Biomedical subjects

Y Sawamura

Publications and source records attributed to Y Sawamura.

At least 145 records · Page 8Linked to original sources

PubMed1995

Synchronous patchy pattern of gene expression for adenylyl cyclase and phosphodiesterase but discrete expression for G-protein in developing rat striatum.

The ontogeny of the gene expression for striatal adenylyl cyclase (AC), 63 kDa calmodulin-dependent phosphodiesterase (63 kDa CaM-PDE) and olfactory G-protein (Golf), all of which are expressed predominantly in the striatum, was studied by in situ hybridization histochemistry. In the peri- and early postnatal striatum, the gene expression for striatal AC and 63 kDa CaM-PDE showed a patchy pattern corresponding to the striatal patchy compartments enriched in several molecules involved in cAMP-signaling system including DARPP-32 (a dopamine and cyclic adenosine 3':5'-monophosphate-regulated phosphoprotein with an apparent M(r) of 32,000). On the other hand, Golf showed a homogeneous expression pattern throughout the striatal development. The present finding suggests that the gene expression for the three molecules directly involved in the cAMP-generating and degrading system is differentially regulated during the striatal development.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1995

Magnetic resonance images reveal a high incidence of asymptomatic pineal cysts in young women.

MACROSCOPIC BENIGN PINEAL cysts, according to previous reports, may preferentially occur in the young population at the fourth decade; symptomatic pineal cysts have been found mainly in females. To confirm the relationship of age and sex to the incidence of pineal cysts, we reviewed 8623 consecutive magnetic resonance images in 6023 patients. Tiny and obscure cysts in the pineal gland were ignored; only the pineal cysts > 5 mm were examined. The cysts were encountered in 79 (1.3%) of 6023 patients evaluated. The cysts predominantly occurred in females; we found 29 cysts in 3008 males and 50 cysts in 3015 females (P < 0.05). Young adults had higher incidence of these cysts, with a peak incidence occurring between the ages of 21 and 30 years, then the incidence gradually decreased with age. We found no significant age distribution in males. However, among all groups, young women between the ages of 21 and 30 years had the highest frequency (5.82%). The incidence of pineal cysts among women between the ages of 21 and 30 years was significantly higher than in any other group (P < 0.001; 21-30 versus 51-60, 61-70, and 71-80). In females, when the incidence below the age of 41 was compared with that above or equal to 41, the z score was 4.98 (P < 0.001). The cystic expansion of the pineal gland in females appeared to begin at adolescence, and presumably the pineal gland decreases in size with aging. In this article, we will also speculate about the relationship of these changes to the secretory activity of the pineal glands.

Adolescent↗

PubMed1995

Surgical indication and results of foramen magnum decompression versus syringosubarachnoid shunting for syringomyelia associated with Chiari I malformation.

Several surgical procedures have been used for the treatment of syringomyelia associated with Chiari I malformation at our institute. The purpose of this article is to evaluate the results of two major surgical procedures, foramen magnum decompression (FMD) and syringosubarachnoid (SS) shunting. The series consisted of 70 patients with syringomyelia associated with Chiari I malformation who were surgically treated. Their ages ranged from 3 to 59 years (median, 29.4 yr). FMD was performed on 33 patients, and SS shunting was performed on 37 patients. The follow-up period ranged from 6 months to 12.5 years, with a mean of 60 months. The clinical and radiological outcomes were analyzed comparing the two groups. We principally performed FMD in patients with symptoms of Chiari I malformation and/or a small syrinx. We prefer to use SS shunting in patients with large syringes. Postoperative magnetic resonance imaging demonstrated that the syrinx had collapsed or decreased in size in 94% of the patients who underwent FMD and in 100% of the patients who underwent SS shunting. Neurological improvements were observed in 82% and in 97% of the patients who underwent FMD and SS shunting, respectively. In particular, the relief of pain was more fully achieved after SS shunting than after FMD. The average time for the syrinx to collapse was 6.3 weeks after surgery in the FMD group and 1.8 weeks in the SS shunting group. These results indicate that clinical symptoms and radiological findings improved much more quickly in the SS shunting group than in the FMD group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

p55 and p75 tumor necrosis factor receptor expression on human glioblastoma cells.

Expression of the two types of tumor necrosis factor (TNF) receptor, p55 and p75, in 12 human glioblastoma cell lines was studied. Reverse-transcription polymerase chain reaction detected messenger ribonucleic acid (mRNA) transcripts of p55 TNF receptor in all 12 cell lines tested, but p75 TNF receptor mRNA in only four cell lines. Flow cytometric analysis with anti-p55 and anti-p75 TNF receptor monoclonal antibodies demonstrated both p55 and p75 proteins in these four cell lines, but the level of expression of p75 molecule was very low. Correlation of p55 and p75 TNF receptor expression with TNF-induced growth suppression and production of bioactive molecules (interleukin-6, interleukin-8, manganase-superoxide dismutase, prostaglandin E2) showed that p55 TNF receptor mediates these TNF actions, but none of the responses were influenced by the presence of the p75 TNF receptor, which apparently has no specific role.

Base Sequence↗

PubMed1995

Molecular species of phospholipids of interleukin-2-dependent murine cytotoxic T lymphocytes.

We reported that phospholipids of interleukin-2 (IL-2)-dependent murine cytotoxic T lymphocytes (CTL) contained high amounts of ether lipids (Biochem. Mol. Biol. Int., 33, 137-146, 1994). In this study, the molecular species of fatty acids at the sn-1 and sn-2 positions were determined. First, phosphatidylcholine mainly consisted of the 1,2-diacyl subclass (78%) in which the major molecular species was 16:0/18:1 (24%). It should be noted that arachidonic acid was abundant in both 1-O-alkyl-2-acyl subclasses in the form of 18:0/20:4 (21%) even though the content of the subclass was low (8%). Second, phosphatidylethanolamine mainly consisted of ether subclasses (93%) and contained a large amount of arachidonic acid in the forms of either 18:0/20:4 (19%) or 16:0/20:4 (10%). Third, phosphatidylinositol, a putative phospholipid involved in transmembrane signal transduction, had a significant amount of arachidonic acid at the sn-2 positions of 1,2-diacyl and 1-O-alkyl-2-acyl subclasses. Fourth, phosphatidylserine, consisting of mostly the 1-O-alkyl-2-acyl subclass (86%), contained arachidonic acid dominantly in the form of 18:0/20:4 (33%). Considering these results, it appears that CTL have the potential to mediate its signal transduction mediated by the bioactive lipids, i.e. arachidonic acid metabolites and the ether lipids.

Animals↗

PubMed1994

Antiproliferative effect of tumor necrosis factor-alpha on human glioblastoma cells linked with cell cycle arrest in G1 phase.

The effects of tumor necrosis factor-alpha (TNF) on proliferation and cell cycle alterations in human malignant glioma cell lines, SF-188 and LN-382, were investigated by flow cytometry with the bromodeoxyuridine-propidium iodide dual staining technique. Low concentrations of TNF (1-100 U/ml) suppressed the growth of SF-188 assessed by cell count, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, and thymidine incorporation assay, but not that of LN-382. After TNF treatment, the percentage of SF-188 cells in the G0/G1 phase increased, while the percentage of cells in the S phase decreased. LN-382 cells did not show any marked change in cell kinetics. TNF arrests certain human glioma cells in the G0/G1 phase resulting in reduction of deoxyribonucleic acid synthesis in the subsequent S phase, suppressing the proliferation pathway.

Brain Neoplasms↗

PubMed1994

[Sealing effect of fibrin glue spray on protection of cerebrospinal fluid leakage through the dura mata].

Fibrin glue, a biologic adhesive, is made with highly concentrated human fibrinogen and clotting factors. It has become used frequently in neurosurgical procedures, in particular in the closure of the dura mata to prevent cerebrospinal fluid leakage. This report evaluates sealing effects of the fibrin glue on cerebrospinal fluid leakage through the dura. (1) Three manipulations for application of fibrin glue were used; i.e., layer, mixture and spray methods. These methods were compared to estimate their sealing effects on water leakage through a 1.2mm pore in an artificial dura. The burst pressure was significantly higher when the spray method was used than when the other two methods were used. (2) Dural incision was made and then sutured at intervals of 2mm, 3mm, 4mm, 6mm, and 8mm. Fibrin glue was applied by a spray method on the sutured dura. The burst pressure of the fibrin plate was over 80cmH2O on every interval of dural suture. (3) Dural defects 2mm, 4mm, 6mm, and 8mm in diameter were made, and then spray of fibrin glue was used to shield the defects. The fibrin clot spreading to the inner and outer surfaces of the pore defect was plug-shaped. The fibrin plug tolerated water pressure over 200cmH2O, in every size of pore. In conclusion, the optimal method for using fibrin glue on the surface of the dura was a spray method. Fibrin plate/clot made by the spray method sealed the dural tear or pore so well that it sustained a water pressure of over 80cmH2O, which is far higher than normal pressure of the intracranial cerebrospinal fluid.

Cerebrospinal Fluid Rhinorrhea↗

PubMed1994

The role of ether-linked glycerophospholipids in cytotoxic T lymphocytes.

We determined the contents of ether-linked glycerophospholipids of murine cytotoxic T lymphocytes (CTL) to evaluate their biological functions. After purifying each glycerophospholipid, we prepared diradylglycerobenzoates after hydrolysis with phospholipase C to separate them into three subclasses, 1,2-diacyl-sn-glycero-3-benzoates, 1-O-alkyl-2-acyl-sn-glycero-3-benzoates, and 1-O-alk-1'-enyl-2-acyl-sn-glycero-3-benzoates. The results showed that the membrane of murine CTL consisted of a large amount of ether-linked glycerophospholipids; contents of 1-O-alkyl-2-acyl-sn-glycero-3-benzoates and 1-O-alk-1'-enyl-2-acyl-sn-glycero-3-benzoates in the total phospholipid were 39.3% and 23.7%, respectively. From these results, it is considered that the ether-linked glycerophospholipids of the biological membranes not only contribute to the membrane stability but also exert a tumoricidal effect or induce cell differentiation by releasing ether-linked lipid metabolites.

Animals↗

PubMed1993

The cerebrospinal fluid in patients with moyamoya disease (spontaneous occlusion of the circle of Willis) contains high level of basic fibroblast growth factor.

The level of basic fibroblast growth factor (bFGF) in cerebrospinal fluid (CF) was measured by an EIA in 15 patients with moyamoya disease, in 11 patients with atherosclerotic occlusive disease, and in 8 patients with spinal disc disease. In the moyamoya patients, bFGF was found in 13 out of 15 CF samples with a mean value of 101 pg/ml. However, bFGF was detected in only 4 out of 11 patients with atherosclerotic disease with a mean of 8 pg/ml. In all the patients with disc disease, bFGF was not detected. The elevated level of bFGF may play a crucial role in the pathogenesis of moyamoya disease.

Adult↗

PubMed1993

Responses of human glioblastoma cells to human natural tumor necrosis factor-alpha: susceptibility, mechanism of resistance and cytokine production studies.

Responses and susceptibility of 14 human glioblastoma cell lines to human natural tumor necrosis factor-alpha (TNF) were studied in vitro. Susceptibility of glioblastoma cells to TNF varied in experimental conditions applied. Most of glioblastoma cell lines were resistant to cytotoxic activity of TNF in a MTT assay at concentrations below 16 U/ml for 72 h exposure. However, TNF at higher dose, in prolonged exposure and against low density of target cells was antiproliferative for certain glioblastoma cultures. TNF exposure at 10 U/ml for 48 h suppressed DNA synthesis in 9 of 14 glioblastoma cultures, but increased in 3 cultures. In addition, colony forming assay showed anti-clonogenic activity of TNF in 5 of 6 glioblastoma cell lines tested. In spite of their low susceptibility to TNF, glioblastoma cells well responded to TNF stimulation at low dose (10 U/ml) for a short period in the absence of cell damage. Productions of Interleukin-6 (IL-6), IL-8-like activity, granulocyte-macrophage colony stimulating factor (GM-CSF), prostaglandin E2 (PGE2) and manganous superoxide dismutase (Mn-SOD) were enhanced or induced by the low-dose TNF stimulation. Mn-SOD, a protein protective against oxidative cell damage, was well induced in time- and dose-dependent manner, however did not correlate with TNF resistance. Whereas the levels of PGE2 in TNF-susceptible cell lines, H-4 and SF-188, were higher than those of other lines. In conclusion, most of glioblastoma cells are resistant to TNF cytotoxic effects, but highly responsive to TNF stimulation. Its effect on glioblastoma cells appears to modulate cell differentiation rather than to kill the cells.

Cell Division↗

PubMed1993

Human glioblastoma cells produce 77 amino acid interleukin-8 (IL-8(77)).

The production of interleukin 8 (IL-8), a neutrophil chemotactic factor, and its amino acid sequence were examined in glioblastoma cell lines in vitro. Neutrophil chemotactic activity was demonstrated in 9 conditioned media of 15 human glioblastoma cell lines. Tumor necrosis factor (TNF)-alpha stimulated secretion of the activity in 7 lines and induced secretion in 4 other lines. ELISA quantification disclosed that the conditioned media contained interleukin 8 (IL-8) in an amount equivalent to the chemotactic activity. The IL-8 secretion increased with the stimulation by TNF-alpha. Northern blot analysis and the RT-PCR method confirmed expression of mRNA in the glioblastoma cells and its augmentation by TNF-alpha and/or IL-beta. Reversed-phase HPLC following ion-exchange chromatography revealed that the chemotactic activity was a single peptide, which was determined to be IL-8 by the retention time and ELISA. Furthermore, amino acid analysis disclosed that a major part of the glioblastoma-cell derived IL-8 peptide was 77 amino acid IL-8 (IL-8(77); with the N-terminal sequence AVLPRSAKELRCQCI-).

Amino Acid Sequence↗

PubMed1993

Cellular and cytokine responses of the human central nervous system to intracranial administration of tumor necrosis factor alpha for the treatment of malignant gliomas.

To elucidate the role of tumor necrosis factor alpha (TNF alpha) as a biological response modifier, we studied cellular and cytokine responses of the central nervous system to TNF alpha administered intracranially in a phase I clinical trial for patients with malignant gliomas. Six patients received injections of TNF alpha (1.25 x 10(3)-10 x 10(3) U/injection) into the tumor cavities, and regional fluids (RF) and lumbar cerebrospinal fluids (CF) were serially sampled before and after the injections. Recruitment of neutrophils occurred, mostly peaking 8 h after TNF alpha injection, and fewer numbers of CD4+ T cells and monocytes/macrophages migrated, subsequently peaking at 24 h. The CF leukocytosis persisted for 48 h and was associated with an increased level of neutrophil chemotactic activity in the CF. This neutrophil chemotactic activity was attributed to interleukin-8 (IL-8) by HPLC. The level of IL-6 activity in the CF and RF consistently increased; beginning 2 h after TNF alpha injection and reaching the maximum between 8 h and 12 h. It returned to the basal level within 48 h. IL-1 beta was detected in the CF of three patients, its level peaking at 8 h. Prostaglandin E2 also increased after injection of TNF alpha, peaking between 4 h and 12 h and then gradually decreasing. Transforming growth factor beta was found in all cases tested and one patient showed a significant change after TNF alpha injection. IL-2 activity, interferon alpha (INF alpha) activity, IFN beta, and granulocyte/macrophage-colony-stimulating factor were not detected in the CF or RF. In conclusion, TNF alpha is biologically effective in inducing migration of immune cells and generating multiple cytokine responses in the human central nervous system.

Adult↗

PubMed1993

Intracerebral hemorrhage caused by a neoplastic aneurysm from small-cell lung carcinoma: case report.

A neoplastic cerebral aneurysm from lung cancer is an extremely rare occurrence despite its high metastatic potential to the brain. We report a neoplastic cerebral aneurysm from small-cell lung carcinoma that caused an intracerebral hematoma. A 63-year-old man underwent an urgent craniotomy for a massive intracerebral hematoma. After evacuation of the hematoma, an anomalous artery was found on the wall and a biopsy was done. The histological examination revealed that the artery was filled with neoplastic cells, and a part of the vessel wall was distended, forming an aneurysm. The histological feature of the tumor cells was consistent with small-cell lung carcinoma, which was disclosed in the left hilus.

Aneurysm, Ruptured↗

PubMed1993

Asymptomatic large hypothalamic hamartoma associated with polydactyly in an adult.

A hypothalamic hamartoma is a congenital tumor-like neural malformation. It is usually seen in children and is associated with neuroendocrinological symptoms, seizures, or psychological impairments. An asymptomatic hypothalamic hamartoma in an adult is extremely rare. This report describes an asymptomatic adult with a large hypothalamic hamartoma associated with polydactyly in his feet. Both polydactyly and hamartoma are rare lesions; therefore, this may not be a coincidental presentation. It is thought to have occurred in the embryonic period presumably between 37 and 40 gestational days.

Adult↗

PubMed1993

Dystrophic axonal formation (spheroid body) in central neurocytoma--case report.

A 30-year-old female presented with a central neurocytoma manifesting as positional headache. Magnetic resonance imaging showed a large calcified mass in the right lateral ventricle. The tumor was completely removed surgically. Light microscopy showed a linear arrangement of well-defined cells (beaded-string pattern) containing small round nuclei with abundant perikarya. A perinuclear halo reminiscent of oligodendroglioma was prominent in some cell groups. The tumor was entirely amitotic and free of atypia. Large, plump spheroid bodies lacking nuclei but containing coarse brown pigments were present among the tumor cells. The tumor cells were immunoreactive to neuron-specific enolase and synaptophysin but not glial fibrillary acidic protein or neurofilament. The ultrastructure of the tumor cells included abundant spheroid bodies containing secretory granules around neurons, indicating a dystrophic or aborted process of neuronal differentiation rather than a completely-differentiated central neurocytoma.

Adult↗

PubMed1993

Human glioblastoma cells produce granulocyte-macrophage colony-stimulating factor in vitro, but not in vivo, without expressing its receptor.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) production and receptor expression by human glioblastomas was studied. Enzyme-linked immunosorbent assay showed four of 10 glioblastoma cell lines spontaneously released GM-CSF (2.9-9.2 pg GM-CSF protein/ml culture medium), which was enhanced by stimulation with tumor necrosis factor-alpha (TNF) (10 U/ml) up to 410 pg/ml. TNF also induced secretion of GM-CSF by another cell line. Northern blot analysis identified increasing GM-CSF gene expression by cells following TNF stimulation. However, no GM-CSF protein was detectable in the cerebrospinal fluid of three malignant glioma patients. Intratumoral administration of TNF in the patients also failed to stimulate GM-CSF levels in the cerebrospinal fluid. A binding assay using flow cytometry with biotinylated GM-CSF and Scatchard analysis using 125I-labeled GM-CSF failed to demonstrate GM-CSF receptor expression on the 13 cell lines. Exogenous GM-CSF stimulation had no effect on production of prostaglandin E2, interleukin-6, or interleukin-8 by glioma cells. Human glioblastoma cells secrete GM-CSF without expressing the receptor in vitro, but there was no evidence of GM-CSF production in vivo.

Glioblastoma↗

PubMed1992

[A case report of spermatocytic seminoma--clinical review of 17 cases in Japan].

A male aged 48 visited our department on October 17, complaining of swelling of his left scrotal content from July, 1990. Physical examination showed the testis to be swollen to the size of a chicken egg, and ultrasound examination disclosed the swelling to be solid and nodular. Left high inguinal orchiectomy was performed on October 29. The testis extirpated was 50 x 40 x 45 mm in size and weighted 80 g; the gross appearance of the cut surface of the testis was nodular with grayish-white color. The lesion was proved to be spermatocytic seminoma histopathologically, but no hemorrhage or necrosis was observed. Radiation in the dose of 36 Gy was given over the left hypogastrium and paraaortic region in 36 Gy each. The patient subsequently did will and has been followed up in our outpatient clinic without evidence of recurrence as of 10 postoperative months. This patient was the 19th reported case of spermatocytic seminoma in Japan. However, General Rules for Clinical and Pathological Studies on Testicular Tumors explain that spermatocytic seminoma is usually seen in a pure form, unassociated with other types of germ cell tumors, making our case actually the 17th case of this particular seminoma if spermatocytic seminomas combined with other germ cell tumors are exclude from the statistical analysis. Reports of spermatocytic seminoma thus defined are reviewed in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Dysgerminoma↗

PubMed1992

[Prostatic carcinoma presenting as an abdominal mass: a case report].

Prostatic carcinoma presenting as an abdominal mass is a very rare disorder. A 64-year-old man was referred to our hospital with the chief complaint of a right lower abdominal mass on March 6, 1984. Physical examination revealed a firm, smooth, fixed, non-tender, pulseless fist size mass in the right lower abdomen. Rectal examination revealed an apple size, smooth and elastic firm prostate which had an induration. Needle biopsy of the prostate showed well-differentiated adenocarcinoma. At first we regarded the abdominal mass as retroperitoneal tumor unassociated with prostatic carcinoma. After preoperative irradiation (20 Gy) to the pelvis, the abdominal mass was resected and bilateral orchiectomy was performed on April 11, 1984. The mass was histologically diagnosed as a metastatic lesion from prostatic carcinoma. On the basis of these findings, we considered the mass to be due to pelvic lymph node metastasis from prostatic carcinoma. His postoperative course was uneventful. In April 1991, he is still alive without evidence of recurrence or bone metastasis.

Adenocarcinoma↗