Biomedical subjects

T Yoshimine

Publications and source records attributed to T Yoshimine.

At least 91 records · Page 5Linked to original sources

PubMed1999

[Choroid plexus metastasis of renal cell carcinoma causing intraventricular hemorrhage: a case report].

We report a rare case of choroid plexus metastasis of renal cell carcinoma causing intraventricular hemorrhage. A 75-year-old female was admitted to our hospital for SAH. Preoperative examination evoked suspicion of an anterior communicating aneurysm as a cause of SAH. Furthermore, there were lesions on the tuberculum sellae and in the left trigone of the lateral ventricle, which were enhanced by Gd-DTPA on MRI. The patient was operated on via the pterional approach on December 3, 1996, but no aneurysm was found. She underwent total removal of the tuberculum sellae mass, which was postoperatively proved to be a meningioma by histological examination. The intraventricular tumor was supposed to be a meningioma, but it was not treated surgically. Two months later, the patient presented hematuria and was diagnosed as having a right renal cancer and underwent right nephrectomy on March 18, 1997. However, postoperatively, disturbance of consciousness continued. A CT scan revealed intraventricular hemorrhage around the tumor in the trigone of the lateral ventricle on March 21. An emergency operation for tumor and clot removal succeeded in improving the patient's condition. Histological examination of the tumor revealed clear-cell type renal cell carcinoma. Solitary choroidal plexus metastasis from renal cell carcinoma is quite rare: only 5 cases have been reported. But only our case was accompanied by intraventricular hemorrhage. Renal cell carcinomas are divided into two types: a slowly progressive type and a rapidly progressive type. Four cases among the reported 5 cases were the slowly progressive type, and our case was regarded as being of the same type.

Aged↗

PubMed1999

[Germinal matrix hemorrhage and hydrocephalus in premature infants].

An analysis of 25 preterm infants with grade 3 or 4 intraventricular hemorrhage and surgically treated progressive hydrocephalus was undertaken to assess mortality, cognitive outcome and motor deficit. All patients underwent surgery at the author's institute since 1981 and represented 4.7% of all intraventricular hemorrhage in premature infants. Surgical procedure was initial placement of a miniature Ommaya's reservoir and conversion to a ventriculoperitoneal shunt diversion. Overall, outcomes were achieved in 64.7% of ambulatory and improvement of cerebroventricular index on follow-up CT image from 0.68 +/- 0.36% to 0.36 +/- 0.31%. The presence of intraventricular hemorrhage continues to be a major problem in low birth weight infants whose rate survival continues to increase as the major improvements in perinatal medicine. We feel that miniature Ommaya's reservoir is quite helpful in the treatment of posthemorrhagic hydrocephalus in the preterm infant who prove refractory to aggressive conservative therapy.

Cerebral Hemorrhage↗

PubMed1999

[Computed assisted area measurement using CT scans: clinical application for craniosynostosis in children].

This paper describes a method for obtaining intracranial area measurements using CT scans with a software for quantitative analysis of tracing data. A Toshiba CT 1010 scanner was used (120 kv, 10 mm slice thickness) to examine 13 children before and after cranioplastic surgery for craniosynostosis. Using Scion Image (Scion Corporation) with Intuos tablet system (WACOM), the intracranial space was measured at approximately same scanning level. Our findings show that the reverse pi and bilateral canthal advancement procedures usually carried out are associated with increased intracranial area, 4.5 +/- 2.1% and 12.0 +/- 8.3%, respectively. This measurement method should be further modified to intracranial volume gain by several surgical procedures.

Craniosynostoses↗

PubMed1998

Regulation of Na+/myo-inositol cotransporter gene expression in hyperglycemic rat hippocampus.

myo-Inositol is accumulated into cells by means of the Na+/myo-inositol cotransporter (SMIT), which is of interest because its activity is upregulated by hyperosmotic stress. We investigated the effects of hyperglycemia on the expression of SMIT mRNA mainly in rat hippocampus. In normal control rats, SMIT mRNA signals were predominantly located in the hippocampus, cerebellum and choroid plexus. Interestingly, massive induction in the hippocampus was observed on the acute stage of induced hyperglycemia in the CA3/CA4, the molecular layer of the dentate gyrus, and the hippocampal fissure. The perivascular cells along the hippocampal fissure also expressed prominent signals. In the cerebral cortex, heterogeneous induction was observed from layers 2 to 6. Furthermore, these changes immediately returned to baseline levels after normalization of glucose levels. These results suggest that regional specificity of permeability of the blood-brain barrier and/or cellular differences in sensitivity to hyperglycemic stress would exist in the brain.

Animals↗

PubMed1998

Neuromagnetic fields preceding unilateral movements in dextrals and sinistrals.

Movement-related magnetic fields were recorded with a whole-head magnetoencephalographic system in three dextrals and three sinistrals during right or left index finger extension. The motor field (MF) demonstrated an asymmetrical isofield map pattern with larger field reversal over the contralateral hemisphere for dominant hand movement and an almost symmetrical pattern for non-dominant hand movement in each subject. The equivalent current dipole moment of the MF for the contralateral hemisphere was significantly larger than the ipsilateral hemisphere for dominant hand movement, and almost equal for both hemispheres for non-dominant hand movement. These results were congruent for both dextrals and sinistrals, suggesting a more important role of the hemisphere contralateral to the dominant hand in unilateral voluntary movement, regardless of handedness.

Brain↗

PubMed1998

Stochastic determination of the chromosomal region responsible for expression of human glial fibrillary acidic protein in astrocytic tumors.

Previous investigators have localized the human glial fibrillary acidic protein (GFAP) gene in the segment 17q21 in chromosome 17. In the present study, we statistically assessed the association between the allelic status in thirty-three microsatellite loci and the immunohistochemical expression of GFAP in twenty human astrocytic tumors. The results demonstrated that the loss of heterozygosity in only one locus (D17S795 located in 17q21.2) was significantly associated with the impaired expression of GFAP (P = 0.0280, Pc = 0.0384 by Fisher's exact test). The adjacent loci located in 17q21.1 and 17q21.3 were not relevant to GFAP expression. Those data suggest that the critical region responsible for GFAP expression (coding sequence and regulatory elements) is located close to the locus D17S795 in the segment 17q21.2.

Astrocytoma↗

PubMed1998

Changes in brain organic osmolytes in experimental cerebral ischemia.

The cell volume is regulated not only by inorganic ions, but also by organic osmolytes, such as amino acids, methylamines, and polyhydric alcohols (polyols). Using proton nuclear magnetic resonance spectroscopy (1H-NMR), we measured the tissue concentrations of amino acids (alanine, aspartate, gamma-aminobutyric acid (GABA), glutamate, glutamine, N-acetyl-aspartate (NAA), taurine), methylamines (glycerophosphorylcholine (GPC), creatine+phosphocreatine (total creatine, tCr)), and polyols (myo-inositol) in the rat brain after middle cerebral artery occlusion (incomplete focal ischemia) or after decapitation (complete global ischemia). The total osmolytes expressed as a sum of total amino acids, total methylamines, and total polyols were significantly decreased at 24 h of focal ischemia (58.7% of control value, P=0.0025) whereas they were not changed following decapitation. The water content was increased from control value of 77.9%-84.1% after focal ischemia (P<0.0001) but not after decapitation. These results suggest that the brain organic osmolytes are involved in the process of edema formation following focal cerebral ischemia. Further elucidation of the cellular mechanisms regulating these organic osmolytes in cerebral ischemia may promote greater understanding of the pathophysiology involved in the evolution of brain edema.

Alanine↗

PubMed1998

Increased transcription of glutamate-aspartate transporter (GLAST/GluT-1) mRNA following kainic acid-induced limbic seizure.

Expression of mRNA for glutamate-aspartate transporter (GLAST/GluT-1/EAAT1) was studied in the brain of the rat which presented recurrent limbic seizure following systemic administration of kainic acid (KA) by in situ hybridization and Northern blot analysis. The expression of GLAST mRNA was markedly increased after 12 h and peaked after 48 h in animals which demonstrated limbic seizure. The induction of the mRNA were observed in the small non-neuronal cells in the hippocampus, especially around CA3 region and hilus. In contrast, there was no change in GLAST mRNA levels in KA injected seizure-free animals. These findings suggest that GLAST mRNA is induced by seizure and increased extracellular glutamate levels during seizure may be important for induction of GLAST mRNA.

ATP-Binding Cassette Transporters↗

PubMed1998

Aberrant muscle activation in patients after resection of non-primary motor areas: demonstration by surface electromyography.

Two patients presented with a tumor involving mainly the supplementary motor area or the premotor cortex. Shortly after tumor resection, each developed transient impairment of voluntary movements. An electromyogram, with the skin electrodes placed over the muscles of the upper arms and forearms, demonstrated aberrant ipsilateral, contralateral or bilateral muscle activation during unilateral motor tasks in both patients. The bilateral activation was more prominent in the patient who had an intact dominant hemisphere. The present study suggests for the first time the importance of non-primary motor areas of the human brain in activating the proper set of muscles on the proper side of the body.

Adult↗

PubMed1998

Cellular dynamics of macrophages and microglial cells in reaction to stab wounds in rat cerebral cortex.

To examine the cellular dynamics of macrophages and microglial cells in response to cerebral injury, we studied the brain adjacent to cortical stab wounds in young adult rats. Brains were obtained 30 min after intravenous infusion of bromodeoxyuridine (BrdU) on one day (day 1) to 28 days (day 28) after wounding. Brain sections were double-labelled immunohistochemically for monocyte/macrophage antigen ED1 and for BrdU. ED1-positive (ED1+) cells were classified morphologically into two groups, ED1+L and ED1+S cells, representing macrophages and microglial cells, respectively. ED1+L cells appeared on day 1 after wounding and rapidly increased in number to reach a maximum on day 3, but quickly disappeared by day 5. ED1+S cells also appeared on day 1, but the increase in number was slower, reaching a maximum only on day 7. ED1+L cells were all negative for BrdU, but some ED1+S cells were stained for BrdU, evidence of proliferation. The present investigation demonstrated different cellular dynamics for macrophages and microglial cells responding to a stab wound, and also indicated differing sources for the two cell type. It may be possible to prevent the accumulation of these cells which are harmful to the brain in reducing the damage suffered.

Animals↗

PubMed1998

A simple method of scalp localization using multiplanar reconstruction of MR images.

BACKGROUND: Image-based scalp localization methods currently used are complex and not standardized. The authors have developed a simple yet accurate method for craniotomy localization using multiplanar reconstruction (MPR) algorithms. METHODS: In this method, the goal is to localize a projected point (defined as T) of the center of the lesion on the scalp. An oblique coronal plane is reformatted using a patient's magnetic resonance (MR) images with MPR algorithms to include both the center of the lesion and bilateral external auditory meati. Then the distance between T and the ipsilateral external auditory meatus or sagittal suture (defined as S) is measured along the scalp contour in the plane. The distance between the bregma and S is also measured. These distances are used for scalp localization, using a tape measure in the operating room. RESULTS: We have had successful scalp localization in six clinical cases. It took about 3 min to measure each distance on the MR console. CONCLUSION: This method for craniotomy planning using MPR algorithms is simple and sufficiently accurate.

Craniotomy↗

PubMed1998

Cellular expression of inducible nitric oxide synthase following rat cortical incision and its suppression by hydroxyl radical scavenger, 1,2-bis(nicotinamido)propane.

Cellular expression of an inducible isoform of nitric oxide synthase (iNOS) was studied immunohistochemically 1,3 and 7 days following rat cortical incision. The induction of iNOS was demonstrated almost exclusively in the macrophages accumulated within the incision cavity on day 3. They were significantly reduced in number by the treatment with 1,2-bis(nicotinamido)propane (P < 0.01), suggesting the involvement of hydroxyl radicals in the macrophage activation after cortical injury.

Animals↗

PubMed1998

Methylmethacrylate casting model of temporal bone: a simple technique for skull base research and education.

Methylmethacrylate casting model of the temporal bone simulating the translabyrinthine approach from the bone surface down to the internal auditory canal was developed in order to help to understand the complex anatomy that is often encountered during skull base surgery. Using a cadaver temporal bone and applying dental impression technique, fine structures, such as semicircular canals and facial nerve, were precisely reproduced in a life-size resin casting model. This simple cost-effective modeling method would facilitate both anatomical research and medical education by improving our understanding of the complex anatomy of the temporal bone.

Journal Article↗

PubMed1998

Temperature distribution produced by laser irradiation in a ventricle model. The use of airflow in neuroendoscopic surgery.

The changes in intraventricular temperature during potassium titanyl phosphate laser irradiation were investigated using a ventricle configuration model. The laser had an output of 3 to 20 watts in 1 second pulse mode. The model ventricular cavity was filled with still air or saline, or irrigated with air or saline. The laser irradiation in a continuous mode with the output of 15 or 20 watts was also examined under air flow or saline irrigation. In pulse-mode irradiation, the temperature increase was less than 5.0 degrees C under all conditions with the outputs up to 10 watts. With 20 watts pulse irradiation, the temperature increase was within 7 degrees C with air flow, and over 20 degrees C in still air. The later condition occasionally induced a plume of steam resulting in excessive temperature elevation at a remote point. With the continuous irradiation of 15 or 20 watt, the temperature increased by about 4.0 degrees C even under saline irrigation, which required over 30 sec to return to the pre-irradiation level. These results indicate the possible use of pulse mode laser irradiation and air flow endoscopic surgery within the ventricular system. With continuous mode laser irradiation, however, the importance of saline irrigation and proper cooling interval is suggested.

Air Movements↗

PubMed1998

Distribution of nerve growth factor in cat brains following topical application of solution or Minipellet.

The distribution of nerve growth factor (NGF) was studied after topical application of NGF solution or NGF Minipellet into the caudate nucleus of cat brains. Each aliquot of NGF solution or a piece of NGF Minipellet contains 200 micrograms of mouse 2.5S beta-NGF. The concentrations of NGF in various areas of the brain were determined by enzyme-linked immunosolvent assay (ELISA). The tissue concentrations of NGF were very high at 6 h after injection of NGF solution (124.0 +/- 2.46 to 2144.0 +/- 16.03 ng g-1), but quickly decreased on day 1. The tissue concentrations of NGF were low at 6 h after implantation of NGF Minipellet, but were considerably increased on day 1 (11.22 +/- 3.36 to 72.04 +/- 20.45 ng g-1), and slowly decreased during the following 6 to 14 days. The present study demonstrates the temporal and spatial profiles of NGF distribution in the brain of middle-sized animals after topical application. Injection of NGF solution resulted in abrupt, but very transient, elevation of tissue NGF. Implantation of NGF Minipellet maintained the tissue NGF at biologically effective levels for 6 to 14 days.

Administration, Topical↗

PubMed1998

Computational imaging of cerebral perfusion by real time processing of DSA images. Clinical applications.

Real time and high resolution functional imaging of cerebral perfusion was developed, which displays the color coded image of the cerebral perfusion index (PI) from the serial images of digital subtraction angiography (DSA). The small (3 x 3 pixels) regions of interest (ROI) were set on the images, and the time density curves of the contrast media for each ROI were obtained. The perfusion indices, corresponding to the mean transit time (MTT), were calculated for all the ROIs on the image in real time (5 sec) by the area over height method and then, converted to the PI image. A large ROI (64 x 64 pixels) was also used to estimate the parenchymal perfusion. In the normal subjects, consistent PI values at the various parts of the cerebral arteries were obtained, which reasonably agreed with the published values when converted to the blood flow. Then the study on the pathological subjects were made. Firstly, the alteration in the PI images agreed well with the CBF SPECT study in the case of moyamoya disease with the synangiosis operation. Secondly, even a 5% change of the parenchymal perfusion could be detected with the PI imaging, which was obscure when inspecting the series of DSA images, in the case of intra-arterial papaverine infusion for delayed vasospasm. Thirdly, the vortex inside a large aneurysm could be estimated with the same resolution as DSA. Our method offers real time, high resolution, projection angle independent and semiquantitative imaging of the cerebral perfusion from the conventional DSA images without introducing any new expensive devices. This method could be used to evaluate the therapeutic change and especially to monitor the rapidly changing cerebral perfusion in interventional angiography.

Aged↗

PubMed1998

Increase in jugular levels of polymorphonuclear neutrophil elastase in patients with acute cerebral infarction.

To elucidate the involvement of activated polymorphonuclear neutrophil (PMN) proteolytic activity in the pathophysiology of cerebrovascular stroke, we measured internal jugular venous and femoral arterial levels of PMN elastase in 6 patients with acute stroke from the day onset (day 0) to 7 days after onset (day 7). Two patients with cerebral infarction demonstrated markedly elevated of PMN elastase in the jugular blood (730 and 1320 micrograms l-1, respectively), but not in the blood (203 and 205 micrograms l-1, respectively) on day 2. Both patients manifested signs of hemorrhagic infarction early on day 2. On day 4, the increased levels of jugular elastase returned to the normal range (< 250 micrograms l-1 in both patients. In contrast, none of the 4 patients with intracerebral hemorrhage demonstrated increased levels of PMN elastase in either the jugular or the arterial blood from days 0 to 7. The present study demonstrated a temporary but significant increase in jugular PMN elastase in patients with cerebral infarction, especially shortly after hemorrhagic infarction.

Acute Disease↗

PubMed1998

Dysembryoplastic neuroepithelial tumor in the insular cortex. Three dimensional magnetoencephalographic localization of epileptic discharges.

A case of dysembryoplastic neuroepithelial tumor in the left insular cortex manifesting with intractable seizures is presented. The multichannel magnetoencephalography (MEG) localized equivalent current dipoles of epileptic discharges at the cerebral cortex adjacent to the tumor. The total removal of the tumor resulted in complete disappearance of seizures. This case demonstrated that multichannel MEG was useful in the three-dimensional localization of irritative zone in the concealed cortices such as inside the sylvian fissure.

Brain Neoplasms↗