Assimilation of the seabird and ship drift data in the north-eastern sea of Japan into an operational ocean nowcast/forecast system.

At the present time, ocean current is being operationally monitored mainly by combined use of numerical ocean nowcast/forecast models and satellite remote sensing data. Improvement in the accuracy of the ocean current nowcast/forecast requires additional measurements with higher spatial and temporal resolution as expected from the current observation network. Here we show feasibility of assimilating high-resolution seabird and ship drift data into an operational ocean forecast system. Data assimilation of geostrophic current contained in the observed drift leads to refinement in the gyre mode events of the Tsugaru warm current in the north-eastern sea of Japan represented by the model. Fitting the observed drift to the model depends on ability of the drift representing geostrophic current compared to that representing directly wind driven components. A preferable horizontal scale of 50 km indicated for the seabird drift data assimilation implies their capability of capturing eddies with smaller horizontal scale than the minimum scale of 100 km resolved by the satellite altimetry. The present study actually demonstrates that transdisciplinary approaches combining bio-/ship- logging and numerical modeling could be effective for enhancement in monitoring the ocean current.

Blockade of in vitro ictogenesis by low-frequency stimulation coincides with increased epileptiform response latency.

Low-frequency stimulation, delivered through transcranial magnetic or deep-brain electrical procedures, reduces seizures in patients with pharmacoresistant epilepsy. A similar control of ictallike discharges is exerted by low-frequency electrical stimulation in rodent brain slices maintained in vitro during convulsant treatment. By employing field and "sharp" intracellular recordings, we analyzed here the effects of stimuli delivered at 0.1 or 1 Hz in the lateral nucleus of the amygdala on ictallike epileptiform discharges induced by the K(+) channel blocker 4-aminopyridine in the perirhinal cortex, in a rat brain slice preparation. We found that 1) ictal events were nominally abolished when the stimulus rate was brought from 0.1 to 1 Hz; 2) this effect was associated with an increased latency of the epileptiform responses recorded in perirhinal cortex following each stimulus; and 3) both changes recovered to control values following arrest of the 1-Hz stimulation protocol. The control of ictal activity by 1-Hz stimulation and the concomitant latency increase were significantly reduced by GABAB receptor antagonism. We propose that this frequency-dependent increase in latency represents a short-lasting, GABAB receptor-dependent adaptive mechanism that contributes to decrease epileptiform synchronization, thus blocking seizures in epileptic patients and animal models.

Activity-dependent changes in excitability of perirhinal cortex networks in vitro.

Rat brain slices comprising the perirhinal cortex (PC) and a portion of the lateral nucleus of the amygdala (LA), in standard medium, can generate synchronous oscillatory activity that is associated with action potential discharge and reflects the activation of glutamatergic and GABAergic receptors. We report here that similar synchronous oscillatory events are recorded in the PC in response to single-shock, electrical stimuli delivered in LA. In addition, we found that the latency of these responses progressively increased when the stimulus interval was varied from 10 to 1 s; for example, the response latency during stimuli delivered at 1 Hz was more than twofold longer than that seen during stimulation at 0.1 Hz. This prolongation in latency occurred after approximately 5 stimuli, attained a steady value after 24-35 stimuli, and recovered to control values 30 s after stimulation arrest. These frequency-dependent changes in latency continued to occur during NMDA receptor antagonism but weakened following application of GABAA and/or GABAB receptor blockers. Our findings identify a new type of short-term plasticity that is mediated by GABA receptor function and may play a role in decreasing neuronal network synchronization during repeated activation. We propose that this frequency-dependent adaptive mechanism influences the excitability of limbic networks, thus potentially controlling epileptiform synchronization.

[A case of an older adult patient with recurrent gastric cancer successfully treated by low-dose S-1 for a long time].

An 88-year-old woman, who had undergone distal gastrectomy for Stage IIIA gastric cancer, was diagnosed with recurrent abdominal lymph node metastasis 11 months after surgery. Creatinine clearance of this patient calculated by Cockcroft-Gault method was 44 mL/min and renal function was impaired, so we reduced the administration dosage to 50 mg/day. S-1 was administered for two weeks followed by one week rest. This schedule induced grade 2 anorexia and fatigue after one week administration, so it was converted to one week administration followed by one week rest. By this dosage and administration schedule, a partial response(PR)was continued for about four years without any adverse reaction. This successful case might indicate that it was important for older adult patients with gastric cancer to consider not only appropriate reduction of the dosage but also shortening of S-1 administration.

Single nucleotide polymorphism-based genome-wide linkage analysis in Japanese atopic dermatitis families.

BACKGROUND: Atopic dermatitis develops as a result of complex interactions between several genetic and environmental factors. To date, 4 genome-wide linkage studies of atopic dermatitis have been performed in Caucasian populations, however, similar studies have not been done in Asian populations. The aim of this study was to identify chromosome regions linked to atopic dermatitis in a Japanese population. METHODS: We used a high-density, single nucleotide polymorphism genotyping assay, the Illumina BeadArray Linkage Mapping Panel (version 4) comprising 5,861 single nucleotide polymorphisms, to perform a genome-wide linkage analysis of 77 Japanese families with 111 affected sib-pairs with atopic dermatitis. RESULTS: We found suggestive evidence for linkage with 15q21 (LOD = 2.01, NPL = 2.87, P = .0012) and weak linkage to 1q24 (LOD = 1.26, NPL = 2.44, P = .008). CONCLUSION: We report the first genome-wide linkage study of atopic dermatitis in an Asian population, and novel loci on chromosomes 15q21 and 1q24 linked to atopic dermatitis. Identification of novel causative genes for atopic dermatitis will advance our understanding of the pathogenesis of atopic dermatitis.

Ruptured fusiform aneurysm of the proximal anterior cerebral artery (A1 segment).

A 42-year-old man presented with a ruptured fusiform aneurysm of the proximal anterior cerebral artery (A(1) segment) manifesting as sudden onset of severe headache. Brain computed tomography revealed subarachnoid hemorrhage in the basal cisterns, and left carotid angiography demonstrated a fusiform aneurysm of the left A(1) segment. He underwent surgery via the left pterional approach. The left A(1) segment exhibited a fusiform configuration. Adequate development of the anterior communicating artery was confirmed. Trapping of the aneurysm was performed. The aneurysm was associated with atherosclerotic changes. The postoperative course was uneventful, and the patient was discharged without neurological deficits 1 month after surgery. Fusiform aneurysm of the A(1) segment is quite rare, and tends to bleed, so must be treated. The atherosclerotic origin indicates long-term follow up to identify subsequent lesions.

Accelerated growth of an orbital schwannoma during pregnancy.

An incidentally diagnosed unilateral orbital mass in a 34-year-old woman grew at an accelerated rate during pregnancy with deterioration of visual function. Removed early after delivery by a transcranial approach, the tumor was histologically diagnosed as a richly vascularized cystic schwannoma containing red blood cell components. The accelerated tumor growth was attributed to intratumoral hemorrhage. Although acoustic schwannomas have been reported to enlarge during pregnancy, this phenomenon has only been described once for orbital schwannomas. Because this type of tumor may enlarge during pregnancy and threaten visual function, surgery should not be delayed.

Head trauma in female professional wrestlers.

The clinical characteristics of head trauma were evaluated in 18 wrestlers belonging to a female professional wrestling organization, 13 regular members and five trainees aged 15-34 years. Medical examinations for head trauma were performed in all wrestlers, and wrestlers treated at our emergency outpatient department were clinically evaluated. In addition, the relationships of head trauma with duration of the wrestling career of 1-16 years (mean 8 years) in the regular members, and less than 1 year in the five trainees, and body mass index (BMI) of 21.0-32.0 in the 16 subjects, excluding two trainees, was evaluated. Chronic symptoms were noted in four of the 18 wrestlers with long wrestling careers (16 years in 1, 13 years in 1, and 5 years in 2). Three wrestlers with symptoms immediately after head trauma showed recurrent retrograde amnesia and had low BMI (21.6, 21.6, and 23.1). Five wrestlers were treated at our emergency outpatient clinic, three required hospitalization and two showed intracranial traumatic changes on computed tomography (acute subdural hematoma in 1 and diffuse brain swelling in 1). Head trauma in female professional wrestlers is associated with longer wrestling career and low BMI. Periodic medical examinations are recommended to monitor for signs of head trauma.

Early dynamic 201Tl SPECT in the evaluation of brain tumours.

OBJECTIVE: To estimate the usefulness of early dynamic 201Tl single photon emission computed tomography (SPECT) studies in distinguishing the histological malignancy of brain tumours. METHODS: Dynamic 201Tl SPECT was performed for 3 min per scan for 15 min immediately after the administration of 201TlCl in 110 patients with brain tumours (111 lesions). The data obtained each 3 min were used for dynamic SPECT, and the five sets of data obtained were added to acquire static SPECT data. For static SPECT, the static thallium index (STI) was calculated as the ratio of 201Tl uptake in the tumour to that of the contralateral normal brain. The ratio of the 201Tl uptake for each 3 min was defined as the dynamic thallium index (DTI). The dynamic thallium rate (DTR), as a per cent, was calculated as DTR=(DTI for every 3 min)/STI H 100. The five values were approximated as a linear function and the slope (%/min) was calculated. RESULTS: In static SPECT, there was no significant difference between the STI of malignant tumours (glioblastoma and anaplastic astrocytoma) and that of benign tumours (low-grade glioma, meningioma, pituitary adenoma, neurinoma and haemangioblastoma) (3.7+/-1.5, 5.0+/-3.5, respectively). On dynamic SPECT, DTI increased markedly over 15 min for malignant tumours. In contrast, the DTI of benign tumours increased slightly, steadily or decreased. The slope of the linear functions calculated from the DTRs was much higher in the malignant tumour group than in the benign tumour group (P<0.001). CONCLUSIONS: We suggest that the performance of 201Tl dynamic SPECT for 15 min is useful for distinguishing malignant brain tumours from benign brain tumours and reduces the examination stress of patients.

[Primary leiomyoma of the liver: a case report].

A 61-year-old woman was referred to our hospital due to a liver tumor discovered at a medical checkup. A hypervascular tumor located in liver segment I, measuring 45 mm in diameter, was visualized on ultrasonography. The tumor showed strong uniform enhancement from an early phase on computed tomography and angiography. Right hepatectomy with total caudate lobe resection was performed. Pathological examination revealed the tumor to be a primary leiomyoma of the liver, positive for smooth muscle actin and desmin on immunohistochemical examination. Primary liver leiomyoma is very rare and only 18 cases have been reported to date. The clinical features of these cases from the literature are also discussed.

Ripple activity in the dentate gyrus of dishinibited hippocampus-entorhinal cortex slices.

Fast oscillations at approximately 200 Hz, termed ripples, occur in the hippocampus and cortex of several species, including humans, and are thought to play a role in physiological (e.g., sensory information processing or memory consolidation) and pathological (e.g., seizures) processes. Blocking gamma-aminobutyric acid type A (GABA(A)) receptor-mediated inhibition represents one of the most often used models of epileptiform discharge. Here we found that bath application of the GABA(A) receptor antagonist picrotoxin (50 microM) to mouse hippocampus-entorhinal cortex slices induced spontaneous epileptiform activity (duration 536.6 +/- 146.1 msec, mean +/- SD; interval of occurrence 14.8 +/- 3.3 sec, n = 12) with two distinct phases of discharge; the first was characterized, in the dentate gyrus only, by high-frequency, field oscillations (ripples) at 206.3 +/- 23.4 Hz (n = 12), whereas the second component corresponded to afterdischarges in the theta range frequency. Ripples, which were also recorded in "minislices" only of the dentate gyrus, were unaffected by application of the mu-opioid receptor agonist (D-Ala2-N-Me-Phe,Gly-ol)enkephalin (10 microM; n = 6) or the N-methyl-D-aspartate (NMDA) receptor antagonist 3-(2-carboxy-piperazine-4-yl)-propyl-l-phosphonate (10 microM; n = 5). In contrast, the non-NMDA glutamatergic receptor antagonist 6-cyano-7-nitro-quinoxaline-2,3-dione (10 microM; n = 5) completely blocked all picrotoxin-induced activities. In addition, application of the GABA(B) receptor agonist baclofen (0.01-0.5 microM; n = 6) dose dependently and reversibly abolished all picrotoxin-induced activities. We also found that application of the gap-junction decouplers carbenoxolone (0.2-0.5 mM; n = 6) or octanol (0.2-0.5 mM; n = 3) blocked the second phase while leaving ripples unchanged. These findings demonstrate that the disinhibited dentate gyrus can generate ripple activity at approximately 200 Hz that is contributed by ionotropic glutamatergic mechanisms and is not dependent on either GABA(A) receptor-mediated or gap-junction mechanisms.

[The development of three dimensional video microscope system for clinical application in neurosurgery].

OBJECTIVE: The employment of surgical microscopy in the field of neurosurgery has significantly contributed not only to the advancement of surgical technique, but also the operative outcome as well. This technology has allowed surgeons to meet the demands for increasingly difficult levels of surgery, which usually require a long operative time. However, the surgeon and the assistant are restricted in their posture for a long time, leading to excessive muscular and ocular stress. To solve these problems, we have developed and clinically applied a three dimensional video microscope system for surgery, using a two binocular camera method, that allows surgical procedures to be performed over a video monitor. METHOD: Two 3CCD cameras were installed on the assistant's lens attachment and the camera lens attachment of the microscope for neurosurgery, manufactured by Carl Zeiss Co., Ltd. The surgery was performed by viewing the three dimensional picture on the monitor, which was created by processing the images from the cameras by a time-division method. In November 1998, the prototype was completed and, with numerous modifications, its clinical application has become possible. Currently, we have used it in 42 clinical cases. RESULTS: 1) Instead of viewing the surgical field through a conventional surgical microscope, the surgeon and the assistant were able to perform microsurgery by viewing the stereoscopic vision on the video monitor, through polarized glasses. 2) The assistant is provided with a separate video monitor, so that the assistant can freely adjust the angle of vision 90-180 degrees, according to where he stands. 3) The nurses, resident surgeons and students can view the same three dimensional images displayed to the surgeon. This effectively contributes to the educational environment. CONCLUSION: Even during a long surgical procedure, the posture of surgeon and assistant became less restricted since there was no need to look through the eyepiece of the microscope and led to significant decrease in physical fatigue and ocular strain. In the 42 clinical trials, the operation proceeded uneventfully, without any serious complications.