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Biomedical subjects

T Satou

Publications and source records attributed to T Satou.

At least 37 records · Page 2Linked to original sources

Expression of metabotropic glutamate receptor 5 is increased in astrocytes after kainate-induced epileptic seizures.

In the CNS there is a differential distribution of the metabotropic glutamate receptor 5 (mGluR5) in neurons and glia. Hippocampal nerve cells contain large amounts of the receptor transcript and protein that are expressed at very low levels in astrocytes. This is unexpected, as mGluR-induced phosphoinositide hydrolysis is substantial in cultured astrocytes and is mediated only by mGluR5 in these cells. In order to detect mGluR5 in astrocytes in vivo, we destroyed in a circumscribed part of the hippocampus nerve cells that have high level of receptor expression. Unilateral injection of kainate into the right amygdala produced epileptic seizures, as well as selective degeneration of nerve cells restricted to the ipsilateral CA3 and CA4 regions of the hippocampus, followed by the development of gliosis. In the affected fields only, mGluR5 immunoreactivity was severely reduced 3 days after kainate injection, followed by a progressive reappearance and lasting presence of the receptor protein. Receptor mRNA virtually disappeared from the pyramidal cell layer of the lesioned CA3/4 region. On the other hand, the message level increased persistently in the CA3 stratum lucidum and radiatum, the site of massive astrogliosis. In these sites, mGluR5 mRNA became detectable in double labeling studies in glial fibrillary acidic protein-positive astrocytes. We showed previously that growth factors induce a pronounced elevation of mGluR5 expression in cultured astrocytes (Miller et al. J Neurosci 15:-6109, 1995). The well-documented increase in the level of growth factors in the damaged brain may underlie the induction of the receptor expression in astrocytes in vivo, which may also be involved in repair processes in the injured nervous tissue.

Amygdala↗

[IFOBT-positive gastric cancer].

Among 888 patients who underwent operation or endoscopic resection for gastric cancer (1994-1998), 75 patients, who had no colorectal disease or only small polyps 5 mm or less in diameter, were positive on the immunologic fecal occult blood test (IFOBT) (the positive group). They are compared with the other 813 patients (the negative group) as to the following 6 points: symptoms, presence of anemia, depth of invasion including macroscopic appearance, location, maximum diameter of lesions, and microscopic findings. The rate of positive-IFOBT gastric cancer was 8.4%. The average blood hemoglobin concentration was significantly lower in the positive group than in the negative group. Advanced cancers, especially type 2 and 3, were significantly more frequent in the positive group than in the negative group. The size of the lesions tended to be larger in the positive group than in the negative group. There was no difference between the groups as to symptoms, location, depth of invasion and microscopic findings. In conclusion, IFOBT-positive patients who have no colorectal disease or only small polyps 5 mm or less in diameter should be recommended to undergo upper gastrointestinal endoscopy.

Female↗

[A Warthin's tumor showing extensive necrosis].

Warthin's tumors are one of the most easily recognizable tumors using light microscopy. However, histopathological diagnosis is difficult in a few cases when characteristic cystic cavities with papillary walling and underlying lymphoid stroma are obscured by reactive changes. We describe a case of an extirpated Warthin's tumor of the right parotid gland which demonstrated extensive necrosis, squamous metaplasia and xanthomatous inflammation. No characteristic structure for this tumor was noticed in a section of an initially sampled specimen. As a result, a destroyed fistula was suspected. An additional sampling was performed to confirm the diagnosis and the sampled specimen fortunately demonstrated the diagnostic structure of a Warthin's tumor excluding malignancy. An awareness of the morphological variation seen in this tumor should lead to additional sampling of specimens, thereby preventing erroneous interpretation.

Adenolymphoma↗

Steroidal saponins from the bulbs of Lilium candidum.

Five new spirostanol saponins and a new furostanol saponin were isolated from the fresh bulbs of Lilium candidum. Their structures were elucidated on the basis of spectroscopic analysis, including two-dimensional NMR spectroscopic techniques and the result of acid hydrolysis. The isolated saponins contained a branched triglycoside moiety assigned as O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->6)]-beta - D-glucopyranose with the formation of an O-glycosidic linkage to C-3 of the aglycone as the common structural feature. The inhibitory activity of the saponins on Na+/K+ ATPase was evaluated.

Carbohydrate Conformation↗

A sudden death case of laryngocele accompanied by infarction of the dorso-lateral portion of the medulla oblongata.

A 70-year-old man, who had a laryngeal tumor discovered by otolaryngological examination during admission for suspicion of facial nerve paralysis was found dead in his bed on the seventh hospital day. Clinical doctors aspirated a large amount of mucous sputum from his larynx during their attempt at resuscitation. Although the direct cause of death was clinically unknown, an autopsy revealed an internal type laryngocele, a type of laryngeal cyst, in the right larynx and infarction of the left dorso-lateral portion of the medulla oblongata. Suffocation resulted from mucous sputum filling his larynx, which had been narrowed by a laryngocele from the right, in an unfortunate association with movement disturbance of the left larynx caused by the infarction of the left dorso-lateral portion of the medulla oblongata. We assumed this to be the direct cause of death, because the heart and lungs showed no remarkable changes that could be ascribed to it. This case offers important suggestions concerning the risks of suffocation due to laryngeal cysts, especially in patients with complications.

Journal Article↗

Smooth muscle tumors of the esophagus: clinicopathological findings in six patients.

Preoperatively, it is difficult to discriminate leiomyoma and leiomyosarcoma of the esophagus, which are rare smooth muscle tumors. The objective of this study was to evaluate the clinicopathological findings of this unusual lesion. A search of the surgery archives of the Toyama Prefectural Central Hospital of Pathology revealed six cases of esophageal smooth muscle tumors. Clinicopathological findings were reviewed retrospectively. Only three patients (50%) presented with dysphagia, and the remaining three patients were asymptomatic. These patients underwent surgical excision. Histologically four of the six tumors were leiomyomas, and the other two tumors were leiomyosarcomas. Two tumors were in the upper to middle esophagus, and the remaining four were in the distal esophagus. On endoscopic examination, all tumors were noted to be polypoid. The two leiomyosarcomas measured over 5 cm and the four leiomyomas less than 4 cm. Neither ulceration nor necrosis proved to be of use in discriminating leiomyoma and leiomyosarcoma. The two patients with leiomyosarcoma died of liver metastasis 10 and 22 months after the treatment. Patients with leiomyosarcoma presented with distant metastasis and/or recurrence, with hematogeneous metastasis being the predominant type of recurrence.

Adult↗

Simple and reproducible model of rat spinal cord injury induced by a controlled cortical impact device.

Consistently reproducible experimental trauma was inflicted on the rat spinal cord (L3-L4) employing a controlled cortical impact device. The spinal cord was injured with one of three sizes of chips; thick (3 mm diameter), medium (2 mm diameter), thin (1 mm diameter). Each chip was applied at 1, 2 and 3 mm deformation depths. The correlations of the magnitude of the primary trauma were examined histopathologically. It was found that the extent and intensity of the trauma could be changed by altering the depth of deformation and the chip diameter at a fixed velocity of 4.6 m per sec. The injury caused by the 2 mm diameter chip at 0.5 mm-deformation damaged one to two segments of the perifocal spinal cord. In the surviving animals, the histological changes could be classified as primary, secondary, and late phase changes, and finally the lesion became a cavity. This study reports the application of a controlled cortical impact device to morphological research on a spinal cord injury. We found that the injury by the 2 mm chip at 0.5 mm deformation was the most advantageous and reproducible model for further investigations.

Animals↗

Esophageal sarcomas: report of three cases.

BACKGROUND/AIMS: Sarcomas of the esophagus, including carcinosarcoma, are rare neoplasms. METHODS: The clinical and pathologic characteristics of 3 patients with esophageal sarcomas are presented, including the only recorded esophageal carcinosarcoma and 2 patients with leiomyosarcoma. RESULTS: All 3 patients were males who presented with dysphagia or an abnormal shadow of the mediastinum on a plain chest X-ray. Two tumors were in the middle esophagus, and the remaining one was in the distal esophagus. On endoscopic examination, all three tumors were noted to be polypoid. These patients underwent surgical excision. One patient died 7 days following the operation, and the remaining 2 patients died of liver metastasis 10 and 22 months following the treatment. CONCLUSION: Esophagectomy or esophagogastrectomy is a surgical choice. Even if metastases are present, a palliative resection can still be performed.

Aged↗

Nematocidal activity of picrodendrins against a species of diplogastridae.

To develop parasiticides, the nematocidal activity of 22 picrotoxane terpenoids, picrodendrins isolated from the Euphorbiaceae plant Picrodendron baccatum (L.) KLUG et URBAN, was measured using a species of Diplogastridae (Nematoda). Picrodendrin P displayed the most potent nematocidal activity with a minimum lethal concentration (MLC) value of 4.4 x 10(-3) M. The nematocidal activity of picrodendrin P was 9-fold more potent than that of kainic acid (4.0 x 10(-2) M) and santonin (4.0 x 10(-2) M) and 6-fold more potent than that of diethylcarbamazine citrate (3.0 x 10(-2) M). Thus, picrodendrin P may eventually be used as a leading parasiticide. In light of the relationship between the structure of picrodendrins and their nematocidal activities, potent nematocidal activity was found to require the following elements within the picrotoxane skeleton: the gamma-lactone that bridges C-3 and C-5, the epoxide group that bridges between C-6 and C-8, a cis-OCH3 group and a trans-CH2OH group related to carbonyl at alpha-methylene-gamma-lactone ring (C-18), and the absence of 4- and 8-hydroxyl groups. These results are the first demonstration of nematocidal activity for these terpenes and thus are important in furthering our understanding.

Animals↗

[Indication of repeat prostatic biopsy following previous negative findings].

BACKGROUND: Many men with clinically suspicious findings would not be diagnosed to have prostate cancer. Establishing criteria for indicating repeat biopsy is imperative for early detection of prostate cancer. METHODS: Eighty-one patients underwent repeat prostatic biopsies under sonographic guidance at Kitasato University Hospital between March 1992 and October 1996. Clinicopathological parameters such as age, prostate specific antigen (PSA), PSA adjusted for transition zone volume (PSAT), PSA density (PSAD), PSA velocity, transition zone volume, prostatic volume, rectal findings, ultrasound findings and initial biopsy histology were compared with the results of repeat biopsy for searching for possible predictors of positive biopsy. RESULTS: Cancer was confirmed in 14 patients (17.3%), 10 patients by the second biopsy (15.4%, 10/65) and 4 patients by the third biopsy (28.6%, 4/14). No cancer was found at the 4th or more biopsies. Twelve (85.7%) of these patients had prostatic volume less than 40 cm3. Univariate analysis indicated PSAT, PSAD, transition zone volume and prostatic volume to be more frequent in men with positive biopsies (p < 0.05). But multivariate logistic regression analysis failed to identify any significant predictors of positive results in repeat biopsies. CONCLUSIONS: No clinicopathological parameters could reliably predict repeat biopsy findings. One or 2 additional sets of biopsies is recommended based on clinical judgement (symptoms, life expectancy, small glands < or = 40 cm3 etc.) for the purpose of early detection of prostate cancer in patients with previously negative biopsy but still with suspicious findings in consideration of approximately 20% false negative rates by the initial biopsy.

Aged↗

[Subcutaneous phaeohyphomycosis of the right thumb].

Black fungi are a group of fungi that are characterized by the development of a pale brown to black color in the cell walls of their vegetative cells, conidia, or both. A mycotic infection caused by a member of black fungi can be subdivided into three clinical entities: phaeohyphomycosis, chromoblastomycosis, and mycetoma. Phaeohyphomycosis is distinguished from mycetoma by the absence of grain (organized, interwoven mycelial aggregates) formation, and from chromoblastomycosis by the absence of sclerotic bodies (thick-walled muriform cells). Phaeohyphomycosis is a rare disease and has been sporadically reported. In the present report, phaeohyphomycosis of the right thumb of a 72-year-old man was presented. A precipitating trauma of two months earlier at the site was recalled. A solitary mass, 10 mm in diameter, was gradually formed in the palm side of the distal right thumb and finally resected. Histological examination disclosed a solitary granulomatous lesion surrounded by an incomplete fibrous capsule. The lesion mainly involved subcutaneous tissue and was composed of multiple pyogranulomas. Pigmented branched septate hyphae and yeast-like cells were sparsely found in the periphery of the abscess and within histiocytic cells of the granulomas. No sclerotic cells were detected. When pigmentation of black fungi in tissue is as faint as in the present case, Fontana-Masson staining is useful to accentuate the presence of melanin-like pigment of fungal cell walls.

Aged↗

A new subculture and nematocidal assay using a species of diplogastridae.

A new subculture method and a novel microplate assay for nematocidal activity using a species of Diplogastridae have been developed. The assay gives results rapidly, with high sensitivity in 4 h, and indicated good correlation between action mechanism and the nematode shape when examining 15 known compounds, including the antiparasitic avermectin, antimalarial quinine, and the gamma-amino-n-butyric acidA (GABAA) activated Cl- channel antagonist picrotoxinin. Thus new assay could be used as a primary screening method for new nematocidal compounds.

Animals↗

New steroidal constituents from the bulbs of Lilium candidum.

Eight spirostanol saponins, including four new compounds, and two known furostanol saponins were isolated from the fresh bulbs of Lilium candidum. The structures of new compounds were determined to be (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->4)] -beta-D-glucopyranoside¿, (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-O-[6-O-acetyl-beta-D-glucopyranos yl- (1-->4)]-beta-D-glucopyranoside¿, (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside¿ and (25S)-spirost-5-ene-3 beta,27-diol 3-O-¿O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O - [beta-D-glucopyranosyl-(1-->4)]-beta-D-glucopyranoside¿, respectively, on the basis of spectroscopic analysis, including two-dimensional NMR techniques, and the result of hydrolysis. The inhibitory activity of the isolated saponins on Na+/K+ ATPase was evaluated.

Carbohydrate Sequence↗

[The immunoreactivity studies of the idiopathic inflammatory myopathy over the past three years in our laboratory].

Biopsied skeletal muscles from patients with inflammatory myopathy (6 cases of polymyositis (PM), 2 cases of dermatomyositis (DM), 5 cases of collagen disease with polymyositis and a case of allergic granulomatous angitis) were examined by comparing immunostained infiltrated cells at perivascular, perimysial and the endomysial sites as well as examining the histochemical findings on serial frozen sections from cases examined by our laboratory over the past three years. CD68 was used for macrophage, L26 for B lymphocytes, CD4 and CD8 for T lymphocytes. Expression of HLA-ABC was examined for Class I antigen and HLA-DR for Class II antigen on the muscle fibers. Many macrophages and CD8-positive T lymphocytes had infiltrated the endomysium in PM. Many CD4-positive T lymphocytes and L26-positive B lymphocytes had infiltrated perivascular sites in DM. These results were almost the same as those in many other reports. HLA-ABC was positive on the muscle sarcolemma in all cases. However, the expression of HLA-DR was not identical in all cases. It is useful to determine the diagnosis and consider a pathogenesis of inflammatory muscle diseases to analyze the infiltrated cells and the site of infiltration even in case showing few of infiltrating cells and necrotic fibers.

Adult↗

[Pagetoid spread of intratubular germ cell neoplasia into rete testis forming tumor-like mass].

Intratubular germ cell neoplasia (ITGCN) is the preinvasive phase of testicular germ cell tumors. ITGCN can spread into the rete testis in a pagetoid manner, but there are very few published data about this phenomenon. Furthermore, the tumor-like mass formed by ITGCN with pagetoid spread into the rete testis has not been documented to date, and the present case is the first to be reported. A tumor-like mass was found close to the superior pole of the left testis in a 39-year-old male and was unrelated to the epididymis. Three other nodules of seminoma surrounded by fibroconnective tissue existed next to the mass. Histological sections revealed ITGCN which was characterized by the presence of large and polygonal germ cells exhibiting clear cytoplasm with distinct cell borders. The cytoplasm was rich in glycogen and the cell membrane was immunohistochemically positive for placental alkaline phosphatase. The nuclei had less coarse chromatin than that of seminoma. ITGCN cells spread in between the lining epithelium of the rete and the basement membrane. This characteristic spread was consistent with pagetoid spread into the rete testis.

Adult↗