Search PubMed⌕ Search

Biomedical subjects

H Baba

Publications and source records attributed to H Baba.

At least 505 records · Page 28Linked to original sources
PubMed1981

A new pattern discriminant method for evoked potentials.

A statistical approach to evaluate evoked potentials (EPs), consisting of three stages in procedure, was proposed with an application to study on postictal changes of visually evoked potentials (VEPs). At the first step, time series data of EPs were reduced by the means of using an autoregressive (AR) model. In this way, EPs were described in terms of AR coefficient vectors. Then statistical distances which are well known as the Mahalanobis' distances were determined as a scale for dissimilarity between patterns of EPs. At the third stage, a retrospective classification through a numerical taxonomy based on similarity of patterns was demonstrated. This procedure will tell us some standards for future experiments as well as an integrative insight of results from present experiment. By the above method, it was suggested that there may be two different processes in postictal recovery of kindled cats.

Animals↗
PubMed1981

Changes of visually evoked potential during seizure development in kindled cats.

The secondarily induced changes of brain function following seizure seen in kindling preparations were studied by means of the visually evoked potential (VEP) in unrestricted cats. The kindling was developed by repeated electrical stimulation to the visual cortex under intermittent photic stimulation (IPS). Generalized convulsion was rapidly developed with a lowering of threshold inducing afterdischarge and an earlier spreading of seizure discharge to the midbrain reticular formation as compared with the previous control experiment without IPS. Following electrical stimulation, a marked enhancement in amplitude and a prolongation in latency of the second negative component, which was not usually recognized before the electrical stimulation, was observed. Such augmentation of VEP developed progressively and finally changed into the epileptic discharge accompanied with myoclonic response. Furthermore, postictal augmentation of VEP which attained to maximum within a few minutes after the end of seizure was confirmed with an elevation of photosensitivity. It was noted that the second negative component continued significantly to exist for more than 60 min contrary to the relatively rapid restoration of the first negative component. These findings are discussed in relation to the mechanism of kindling phenomenon.

Animals↗
PubMed1980

Intra- and postoperative autotransfusion in open heart surgery under simple hypothermia in children.

A new autotransfusion unit was developed by the authors and the favorable results of 21 operations of open heart surgery under simple hypothermia were described. The patients were all children with simple congenital heart diseases. The amounts of autotransfused blood ranged from 2.8 to 15.5 ml/kg. Intraoperative autotransfusion proved to be an effective means of minimizing blood loss during surgery (range 3.2 to 12.8 ml/kg) and performing open heart surgery without donor blood transfusion. Postoperative autotransfusion (range 0 to 14.3 ml/kg) served as a supplementary means of avoiding homologous blood transfusion. Among the 21 autotransfused patients, there were no complications, while two patients developed hepatitis out of 19 patients who received homologous blood in the control group.

Adolescent↗
PubMed1980

Enhancement of cooling and rewarming by a jet water system in surface-induced deep hypothermia.

To shorten the time of cooling and rewarming in surface-induced deep hypothermia, we devised a jet water system for hypothermia which was constructed within the water bath of the operating-table. In the clinical applications for open heart surgery under surface-induced deep hypothermia, we found that the time required for cooling and rewarming, particularly the later, was significantly reduced without any adverse effects.

Adolescent↗
PubMed1980

EEG activities during kindling in frog.

The "kindling" phenomenon was investigated in relation to the EEG activities in frog, Rana nigromaculata. Repetitive electrical stimulation to the unilateral hippocampus produced the following results: (1) Prolongation in duration of after-discharges (AD) and shortening of AD intervals; (2) Appearance and enhancing of spontaneous epileptiform discharges (SEDs), which were suppressed by isolation of hippocampus; (3) Increase in power and duration of background EEG with a specific frequency (9 Hz in the nontreated group and 5 Hz in the hippocampal commissural bisected group), which coincided with the half length of the AO intervals during the steady phase; (4) Marked increase in the late components with peak latencies of 25 and 50 msec in the interhippocampal impulse responses as estimated from the bilateral background hippocampal EEG through an autoregressive model, of which the former only was suppressed by commissural section, while both were suppressed by hippocampal isolation. From the above evidences obtained in frogs, it may be inferred that the brain structures, e.g., thalamus, hypothalamus, reticular formation, etc., play an important role in kindling formation and that the alteration in background EEG generating system during kindling is closely associated with the sporadic epileptiform EEG activities.

Action Potentials↗
PubMed1979

Right-sided cervical aortic arch associated with tetralogy of Fallot and peculiar tortuosity of the descending aorta.

A right-sided cervical aortic arch, tetralogy of Fallot, and a peculiar tortuosity of the descending aorta in which the aorta formed triple loops were diagnosed by angiocardiography in a 12-year-old girl. Histologic examination of the biopsied wall of the left subclavian artery, taken at the time of a Blalock-Taussig anastomosis, revealed no elastic-tissue defect.

Angiocardiography↗