of the metabolic adaptation of phenylalanine to cold exposure.

Central AMPK contributes to sleep homeostasis in mice

AMP-activated protein kinase (AMPK) is an energy-sensing molecular signal involved in glucose and lipid metabolism. The known interaction of sleep with energy metabolism led us to investigate the role of central AMPK in sleep homeostasis. Sleep deprivation (SD) for 6 h increased p-AMPK protein in the hypothalamus and also increased the mRNA level of Ca(2+)/calmodulin (CaM)-dependent protein kinase kinase beta (CaMKK2), an activator of AMPK, and carnitine palmitoyltransferase 1 (CPT1), a downstream signaling factor of AMPK. Central injection of compound C (CC), an inhibitor of AMPK, suppressed EEG delta power during NREM sleep, while 5-aminoimidazole-4-carboxamide riboside (AICAR), an activator of AMPK, enhanced EEG delta power. The treatment of both CC and AICAR attenuated rebound responses of delta power in NREM sleep after SD. These results indicate that central AMPK is involved in the regulation of sleep depth and sleep homeostasis.

Fermented ginseng improves the first-night effect in humans

STUDY OBJECTIVES

The goal of this study was to clarify whether ginseng fermented by lactic acid bacteria (fermented ginseng, FG), can improve the first-night effect (FNE) in humans.

DESIGN

Behavioral tests and quantification of mRNA expression related to GABAergic neurotransmission in brain (glutamic acid decarboxylase 1, gamma-aminobutyrate aminotransferase [Abat], gamma-aminobutyric acid transporter 1 [GAT1], gamma-aminobutyric acid transporter 4, gamma-aminobutyric acid A receptor subunit alpha 1 and gamma-aminobutyric acid A receptor subunit alpha 2) were carried out in FG-treated mice. We also performed double-blind sleep recordings of human subjects given FG or placebo.

SETTING

A university-based sleep laboratory.

PATIENTS OR PARTICIPANTS

Sixteen healthy male volunteers (aged 20.69 +/- 0.44 years) were observed in the human study.

INTERVENTIONS

At the end of administration, 2 consecutive all-night polysomnography recordings were performed. Subjects also completed psychological questionnaires, and urine and saliva samples were taken to analyze stress-sensitive markers.

MEASUREMENTS AND RESULTS

The light-dark transition test demonstrated that FG had some anxiolytic effect in mice, but other anxiety measures were unaffected. The hippocampal mRNA expression showed a decrease of Abat and GAT1 suggesting an increase of GABA. Other regions (amygdala and cerebellum) showed no differences. Furthermore, there was some evidence (using simple pairwise comparisons but not supported in the full ANOVA model) that administration of FG tended to diminish decreases in total sleep time and sleep efficiency (seen as first night effects in the placebo group) without affecting sleep architecture.

CONCLUSIONS

Our results suggest the administration of FG could improve the FNE in humans. The improvement may be related to an anxiolytic effect of FG which acts via GABAergic modification.

Heparin versus danaproid for prevention of venous thromboembolism after hip surgery

PURPOSE

To compare the prevalence of deep vein thrombosis (DVT), pulmonary thromboembolism (PTE), and bleeding complications in patients receiving heparin or danaproid after hemiarthroplasty or osteosynthesis for hip fractures.

METHODS

37 men and 138 women aged 47 to 100 (mean, 80) years underwent either hemiarthroplasty or osteosynthesis for hip fractures; 5 patients with dementia were excluded. All patients received preoperative elastic stocking and postoperative intermittent pneumatic compression. They were divided into 3 groups based on their admission period: controls (n=71), unfractionated heparin (n=44), and danaproid sodium (n=55). Drugs were administered from postoperative day 1 to 7. At day 7, all patients undertook radioisotope venography of the legs and lung perfusion scintigraphy.

RESULTS

In the control, heparin, and danaproid groups respectively, the DVT rates were 31%, 9.1%, and 5.5%, and the PTE rates were 5.6%, 4.5%, and 1.8%. Only the DVT rate in the control group was significantly higher than that in the heparin and danaproid groups. In the heparin group, one patient had gastrointestinal bleeding, 5 developed wound haematomas, and one had leakage from the drain site for 2 weeks.

CONCLUSION

Danaproid sodium appeared more effective and safer than heparin, with no bleeding complications occurred.

Bezafibrate, a peroxisome proliferator-activated receptors agonist, decreases body temperature and enhances electroencephalogram delta-oscillation during sleep in mice

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor family. PPARs play a critical role in lipid and glucose metabolism. We examined whether chronic treatment with bezafibrate, a PPAR agonist, would alter sleep and body temperature (BT). Mice fed with a control diet were monitored for BT, electroencephalogram (EEG), and electromyogram for 48 h under light-dark conditions. After obtaining the baseline recording, the mice were provided with bezafibrate-supplemented food for 2 wk, after which the same recordings were performed. Two-week feeding of bezafibrate decreased BT, especially during the latter half of the dark period. BT rhythm and sleep/wake rhythm were phase advanced about 2-3 h by bezafibrate treatment. Bezafibrate treatment also increased the EEG delta-power in nonrapid eye movement sleep compared with the control diet attenuating its daily amplitude. Furthermore, bezafibrate-treated mice showed no rebound of EEG delta-power in nonrapid eye movement sleep after 6 h sleep deprivation, whereas values in control mice largely increased relative to baseline. DNA microarray, and real-time RT-PCR analysis showed that bezafibrate treatment increased levels of Neuropeptide Y mRNA in the hypothalamus at both Zeitgeber time (ZT) 10 and ZT22, and decreased proopiomelanocortin-alpha mRNA in the hypothalamus at ZT10. These findings demonstrate that PPARs participate in the control of both BT and sleep regulation, which accompanied changes in gene expression in the hypothalamus. Activation of PPARs may enhance deep sleep and improve resistance to sleep loss.

Diurnal amplitudes of arterial pressure and heart rate are dampened in Clock mutant mice and adrenalectomized mice

Arterial pressure (AP), heart rate (HR), and cardiovascular diseases, including ischemic heart attack and cerebrovascular accident, show diurnal variation. Evidence that circadian-related genes contribute to cardiovascular control has been accumulated. In this study, we measured the AP and HR of Clock mutant mice on the Jcl/ICR background to determine the role of the Clock gene in cardiovascular function. Mice with mutated Clock genes had a dampened diurnal rhythm of AP and HR, compared with wild-type control mice, and this difference disappeared after adrenalectomy. The diurnal acrophase in both mean arterial pressure and HR was delayed significantly in Clock mutant mice, compared with wild-type mice, and this difference remained after adrenalectomy. Clock mutant mice had a lower concentration of plasma aldosterone, compared with wild-type mice. Our data suggest that the adrenal gland is involved in the diurnal amplitude, but not the acrophase, of AP and HR, and that the function of the Clock gene may be related to the nondipping type of AP elevation.

Vitamin A deficiency induces a decrease in EEG delta power during sleep in mice

Recent report (Maret, S., Franken, P., Dauvilliers, Y., Ghyselinck, N.B., Chambon, P., Tafti, M., 2005. Retinoic acid signaling affects cortical synchrony during sleep. Science 310, 111-113.) has suggested that vitamin A (retinol and its derivatives) is genetically involved in the electroencephalogram (EEG) delta oscillation during sleep. However, this finding has not yet been confirmed by other studies. In this study, we attempted to record the sleep EEG and behavior, and to quantify striatal monoamines in mice fed a vitamin A-deficient (VAD) diet for 4 weeks, in order to clarify the linkage between the delta oscillation and vitamin A. VAD mice demonstrated a significant decrease in the delta power of the EEG. However, 6-h sleep deprivation caused the recovery of the delta power in VAD mice to a level similar to that of the control. VAD also caused the decrease of spontaneous activity throughout 24-h period. Furthermore, dihydroxyphenylacetic acid, a metabolite of dopamine, was decreased significantly in the striatal tissue of VAD mice. Our present results suggest that the deficiency of vitamin A causes the attenuation of delta power in NREM sleep and spontaneous activity. These attenuations may be related to the alteration of striatal dopaminergic function.

Anxiolytic effect of music depends on ovarian steroid in female mice

Music is known to be able to elicit emotional changes, including anxiolytic effects. The gonadal steroid hormones estradiol and progesterone have also been reported to play important roles in the modulation of anxiety. In the present study, we examined whether the effect of music on anxiety is related to ovarian steroid in female mice. Behavioral paradigms measuring anxiety were tested in gonadally intact (SHAM) and ovariectomized (OVX) female mice chronically treated with either placebo (OVX/Placebo), 17beta-estradiol (OVX/E), or progesterone (OVX/P). In the elevated plus maze, light-dark transition, and marble burying tests, SHAM and OVX/P mice exposed to music showed less anxiety than those exposed to white noise or silence while OVX/placebo mice did not show these effects at all. OVX/E mice showed the anxiolytic effect of music only in the marble burying test. Furthermore, pretreatment with progesterone's metabolite inhibitor completely prevented the anxiolytic effect of music in behavioral tests, while pretreatment with a progesterone receptor blocker did not prevent the anxiolytic effect of music. These results suggest that exposure to music reduces anxiety levels, and ovarian steroids, mainly progesterone, may be involved in the anxiolytic effect of music observed in female mice.

Effect of repetitive transcranial magnetic stimulation applied over the premotor cortex on somatosensory-evoked potentials and regional cerebral blood flow

Somatosensory-evoked potentials (SEPs) are attenuated by movement. This phenomenon of 'gating' reflects sensorimotor integration for motor control. The frontal N30 component after median nerve stimulation was shown to be reduced in amplitude prior to hand movement. To investigate the mechanism of this sensory gating, we recorded median SEPs immediately before and after application of monophasic very low-frequency (0.2 Hz) repetitive transcranial magnetic stimulation (rTMS) of 250 stimuli over motor cortex (MC), premotor cortex (PMC), or supplementary motor area (SMA) in 9 healthy volunteers. The stimulus intensity for MC or PMC was set 85% of the resting motor threshold for the hand muscle, and that for SMA was at the active motor threshold for the leg muscle. SEPs showed significant increases in amplitudes of the frontal N30 component after PMC stimulation, but not after SMA or MC stimulation. Low-frequency (1 Hz) biphasic stimulation over PMC showed no significant N30 changes in 6 out of 9 subjects tested, indicating the effect being specific for 0.2 Hz monophasic stimulation. To examine the functional anatomy of the N30 change, single photon emission computed tomography was performed immediately before and after monophasic 0.2 Hz rTMS over PMC in all the 9 subjects. Regional cerebral blood flow showed significant increases mainly in PMC and prefrontal cortex, indicating the involvement of these cortical areas in sensory input gating for motor control.

Exposure to music in the perinatal period enhances learning performance and alters BDNF/TrkB signaling in mice as adults

Music has been suggested to have a beneficial effect on various types of performance in humans. However, the physiological and molecular mechanism of this effect remains unclear. We examined the effect of music exposure during the perinatal period on learning behavior in adult mice, and measured the levels of brain-derived neurotrophic factor (BDNF) and its receptor, tyrosine kinase receptor B (TrkB), which play critical roles in synaptic plasticity. In addition, we measured the levels of 3-phosphoinositide-dependent protein kinase-1 (PDK1) and mitogen-activated protein kinase (MAPK), downstream targets of two main pathways in BDNF/TrkB signaling. Music-exposed mice completed a maze learning task with fewer errors than the white noise-exposed mice and had lower levels of BDNF and higher levels of TrkB and PDK1 in the cortex. MAPK levels were unchanged. Furthermore, TrkB and PDK1 protein levels in the cortex showed a significant negative correlation with the number of errors on the maze. These results suggest that perinatal exposure of mice to music has an influence on BDNF/TrkB signaling and its intracellular signaling pathway targets, including PDK1, and thus may induce improved learning and memory functions.

Geranylgeranylacetone, an inducer of HSP 70, attenuates REM sleep rebound after sleep deprivation

The effect of pretreatment of geranylgeranylacetone (GGA), an inducer of heat shock protein (HSP) 70, on responses in sleep and core body temperature (Tcore) against sleep deprivation (SD) was examined in rats. After 3 days of GGA or vehicle injection, a 6-h period of SD was performed. During the recovery period, both rapid-eye movement (REM) and non-REM (NREM) sleep were increased in both GGA- and vehicle-injected rats. However, in GGA-injected rats, REM-sleep rebound was significantly suppressed, while NREM-sleep rebound remained unaffected. In addition, the increase of Tcore caused by SD was also attenuated in GGA-injected rats. In the hippocampus, both SD and the GGA pretreatment induced an increase in the expression of HSP70 mRNA, indicating that the SD functions as a stress for hippocampal neurons and that the GGA induces HSP70 expression. The findings suggest that pretreatment with GGA suppresses REM sleep rebound and the response of Tcore against SD.

Total hip arthroplasty with a sliding iliac graft for acetabular dysplasia

We describe a new technique of reconstruction of the deficient acetabulum in cementless total hip arthroplasty. The outer iliac table just above the deficient acetabulum is osteotomised and slid downwards. We have termed this an iliac sliding graft. Between October 1997 and November 2001, cementless total hip arthroplasty with an iliac sliding graft was performed on 19 patients (19 hips) with acetabular dysplasia. The mean follow-up was 3.4 years (2 to 6). The mean pre-operative Harris hip score was 45.1 which improved significantly to 85.3 at the time of the final follow-up. No patient had post-operative abductor dysfunction. Incorporation of the graft was seen after two to three months in all patients. Resorption of the graft and radiolucencies were infrequent. This technique is a useful alternative to femoral head autografting when the patient's own femoral head cannot be used.

Effect of mood state on anticipatory postural adjustments

Static postural control has been demonstrated to link with psychological state. However, the effect of psychological state on dynamic postural control remains unclear. In this study, we examined the effect of mood state on anticipatory postural adjustment (APA), one of the most important functions for dynamic postural control. Fourteen healthy male subjects performed unilateral arm elevation tasks after completing a Profile of Mood States (POMS) questionnaire. Mood state measured by POMS and the latency or amplitude of the APA in the ventral muscles (rectus femoris, tibialis anterior) of the lower limb showed significant negative correlations. The correlation between the mood state and APA amplitude in the soleus was found to be significantly positive. There were significant negative correlations between the mood state and reaction-time. These findings suggest that it is possible that dynamic postural control is affected by mood state.

Premovement gating of somatosensory evoked potentials after tibial nerve stimulation

Somatosensory evoked potentials (SEPs) are attenuated or gated during movement. The mechanism for this includes both centrifugal gating of afferent input and competition with other afferents caused by the movement (peripheral gating). Using a paradigm in which the signal for triggering movement is the electric stimulus for SEPs, we studied the gating of SEPs after tibial nerve stimulation prior to foot movement, and compared it with that during counting task. Significant gating was found for P40 component, which distributed centrally and ipsilaterally to the side of the stimulation, whereas the contralateral N40 component showed no changes. Dissociated gating of P40 and N40 indicates multiple generators of these components, in contrast to the previous view of a single generator dipole projecting tangentially. Together with the previous findings in median SEPs, these gating phenomena should represent a general mechanism for sensori-motor integration in preparation for limb movement.

Focal eosinophilic myositis

Idiopathic hypereosinophilic syndrome (HES) is a heterogeneous group of disorders with the common features of prolonged eosinophilia of underdetermined cause and multiple organ system dysfunction. Focal eosinophilic myositis is an uncommon manifestation of HES. We report a case of focal eosinophilic myositis with tender muscle swelling followed by proximal weakness, but without non-systemic symptoms and muscle trophism in the lower limbs. Muscle biopsy specimen showed acute myositis with eosinophil infiltration. Electromyographic features were typical of myositis. The clinical and biochemical response to corticosteroids was excellent, and a relapse that occurred because the steroid dose was not lowered, responded well.

Histologic analysis of the tibial bone tunnel after anterior cruciate ligament reconstruction using solvent-dried and gamma-irradiated fascia lata allograft

Anterior cruciate ligament (ACL) reconstruction using free tendon graft requires biologic fixation in the bone tunnel. This report describes the intratunnel histology retrieved from a 47-year-old woman who underwent high tibial osteotomy 17 months after ACL reconstruction using a hybrid graft (a solvent-dried and gamma-irradiated fascia lata allograft as a core wrapped with iliotibial autograft). The patient underwent revision because of pain resulting from osteoarthrotic change, and the graft appeared to be taut and healthy on second-look arthroscopy. The sample was taken from the site of the metaphyseal osteotomy site. Histologic examination of the samples was performed with a light microscope (H&E and Masson trichrome stain). Biologic fixation of the graft to the bone was evident from observation of collagen fiber continuities, resembling Sharpey fibers. Integration of the autograft and allograft seemed to have occurred; the junction between the allograft and the autograft could not be determined. However, there was a difference in ligamentization depending on location. In the peripheral region of the graft (the autograft region), the collagen fibers showed a distinct crimped pattern; the fibroblasts were arranged regularly along the major axis of the collagen fiber bundle. In the central part of the graft (the allograft region), remodeling seemed to be delayed. There were acellular, bubbly or myxoid degeneration areas in which the fiber bundles were less oriented and there was increased vascularity.

Optically encoded second-harmonic generation in germanosilicate glass by a femtosecond laser

Second-harmonic generation in germanosilicate glasses was encoded by coherent superposition of the 810-nm fundamental and the 405-nm second-harmonic light of a femtosecond laser. The difference spectra between the absorption spectra of the glasses before and after preparation were measured. An evident correlation between the induced second-order nonlinearity and the creation of a Ge electron center was observed, suggesting that a band-to-band transition by multiphoton absorption is probably responsible for the photoinduced second-harmonic generation.

Morphodifferentiation of skeletal muscle fiber ends at the myotendinous junction in the postnatal Chinese hamster: a scanning electron microscopic study

The postnatal morphodifferentiation of muscle fiber ends at the myotendinous junction was examined by scanning electron microscopy in gastrocnemius muscles of the Chinese hamster. Muscle fiber ends during the first week were simply conical or slightly complex, having a few pit-like invaginations and longitudinal and narrow clefts. By the second week, fiber ends gradually became complicated with an increased number of clefts and finger-like processes. Pits and short clefts linearly arranged towards the fiber tip were visible until the second week. This possibly indicates the linear elongation of the clefts by the fusion of adjacent pits to one another and to preexisting clefts. By the fourth week, the fiber ends had almost fully matured and displayed numerous cytoplasmic processes and lateral grooves.

Massive autoclaved allografts and autografts for limb salvage surgery. A 1-8 year follow-up of 23 patients

We performed 23 reconstructions with bone grafts autoclaved at 135 degrees C for 10 minutes for extensive bone defects after tumor resection. In 15 cases, the resected specimens were autoclaved and used as autografts. In 7 cases, allografts obtained from amputated extremities or cadavers were autoclaved and immediately stored at -80 degrees C prior to their use. A combination of the two was used in 1 case. The grafts were used in combination with prostheses or other forms of internal fixation. The mean follow-up was 49 (14-98) months. Incorporation of the hostgraft junction was observed radiographically after a mean of 11 (6-17) months in all cases. No recurrence due to the autoclaved bone was observed. However, 10 patients suffered complications, including infection, bone resorption, fracture and loosening of the prosthesis. In terms of Mankin's evaluation of bone grafts, 12 patients were evaluated as good or excellent. We conclude that despite the complications, autoclaved autografts and allografts are viable options for reconstruction in many countries because of the difficulty of obtaining large quantities of fresh frozen allografts.

[The clinical efficacy of imipenem/cilastatin sodium in orthopedic infections and drug levels in the bone tissue]

We evaluated the clinical efficacy of imipenem/cilastatin sodium (IPM/CS--a carbapenem antibiotic) against orthopedic infections, and the drug levels of the bone tissues were determined. The clinical efficacies for 6 patients in the infection group were good in 3 cases, and fair in the other 3; giving an efficacy rate of 50%. Bacteriologically, 8 strains were isolated from patients with the infection and an eradication rate of 87.5% was obtained upon the treatment. In 39 patients that were given the drug prophylactically, no postoperative infections occurred. Mean IPM levels in the bone and the bone marrow at 1 hour after administration in 5 patients of the prophylactic group were 17.3 micrograms/ml and 5.9 micrograms/g, respectively. The ratio of concentrations the bone to those in the bone marrow was 34.6%. The results of this study suggest that IMP/CS reaches to the bone tissue providing sufficient concentrations and that the drug is efficacious for the prophylaxis and the treatment of orthopedic infections.

Topographic comparison of subneural apparatuses at neuromuscular junctions in normal and dystrophic (mdx) mice: a scanning electron microscope study

The differences in the morphodifferentiation of subneural apparatuses (SNAs) at neuromuscular junctions (NMJs) in the extensor digitorum longus muscle of normal and dystrophic (mdx) mice were examined by scanning electron microscopy. In normal mice, primitive shallow cup-like synaptic troughs present at birth had developed to anastomosing grooves containing both pit-like and slit-like junctional folds (JFs) during the 2nd postnatal week. At the 35th day, the SNAs had developed to almost the adult forms, consisting of labyrinthine synaptic grooves with exclusively slit-like JFs. In the mdx mice, the SNAs showed transformation similar to those in the normal mice until the 35th postnatal day. After this period, SNAs with a number of cup-like depressions occurred and increased in number. These morphological changes seemed to be found on regenerating muscle fibers after necrosis, probably indicating the remodelling of their NMJs.

[A case of rheumatoid arthritis associated with pernicious anemia and bronchiolitis obliterans organizing pneumonia]

A case of rheumateid arthritis (RA) with pernicious anemia (PA) and wandering multiple patchy densities in bilateral lung fields is reported. A 72-year-old woman was hospitalized in February 1994, because of cough. She had already advanced RA (Class IV, Stage IV). She showed macrocytic and hyperchromic anemia as follows ; red-cell count (RBC), 176 x 10(4)/microliters; hemoglobin (Hb),7.2 g/dl; hematocrit (Ht), 21.0% ; MCV, 119.3 fl; and MCH, 40.9 pg. Chest roentgenogram revealed multiple patchy densities in bilateral lung fields and there was no response to the administration of antibiotic agents. From these clinical pictures bronchiolitis obliterans organizing pneumonia (BOOP) was highly suspected. After steroid injection into the joint space, the abnormal lung shadows disappeared. Anemia had been recovering spontaneously, but recurred in July. The results of blood examination were as follows ; RBC, 162 x 10(4)/microliters; Hb, 6.7ng/dl; Ht, 19.1%; MCV, 117.9 fl; and MCH, 41.4 pg. Anti-intrinsic factor antibody was positive. The level of serum vitamin B12 was low, 76 pg/ml. Sternal bone marrow aspiration showed magaloblastic changes with hypersegmentation of granulocytes. PA was diagnosed and improvement was noted after the intramuscular administration of vitamin B12. Subjective symptoms based on RA did not change during the clinical course. It is suggested that the pathogenesis about the combination of RA, BOOP and PA is related to common immunological abnormalities in our patient. A case of RA with PA and BOOP has not been reported previously, thus this case is considered clinically valuable.

Bioabsorbable osteosynthetic implants of ultra high strength poly-L-lactide. A clinical study

We have developed reasonably strong but bioabsorbable osteosynthetic screws, pins and nails made of ultra high strength poly-L-lactide (PLLA) and evaluated their use in 143 patients. The PLLA implants have the highest strength among those reported to date. They lose about 10% of their initial strength within 8 weeks, about 40% within 4 weeks and nearly 100% within 20 weeks in vivo. The patients were aged from 9 to 78 years, and the follow up was from 2 to 6 years. The implants were used for fixation of bone grafts in 84 patients, peri- and intra-articular fractures in 49, after osteotomy in 8, and in 2 others. Bony union was not achieved in only one case. In the early stages of the study, breakage of screws occurred in 12 cases (8%), mostly because of an inappropriate size of tap; these problems have not occurred after improvement of the tapping system. There were no cases with abnormal blood tests, infection or foreign body reaction.

[Multiple cerebral infarction by blood-borne tumor emboli in carcinoma of the mid-pharynx: an autopsy case]

In May, 1989, a-54-year old man was admitted complaining of sore throat and tumor of the neck which had persisted for 2 months. Mid-pharyngeal tumor was diagnosed as poorly differentiated squamous cell carcinoma (stage, T3N2M0) and the patient was treated with radiation (Co 65Gy) from May 30 to July 24 and chemotherapy (UFT), which therapies were effective. On Aug. 16, sudden onset of consciousness disturbance and hemiparesis was revealed, and MRI showed small cerebral infarction. He died on Oct. 23, of pneumonia. Pathological diagnosis revealed a case of carcinoma of the mid-pharynx with wide-spread tumor embolism. Multiple cerebral and myocardial infarctions, thrombus in pulmonary arteries and congestion of kidneys with tumor emboli, due to "disseminated intravascular carcinomatosis" were noticed. A direct cause of death was dyspnea due to multiple lung metastases, pneumonia and tumor embolism in the pulmonary and coronary arteries.

[Intraoperative monitoring of facial electromyographic responses during neurovascular decompressive surgery for hemifacial spasm]

In this paper, we reported our experience of intraoperative facial electromyographic recordings obtained during microvascular decompression for hemifacial spasm.

MATERIALS AND METHODS

Intraoperative electromyographic recordings from the mentalis muscle during stimulation of the temporal branch of the facial nerve has been attempted in 31 patients. No muscle relaxants were used except for those before intubation. Of 31 patients, 22 were female and 9 were male. The age on admission ranged from 31 to 60 years with a mean of 54 years.

RESULTS

1. Abnormal response appeared with a latency of about 10 msec after stimulation. This response disappeared in 30 out of 31 patients at the end of operation. In 4 patients, the abnormal response disappeared prior to decompression of the nerve. 2. 30 patients in whom the abnormal response disappeared were free of spasm immediately after surgery. Hemifacial spasm has been relieved in 28 patients with a follow up period of 6 months to 2 years and 7 months. The remaining two patients had mild spasm. The one patient in whom the abnormal response did not disappear had persistent hemifacial spasm.

CONCLUSION

The authors think that intraoperative facial electromyographic recording is useful to identify the blood vessel that is causing the spasm and to ensure that decompression of the nerve has been accomplished.

Follow-up study on metastatic cerebellar tumor surgery--characteristic problems of surgical treatment

Recently, the incidence of metastatic cerebellar tumors has increased. The authors operated on 12 cases of metastatic cerebellar tumors, with total or subtotal removal of nodules in brain metastases. Surgical complications observed as a result of postoperative investigation are presented. 1) Some cases developed carcinomatous meningitis within a short period. During removal of a tumor on the superior cerebellar surface attention should be paid to the prevention of dissemination to the cerebral cisterns adjacent to the tumor. 2) Some cases demonstrated peritoneal metastasis probably due to dissemination via the ventriculoperitoneal shunt tube, suggesting that great care should be taken during a shunt operation after removal. 3) Both carcinomatous meningitis occurring after removal and remote metastasis via the shunt tube were related to recurrence after removal of the cerebellar metastatic lesion, raising the issue of whether or not total macroscopic removal should be included in the indications for surgical treatment of cerebellar metastasis. Those cases in which surgery is indicated should also be routinely treated by postoperative irradiation.

Clinicopathological study of multiple gliomas--report of three cases

Three cases of multiple gliomas with postmortem findings including a rare case of multicentric glioma are presented. A 59-year-old female was hospitalized with decreased mental activity and gait disturbance. Computed tomographic (CT) scans and magnetic resonance (MR) images showed two independent mass lesions in the left frontal and the right temporal lobes, shown by postmortem to have no communication. Histologically, they were a gemistocytic astrocytoma and an anaplastic astrocytoma, respectively. Therefore, multicentric glioma was diagnosed. A 66-year-old male was admitted with slow mentation and gait disturbance. CT scans and MR images demonstrated two mass lesions; one overriding the bilateral frontal lobes through the corpus callosum and the other in the left temporal lobe. Postmortem examination showed that both lesions were glioblastoma and the left temporal tumor was accompanied by subarachnoid dissemination. A 29-year-old male was hospitalized with gustatory hallucination and convulsions of the right upper extremity. CT scans revealed two mass lesions in the right frontal and the left temporal lobes. MR images demonstrated communication between the two lesions through the corpus callosum. The left temporal tumor developed into the occipital lobe and another new lesion appeared in the right temporal lobe despite chemotherapy and irradiation. Postmortem examination revealed communication between the three masses through the corpus callosum. Histologically, all three tumors were glioblastoma. Multicentric gliomas have been reported at various incidences from 2.3 to 9.1%. However, multicentric gliomas with multiple tumors of different histologies are very rare and only 16 cases have been reported. MR imaging is more valuable than CT scanning to detect communication between two or more lesions.

Scanning electron microscope study of neuromuscular junctions in different muscle fiber types in the zebra finch and rat

Examination by scanning electron microscopy revealed differences between neuromuscular junctions in the muscle fibers of the zebra finch (bird) and rat. The neuromuscular junctions between the anterior and posterior latissimus dorsi muscles of the zebra finch were compared. The junctions of the former, exclusively slow tonic fibers, were small and numerous along the long axis of a single muscle fiber. The synaptic depressions per junction were few. The junctions of the latter, exclusively fast twitch fibers, were large and consisted of more synaptic depressions than the former. Junctional folds were occasionally found in some depressions. The neuromuscular junctions between the extensor digitorum longus and soleus muscles of the rat were also compared. The former consisted almost entirely of fast twitch muscle fibers, whereas the latter consisted of both slow twitch fibers (75%) and fast twitch fibers (25%). The junctions in the extensor digitorum longus muscle were almost all labyrinthine gutters containing exclusively slit-like junctional folds. In the soleus muscle, two types of junctions were observed. One type was similar to that of the extensor digitorum longus muscle; the other was characterized by labyrinthine gutters containing sparse, narrow slit-like and pit-like junctional folds. We suggest from these structural differences of the subneural apparatuses that the junction of the fast twitch muscle is characterized by the subneural apparatus containing numerous slit-like junctional folds, and that of the slow twitch muscle fiber characterized by the apparatus containing sparse, narrow slit-like and pit-like junctional folds.

[Evaluation of recurrent metastatic brain tumor of lung cancer origin]

The authors examined numerous clinical features in 15 patients in whom brain metastases from lung cancer recurred after total or subtotal removal. The incidence of recurrence after initial removal of brain nodules was 46.9% (15 of 32 cases). There was no significant correlation between the incidence of recurrence and the histology of the lung cancer, the site of brain nodules, or age. Recurrent brain nodules were the cause of or contributed to death in 60% of recurrent cases. Recurrence was within 3 months of initial removal of brain nodules in 10 of the 15 patients. Brain metastasis recurred only at the initial site in 11 cases (73.3%). Three patients developed carcinomatous meningitis and one had multiple metastases in addition to recurrence or regrowth at the original site. The primary lung cancer was relatively stable at the time of recurrence of brain nodules in 60% of the patients. Tumor removal and radiotherapy are highly recommended for prevention of early recurrence following initial removal of brain metastases. Removal of metastatic tumor is advised in the event of recurrence after 1 year from initial surgery, since the outcome after second surgery tends to be fair. However, tumor removal and radiotherapy are sometimes capable of inducing recurrence of brain nodules. Therefore, it is hoped that more effective cancer chemotherapy will be developed in the near future.