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Biomedical subjects

T Nagamine

Publications and source records attributed to T Nagamine.

At least 181 records · Page 10Linked to original sources
PubMed1996

Hepatocellular carcinoma with pleural metastasis complicated by hemothorax.

Hemothorax can be caused by rupture of hepatocellular carcinoma (HCC). Hemoperitoneum is a well-known cause of death caused by rupture of a primary HCC lesion. Rupture of a HCC metastasis has not been adequately described. This is the first report of a HCC patient who died of hemothorax due to rupture of a pleural metastasis. The patient, a woman, died in respiratory failure 2 wk after rupture of her HCC metastasis in the pleura. Autopsy revealed moderately differentiated HCC in the liver, lung, and pleura. We discuss treatment options for ruptured pleura-based HCC metastases.

Adult↗
PubMed1996

P300 abnormalities in patients with selective impairment of recent memory.

We recorded auditory event-related potential (ERP) by using the standard oddball paradigm in seven amnestic patients. Patients were divided into three groups according to brain CT or MRI findings. (1) Three patients with no detectable lesion, including two patients studied during the episode of transient global amnesia, showed a well-defined P300. (2) Three patients with detectable lesions in the mesial temporal lobes did not show any wave form corresponding to P300. In two of these three patients, the ERP wave form showed a significant change in accordance with the improvement of MRI findings. (3) One patient who had a hypothalamic lesion due to total resection of craniopharyngioma showed a low-amplitude P300. Although neuropsychological examinations showed selective and severe impairment of recent memory function in all of these patients, no significant relationship was found between the degree of memory disturbance and P300 abnormality. These results suggest that P300 is more affected by existence and extension of brain lesions, especially in the mesial temporal lobes, rather than degree of memory disturbance. However, these results do not necessarily suggest that the potential generated in the mesial temporal lobes is directly recorded as a component of the scalp-recorded P300.

Adult↗
PubMed1996

[Recent features of parasites detected from clinical specimens].

It is generally considered that we have already been through with problems caused by various kinds of parasites which had once raged throughout the country. On the contrary to our common concept, we occasionally encounter some kinds of parasites in a laboratory as well as in clinical fields, which have become unfamiliar to us in these days. Parasitic diseases are in the first place, proper and limited to certain local regions, but the present situation has been greatly changed. Nowadays, specific parasites are no longer limited to polluted areas, but also they can be detected in any part of the world owing to facilitated transportations and a promoted international exchange of people. A recent gourmet boom is also one of the causes of infection as seen in anisakiasis. This study was conducted on the investigation of parasites detected from clinical specimens in our laboratory during the period from 1989 to 1993. 1) The following parasites were detected : (1) Strongyloides stercoralis, (2) Giardia lamblia, (3) Diphyllobothrium latum, (4) Schistosoma mansoni, (5) Entamoeba histolytica, (6) Necator americanus, (7) Isospora belli. 2) Strongyloides stercoralis was detected at the highest frequency. This result gives an account of high prevalence of the parasite among the inhabitants in Okinawa. In addition, the agar plate medium method which has been newly adopted has definitely led to far-advanced results for detection of this parasite. 3) Schistosoma mansoni and Necator americanus were found from foreigners one of whom was a Tanzanian and the other was a Dominican. 4) Isospora belli was found from those compromised cases such as ATL and AIDS.

Animals↗
PubMed1996

Event-related potentials during paired associate memory paradigm.

We have studied event-related potentials (ERPs) during a visual paired association task with delayed discrimination in 10 normal right-handed subjects. After subjects completely memorized 4 pairs of figures during a learning period, they were presented with each cue (S1) and asked to judge whether the following figure (S2) formed one of the memorized pairs or not. A choice reaction task with delay was used for control in an attempt to identify brain activity specifically related to memory function. ERPs were recorded from 21 scalp electrodes and those occurring between the S1 and S2 presentation were analyzed. Two ERP components associated with memory function were identified in the difference waveform between the responses in the paired association task and those in the choice reaction task. One was a posterior positive component which appeared between 390 ms and 1100 ms after the S1 presentation and the other was a sustained frontal negative component which began at about 1100 ms after S1 and ended just before the S2 presentation. Both potentials were distributed predominantly on the scalp overlying the left hemisphere. It is postulated that the early posterior positive component may reflect retrieval of information from association memory, whereas the late frontal negativity may reflect retention of information in working memory.

Adult↗
PubMed1995

Production of waxy (amylose-free) wheats.

The Waxy (Wx) protein has been identified as granule-bound starch synthase (GBSS; EC 24.1.21), which is involved in amylose synthesis in plants. Although common wheat (Triticum aestivum L.) has three Wx proteins, "partial waxy mutants" lacking one or two of the three proteins have been found. Using such partial waxy mutants, tetra- and hexaploid waxy mutants with endosperms that are stained red-brown by iodine were produced. Both mutants showed loss of Wx protein and amylose. This is the first demonstration of genetic modification of wheat starch.

Electrophoresis, Polyacrylamide Gel↗
PubMed1995

Effect of biotin on ammonia intoxication in rats and mice.

The effects of biotin on ammonia concentration in blood and brain were evaluated in hyperammonemic rats and mice. Rats were injected with 5 mmol/kg BW of ammonium acetate, and mice were injected with 10 mmol/kg BW. Increases in blood ammonia levels in rats 15-30 min after ammonia loading were prevented by treatment with 0.2 ml/100 g BW of biotin or 0.04 ml/100 g BW of arginine-glutamate with statistical significance. Blood ammonia levels after ammonia loading were lower, although not significantly, in the arginine glutamate-treated rats than in the biotin-treated animals. In mice also, increases in blood and brain ammonia levels after ammonia loading were prevented by the administration of biotin. The decrease in brain glutamate and aspartate after ammonia loading was lower and the brain glutamine level was higher in biotin-treated mice than in the controls. These findings indicate the protective effect of biotin against ammonia intoxication.

Acetates↗
PubMed1995

Pain-related somatosensory evoked potentials following CO2 laser stimulation of foot in man.

Since our previous study of pain somatosensory evoked potentials (SEPs) following CO2 laser stimulation of the hand dorsum could not clarify whether the early cortical component N1 was generated from the primary somatosensory cortex (SI) or the secondary somatosensory cortex (SII) or both, the scalp topography of SEPs following CO2 laser stimulation of the foot dorsum was studied in 10 normal subjects and was compared with that of the hand pain SEPs and the conventional SEPs following electrical stimulation of the posterior tibial nerve recorded in 8 and 6 of the 10 subjects, respectively. Three components (N1, N2 and P2) were recorded for both foot and hand pain SEPs. N1 of the foot pain SEPs was maximal at the midline electrodes (Cz or CPz) in all data where that potential was recognized, but the potential field distribution was variable among subjects and even between two sides within the same subject. N1 of the hand pain SEPs was maximal at the contralateral central or midtemporal electrode. The scalp distribution of N2 and P2, however, was not different between the foot and hand pain SEPs. The mean peak latency of N1 following stimulation of foot and hand was found to be 191 msec and 150 msec, respectively, but there was no significant difference in the interpeak latency of N1-N2 between foot and hand stimulation. It is therefore concluded that N1 of the foot pain SEPs is generated mainly from the foot area of SI. The variable scalp distribution of the N1 component of the foot pain SEPs is likely due to an anatomical variability among subjects and even between sides.

Adult↗
PubMed1995

Movement-related cortical potentials associated with voluntary muscle relaxation.

We recorded movement-related cortical potentials (MRCPs) associated with voluntary muscle relaxation, which was not accompanied by contraction of the antagonist or any other muscles, in 10 normal subjects. Voluntary, self-paced relaxation of the wrist extensors from the extended position was employed as the relaxation task, and wrist flexion by muscle contraction was employed as the contraction task. The accelerogram was used to obtain the trigger signals for both tasks. The electromyograms of the ipsilateral agonist and antagonist, the proximal muscles and the contralateral corresponding muscles were monitored to confirm the absence of muscle contraction for the relaxation task. All MRCP components were identified in both tasks; Bereitschaftspotential (BP), negative slope (NS'), parietal peak of motor potential (ppMP) and frontal peak of motor potential (fpMP). BP started earlier and was larger at the contralateral parietotemporal electrodes for the relaxation than for the contraction task, and the slow positive shift at the bilateral frontopolar electrodes was seen more often in the relaxation task. It is concluded that the voluntary muscle relaxation needs a cortical preparatory process similar to voluntary muscle contraction, and needs a more extensive and longer preparation process in the primary motor area and possibly in other motor areas as compared with the contraction.

Adult↗
PubMed1995

REM sleep without atonia at early stage of sporadic olivopontocerebellar atrophy.

In order to investigate whether REM sleep without atonia (RWA) is detected even at early stage of sporadic olivopontocerebellar atrophy (OPCA), all-night polysomnography with video monitoring was performed on 5 patients presenting with no nocturnal behavioral complaints. RWA associated with sleep talk and/or minor movements in the head, neck, face and extremities was documented in all cases. Preserved proper NREM/REM cycle and relatively normal sleep architecture suggest the abnormality is confined to REM sleep. Dysfunction of the mechanisms underlying muscle atonia in REM sleep, especially functional or anatomical interruption of ponto-medullary pathways mediating REM sleep atonia, seems to cause RWA in these patients. RWA may be a clinically important finding as a sign of brainstem dysfunction at early stage of neurodegenerative diseases.

Aged↗
PubMed1995

Peri-rolandic and fronto-parietal components of scalp-recorded giant SEPs in cortical myoclonus.

Scalp topography of giant SEPs to median nerve stimulation was studied in 4 patients with cortical myoclonus of various etiology. The positive peak (P30) at the contralateral parietal area was simultaneously accompanied by a negative peak at the frontal area (N30), and at least one of these two peaks was enhanced in 2 patients. Another positive peak (P25) and a negative peak (N35) were also identified at the peri-rolandic area with different latency from P30 and N30, respectively, in all patients. N35 was enhanced in 3 patients, and P25 in 2 patients. It is concluded that, as seen in normal subjects, tangential (P30-N30) and radial (P25 and N35) components of SEPs are most likely distinguishable in giant SEPs, and that either one or both of those components is enhanced in different ways depending on the patients.

Adolescent↗
PubMed1995

Cross-protection against influenza virus infection in mice vaccinated by combined nasal/subcutaneous administration.

The effects of a combination of intranasal (i.n.) and subcutaneous (s.c.) administration of inactivated influenza vaccine for priming and boosting on the cross-protection against antigenically drifted virus challenge were examined in Balb/c mice. Mice were primed through the i.n. or s.c. route with a CTB*-A/Kumamoto/37/79 (H1N1) combined vaccine (CTB*: cholera toxin B subunit supplemented with 0.2% of the holotoxin) and boosted through the i.n. or s.c. route with another drift virus vaccine, A/Bangkok/10/83 (H1N1), 4 weeks later. Two weeks after boosting, the mice were challenged with a third drift virus, A/Yamagata/120/86 (H1N1). The combination of i.n. priming and i.n. boosting afforded the highest cross-protection, while combinations of s.c. priming and i.n. or s.c. boosting afforded little cross-protection. In parallel with the protective activity, anti-A/Yamagata haemagglutinin-reactive IgA and IgG antibodies were detected in nasal and bronchoalveolar wash specimens. These results suggest that cross-protection against a variant virus challenge is most favourably provided by i.n. priming with the CTB* combined vaccine and i.n. boosting with the vaccine, which optimally induces cross-protective IgA and IgG antibodies.

Administration, Intranasal↗
PubMed1995

Construction of a morphological filter for detecting an event-related potential P300 in single sweep EEG record in children.

A morphological filter for single sweep records of event-related potential (ERP) obtained in an auditory oddball paradigm, especially P300 waveform, was constructed. By combining four basic operations; erosion, dilation, opening and closing, we could derive a desired filter whose properties fit the current objectives. The morphological filter for the single sweep records of ERP was constructed by taking into account the features of the signal and noise components. The morphological filter had superior properties for distinguishing the signal from the noise even when both were within the same frequency band, as in case of children. The constructed morphological filter was evaluated by using the simulation data of ERP and then applied to the actual ERP data obtained from nine normal children. The constructed morphological filter was proved to be an appropriate tool for single sweep analysis of ERP.

Adolescent↗
PubMed1995

Physiological study of cervical dystonia. Task-specific abnormality in contingent negative variation.

To investigate the pathophysiology of dystonia, we recorded contingent negative variation (CNV) in 12 patients with cervical dystonia and in 12 age-matched normal subjects. In a simple reaction time paradigm, the subjects were given a pair of a warning stimulus and a subsequent stimulus that triggered head rotation to either side or extension of the fingers. In normal subjects, CNVs for head rotation were not affected by neck muscle pre-activation simulating torticollis, and were always symmetrical with equally high amplitudes over the frontal and central leads. By contrast, CNVs for finger movement had the maximum over the central lead and showed a characteristic distribution; those for the right finger movement had the left hemisphere dominance, whereas those for the left finger movement had similar amplitudes over both hemispheres. In patients with rotatory torticollis (rotatocollis), the components of CNVs for head rotation were markedly attenuated in all the leads, except for the initial negative deflection (orienting response). As a whole, cervical dystonia patients had significantly lower amplitudes of late CNVs for head rotation than normal subjects (P < 0.001), whereas late CNV amplitudes in finger extension did not differ in the two groups. Their reaction times for head rotation were similar, but durations of EMG activities were prolonged in the patients because of co-contractions of the antagonists. The task-specific CNV amplitude loss is therefore not explained by reaction times or by the abnormal neck muscle activities prior to the movement, but it reflects a failure of neural activities preparing for a phasic neck movement, resulting in co-contraction of the agonists and the antagonist. Dystonia may be associated with defective retrieval or retaining of specific motor programmes or subroutines in response to sensory stimuli.

Adult↗
PubMed1995

Presence of Bereitschaftspotential preceding psychogenic myoclonus: clinical application of jerk-locked back averaging.

The method of jerk-locked back averaging was applied to six patients with clinically diagnosed psychogenic myoclonus. Five patients had a slow negative EEG shift corresponding to Bereitschaftspotential at the central region starting 0.7 to 2.1 seconds before the onset of the myoclonic jerk. One patient had no potential preceding the myoclonic jerk, whereas a small negative potential preceded the voluntary movement mimicking the jerk. The demonstration of Bereitschaftspotential before an apparently involuntary myoclonic jerk helps the clinical diagnosis of psychogenic myoclonus, although the absence of Bereitschaftspotential does not necessarily indicate that the movement is involuntary. Jerk-locked back averaging is clinically useful as a specific laboratory examination in this condition.

Adult↗