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Biomedical subjects

S Maejima

Publications and source records attributed to S Maejima.

At least 19 recordsLinked to original sources
PubMed1996

Comparative study of CA242 and CA19-9 in chronic pancreatitis.

CA242 has been proved to be useful in the diagnosis of pancreatic cancer. The aim of the present study was to clarify the mechanisms contributing to the high specificity of CA242 as compared with CA19-9 resulting from scarce serum elevation of this antigen in patients with chronic pancreatitis by correlating serum levels and endoscopic retrograde choledocho-pancreatography (ERCP) findings and by immunohistochemical analysis. Serum CA19-9 levels were significantly elevated in patients with calcification and with main pancreatic duct (MPD) stenosis or obstruction. On the other hand, serum CA242 levels showed no significant elevation in patients with such factors. Even though such pathological conditions were considered to lead to the stagnation of pancreatic juice, serum CA242 levels seemed to be less affected than serum CA19-9 levels. Immunohistochemical studies of chronic pancreatitis tissues revealed that CA242 was expressed less frequently and less intensely than CA19-9, and the difference in expression was more prominent in the centroacinar cells and terminal ductules. From the results of the present study, it is conceivable that CA242 is less influenced by the stagnation of the pancreatic juice than CA19-9 because of the low levels of expression in ductal systems, which results in the release of this antigen into the circulation in lower amounts than that of CA19-9.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

Mandibular reconstruction using computer-generated three-dimensional solid models.

In mandibular reconstruction, it is necessary to know the exact, three-dimensional extent of the mandible and its defect; the bone graft must be the exact size and dimension of the defect, to assure a precise three-dimensional configuration of the mandible. Previously, the bone graft had to be reshaped during the operation by trial and error, often a time-consuming procedure. The operative procedure has been simulated in advance using three-dimensional, solid models, which has shortened the operating time required.

Bone Transplantation↗
PubMed1993

Thalamic neuronal hyperactivity following transection of the spinothalamic tract in the cat: involvement of N-methyl-D-aspartate receptor.

Single neuron activities responding to peripheral stimuli with short latencies were recorded within the thalamic nucleus ventralis posterolateralis (VPL) after transection of the spinothalamic tract (STT) in the cat under alpha-chloralose anesthesia. The VPL neurons showed spontaneous and evoked hyperactivity after STT transection, which was revealed at 1-2 weeks. The spontaneous hyperactivity further progressed until 3-4 weeks. These hyperactivities were observed in core-area neurons as well as neurons found in the shell area, suggesting that some, if not many, of the N-methyl-D-aspartate (NMDA) receptor antagonist (MK-801, 4-16 mg; i.v.) attenuated both the spontaneous and evoked hyperactivity observed after STT transection. No such effects were demonstrated in sham-operated animals. These findings suggest that VPL neurons become hyperactive after STT transection through recruitment of NMDA receptors. The hyperactivity of VPL neurons may represent an important background process in the production of deafferentation pain induced by lesions involving the STT.

Amino Acids↗
PubMed1993

Dynamic changes in cytochrome oxidase activity in the rat somatosensory cortex following thalamocortical deafferentation.

The changes in cytochrome oxidase (CYO) activity in the primary somatosensory cortex (SI) induced by unilateral lesions restricted to the posterior ventrobasal region of the thalamus were investigated by histochemical techniques and photometric semi-quantitation in the rat. The CYO activity decreased rapidly and dramatically in layer IV of the lesioned side, reaching its lowest level within 2 weeks, and remained depressed at 8 weeks post-lesion. Segmentations normally seen in layer IV corresponding to barrels remained absent. While less marked decreases were also noted in other layers, obvious recovery was subsequently observed, attaining levels comparable to those on the intact size at 6 or 8 weeks post-lesion. The persistent decrease in layer IV appears to reflect a reduced thalamocortical activation of the dendritic profiles and neuronal perikarya. The recovery in other layers may represent an increase in the resting level of the initially depressed neuronal activity near to the original levels. The persistent reduction of function in the inhibitory surround, which is normally activated by thalamocortical input, may contribute to the increase in CYO activity.

Afferent Pathways↗
PubMed1993

T-cell non-Hodgkin's lymphoma of the lung.

We report a case of primary T-cell non-Hodgkin's lymphoma of the lung. A definite diagnosis was made histologically at open lung biopsy. Atypical cells in the biopsy specimen reacted with monoclonal T-cell markers. Transbronchial lung biopsy and bronchoalveolar lavage fluid were useful in the diagnosis. Primary T-cell lymphoma of the lung is rare and is reviewed in this report.

Adult↗
PubMed1990

Spinal cord responses to feline transcranial brain stimulation: evidence for involvement of cerebellar pathways.

The physiological characteristics of spinal cord responses recorded from the spinal epidural space of the cat to transcranial brain stimulation were studied, in comparison with the spinal cord responses to direct stimulation of the motor cortex or cerebellum. The conduction velocity of the initial wave of the responses to transcranial brain stimulation (122.3 +/- 16.3 m/sec mean +/- SD, n = 5) was much faster than the conduction velocity of the initial wave of the responses to motor cortex stimulation (68.3 +/- 14.7, n = 5) and similar to the conduction velocity of the initial wave of the responses to cerebellar stimulation (120.2 +/- 16.2, n = 5). Furthermore, the conduction velocity of any component in the subsequent polyphasic waves at any intensity was not similar to the conduction velocity of the initial wave of the responses to motor cortex stimulation. All components of the responses to motor cortex stimulation disappeared after intercollicular transection. In contrast, the initial wave of the responses to cerebellar stimulation and transcranial brain stimulation remained unaffected by intercollicular transection. The initial wave caused by anodal transcranial brain stimulation was eliminated by ablation of the cerebellum. However, cathodal transcranial brain stimulation sometimes can produce an initial wave that can be eliminated only by transection at the medullospinal junction. The initial wave of the responses to cerebellar stimulation was largest in amplitude when the vicinity of the dentate nucleus was stimulated. These results suggest that responses to activation of the cerebellum, rather than corticospinal neurons arising from the motor cortex, represent a major component of the spinal cord responses to transcranial brain stimulation in cats. The data obtained indicate that it is difficult to activate the motor cortex selectively by transcranial brain stimulation in cats.

Animals↗
PubMed1990

[Roentgenographic manifestations of peripheral bronchogenic carcinomas].

Peripheral bronchogenic carcinomas in early clinical stage are discovered by plain chest roentgenogram, and good prognosis will be expected by surgical resection. 20 bronchogenic carcinomas (18 adenocarcinomas, one squamous cell carcinoma, and one large cell carcinoma) in 19 patients were examined. 9 cases presented noduler lesion on the plain chest roentgenogram, and the other presented 7 focal patchy shadow and 4 band-like shadow. Thin-section CT could demonstrated indented pleura (95%), notch (95%), convergence of peripheral vessels (70%), irregular border (75%). In adenocarcinomas, thin-section CT demonstrated airbronchogram or airbronchiologram (61%), multiple small cavitation (61%), and heterogeneous density (56%). CT-pathologic correlation proved thin-section CT could demonstrate tumor's internal texture and fine detail of tumor-lung interface. Small peripheral lung cancer in early stage could be discovered by plain chest roentgenogram, and thin-section CT was useful for the diagnosis of small peripheral bronchogenic carcinomas, especially adenocarcinomas.

Adenocarcinoma↗
PubMed1989

Changes in serum levels of Forssman-like antibody in patients with gastric cancer.

Because Forssman antigen, one of the most well-known heteroantigens, has been noted in certain cancerous tissues, it would seem that the serum levels of the Forssman antibody of patients with these cancers would be low, owing to the absorption of the naturally occurring antibody by the Forssman antigen-containing cancerous tissues. This hypothesis was tested by researchers assessing the serum hemolysin titers of 174 patients with cancer (gastric cancer, 100; colonic cancer, 40; and other cancers, 45) and of 856 age-matched, sex-matched, and blood type-matched healthy individuals against the serum levels of sheep red blood cells. Serum levels of the hemolysin of patients with gastric cancer tend to be lower than those of patients with other types of cancer and also lower than those of age-matched and sex-matched controls. The decrease was especially prominent in patients with moderately differentiated adenocarcinoma of the stomach. Preoperative and postoperative serum samples of 40 patients with gastric cancer were analyzed therefore to determine the effect of surgically removing the cancer on the serum level of the hemolysin. The results showed that the serum levels of the hemolysin antibody increased in all 40 patients after the successful surgical removal of the cancer. However, in patients with recurrence of the cancer, the serum levels of hemolysin decreased again in 11 of 11 patients. These results indicate that the serum levels of the Forssman-like hemolysin could be used as an index of recurrence in patients with gastric cancer after surgical removal of the cancer.

Adenocarcinoma↗
PubMed1989

[Delayed radiation necrosis of the temporal lobe following radiation therapy of maxillary carcinoma].

A case of delayed radiation necrosis following radiation therapy for maxillary carcinoma was reported. The diagnosis of this case for the radiation necrosis was clinically suggestive and established by the pathological findings of autopsy. This 66 year-old man had been treated by the partial resection for the right maxillary carcinoma with chemotherapy (pepleomycin 110 mg, adriamycin 20 mg). Pre- and postoperatively total dose of 5040 rads were irradiated with cobalt therapy during 42 days at a dose of 180 rads and 5 times in a week through two ports at 8 x 8 cm field including right orbital region. Three years 7 months after radiation therapy he complained of disorientation, recent memory disturbance and slight left hemiparesis. On enhanced CT irregular ring enhanced mass lesion was seen in left temporal lobe inside the radiation field with extensive low density over temporal lobe on plain CT. MR imaging demonstrated that T 1-weighted spin echo images with a 50-msec repetition time (TR) and 22-msec echo time (TE) had irregular low signal intensity and extensive high signal intensity combined with partially low intensity in the central area on T2 weighted spin echo images with 2300 msec TR and 100 msec TR. There were not appeared vascular obstruction and stenosis on right carotid angiogram. He improved remarkably on clinical symptoms and CT by treating of dexamethasone and osmotic diuretics, but died of pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Preoperative determination of the level of spinal cord lesions from the killed end potential.

To determine preoperatively the level of lesions in acute cervical cord injury, the killed end potential of the spinal cord was recorded with a pair of electrodes placed in the spinal epidural space, one initially being placed rostrally to the lesions for obtaining recordings and the other placed caudally to the lesions for stimulation. The level associated with the largest killed end potential was clearly determined without much difficulty, with sequential recordings on stepwise withdrawal of the recording electrode, in four of five cases investigated. In two cases subjected to surgery, the recording electrode left in place at the level associated with the largest killed end potential was found to be located at, or a few millimeters below, the center of the lesions. This demonstrates the preoperative localizing value of the killed end potential for determining the level of lesions responsible for myelopathy.

Evoked Potentials↗
PubMed1988

Corticospinal direct response in humans: identification of the motor cortex during intracranial surgery under general anaesthesia.

The corticospinal direct (D) response to stimulation of the motor cortex exposed for intracranial surgery was recorded in 20 cases from wire electrodes inserted into the spinal epidural space. The D response was obtained from stimulation of restricted areas of the cerebral cortex, that is, the hand, trunk and thigh areas of the motor cortex. The D response was resistant to anaesthesia and unaffected by muscle relaxants. Thus, recordings of the D response are useful for identifying the location of the motor cortex during intracranial surgery under general anaesthesia.

Anesthesia, General↗
PubMed1987

Meningeal chondrosarcomatous tumor associated with meningocytic differentiation.

Most meningeal chondrosarcomatous tumors have been regarded as identical to similar tumors occurring elsewhere in the body. The neoplasm reported here, however, clearly demonstrated transitions between usual meningiomas and chondrosarcomatous tumors. The present case thus provides evidence in support of Cushing's and Eisenhardt's proposal that some meningeal chondrosarcomatous tumors are derived from meningeal cells and are histogenetically related to meningiomas.

Aged↗
PubMed1986

Responses of raphe-spinal neurons to stimulation of the pontine parabrachial region producing behavioral nociceptive suppression in the cat.

Cholinergic stimulation of the pontine parabrachial region (PBR) produces behavioral nociceptive suppression in the awake cat. This report shows that electrical stimulation of both PBR sites (verified to be associated with behavioral nociceptive suppression on cholinergic stimulation) and the periaqueductal gray (PAG) excites raphe-spinal neurons which have been implicated in descending nociceptive suppression. Although several lines of evidence have strongly indicated that pathways from the PBR and PAG for nociceptive suppression are anatomically as well as neurochemically distinct, the results of the present study appear to suggest that certain components of the pathways from the PBR may be synergic in function with those from the PAG with regard to the activity of raphe-spinal neurons.

Animals↗