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Biomedical subjects

T Nagashima

Publications and source records attributed to T Nagashima.

At least 37 records · Page 2Linked to original sources
PubMed2001

Antineutrophil cytoplasmic autoantibody specific for proteinase 3 in a patient with shunt nephritis induced by Gemella morbillorum.

A 17-year-old girl had been placed with ventriculoperitoneal, then ventriculoatrial shunts for congenital hydrocephalus since birth. The patient originally was diagnosed as having a lupus-like disease, but later turned out to have shunt nephritis, presenting with fever, proteinuria, pancytopenia, and hypocomplementemia. Antineutrophil cytoplasmic autoantibody specific for proteinase 3 (PR3-ANCA) was detected in her serum. The patient received oral prednisolone and repeated methylprednisolone pulses, with essentially no beneficial effects. A gram-positive coccus, Gemella morbillorum, was recovered from her blood as well as cerebrospinal fluid, and the culture of the shunt catheter established the diagnosis of shunt nephritis. Removal of the shunt catheter improved symptoms dramatically and decreased PR3-ANCA in serum to an undetectable level. Because steroids had no effects and the control of bacterial infection lowered PR3-ANCA levels, the antibody would have been induced by continuous infection with G morbillorum.

Adolescent↗
PubMed2001

Evaluation of waste pyrolysis characteristics in a pressurized fluidized bed reactor.

To obtain the distribution of fuel components to gas, tar and char in a pressurized fluidized bed waste pyrolyzer, experiments were conducted with a laboratory scale fluidized bed reactor. Waste samples were fed batchwise from the top of the reactor into the fluidized bed of silica sand and pyrolyzed by nitrogen/nitrogen-O2 gas and the effects of pressure, particle size, heating rate and oxygen addition were investigated. In the case of rubber, the char yield tended to increase a little and the tar yield decrease over the pressure of 304-709 kPa. In comparison with the thermogravimetry data it was clearly demonstrated that the char yield from fluidized bed pyrolysis is much lower. A small amount of oxygen addition decreased both tar and char yields but its further increase did not affect them very much.

Air Pollution↗
PubMed2001

A mitochondrial encephalo-myo-neuropathy with a nucleotide position 3271 (T-C) point mutation in the mitochondrial DNA.

We report three members of a family, who exhibited a phenotype similar to 'myoclonus epilepsy with ragged-red fibers' but had a genotype usually associated with 'mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes'. The patients, a 48-year-old female, and her two sons, aged 21 and 19 respectively, presented with photo-reactive syncopal episodes, disturbances of gait and writing, dysarthria and finger tremor since the 3rd and 2nd decade of life, respectively, that were accompanied also by numbness and weakness of the extremities. Subsequently, cerebellar ataxia and myoclonus were also noted. Electromyography revealed both myogenic and neurogenic muscular changes, and nerve conduction studies demonstrated a sensory-motor neuropathy. Biopsy showed ragged-red fibers with strongly stained SDH-positive vessels in skeletal muscles, and a marked loss of myelinated fibers of the sural nerves. Mitochondrial (mt) DNA analyses of peripheral blood, muscles and nerves revealed that all members had a heteroplasmic np3271 (T-C) point mutation in the mitochondrial tRNA-Leu gene (UUR). This family is unique, in that all patients presented with a myoclonus epilepsy with ragged-red fibers-like phenotype and had a distinctive peripheral neuropathy, while the detected mtDNA 327l (T-C) mutation has been reported to date only in rare cases of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes

Adult↗
PubMed2001

Quantification of early blood-brain barrier disruption by in situ brain perfusion technique.

Osmotic disruption is currently being used to circumvent the blood-brain barrier (BBB) and enhance the delivery of therapeutic molecules in human brains. To date, however, the time course during the early phase of disruption has not been clarified. In order to demonstrate the rapid change in cerebrovascular permeability after BBB disruption in rats, we developed a method of in situ brain perfusion to demonstrate the earliest reversibility in cerebrovascular permeability. Osmotic BBB disruption was attained by intracarotid infusion of hypertonic mannitol. Perfusate containing [14C]-sucrose was infused at different time points following osmotic stress followed by measuring cerebrovascular permeability. The earliest BBB disruption was seen to occur 5 min after osmotic stress, after which the exact time course of cerebrovascular reversibility was studied. The protocol reported here, in contrast with those reported in previous studies, was shown to be qualitative, simple, and fast. In addition, the method can be applied to measure any low BBB permeability molecules. This protocol should be helpful for any research focused on enhancing drug delivery into the brain following osmotic BBB disruption.

Animals↗
PubMed2001

Adult T-cell lymphoma involving the leptomeninges associated with a spinal cord schwannoma.

Adult T-cell lymphoma (ATL-L) developing initially in the meninges is rare. An autopsy case of ATL-L with an acute onset of meningitis and generalized lymphadenopathy in association with a cervical cord schwannoma is reported here. A 78-year-old woman with sensori-motor weakness of both arms over a 1-year period, developed febrile episodes and drowsiness with neck stiffness. Lumbar puncture revealed an increased protein content (161 mg/dL) and increased cell count (463/3) consisting of 99% of lymphocytes which contained atypical lymphocytes with multilobulated nuclei ('flower cells'), which are characteristic of ATL-L. Viral titers were positive only for HTLV-I antibodies (serum X 640: CSF X 16). Biopsy of an enlarged retroperitoneal lymph node revealed malignant lymphoma of the T-cell type. Brain MRI was negative, whereas an intradural extramedullary mass was found at the C4 level. With a diagnosis of ATL-L stage IV, chemotherapy was commenced, which was effective in reducing the generalized lymphadenopathy as well as the cervical mass and restoring the CSF findings to normality. The cervical cord mass was verified to be a solitary schwannoma, and ATL-L involvement was found not only in the leptomeninges, but also within the cervical cord schwannoma.

Aged↗
PubMed2001

A new technique for intraoperative visual monitoring during spinal surgery: angiofiber and endoscopic ultrasonography.

PURPOSE: This paper is focused on our clinical use of endoscopic ultrasonography (EUS) and angiofiber (AF) for spinal microsurgery. METHODS: EUS and AF were used in seven operations for syringomyelia and spinal tumor. We used EUS for extradural observation, and AF for extra and intra-dural, subarachnoid and intraluminal visual evaluation of the lesions. RESULTS: EUS images of the spinal cord, roots and lesions were clear, providing precise evaluation of the lesion and the course of the shunt tube in real time during surgery. AF could provide clear vision of the syrinx lumen or subarachnoid space. Because these fine instruments could be advanced under the unresected laminae, sonographic and endoscopic images were obtained from beyond the extent of laminotomy, where the microscope could not reach. CONCLUSION: Combined together, EUS and AF contributed to accurate and safe spinal surgery while minimising the laminotomy.

Adolescent↗
PubMed2001

Treatment of tuberculum sellae meningiomas:a long-term follow-up study.

Surgical techniques and their results for tuberculum sellae meningiomas were studied. Thirty-three cases, the first of which was operated in 1980, were analysed. There were 4 men and 29 women with an average age of 46.7 years. Eight cases underwent reoperations. The mean follow-up was 10.7 years. Approaches were pterional for 15 patients, FOZ/FO for 10, bilateral subfrontal for 6, and others for 2. Simpson's grade (I, II, III, IV) were 12, 9, 0, and 12 cases respectively. Recurrence rate was 0% for grade I and 58.3% for grade IV. The FOZ/FO approach resulted in a lower Simpson's grade (P=0.05), but other factors were not related to Simpson's grade (P=0.05). The postoperative visual outcome did not depend on total (grade I and II) or subtotal (grade III and IV) removal (P=0.01). We conclude that radical removal of the tumours may result in lower recurrence rate without increasing surgical complications. Furthermore, skull base approaches can improve the rate of radical removal of tuberculum sellae meningiomas.

Adult↗
PubMed2001

Identification of a silent pituitary somatotropic adenoma based on a paradoxic response of growth hormone on a thyrotropin-releasing hormone or gonadotropin-releasing hormone provocation test.

Preoperative endocrinologic identification and surgical removal of a silent somatotropic adenoma among patients with either amenorrhea or galactorrhea, or both, are beneficial for the restoration of menstruation and ovulation. Paradoxic rises of serum growth hormone in either a thyrotropin-releasing hormone or a gonadotropin-releasing hormone provocation test and high serum growth hormone levels were noted in the 3 patients with a silent somatotropic adenoma.

Adenoma↗
PubMed2001

Histopathological analyses of silent pituitary somatotroph adenomas using immunohistochemistry, in situ hybridization and confocal laser scanning microscopic observation.

To characterize the morphological and functional aspects of silent somatotroph adenomas with paradoxical responses of GH in TRH or GnRH provocation tests, which are considered to be a useful strategy for endocrinological identification of silent somatotroph adenomas, we examined three silent somatotroph adenomas histopathologically. The adenomas were investigated by immunohistochemistry, including the highly sensitive catalyzed signal amplification system, the non-radioisotopic in situ hybridization method, and confocal laser scanning microscopy. GH production and GH-immunopositive secretory granules in the adenoma cells were demonstrated histopathologically, and the adenomas were interpreted as being densely granulated somatotroph adenomas. Endocrinological identification of silent somatotroph adenomas in combination with paradoxical responses of GH in TRH or GnRH provocation tests may elucidate the increasing number of silent somatotroph adenomas that have been regarded as mammotroph or clinically inactive adenomas. One should be aware of the differences between the previously reported silent somatotroph adenomas, most of which are sparsely granulated somatotroph adenomas, a somatotroph adenomas with paradoxical and the silent somatotroph adenomas, most of which are sparsely granulated somatotroph adenomas, and the silent somatotroph adenomas with paradoxical responses of GH in TRH or GnRH provocation tests, which are densely granulated somatotroph adenomas.

Adenoma, Chromophobe↗
PubMed2001

Dynamic helical CT-guided needle localization of non-palpable and mammographically occult breast lesions. Case reports.

Dynamic helical CT-guided needle localization of non-palpable and mammographically occult breast lesions is described. Dynamic helical CT-technique enabled fast volume scanning of the whole breast during the early contrast enhancement phase, which provided sufficient contrast to localize the target lesions. The procedures were successfully completed without complications.

Biopsy, Needle↗
PubMed2001

Novel inactivating missense mutations in the thyrotropin receptor gene in Japanese children with resistance to thyrotropin.

We describe Japanese siblings with resistance to thyrotropin (TSH) who are compound heterozygotes for two novel mutations in the TSH receptor gene. The affected siblings had increased serum TSH, normal serum thyroid hormones, and normal positioned but slightly hypoplastic thyroid glands. The mutated paternal allele has the substitution of His (CAC) in place of Arg (CGC) at codon 450 (R450H) of the TSH receptor. The mutated maternal allele has the substitution of Ser (AGT) in place of Gly (GGT) at codon 498 (G498S) of the TSH receptor. COS-7 cells transfected with the R450H mutant exhibited a slightly decreased TSH binding and a slightly decreased cyclic adenosine monophosphate (cAMP) response to TSH, whereas cells transfected with the G498S mutant exhibited a markedly decreased TSH binding and a markedly decreased cAMP response to TSH. Flow immunocytofluorometry analysis demonstrated that the G498S mutant resulted in extremely low expression at the cell surface as compared with the wild type receptor and the R450H mutant, in spite of a normal intracellular synthesis. The present cases are the first Japanese patients with TSH resistance in whom mutations in the TSH receptor gene have been identified. These novel mutations may contribute to understanding of the struc-ture-function relationship of the TSH receptor.

Adult↗
PubMed2001

Colon cancer with meningeal carcinomatosis and myelodysplastic syndrome in a patient who underwent intensive chemotherapy for acute myelogenous leukemia: a case report.

A 59-year-old man was admitted to our hospital because of disturbance of consciousness and hyponatremia. The patient had suffered from acute myelogenous leukemia (AML) with 46,XY and received chemotherapy for 5 years. Meningeal carcinomatosis was diagnosed due to the detection of carcinoma cells in the cerebrospinal fluid (CSF). Hyponatremia was caused by syndrome of inappropriate secretion of anti-diuretic hormone (SIADH). Bone marrow examination revealed myelodysplastic syndrome (MDS) with deletion of the long arm of chromosome 7. Emergence of a new abnormal clone was suggested. The patient died from brain herniation. Post mortem examination showed adenocarcinoma in the colon. An association between chemotherapy and both colon cancer and MDS was suggested.

Adenocarcinoma↗
PubMed2001

Endoscopic treatment for a huge neonatal prepontine-suprasellar arachnoid cyst: a case report.

A huge prepontine-suprasellar arachnoid cyst was identified by fetal sonography and magnetic resonance imaging. It was successfully treated with a two-stage operation using a neuroendoscope. The first operation during the neonatal period consisted of implantation of a cyst-peritoneal shunt. In the second operation, the cyst was fenestrated with the aid of a neuroendoscope. The cyst membrane was seen to cover the foramen magnum and to extend continuously to the ventral surface of the brain stem. At the foramen magnum, it was pulsating synchronously with the pulsation of the vertebral artery, which was suggestive of the mechanism of cyst growth. A ventriculo-peritoneal shunt was inserted to replace the cyst-peritoneal shunt. Endoscopic cyst fenestration is a less invasive alternative for the treatment of arachnoid cysts and can also be used for young children. In that case, however, special care should be taken to avoid complications, especially if the cyst exerts considerable pressure on the critical areas of the brain.

Adult↗
PubMed2001

Pelvic arteriovenous malformation with iliac vein thrombosis. A case report.

BACKGROUND: Congenital arteriovenous malformations (AVMs) of the pelvis are relatively rare and are difficult to treat because of diffuse extension and the number of feeding vessels. METHODS: We describe a patient with a pelvic AVM with shunts who also developed iliac vein thrombosis. The AVM was diagnosed during evaluation of what had initially appeared to be a venous stasis ulcer. RESULTS: The ulcer was successfully treated by Palma s procedure, partial resection of the feeding vessels, and transcatheter arterial embolization. CONCLUSIONS: Coexistence of a pelvic AVM with an iliac vein thrombosis has not previously been reported.

Aged↗
PubMed2000

Stereoselectivity of methyl aryldiazoacetate cyclopropanations of 1,1-diarylethylene. Asymmetric synthesis of a cyclopropyl analogue of tamoxifen.

[formula: see text] Dirhodium tetrakis(S-(N-dodecylbenzenesulfonyl)prolinate) (Rh2(S-DOSP)4)-catalyzed decomposition of methyl phenyldiazoacetate in the presence of 1,1-diarylethylenes results in intermolecular cyclopropanation with high enantioselectivity (up to 99% ee) and moderate diastereoselectivity (up to 80% de). The reaction was applied to the asymmetric synthesis of a cyclopropyl analogue of tamoxifen.

Benzene Derivatives↗
PubMed2000

Blood-brain barrier formation of grafted human umbilical vein endothelial cells in athymic mouse brain.

Human umbilical vein endothelial cells (HUVECs) were transplanted in athymic mouse brain and neovascularization of grafted endothelial cells was studied. HUVECs were transfected by a reporter gene pEGFPE-N1 in vitro and grafted stereotactically in unilateral striatum of adult nude mice. Histological studies in 4 weeks revealed that grafted HUVECs newly formed microvessels in brain, which were migrated and fused with host vessels. Intravenous injection of Evans blue before sacrificing animals resulted in no extravasation of dye, indicating that a blood-brain barrier (BBB) was formed by the grafted HUVECs. Immunohistochemistry demonstrated that host astrocytes extended glial feet on the grafted endothelial cells and a part of the newly formed vessels was positive with glucose transporter-1. These results indicate that endothelial cells from an ectopic origin have the potential to form a BBB after grafting in the central nervous system.

Animals↗