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Biomedical subjects

K Yamashiro

Publications and source records attributed to K Yamashiro.

At least 145 records · Page 8Linked to original sources
PubMed1986

[Clinicopathologic study of intramammary cancer residuals after outpatient excisional biopsy of breast cancer].

Seventy-four breast cancer patients, who had undergone outpatient excisional biopsy followed by radical mastectomy, were divided into three groups according to the types of intramammary cancer residuals: no cancer residuals--45 patients, noninvasive cancer residuals--15, and invasive cancer residuals--14. The invasive cancer residual group included nine patients with axillary metastasis and showed a significantly higher rate of five-year recurrence (8/14) than the other two groups. In some of the patients with invasive cancer residuals, the lesions were more advanced and aggressive by nature. Histopathologically, invasive cancer residuals closely correlated to the nondesmoplastic infiltrating tumor border, and noninvasive cancer residuals to intraductal cancerous spread. Most intramammary cancer residuals were found close to the wounds made by biopsy.

Ambulatory Surgical Procedures↗
PubMed1985

Monitoring of sensory evoked potentials during surgery of skull base tumours.

Despite advances in instrumentation and the use of microsurgical techniques, neurosurgical procedures involving extensive areas of skull base or other critical areas of brain still carry significant risk for neurological injury. The use of intraoperative recording of sensory evoked potentials (SEP) has been advocated to monitor neurologic function during these major neurosurgical procedures to reduce the risk of injury to neural structures. This report summarizes our experience with intraoperative monitoring of SEP in over 200 patients, and details our findings in a group of 12 patients with skull base and posterior fossa tumours. Somatosensory evoked potentials (SSEP) were monitored in all patients, and brain stem auditory evoked potentials (BAEP) in five. While minor changes in BAEP and SSEP parameters were noted in most patients, significant changes occurred in five. Irreversible loss of BAEP in one patient was associated with complete hearing loss postoperatively. Marked, persistent alteration of both BAEP and SSEP was associated with postoperative brainstem dysfunction. No patient with stable BAEP and SSEP at the end of the procedure suffered additional neurological deficit. We conclude that intraoperative SEP monitoring may be valuable in minimizing neural injury during major neurosurgical procedures.

Adult↗
PubMed1985

Spasmodic head movements produced by destruction of unilateral ventromedial tegmentum in cats.

In cats, unilateral electrolytic destruction in the dorsomedial parts of the ventral tegmental area (VTA) (Tsai) led to the appearance of torticollic rotatory head postures associated with a marked drop of the corresponding caudate serotonin. Results obtained from fluorescence histochemistry and brain dialysis also revealed that decrease in serotonin shared the leading role. However, since a chemical lesion produced by neurotoxic agents failed to induce such abnormal postures, concomitant interruption of nonaminergic fibers at VMT might also be the essential factor. Among them the interstitial nucleus (Cajal) and its descending tract were the most suspicious.

Animals↗
PubMed1985

[Clinicopathological study of breast cancer--histologic tumor border and prognosis].

Based on histologic observations, tumor borders of 730 breast cancer patients were divided into five categories of border grade (BG); BG I (noninvasive), BG II (pushing), BG III (desmoplastic infiltrating), BG IV (nondesmoplastic infiltrating), and BG V (disseminating). From BG I to BG V, both the percentage of lymph node metastasis and four or more nodal metastases increased gradually, and the same results were obtained in various cases of the same tumor size. Further, tumor emboli in lymphatics were found only in the cases showing a tumor border above BG III, and more frequently detected with the increase in border grade. Therefore it was confirmed that histologic tumor borders not only exhibit the spreading fashions of breast cancer cells in the primary site, but also correlate with the lymphogenous metastasis very closely. Patients with either BG IV or BG V showed lower survival rates.

Breast Neoplasms↗
PubMed1984

[Four case reports of sarcoma combined with carcinoma].

We report 4 cases of double cancer, combined sarcoma and carcinoma. Case 1 was a 50-year-old woman, had a malignant fibrous histiocytoma in the leg and an advanced gastric carcinoma. The soft tissue sarcoma was resected and the gastric carcinoma was treated with chemotherapy. She died from pulmonary metastasis from the sarcoma. Case 2 was a 72-year-old woman with a liposarcoma in the leg and a thyroid carcinoma. Both tumors were resected, however, she died from pulmonary metastasis from the carcinoma. Case 3 was a 65-year-old man with a liposarcoma in the buttock and lung carcinoma. Both tumors were resected and he is alive and disease-free. Case 4 was a 47-year-old man with spindle cell sarcoma of the tibia and a rectal carcinoma. Both tumors were treated surgically, but he died from pulmonary metastasis from the sarcoma. We suggest that the combination of sarcoma and carcinoma is very rare and that the prognosis in these cases is very poor.

Adenocarcinoma↗
PubMed1983

Platelet tocopherol levels in mucocutaneous lymph node syndrome (MCLS: Kawasaki disease).

Studies of changes in platelet tocopherol in 16 children with mucocutaneous lymph node syndrome (MCLS) were undertaken during the disease course. Plasma tocopherol was lowest at the beginning of the disease (during the first 1 to 2 weeks), while it increased with improvement in symptoms at 4 to 5 weeks. Platelet tocopherol however was lowest in the first 2 to 3 weeks, and at about the 4th week or later increased. When compared with normal levels, determined in 24 children without MCLS (5 to 14 years old), the lowest level seen throughout the disease course coincided with it. Thus, platelet tocopherol may be generally higher in MCLS. There was little correlation between plasma and platelet tocopherol levels which were simultaneously assayed, (r = 0.26, p less than 0.1, n = 44), while, the correlation between platelet tocopherol and plasma tocopherol/total lipid ratio was increased significantly to 0.55 (p less than 0.001, n = 38). Individual patients in whom platelet tocopherol and plasma tocopherol/total lipid ratios were repeatedly assayed, were divided into two groups based on the Asai scoring, as a high risk group and a low risk group. No correlation was observed between the risk grades and either platelet tocopherol or tocopherol/total lipid ratios in plasma.

Blood Platelets↗
PubMed1983

[Surface negative waves in penicillin-induced epileptogenesis in cats].

The "surface negative (SN) wave" produced by pyramidal tract stimulation and recorded at the cortical surface has been identified as a reflection of postsynaptic potentials generated through recurrent inhibitory pathways (Humphrey, et al.). We studied changes in SN wave in an attempt to examine inhibitory mechanisms underlying epileptogenesis in immobilized cats. 1) A single shock applied to the cerebral peduncle evoked alpha and beta wave at the surface of ipsilateral anterior sigmoid gyrus (Fig.1 A). A train of 4 shocks with 4 msec shock-interval elicited SN wave which had a peak latency of 20 msec and decayed in 60-80 msec (Fig. 1 B,C,D). 2) The spindle-like after-discharges elicited by direct cortical shock were markedly suppressed with conditioning stimulation of the ipsilateral pyramidal tract (Fig. 2). Spike-and-wave complexes and other ECoG paroxysms produced by intramuscular administration of penicillin (Pc) were also depressed by repeated stimulation of the cerebral peduncle (Fig. 3). These facts revealed that the inhibitory effects of pyramidal tract stimulation caused to suppress the occurrence of epileptic discharges. 3) SN wave gradually diminished in amplitude after topical application of Pc at the anterior sigmoid gyrus (Fig. 4 A-D). It disappeared completely when tonic-clonic sustained paroxysms occurred at the focus (Fig. 4 E). These effects are due presumably to depression of recurrent postsynaptic inhibition caused by topical penicillin. 4) SN wave observed at the contralateral secondary focus was almost unchanged during interictal and ictal stage (Fig. 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1982

[A histopathological study on a glioma with radiation necrosis and brain stem spongiform degeneration (author's transl)].

A histopathological study on an autopsy case of 38-year-old female who had suffered from huge glioma and received radiation therapy as well as operation and chemotherapy was reported. The tumor mainly involved the right frontal lobe and partially invaded to the left cerebral hemisphere. Subarachnoidal dissemination of tumor cells was noticed in cerebellum, brain stem and spinal cord. Under the microscope the tumor was mainly consisted of astrocytic tumor cells, while oligodendrocytic ones and those with anaplastic or bizarre nuclei were observed among them. Though ependymomatous appearance was partially seen, no true rosette was found. From these findings the tumor was histologically diagnosed as anaplastic glioma. Simultaneously, there was massive coagulative necrosis which was limited to the irradiated area in the tumor tissue and surely attributable to irradiation. In addition, proliferation of gemistocytic astrocytes which was independent of glioma itself was widely observed in the field of irradiation. Another remarkable finding was spongiform degeneration which was located in the subpial area of brain stem including degenerative products of myelin sheaths and axons with neither inflammatory changes not gliosis. In some papers it is suggested that such a lesion has something to do with irradiation or chemotherapy. But in our case this lesion was found in non-irradiated area and no intramedullary injection of chemical agents was performed. Further, the distribution of this lesion was for the most part restricted to the domain of the pontine cistern which had been huge owing to stagnant hemorrhagic fluid. Therefore, it is highly probable that this lesion was caused by the abnormal pia-glial barrier.

Adult↗