Raphe-cell transplantation into the hippocampus of the hydrocephalic rat brain.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
T Tsubokawa
Publications and source records attributed to T Tsubokawa.
Extraction of angiogenesis factor from chronic subdural haematomas. Significance in capsule formation and haematoma growth.
The extraction of angiogenesis factor (AGF) from the contents of chronic subdural haematomas was attempted in order to explain the angiogenesis in the capsule. AGF was extracted from eight patients using the modified Phillip's method, which has previously been used for the extraction of tumour angiogenesis factor. The thickness of the haematoma capsule was measured immediately after removal. The Hounsfield units were evaluated as the average value of three areas in the haematoma on CT scans. Chromatographic separation of the treated contents gave five fractions. The highest activity was observed in the fourth fraction on bioassay by the air sac method. The intensities of AGF activity varied from patient to patient. Although no correlation existed between the degree of AGF activity and thickness of the capsule, a positive correlation was seen between the activity and the density of the contents as indicated by Hounsfield's units on a CT scan. This may indicate the existence of a sequence of cause and effect between increase in the AGF activity and haemorrhage in the capsule of the haematoma. AGF activity increases after haemorrhage in the haematoma capsule, leading to acceleration of angiogenesis in the capsule, which promotes the haemorrhagic cause in the haematoma. Thus, a vicious circle between AGF in the haematoma, angiogenesis in the capsule and haemorrhage in the haematoma is established. It is considered that this gives rise to growth of the haematoma.
Adult↗
Features of chronic subdural haematoma developed from definitely identified acute subdural haematoma.
Follow-up results for 13 cases of acute subdural haematoma, which were identified by CT scan within two days of head injury and treated conservatively, were classified into two groups: In the first group of seven cases the acute subdural haematoma disappeared spontaneously within two weeks; in the second group the other six cases revealed clinical signs and CT scan findings which were identical to chronic subdural haematoma and underwent surgery within three weeks after the head injury. This group showed low ICP signs, such as the chronic stage of cerebral thrombosis, atrophic brain or subdural fluid collection with acute subdural haematoma at the initial CT scan, and most of these cases had only minor head injury. Common features of the operative findings in this second group, in which chronic subdural haematoma developed, included the identification of an external haematoma capsule based on the fibrin layer and granulation tissue beneath the dura. Also, fluid type haematoma was present under these structures, but no inner membrane of the haematoma could be identified other than the non-transparent white arachnoid membrane. Our results indicate the importance of a low ICP in determining whether or not acute subdural haematoma progresses to chronic subdural haematoma.
Adolescent↗
Deep-brain stimulation in a persistent vegetative state: follow-up results and criteria for selection of candidates.
Eight cases of a persistent vegetative state caused by brain damage were treated by chronic deep-brain stimulation (stimulation target: the mesencephalic reticular formation and/or non-specific thalamic nucleus) over a period of more than 6 months. Three of the patients are currently able to communicate and to express their demands by voice and one other patient has recovered very close to this state. These four cases showed changeable spectrograms with desynchronization on continuous EEG recording and all components of the BSR and SER could be recorded except for prolonged latency of both N20 (SER) and the V wave (BSR) 2 months after the initial coma. Following chronic deep-brain stimulation, EEG and behavioural arousal responses were observed with increased r-CBF, r-CMRO2 and r-CMRGL in the whole brain tissue. After 3-6 months of chronic deep brain stimulation, the prolonged coma scale rose in four of the eight cases and three cases emerged from the persistent vegetative state. Transmitter substances and their metabolites were also found to be increased in the CSF after chronic deep-brain stimulation. Based on these findings, chronic deep-brain stimulation represents a useful kind of treatment that can lead to emergence from a persistent vegetative state, if the candidate is selected by electrophysiological studies 2 months after the initial insult and if the stimulation is applied for more than 6-8 months using a high-safety chronic deep-brain stimulating instrument.
Adult↗
Prediction of outcome of prolonged coma caused by brain damage.
Thirty-one prolonged coma patients, who continued in a comatose state for at least 2 months, were classified electrophysiologically employing EEG, a compressed spectral array of continuous EEG frequency analysis, BSR, SEP and SSEP. The prognoses of long-term follow-up (at least 8 months) in these patients were compared with the results of such electrophysiological analysis and with the neurological gradings of the prolonged coma patients. In the continuous EEG frequency analysis, 22 cases were classified as having a changeable spectrogram, nine cases as having a slow monotonous spectrogram, and no cases as having a borderline spectrogram. We also classified the changeable spectrograms into the following three patterns: no desynchronization, slight desynchronization, and desynchronization. The nine cases with a slow monotonous spectrogram revealed severe damage of the brain stem and cerebral function with multimodality evoked potentials, and most of these cases could not survive without assisted respiration. The 22 cases with a changeable spectrogram had mild damage of the brain stem and cerebral function with multimodality evoked potentials, and these cases were identical with a persistent vegetative state. Three of the cases showed a changeable spectrogram that revealed a desynchronization pattern, normal BSR and normal N20 of SEP and SSEP, recovered spontaneously from the persistent vegetative state within 6 months after electrophysiological evaluation. We conclude that not only a neurological but also an electrophysiological classification is necessary to evaluate the brain function and prognosis of prolonged coma.
Adolescent↗
Area of paresthesia as determinant of sensory block in axillary brachial plexus block.
BACKGROUND AND OBJECTIVES: Paresthesia is widely considered a useful indicator for locating components of the brachial plexus using the axillary approach. While establishing axillary brachial plexus blocks, the authors attempted to correlate the area of paresthesia with the effectiveness of the sensory block. METHODS: Axillary brachial plexus blocks were established in 222 consecutive adult patients scheduled for elective surgery of the hand or forearm. After paresthesia was elicited in the distribution of one of the three terminal nerves of the hand (median, radial, or ulnar nerve), 30 microliters 1.5% mepivacaine without epinephrine was injected after advancing an indwelling catheter. Sensory block of each terminal nerve was assessed 20 minutes after the injection. RESULTS: The median and radial nerves were blocked with the highest reliability (87% and 93%, respectively) after paresthesia was elicited in the areas supplied by the corresponding nerves. The ulnar nerve was blocked most reliably ( > 85%) after the elicitation of paresthesia in its area of distribution as well as when no paresthesia was induced. The most reliable block of the musculocutaneous nerve (72%) was achieved after paresthesia was induced in the area supplied by the median nerve. CONCLUSION: Eliciting paresthesia at the nerve supplying the area of a planned surgical incision is a reliable determinant of successful axillary brachial plexus block.
Adult↗