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Biomedical subjects

K Yamashiro

Publications and source records attributed to K Yamashiro.

At least 127 records · Page 7Linked to original sources
PubMed1988

[An autopsy case of a gastric cancer associated with elevated AFP, CEA and CA19-9].

A 48-year-old male developed gastric cancer (Borrmann III) with lung and liver metastases. Laboratory examination revealed a markedly elevated AFP (24, 241 ng/ml), CEA (9739.8 ng/ml), and CA-19-9 (726U/ml). Nevertheless, he underwent a subtotal gastrectomy for the hemostasis of a bleeding malignant lesion. Histological examination showed a moderately differentiated adenocarcinoma. A PAP for an AFP and a CEA disclosed positive staining. In addition, An autopsy revealed metastases to the liver and lungs with a positive result of PAP for AFP and CEA. Further, CA19-9 also was confirmed weakly in these same tissues, histochemically. Therefore this gastric cancer was considered an AFP, CEA, and CA19-9-producing tumor. Gastric cancer with 3 elevated tumor markers in the same patient is rare and its mechanism may elucidate the origin of gastric cancer and the resulting differentiation in the foregut.

Adenocarcinoma↗
PubMed1988

[A case of hypercalcemia with ovarian carcinoma].

A 45-year-old female manifested lower abdominal fullness and symptoms of hypercalcemia with nausea, vomiting, and thirst. Physical examination showed a right ovarian mass and laboratory data demonstrated hypercalcemia (14.6 mg/dl). The radiographic findings confirmed a right ovarian tumor without any evidence of bone metastasis. Tests revealed that her PTH, nephrogenic urinary cyclic AMP, and 1-25 (OH)2 Vitamin D were not high but that her prostaglandin E2 (PGE2) was elevated. After correction of her calcium elevation with infusion and prednisolone, right oophorectomy with tumor excision was performed. A histological examination of the tumor revealed a mucinous cysto-adenocarcinoma. The postoperative course has been uneventful, with normal calcium and PGE2 values. This case illustrates that hypercalcemia associated with an ovarian carcinoma (Malignancy-associated hypercalcemia) can be mediated by the patient's PGE2 in part.

Combined Modality Therapy↗
PubMed1988

[Cerebral aspergillosis as a cerebral vascular accident].

Cerebral aspergillosis is one of the most common mycotic infections in the central nervous system causing different clinical features such as brain abscess, granuloma, meningitis, and encephalitis. Cerebral aspergillosis, however, may lead to a cerebral vascular accident such as intracranial hemorrhage or cerebral infarction. In this report, we present two patients with cerebral aspergillosis accompanied by intracranial hemorrhage. A total of 124 reported cases of cerebral aspergillosis are reviewed to ascertain the pathogenesis of the associated vascular lesion. The first patient was a 9-year-old girl, who developed drowsiness with a headache during the medical treatment for acute myelocytic leukemia. CT disclosed subarachnoid and intraventricular hemorrhage. The autopsy revealed that the aspergillus arteritis was the cause of repeated hemorrhage. The second patient was a 15-year-old boy with allergic purpura and renal failure, who suddenly developed a stupor with convulsive seizure. CT disclosed an intracerebral hemorrhage in the right parieto-occipital area. The patient gradually deteriorated and died in spite of the surgical removal of the hematoma. The autopsy revealed that the hemorrhage was caused by the aspergillus arteritis. Cerebral aspergillosis has two routes of infection to the central nervous system: hematogenous dissemination from the distant site (usually the lung) and direct extension from the contiguous site (usually the paranasal sinuses or orbit). The primary mechanism of neuropathology is different between these two types. Primary cerebral arteritis is most often seen in patients with the former type, whereas primary basal meningitis occurs in the latter. The incidence of clinico-pathological features is different between hematogenous dissemination type and direct extension type.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Thalamotomy in generalized dystonia.

A prospective long-term semiquantitative evaluation of the results of ventral intermediate-posterior ventral oral nucleus thalamotomy on the different aspects of dystonia was made in 29 patients with secondary disease, 12 with nonfamilial, eight with (non-Jewish) familial, and seven with atypical DMD. The effect of disease progression, even in secondary patients, on surgical outcome was reviewed. Thalamotomy resulted in a long-term improvement in limb function of more than 25% to 50% in 23% of the patients, over 50% in 34% of patients, but midline features responded poorly. Manual dexterity was little changed in secondary cases because of underlying paralysis but improved 38% in cases of DMD. Involvement of neck and trunk, of three to four limbs, and progressive disease prognosticated for a poorer result, but phasic and tonic, familial, and nonfamilial dystonia respond equally well and age at surgery made no difference. Significant complications in 29 secondary cases included one death 31 days postoperative, one case of worsened hemiparesis, two cases of worsened dysarthria, two cases of worsened locomotion, one case of hydrocephalus requiring shunting, and one case of need for permanent tracheotomy. In 27 cases of typical and atypical DMD, there were two instances of hemiparesis, two of significant speech deterioration, three of hand ataxia, one of postoperative seizures, and one of hydrocephalus requiring shunting for an overall significant morbidity rate of 21%. The limiting factor in treating secondary dystonia is the underlying spastic paralysis but that in DMD is the relentless postoperative progression. The overall results of this study are remarkably similar to those of other published series: a quarter of the patients improved by 25% to 50%, a quarter to a third by more than 50%. The analysis of effect on specific features of the disease may be useful in the future for predicting outcome in a particular patient.

Dystonia↗
PubMed1987

Origin of the initial negative potential (N15) recorded on the skull by superficial radial nerve stimulation in the cat.

The origin of the initial prominent negative potential with a latency of about 15 msec (N15), recorded on the skull by superficial radial nerve stimulation was studied in the cat, and the following results were obtained. In the direct recording from the cortex, SEPs were elicited from the SI and SII areas, as well as the lateral gyrus and anterior suprasylvian gyrus. Among various wave forms recognized in the SI area, diphasic positive-negative (P-N) potential obtained from the postero-lateral part was most distinct, representing the primary evoked potential. Responses recorded on the dura and those directly on the cortex showed similar wave patterns over many sites. Although different forms of evoked potentials were recorded extensively over the skull, the most prominent negative potential was elicited at the site corresponding to the postero-lateral part of the SI area. The latency of this potential was approximately in agreement with that of the negative component of the P-N potential recorded on the cortex. Based on the intracortical laminar analysis of P-N potential, the positive component of this potential was assumed to reflect the activity of cells in the deeper layer of the cortex. The negative component, on the other hand, might represent activities of apical dendrites of the cortex. From the result of functional elimination of the cortex, however, this positive component was thought to contain potentials from far field neural structures. N15 recorded on the skull completely disappeared during cortical spreading depression.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMed1987

Microelectrode techniques in localization of stereotactic targets.

Although physiological corroboration of the target is essential in functional stereotactic surgery, the collected data can also be used for the offline study of normal and abnormal brain function. Such studies have the advantage of being made in actual clinical states with the unique opportunity of communicating with the patient. Correlations were made between microelectrode recordings and microstimulation at the same thalamic site with the same microelectrode in 'normal' patients, in those with tremor and in those with central and deafferentation pain. Human somatosensory organization is similar to that of subhuman primates. Five types of tremor cells have been identified-unresponsive nonsynchronous, unresponsive synchronous, kinaesthetic, voluntary, and voluntary with receptive field. While the last two qualify in latency and connectivity as tremor pacemakers, system analysis suggests an important element of long loop feedback as well. In the pain patients, five features were identified-somatotopic reorganization, altered firing in reorganized cells, bursting cells induction of burning widespread in thalamus and reproduction of the patient's pain by microstimulation-possibly a 'central allodynia' found in deafferented somatosensory thalamus particularly in patients with allodynia or hyperpathia. All but the latter effects may be merely the consequence of deafferentation and were seen in a 'control' stroke patient with dystonia, sensory loss but no pain.

Brain Mapping↗
PubMed1987

Origin of short latency somatosensory evoked potential in cats: especially potentials derived from thalamus and cortex.

Short latency somatosensory evoked potential (SSEP) was recorded in cats to identify the potentials originating from the cortex and the thalamus, and the following results were obtained. When SSEP was elicited on the bregma by stimulation of the contralateral superficial radial nerve, P2, P4, P4.5, P5.5, P7, P8, N8.5, P11, P9.5, N11.5, N12.5 and N14 were recognized. Of these components N11.5, N12.5 and N14 consisted of large negative potential (LNP). When KCl was applied to the sensorimotor cortex to induce spreading depression, the positive component of the primary evoked potential was markedly decreased and the negative component disappeared. In SSEP, components preceding N8.5 were unchanged. N8.5-P11 and P11-N12.5, however, markedly diminished or disappeared. The latency of the first component of the field potential recorded in the VPL nucleus of the thalamus was about 5 ms. When a small amount of Nembutal was injected into VPL nucleus, components between P2 and P4.5 remained unchanged, but P5.5 disappeared. P7, P8 and N8.5 were preserved. The amplitude of N8.5-P11 was markedly decreased and LNP disappeared. From these results, among various components of SSEP, P5.5 should originate from the thalamus, and P7, P8 and N8.5 from the extralemniscal system. N8.5-P11 should mainly represent post-synaptic potential (PSP) in the deep somatic layer, and P11-N12.5 represent PSP in the apical dentrites of the sensorimotor cortex. N14 probably represents PSP via the diffuse projection system. Thus, LNP should consist of complex potentials of specific and non-specific sensory systems.

Animals↗
PubMed1987

Malignant lymphoma, large cell immunoblastic clear cell showing unusual histologic picture.

A case of malignant lymphoma, large cell, immunoblastic clear cell (WF) in a 59-year-old woman was reported. This patient showed no remarkable symptoms except generalized lymphadenopathy and slightly elevated serum levels of IgG and IgM. Histologic examinations were performed twice at about 6 months interval. Marked differences were noticed between the period, and they were histopathologically interesting and unusual findings. By immunological staining in situ, T-clear cells showed a subset marker of helper/inducer's characteristics. It was suggested that this case was different from AILD-like T-cell lymphoma in histogenesis. The results of marker study and the changes in histopathological morphology among two biopsied specimens were presented.

B-Lymphocytes↗
PubMed1987

[A case of malignant paraganglioma arising from the retroperitoneum].

We report the case of 38-year-old male with a malignant and functional paraganglioma arising from the retroperitoneum. He was admitted to our hospital with a pathological fracture of the right femur, A diagnosis of paraganglioma was made after taking a biopsy specimen and discovering a hypervascular retroperitoneal tumor. The level of catecholamine in his urine was greatly increased, accompanied with hypertension, rapid pulse and sweating. He was treated with chemotherapy, radiotherapy and surgical therapy. However, he died from pulmonary metastasis.

Adult↗
PubMed1987

[A case of metastatic malignant melanoma mimicking pancreatic pseudocyst].

A 74-year-old male was admitted to our hospital complaining of an abdominal mass. Abdominal US and ERCP disclosed a cyst in the pancreas, communicating with a crater in the stomach. Spontaneous rupture of a pancreatic pseudocyst into the stomach was considered. Laparotomy demonstrated an irregular black pancreatic cyst, and histological examination showed atypical spindle shaped cells with brown to black pigmentation, compatible with malignant melanoma. Autopsy confirmed the diagnosis of malignant melanoma involving the pancreas, stomach and other organs. Efforts to elucidate the primary site were unsuccessful, Metastatic melanoma without a primary site is well known and has been reported to occur in from 2.4% to 8.7% of all cases. This case suggests that malignant melanoma must be considered in cases of tumors with various symptoms and multiple metastases without a definite primary site.

Aged↗
PubMed1987

[A case report of malignant schwannoma originating from the bone].

While malignant schwannoma is encountered frequently as soft tissue sarcomas, it rarely is found to originate in the bone. We have had a case of malignant schwannoma originating from the tibia of a 47-year-old man. He died from uremia, that resulted from lung, spinal vertebral body, and lymph nodes metastases, despite surgical treatment and chemotherapy. In cases of rare bone tumors, the clinical diagnosis of tumoral manifestations originating in the bone is more important than the histopathological diagnosis.

Bone Neoplasms↗
PubMed1986

Comparison in man of short latency averaged evoked potentials recorded in thalamic and scalp hand zones of representation.

Recordings were performed in the thalamus of 13 patients suffering from either abnormal movements or intractable pain, with the aim of delimiting the region to be destroyed or stimulated in order to diminish the syndrome. In 11 of these patients averaged evoked potentials were recorded simultaneously from the scalp and specific thalamus (VP) hand area levels following median nerve stimulation. These recordings were done during the operation or afterwards when an electrode was left in place for a program of stimulation. The latencies of onsets and peaks on the scalp 'P15' were compared with those of the VP wave; a clear correspondence was found. Moreover, when increased stimulation was used, both waves began to develop in parallel. Thus in the contralateral 'P15' a component exists due to the field produced by the thalamic response. To explain the presence of an ipsilateral scalp 'P15' wave, we propose that a second wave having the same latency and a slightly shorter peak exists on the scalp due to a field produced by a brain-stem response. This double origin of 'P15' is also shown by the different changes which the ipsilateral and contralateral waves present during changes in alertness. The scalp 'N18-N20' is also composed of at least 2 components. The first peak appears on the scalp with a latency shorter than that of the negativity which develops in the thalamus. The N wave, moreover, increases in latency with rapid stimulus repetition. We propose with others that 'N18' is a cortical event reflecting the arrival of the thalamo-cortical volley. The second component, 'N20,' has a peak latency closely correlated to that of the thalamic negativity. This component was present alone in 'N' when rapid stimulation (greater than 4/sec) was used, which did not change the thalamic response. It must be a field produced by the thalamic negativity.

Electrodes↗
PubMed1986

Changes of somatosensory evoked potential accompanying ischaemia and hypoxia in cats.

Changes of evoked potential accompanying haemorrhagic hypotension and hypoxia were investigated on cats to evaluate the usefulness of SEP as a monitor in an intensive care unit (ICU), and the following results were obtained. Positive-negative diphasic potential was elicited at posterior sigmoid gyrus(PSG) by contralateral superficial radial nerve stimulation. This potential was recorded at the restricted area of the posterior border of PSG and regarded as primary somatosensory evoked potential. In the initial stage of haemorrhagic hypotension, both positive and negative components of SEP occasionally increased in amplitude. In profound hypotension in which CBF fell to less than the critical level of 30 ml 100 g-1 min-1, the latency was retarded and the amplitude was decreased. At CBE less than 10 ml 100 g-1 min-1, SEP disappeared. Within the range of CBF between 10 and 30 ml 100 g-1 min, a close correlation was noted between CBF and SEP amplitude. Transient increase of SEP amplitude was also observed during hypoxia induced by inhalation of nitrogen gas. (3) In normal state SEP was decreased in amplitude by conditioning stimulation of the nucleus lateralis posterior (LP nucleus) of the thalamus. This might be explained by the fact that intracortical inhibitory interneurons were activated by stimulation of LP nucleus. After haemorrhagic hypotension and hypoxia, however, the inhibitory effect on SEP elicited by LP nucleus stimulation attenuated or disappeared. Because of the initial impairment of the inhibitory interneurons by ischaemia and hypoxia, the amplitude of SEP might increase transiently. In conclusion, the authors thought that SEP might be less useful than EEG in ICU, because of its insensible change to hypoxia and ischaemia.

Animals↗
PubMed1986

[Massive osteoplastic bone metastasis of hepatocellular carcinoma--a case report].

Massive osteoplastic bone tumor in hepatocellular carcinoma is very rare. A 48-year-old man was misdiagnosed as osteosarcoma of the right proximal tibia with dense sclerosis and marked periosteal spiculation. Histologically, there were many osteoids and immature trabeculi. Tumor cells with spindle nuclei were not atypical and had few mitoses. Three years later, he suddenly died of rupture of cerebral aneurysm. Autopsy revealed small hepatocellular carcinoma with distant metastases of the tibia, lumbar spine and lung. In this case, it was extremely difficult to decide whether or not we were dealing with primary malignant tumor.

Bone Neoplasms↗