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Biomedical subjects

S Wada

Publications and source records attributed to S Wada.

At least 379 records · Page 21Linked to original sources
PubMed1988

[Scalp recorded P13 and spinal recorded N13 in short latency somatosensory evoked potentials].

Using non-cephalic reference and by median nerve stimulation, P 13 component and N 13 component are recorded on the scalp (scalp P 13) and the posterior neck (spinal N 13), respectively, in the short latency somatosensory evoked potentials (SSEP). The purpose of this study is to disclose the origin, characteristics and clinical significance of these two components. Ten healthy volunteers served for normal subjects. Ten patients with pontine lesion or brain death were studied. The effect of barbiturate was also studied in additional 5 patients during anesthesia for cranioplastic surgeries. Electrical stimuli of 0.2 msec square wave pulse were used in routine examination. To confirm the effects of stimulation frequency, 3, 6, 9, 12, 15, 18, 21, 24 and 27 Hz were also used in normal subjects. Recording electrodes were placed in the following sites. (1) Scalp electrode at the Shagass' point contralateral to the stimulated side (Par.). (2) Posterior neck electrode on the spinous process of the fifth cervical vertebrae (Cv5), (3) Anterior neck electrode on the thyroidal cartilage (Ant. C). (4) Erb's electrode just above the mid-clavicular point ipsilateral to the stimulation. Erb's electrode contra-lateral side of stimulation was used as a reference. Spinal N 13 on posterior neck reversed its polarity into P 13 (spinal P 13) on the anterior cervical electrode. A study with different stimulus rates revealed that the latency of scalp P 13 significantly prolonged at 24 Hz stimulation. On the other hand, the latency of spinal N 13-P 13 easily prolonged even at 18 Hz. This suggested that spinal N 13-P 13 were generated polysynaptically.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Craniopharyngioma in the third ventricle].

A rare case of craniopharyngioma wholly located within the third ventricle is reported. A 55-year-old female was admitted to our hospital with the complaints of headache and fever of unknown origin. Neurological findings were normal. Computed tomography (CT) scan showed homogeneously enhanced mass lesion within the third ventricle. Axial and coronal CT scans disclosed an intact suprasellar cistern. The tumor was completely removed using an interhemispheric trans-lamina terminalis approach. Histological diagnosis was squamous cell type of craniopharyngioma. Post-operative diabetes insipidus was well controlled, and irradiation of 50 Gy was performed. Craniopharyngioma located entirely in the third ventricle was reviewed, and etiology, clinical feature and treatment were discussed.

Brain↗
PubMed1988

[Lazarus' sign and respiratory-like movement in a patient with brain death].

In the diagnosis of brain death, it is generally accepted that respiratory function has to be absent, however, spinal reflexes can be preserved. We presented a patient who showed a complex movements of upper limbs (Lazarus' sign) and respiratory like movement during the apnea test for the determination of brain death. This 72-year old female admitted to our hospital in a semicomatous state due to severe subarachnoid and ventricular hemorrhage. Her conscious level suddenly deteriorated to deep coma because of second hemorrhage on the same day. She became apnea and no brain stem reflexes elicited. Three days later, electrophysiological examination revealed a flat recording of electroencephalography, absence of auditory evoked potentials and no response of blink reflex. Short latency somatosensory evoked potentials obtained by median nerve stimulation showed the presence of Erb's N9 and spinal N13-P 13 components originating from cervical dorsal horn, however, the scalp P13 generated by cervico-medullary junction was absent. This patient fulfilled all other criteria for brain death. Four days after, an apnea test was performed. Spontaneous movements of both upper limbs were observed starting between 7 and 8 minutes after disconnecting the intubation tube from the ventilator. Both arms flexed at the elbow, abducted and elevated from the bed. Then, both hands were brought up to chest. Wrist and fingers were in a neutral position (Lazarus' sign). Simultaneously, shallow and irregular respiration like movements were recognized. These movements ceased immediately after connecting the respirator. These two types of movements were reproducible except for in the final test. Blood pressure gradually decreased, and cardiac arrest occurred one hour after.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Correlation between abnormal SSEP and clinicoradiological findings in cervical lesions].

The purpose of this paper is to evaluate the short latency somatosensory evoked potentials (SSEP) in the diagnosis of cervical lesions. Recordings were obtained from 59 patients with cervical lesions which included 24 cases of cervical spondylosis, 4 cases of disc herniation, 14 cases of OPLL, 4 cases of intramedullary tumor, 7 cases of extramedullary tumor and 6 cases of syringomyelia. SSEP changes in these cases were classified into three major types as follows: type I; normal SSEP, type II; prolongation of interpeak latency, and type III; absence of the component of SSEP. Types II and III were subdivided into two subgroups, respectively, as follows: type IIa; prolongation of interpeak latency between P9 and P11, type IIb; prolongation of P11-P13, type IIIa; no responses after P11 and type IIIb; no responses after P13. Type I was detected in 25 cases (42%), type II in 16 cases (27%), and type III in 18 cases (31%). These SSEP findings were compared with clinicoradiological findings. In type I, the locations of the lesions confirmed by the radiological findings were variable, and there was no definite tendency in the localizations. 80% of type I showed only numbness of extremities or disturbance of the superficial sensations. The cervical lesion was located just under the C5 vertebral level in type IIa and IIIa, while the lesion was extended above the C4 vertebral level in type IIb and IIIb. These results were explained by the generation sites of P11 and P13 (P11 originated from the lower dorsal column, and P13 from nearby the dorsal column nucleus).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[Clinical significances of auditory brainstem responses (ABRS) in cases with intracranial lesion].

In 47 cases with intracranial lesions, auditory brainstem responses (ABRS) were studied. From a detailed analysis of these data, the following results were concluded: In some cases, the intramedullary and extramedullary pontine tumor could be differentiated by ABR, A very small cerebello-pontine angle tumor was detected by ABR, ABR monitering was useful to evaluate brainstem function during the surgical operation, and ABRS were clinically very useful methods for predicting the outcome of a severe head injury and diagnosis of brain death. These results indicate that ABRS contribute to functional diagnosis of various diseases of the central nervous system.

Adolescent↗
PubMed1987

Human immunodeficiency virus contains an epitope immunoreactive with thymosin alpha 1 and the 30-amino acid synthetic p17 group-specific antigen peptide HGP-30.

We have reported that an antiserum prepared against thymosin alpha 1 [which shares a region of homology with the p17 protein of the acquired immunodeficiency syndrome (AIDS)-associated human immunodeficiency virus] effectively neutralized the AIDS virus and prevented its replication in H9 cells. Using HPLC and immunoblot analysis, we have identified from a clone B, type III human T-lymphotropic virus (HTLV-IIIB) extract a protein with a molecular weight of 17,000 that is immunoreactive with thymosin alpha 1. In contrast, no immunoreactivity was found in retroviral extracts from a number of nonhuman species including feline, bovine, simian, gibbon, and murine retroviruses. Heterologous antiserum prepared against a 30-amino acid synthetic peptide analogue (HGP-30) does not cross-react with thymosin alpha 1 but does react specifically with the p17 protein of the AIDS virus in a manner identical to that seen with an HTLV-IIIB p17-specific monoclonal antibody. The demonstration that this synthetic analogue is immunogenic and that antibodies to HGP-30 cross-react not only with the synthetic peptide but also with the HTLV-IIIB p17 viral protein provides an additional, and potentially more specific, candidate for development of a synthetic peptide vaccine for AIDS. In addition, the p17 synthetic peptide (HGP-30) may prove to be useful in a diagnostic assay for the detection of AIDS virus infection in seronegative individuals.

Amino Acid Sequence↗
PubMed1987

Four congenitally blind children with circadian sleep-wake rhythm disorder.

Four congenitally blind children aged 4-12 years, with severe or moderate mental retardation, were chronobiologically studied. Three of them showed a free-running rhythm of sleep-wake, and the fourth showed an irregular sleep-wake rhythm. To entrain their sleep-wake rhythm to a 24-h rhythm, several trials based on chronotherapy were performed. The free-running rhythms in the three children were considered their own endogenous rhythms, revealed through some disorder in the mechanism synchronizing the endogenous rhythm to the normal 24-h environmental rhythm. The irregular sleep-wake rhythm in the fourth child may have been the result of immaturity or failure of the pacemaker of the circadian rhythm. Because of their severe mental retardation, all the children were lacking in social time cues, which are the most potent "Zeitgebers" for human biological clocks.

Blindness↗
PubMed1987

Sensory nerve endings in the mucosa of the epiglottis--morphologic investigations with silver impregnation, immunohistochemistry, and electron microscopy.

This study was conducted in order to investigate the structure of sensory nerve endings of the human epiglottis and substance P immunoreactive nerve fibers of the canine epiglottis in relationship to physiologic functions of the larynx. The human epiglottis was observed by light microscopy (silver impregnation) and electron microscopy, and the canine epiglottis was studied by peroxidase-anti-peroxidase (PAP) immunohistochemistry. The results are summarized as follows: (1) In the membranes of the epiglottis, we observed free endings of simple or complex tree shape, corpuscle endings with glomerular patterns, and taste-bud-like structures, and (2) electron microscopic studies revealed varicosity of the terminal axon with processes that contained small, clear and large, dense cored vesicles. Substance P was observed in these structures, and it was suggested that substance P was related to perception in the larynx.

Animals↗
PubMed1987

Substance P immunoreactive nerve fibers of the canine laryngeal mucosa.

Substance P (SP) immunoreactive nerve endings in the laryngeal mucosa were studied by PAP immunohistochemistry with light and electron microscopy. SP immunoreactive sensory endings were observed in the epithelium as intra-epithelial free nerve endings and taste bud-like structures. A small number of autonomic SP immunoreactive nerve fibers were observed running parallel to arterioles which were over 30 micron in diameter and terminated in glandular cells. Contrary to findings by silver impregnation, intraepithelial free nerve endings were more frequently observed on the lower surface of the vocal cord. The taste bud-like structures were classified into two different types: simple terminations and reticular terminations, according to the mode of the SP immunoreactive nerve fiber. Immature or degenerated taste bud-like structures in the larynx were assumed to be mechanical receptors because these receptors lacked outer taste pores and taste hairs.

Animals↗