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Biomedical subjects

M Yasue

Publications and source records attributed to M Yasue.

At least 73 records · Page 4Linked to original sources
PubMed1988

[Clinical investigation of cerebellar astrocytomas in childhood].

Between 1970 and 1985, 58 children with pathologically proven cerebellar astrocytoma were treated at the Children's Memorial Hospital in Chicago. Histological distribution indicated 54 were Grade 1-2 and the remaining 4 patients had Grade 3 astrocytoma. Thirty-eight were evaluated by CT scans and classified into 3 groups, (1) cyst with mural nodule, (2) cyst within tumor and (3) solid type. All patients underwent a posterior fossa craniotomy and 2 cases (3.4%) died shortly after the operation. Forty-two patients underwent visible total resection and 16 subtotal or less resection. The recurrence rate in subtotal resection group (53.3%) is much higher than in total resection group (9.8%) (p less than 0.01) and the highest in solid type. Seven out of 8 cases who developed recurrence after subtotal removal were in the midline location, and 6 out of 7 cases who did not show any recurrence were cystic in nature. About two-thirds of patients had good outcome, 32% had fair and 4% had poor outcome. The hemispheric tumors led the patient to a better outcome but the midline solid tumors caused poor outcome. Fifty patients were diagnosed to have hydrocephalus preoperatively. Postoperative permanent hydrocephalus developed in at least 30% of the patients, and was more common in the midline solid type tumor. We stress that an attempt of total resection should be done at initial craniotomy. Residual or recurrent tumor are to be resected if they show increasing size on serial CT scans or cause symptoms. Radiotherapy does not afford any additional effects to benign cerebellar astrocytomas.

Adolescent↗
PubMed1988

[Intraoperative radiation therapy (IORT) of adenocarcinoma of the pancreas].

Fifty-four patients were given intraoperative radiation therapy (IORT) for adenocarcinoma of the pancreas between April, 1980 and August, 1987 at Aichi Cancer Center Hospital. Thirty-five of these patients with well-advanced cancer underwent palliative IORT of their main primary lesions which could not be resected. Twenty (or 57%) of them had liver and/or peritoneal metastases. Electron irradiation at doses of 12 Gy (1 patient), 15 Gy, 20 Gy, 22 Gy, 22.5 Gy, 25 Gy and 30 Gy was given to these patients in single doses. Gastric and/or biliary bypasses were performed in 27 (77%) of them following IORT. Twenty (80%) of the 25 patients in this group who had intractable back pain before this treatment achieved relief of pain within one week postoperatively. The median survival for this group of 35 unresectable cases was 5.3months (range 0.5-28.6 months). The remaining 19 patients underwent pancreatectomy and received adjuvant IORT to the bed of the pancreas. Two of the patients in this group had liver metastases and one patient had peritoneal seeding. All of the visible metastatic lesions were removed by local excision in these three patients. Posterior surgical margins were cancer-positive in 8 patients, suspicious in 6 and negative in 5. IORT doses were 20 Gy (7 patients), 25 Gy and 30 Gy. Median survival for this group of 19 resectable cases was 9.4 months, including 10 patients who remain alive at the time of this report (August 15, 1987). The longest survival has been 6 years 10 months in one patient after absolute non-curative distal pancreatectomy followed by 20 Gy of IORT for cancer of the body of the pancreas with a microscopically proven cancer-positive posterior surgical margin. The other nine are alive at 5 years 10 months, 2 years 4 months, 1 year 5 months, 1 year, and within one year (5 patients), respectively. Survival rates were compared between one group of 41 patients operated on in the 5 years before we began IORT and another group of 70 patients operated on after IORT introduction. The latter group included 16 patients who did not receive IORT for various reasons. The background factors were rather worse in the latter group, but both the survival rates and the staying-home survival rates were significantly better (p less than 0.05). One-year survival rates were 7% in the before-IORT period and 26% in the after-IORT period. One-year staying-home survival rates were 2% and 18%, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗
PubMed1988

[Cortical and subcortical somatosensory evoked potentials to median nerve stimulation in man].

In order to define the precise locations of precentral and postcentral gyri during neurosurgical operations, somatosensory evoked potentials to contralateral median nerve stimulation were recorded from the cerebral cortex in 19 cases with organic cerebral lesions which located near the central sulcus. In addition to that, distribution patterns of early components of SEPs were displayed by Nihonkoden Atac 450 in 3 cases who had bone defects after wide decompressive craniectomy but were without any sensory disturbances In 4 cases, in whom deep electrodes were inserted for the stereotaxic operations or other reasons, frontal subcortical SEPs were recorded in order to know the origins of frontal components of SEPs. From the parietal cortex, N19, P22 and P23 were observed. And from the frontal cortex, P20 and N25 were obtained. Their average peak latencies were as follows; (table; see text) Because all subjects had organic lesion in the brain, the peak latencies were a little bit longer, and their standard deviations were larger than those in normal cases. Usually, clear-cut phase reversal could be observed between N19 and P20 across the central sulcus. So, the precentral and postcentral gyri were easily identified during the operations. N19 and P23 appeared over the wide areas of the parietal cortex. Also, P20 and N25 were recorded almost whole areas of the frontal cortex. On the other hand, P22 appeared from relatively restricted part of the postcentral gyrus where sensory hand area might have been located. Depth recording from the frontal subcortical area revealed that P20 could be recorded from the bilateral frontal subcortical areas and there observed no phase reversal between the cortical and subcortical SEPs.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Diseases↗
PubMed1987

[Changes in short latency SEPs (S-SEPs) to median nerve stimulation in brain dead patients].

Short latency SEPs (S-SEPs) to median nerve stimulation consist of positive waves of P1, P2, P3 and P4, followed by negative waves of N 16 and N 19. These potential reflect activities of peripheral nerve, dorsal column of the cervical cord and medial lemniscus. The origins of these waves are considered as follows, P1--peripheral part of the brachial plexus, P2--the entry into the spinal cord or the dorsal column, P3--dorsal column nucleus or upper cervical cord, P4--the medial lemniscus, N 16--rostral brain stem or the thalamus, and N 19--thalamocortical projection or the cortex. The purpose of the present study is to elucidate changes of S-SEPs in brain dead patients. Fifteen brain dead patients were examined with S-SEPs. In addition to that, thirteen cases with lesions of subcortical or the brain stem but not in the state of brain death were studied for the controls. S-SEPs with non-cephalic references, conventional SEPs with earlobe reference and the evoked potentials at the Erb's point were recorded in all these cases. Serial recordings were performed in six brain dead cases during the process of rostro-caudal deterioration of the brain stem functions due to cerebral herniation. In the state of brain death, only P1 and P2 were recorded in eleven cases, and in three cases, only P1 was recorded. The other case with anoxic brain damage showed flat S-SEPs and the evoked potentials at the Erb's point could merely be obtained by the supramaximal stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

[A randomized controlled trial of surgical adjuvant therapy with mitomycin C, 5-fluorouracil and OK-432 in patients with gastric cancer].

The effect of postoperative immunochemotherapy with mitomycin C (MMC), 5-fluorouracil (5-FU) and OK-432 was evaluated as an adjuvant therapy after curative resection for gastric cancer. Immediately after surgery, patients were randomly allocated to the following three treatments: (A) chemotherapy with MMC and 5-FU (32 cases); (B) chemoimmunotherapy with MMC, 5-FU and OK-432 (33 cases); and (C) surgery alone as control (34 cases). There were no significant differences in the background factors influencing survival time among the groups, and there was no dose-distribution of chemotherapeutic agents between groups A and B. While the differences were not statistically significant, the survival rate and disease-free interval of group B were better than those of groups A or C. Side effects such as gastroenteric disorder, leukopenia (less than 3,000/mm3), thrombocytopenia (less than 7 X 10(4)/mm3) and increase of serum transaminase level (GPT greater than or equal to 100 units) were less frequently observed in group B than in group A. The results of the present study seemed to indicate that chemoimmunotherapy with OK-432 may be effective for surgical adjuvant therapy.

Aged↗
PubMed1985

Total pelvic exenteration for advanced carcinoma of the lower colon.

Thirteen patients with advanced carcinoma of the lower colon and no evidence of extrapelvic metastasis were submitted to total pelvic exenteration. Nine of the 13 patients had ureteral urinary diversion by the ileal segment conduit. Three had colonic conduit bladder using the terminal portion of the descending colon. One patient had bilateral uretero colonic anastomosis. The operative mortality rate was 7.7%. Determinate 5-year survival rate of 38.5% was achieved. Histological examinations of the surgical specimen revealed associated abscesses adjacent to the tumor in six cases, although the cancer extended to the bowel wall and adhered to the surrounding structures in all specimens. Total pelvic exenteration assures a better quality of life, lessening of symptoms, disease control and, in selected patients, a cure.

Adenocarcinoma↗
PubMed1985

Diagnosis and operation for locally recurrent rectal cancer.

Local recurrence of rectal cancer following abdominoperineal resection is rarely amenable to limited resection. Six patients with deeply invading recurrent lesions had pelvic exenteration combined with sacral resection. This procedure seems a reasonable treatment for palliation and the chance of cure in selected patients. In order to select good candidates for this extensive procedure, carcinoembryonic antigen (CEA) assays and the diagnosis of locally recurrent tumor with pelvic computed tomography (CT) were evaluated. CEA assay is valuable for diagnosing most recurrent rectal cancers, but it is inadequate for early detection. A high CEA level often indicates extrapelvic tumor spread. CT examination is very valuable for the early detection and localization of recurrence in relation to pelvic structures.

Adenocarcinoma↗
PubMed1985

Dynamic EEG topography and analysis of epileptic spikes and evoked potentials following thalamic stimulation.

Dynamic EEG topography is used to study evoked potentials following thalamic stimulation as well as epileptic spikes and spike-wave complexes during stereotactic operations. Dynamic EEG topography is an effective method for displaying the distribution pattern of evoked potentials following thalamic stimulation. This technique makes it possible to observe successive increases in augmenting responses and to define the localization of epileptic foci.

Brain Mapping↗