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Biomedical subjects

Takeshi Kondoh

Publications and source records attributed to Takeshi Kondoh.

At least 19 recordsLinked to original sources
PubMed2005

Acquired lumbar epidermoid cyst in an adult.

A 61-year-old female complained of low back pain, and had been treated by spinal anesthetic injection more than 70 times over 14 years. Magnetic resonance (MR) imaging, performed at the age of 47 years, revealed no abnormal lesion. However, she developed irritable hypesthetic pain in the left leg at 61 years of age. MR imaging revealed a round mass appearing isointense on the T1-weighted and slightly hyperintense on the T2-weighted images. Laminectomy revealed an epidermoid cyst, which was removed. This case clearly demonstrates that adults can acquire epidermoid tumor which very probably has an iatrogenic origin. The incidence of epidermoid tumor is low, but we should be aware of the potential adverse complications such as formation of epidermoid tumors after lumbar puncture.

Epidermal Cyst↗
PubMed2005

Estimation of contrast of refraction contrast imaging compared with absorption imaging-basic approach.

PURPOSE: We discuss the usefulness of the refraction contrast method using highly parallel X-rays as a new approach to minute lung cancer detection. The advantages of refraction contrast images are discussed in terms of contrast, and a comparison is made with absorption images. MATERIALS AND METHODS: We simulated refraction contrast imaging using globules with the density of water in air as models for minute lung cancer detection. The contrast intensified by bright and dark lines was compared on a globule with the contrast of absorption images. We adopted the Monte Carlo simulation to determine the strength of the profile curve of the photon counts at the detector. RESULTS: The obtained contrasts were more intense by two to three digits than those obtainable with the absorption contrast imaging method. CONCLUSION: The contrast in refraction contrast imaging was more intense than that obtainable with absorption contrast imaging. A two to three digit improvement in contrast means that it is possible to greatly reduce the exposure dose necessary for imaging. Therefore, it is expected to become possible to detect the interfaces of soft tissues, which are difficult to capture with conventional absorption imaging, at low dosages and high resolution.

Absorption↗
PubMed2005

Ultrasonographic screening of carotid artery in patients with vascular retinopathies.

BACKGROUND AND PURPOSE: Retinal vasculopathy is commonly found with complaint of burred vision by ophthalmologist and closely related to asymptomatic cerebrovascular disease. The purpose of this study was to evaluate patients with microvascular retinopathy by ultrasound sonography of neck carotid artery and to find high risk group for stroke at outpatient of ophthalmology with associated retinopathy. METHODS: Between 1999 and 2001, a total of 480 consecutive patients visited at outpatient of ophthalmology with a complaint of burred vision were evaluated by ultrasound sonography of neck carotid artery. The patients were divided to with retinopathy (n=253) and without retinopathy (n=227). The former was subgrouped as follows; central retinal vein occlusion (CRVO; n=11), branch of retinal vein occlusion (BRVO; n=71), retinal artery occlusion (RAO; n=8), hypertensive retinopathy group-I (according to Keith, Wagener and Barker's criteria) (HTN-R I; n=43) and group-II (HTN-R II; n=42), and diabetic retinopathy (DM-R; n=78). The latter group was with various ophthalmological diseases, mainly inflammation of cornea, with healthy retinal vessels and constituted as the control group. RESULTS: There was no statistically significant difference between patients with retinopathy and the control group with respect to sex distribution, nor among the retinopathy groups. Patients with retinopathy had a mean age of 68 years, while those with HTN-R I and II were older with a mean age of 71 years. By ultrasonography, RAO showed pathology in intima-media thickness (IMT; 1.13 +/- 0.55 vs. 0.81 +/- 0.26 mm in control), average number of plaques (1.88 +/- 0.99), degree of stenosis of internal carotid artery (42.4 +/- 28.5%) and common carotid artery (27.4 +/- 21.3%). Those with DM-R had the second thickest IMT (0.96 +/- 0.42 mm) and the second highest quantity of plaque (1.23 +/-1.23), and the second most stenotic common carotid artery (13.1 +/- 17.28%). CONCLUSION: Moderate sclerotic changes are found in ophthalmology patients with RAO and DM-R, although the degree pathology do not indicate medical nor surgical prophylactic treatment. Retinal vein occlusion, that has been discussed with diminished retinal blood circulation, does not show any differences in comparison with control group and ultra sonography has less value for screening of asymptomatic carotid atherosclerosis.

Aged↗
PubMed2004

Morphological differentiation of bone marrow stromal cells into neuron-like cells after co-culture with hippocampal slice.

Adult green mice marrow stromal cells were co-cultured with hippocampal slices. Differentiation to neuron-like or non-neuron-like cells occurred exclusively inside slice boundaries starting at day 3, and then decreased gradually over 35 days. Neuron-like cells tended to form network-like connections around day 14. The use of retinoic acid greatly increased the number of differentiated cells, and the most effective concentration was 10(-6) M. NeuN immunohistochemistry was positive in 9.6+/-1.7% of morphologically differentiated neuron-like cells. Both GFAP and Iba1 immunostaining were negative. We concluded that bone marrow stromal cells can be differentiated into neurons, and direct contact with the host brain tissue is essential for this to occur. Retinoic acid significantly increases the number of differentiated cells, as has been reported with other stem cells.

Animals↗
PubMed2004

In vivo transgene expression using an adenoviral tetracycline-regulated system with neuron-specific enolase promoter.

A recombinant adenoviral tetracycline-regulated system with neuron-specific enolase (NSE) promoter was injected stereotaxically into the striatum of rat brains. The efficiency of in vivo transfection was quantified by counting the number of green fluorescent protein (GFP)-positive cells at 3 days, 1 week, and 4 weeks after injection. NeuN immunohistochemistry demonstrated that expression of gammaPKC-GFP was dominant (20-99%) in neuron and expression of gammaPKC-GFP in neuron was significantly higher in pups than adult rats. These results indicate that tetracycline-inhibitable transcription factor (tTA) can drive tetracycline-responsive promoter (TetOp) under the control of NSE promoter, thereby efficiently and selectively expressing gammaPKC-GFP in neurons in vivo.

Adenoviridae↗
PubMed2004

Cytological and bacteriological studies of intraoperative autologous blood in neurosurgery.

BACKGROUND: To ensure the safety of salvaged blood in neurologic surgery, reinfused blood through the Cell Saver System (CSS) (Hemonetics) was investigated cytologically and bacteriologically. METHODS: Specimens of reinfused blood were cytologically examined with Papanicolaou or Giemsa stains. Reinfused blood and air in the operating theater were investigated by microbiologic techniques. The concentration of dust particles in the theater was determined. RESULTS: Tumor cells were positive in reinfused blood in 5 of 9 specimens with glioblastoma, in 2 of 8 with pituitary adenoma, and 1 of 13 with meningioma. The probability of migration of meningioma cells into reinfused blood was significantly low in comparison with that of glioma cells. Of the 30 specimens studied microbiologically, the bacterial growth was detected in salvaged blood of 14 specimens (46.7%) and in the air of the operating theater for 8 specimens (26.7%). In craniotomy, the contamination rate was 10 of 26 specimens of reinfused blood (38.5%). Most microorganisms were found to be staphylococci. No statistically significant correlation could be found between salvaged blood and air as to contamination or between reinfused blood and the concentration of dust particles in the theater as to bacteriologic results. No infectious complications were found after the operation, though salvaged blood through the CSS was reinfused in 37 patients without glioblastoma or transsphenoidal approach. CONCLUSIONS: The CSS cannot always entrap tumor cells. Salvaged blood should not be reinfused in the patients with glioblastoma or transsphenoidal surgery. None of the patients with reinfusion had any infectious complications. Reinfusion of salvaged blood seems to be safe in neurosurgery.

Blood↗
PubMed2004

Improvement of visual acuity caused by opticochiasmal astrocytoma after treatment for associated hydrocephalus--case report.

A 33-year-old male presented with syncopal attacks. He had a history of slowly progressive deterioration of visual acuity in both eyes. His visual deterioration began in the left eye at age 12 years and in the right eye at age 20 years. His left eye was completely blind by age 33 years. He had received no prior treatment for these visual disturbances. Magnetic resonance (MR) imaging on admission showed a large tumor with inhomogeneous intensity occupying the bilateral optic canals and orbital cavities, with extension to parasellar region. Arachnoid cysts were found in the left middle fossa and supracerebellar space, which had caused herniation of the cerebellar tonsils to the foramen magnum. Open biopsy and histology verified that the tumor was pilocytic astrocytoma. Arachnoid cysts associated with the hydrocephalus were treated with a ventriculoperitoneal shunt. Seven years after surgery, visual acuity of the right eye had improved although the left eye remained blind. Follow-up MR imaging demonstrated marked reduction in size of the ventricles and arachnoid cysts, but the tumor size did not change. This case illustrates the benign nature of low-grade glioma in this region in spite of the large size and long history. Deterioration of visual acuity may be reversible in some cases of opticochiasmal astrocytoma. In our case, the improvement in visual acuity probably resulted from growth arrest of the tumor and improvement in the dynamics of cerebrospinal fluid flow.

Adult↗
PubMed2004

[Intracranial hypovolemic syndrome with subdural hygroma developed massive hematoma: timing of treatment and histology of dural hypertrophy].

We report a case of a 43-year-old man treated by craniotomy for chronical subdural hematoma (CSH) due to spontaneous intracranial hypovolemia. The patient complained of sudden onset severe headache. Initial CT scan showed normal brain structure, and his headache improved with bed rest in a few days. However, MR images obtained for vertigo one month later demonstrated bilateral subdural hygroma extending to the supracerebellar space and diffuse dural enhancement after gadolinium infusion. We diagnosed bilateral subdural hygroma due to spontaneous intracranial hypovolemia, and observed him conservatively. Four months after onset, he complained of severe headache again and MR images revealed enlargement of bilateral CSH with mass effect, which had heterogenous intensity on the right convexity. We evacuated hematoma on the right by craniotomy and aspirated the left side hematoma using a burr hole. His headache improved 2 weeks after the operation with strict bed rest. The follow-up MR images showed disappearance of abnormal meningeal enhancement and improvement of brain sagging.

Adult↗
PubMed2003

Congenital cavernous angioma exhibits a progressive decrease in size after birth.

CASE REPORT: We report a case of congenital intracranial cavernous angioma, which was initially found at a gestational age of 34 weeks in utero as a mass lesion associated with hydrocephalus. After birth, the patient was treated for hydrocephalus first by external drainage and then by ventricular peritoneal shunt. The natural course of the mass lesion was observed until the age of 8 months when the histopathological diagnosis confirmed the cavernous angioma after tissue was obtained by surgery. CT scans repeated monthly during this period demonstrated that the angioma continuously decreased in size. There was no evidence of hemorrhage in the angioma on serial CT scans. The histopathology revealed thrombosis of cavernous vessels with hyaloid changes in the angioma. DISCUSSION: The mechanisms of the decreasing size of the cavernous angioma have often been discussed in relation to spontaneous hemorrhages and resolution. The present case suggests a mechanism in which the spontaneous formation of a thrombus might be the dominant factor for the decrease in size. Thrombus formation may result from low perfusion due to the large size of the angioma.

Brain Neoplasms↗
PubMed2003

Primary granulocytic sarcoma in the sphenoidal bone and orbit.

CASE REPORT: We report a case of a primary cranial chloroma in boy aged 2 years and 8 months. The symptoms were progressive bilateral exophthalmos, right abducens palsy, and bilateral papilledema. The tumor was partially calcified and was a round mass located in the bilateral sphenoidal bone extending into the orbit. Laboratory study did not show hematological abnormality. The tumor was partially removed by bilateral frontotemporal craniotomy and a diagnosis of primary granulocytic sarcoma was made from the surgical specimen. Progressive deterioration of visual acuity was seen and chemotherapy started on the 11th postoperative day followed by local cranium irradiation (24 Gy). The patient has been in complete remission for 37 months. The visual acuity recovered partially and follow-up magnetic resonance imaging showed a significant decrease in the size of the tumor. DISCUSSION: Radiological diagnosis of primary intracranial granulocytic sarcoma is difficult. Surgical removal may be an option for progressive neurological deterioration but chemotherapy is more important for both neurological stabilization and induction of remission.

Brain Neoplasms↗
PubMed2003

Moyamoya syndrome after prophylactic cranial irradiation for acute lymphocytic leukemia.

A 9-year-old boy presented with an episode of syncope, and MR imaging revealed bilateral internal carotid artery stenosis with moyamoya vessel formation. He had had prophylactic cranial irradiation at a total dose of 24 Gy for the treatment of acute lymphocytic leukemia at the age of 4. Following this, he was in a complete state of remission for 6 years. During an observation period of a year after the onset of syncope, MR imaging showed development of multiple ischemic lesions in both hemispheres. He developed a transient ischemic attack of mild motor weakness in his arm and an indirect anastomosis was performed on the severely affected side at the age of 10. Radiation-induced vasculopathies are known to be associated with primary diseases of intracranial tumors, but the frequency is unclear. Ours is the third case in whom prophylactic cranial irradiation for a hematological disorder might have induced cerebral vasculopathies.

Brain Ischemia↗
PubMed2003

Distal anterior inferior cerebellar artery aneurysm occult on magnetic resonance angiography one month prior to rupture--case report.

A 77-year-old man suffered subarachnoid hemorrhage due to a ruptured aneurysm of the distal anterior inferior cerebellar artery (AICA). He had a history of hearing disturbance in the left ear for more than 3 years. Computed tomography on three separate occasions had found no abnormalities. One month before the hemorrhage, he came to our outpatient service complaining of vertigo. Magnetic resonance (MR) imaging and MR angiography detected no abnormality. Conventional angiography demonstrated an aneurysm of 8 mm diameter in the distal AICA region after the hemorrhage. Filling and wash out of the aneurysm sac by contrast medium was markedly delayed, which suggested that MR imaging had failed to detect the flow void because of the slow blood flow in the dome. The aneurysm was clipped successfully. He was discharged with mild dysarthria on the 33rd postoperative day. MR angiography has limitations in detecting unruptured aneurysms and there is certainly a high risk group of false negatives, including aneurysms located in the distal region of the main trunk.

Aged↗
PubMed2003

Expression of mPOU protein in the human pituitary adenomas.

OBJECTIVE: mPOU is a POU protein classified as class VI. It is present in the pituitary gland as well as the brain, heart muscle, skeletal muscle, lung, and lymphocytes. In our previous investigation, mPOU bound to the Pit-1-binding DNA elements of the rat PRL gene, and promoted transcription of the GH and PRL genes. In this study, we immunohistologically investigated the expression of mPOU in pituitary adenomas. METHODS: 17 patients with pituitary adenoma underwent tumor excision by transsphenoidal approach at our hospital (PRL: 5, GH: 4, FSH: 1, non-functioning: 7). The expression in the tissue sections was investigated using immunostaining (ABC method). RESULTS: In all GH-producing and PRL-producing adenomas, mPOU protein was specifically expressed, particularly in the nuclei. DISCUSSION: Pit-1 has been considered to be a factor determining the expression of GH and PRL genes, but mPOU may also be involved in the expression.

Adenoma↗
PubMed2002

The anti-dementia drug FK960 stimulates glial glutamate release via a PKA pathway.

The present study was conducted to understand the mechanism underlying the facilitatory action of FK960, an anti-dementia drug, on hippocampal neurotransmission. FK960 facilitated hippocampal neurotransmission in normal mice, and also in mice lacking the glial glutamate transporter, GLT-1 (glut-1(-/-)), but to a lesser extent. FK960 enhanced glutamate release from cultured hippocampal astrocytes from normal rats and mice, while the drug had no effect on the release from cultured rat hippocampal neurons. The glutamate release was still obtained with cultured hippocampal astrocytes from glut-1(-/-) mice, suggesting that the release is not due to GLT-1-mediated counter transport of glutamate. The FK960 action was inhibited by H-89, a selective inhibitor of cAMP-dependent protein kinase (PKA), bafilomycin A1, an inhibitor of vesicular transport, or BAPTA-AM, a chelator of intracellular Ca(2+). FK960 caused an increase in intracellular Ca(2+) concentrations by stored Ca(2+) release in cultured rat hippocampal astrocytes, and H-89 abolished the increase. Forskolin, a PKA activator, mimicked the effect of FK960 on intracellular Ca(2+) mobilizations. Taken together, it appears that FK960 stimulates glutamate release from astrocytes, likely as a result of raising intracellular Ca(2+) concentrations via a PKA pathway. The FK960 action would increase synaptic glutamate concentrations, in part responsible for the facilitation of hippocampal neurotransmission. The results of the present study may provide a new idea that agents targeting astrocytes could serve as anti-dementia drugs.

Animals↗
PubMed2002

MMP-9 and EBA immunoreactivity after papaverine mediated opening of the blood-brain barrier.

Papaverine is a non-specific vasodilatory drug, which was found to unexpectedly cause opening of the blood-brain barrier (BBB). We studied the expression of two endothelial cell related markers, endothelial barrier antigen (EBA) as a marker of BBB intactness, and matrix metalloproteinase-9 (MMP-9), an extracellular matrix molecule, the activation of which results in BBB opening. Immunoreactivity was quantified after intra-carotid injection of papaverine in rats. BBB opening was identified at 1 h, but had been reversed by 24 h. Reduction in EBA-immunoreactivity occurred at 3 h, whereas MMP-9 was not observed until 24 h. The activation of MMP-9 thus occurred much later than BBB opening, which suggests a different role for MMP-9 when selective and reversible opening of the BBB is produced by pharmacological manipulation.

Animals↗
PubMed2002

Adenosine triphosphate accelerates recovery from hypoxic/hypoglycemic perturbation of guinea pig hippocampal neurotransmission via a P(2) receptor.

The present study was designed to assess the effects of adenosine triphosphate (ATP) on hippocampal neurotransmissions under the normal and hypoxic/hypoglycemic conditions. ATP reversely depressed population spikes (PSs), which were monitored in the dentate gyrus of guinea pig hippocampal slices, in a dose-dependent manner at concentrations ranged from 0.1 micro M to 1 mM. A similar depression was obtained with the P(2) receptor agonist, alpha,beta-methylene ATP (alpha,beta-MeATP), and the effect was inhibited by the P(2) receptor antagonists, suramin and PPADS. The inhibitory action of ATP or alpha,beta-MeATP was inhibited by the gamma-aminobutyric acid(A) (GABA(A)) receptor antagonist, bicuculline, but it was not affected by theophylline, a broad inhibitor of adenosine (P(1)) receptors, tetraethylammonium, a broad inhibitor of K(+) channels, or ecto-protein kinase inhibitors. ATP or alpha,beta-MeATP enhanced GABA release from guinea pig hippocampal slices, that was inhibited by deleting extracellular Ca(2+) or in the presence of tetrodotoxin, while ATP had no effect on GABA release from cultured rat hippocampal astrocytes or postsynaptic GABA-gated channel currents in cultured rat hippocampal neurons. Twenty-minutes deprivation of glucose and oxygen from extracellular solution abolished PSs, the amplitude recovering to about 30% of basal levels 50 min after returning to normal conditions. ATP or alpha,beta-MeATP accelerated the recovery after hypoxic/hypoglycemic insult (approximately 80% of basal levels). Adenosine diphosphate and adenosine monophosphate accelerated the recovery, but to a much lesser extent, and adenosine had no effect. The results of the present study thus suggest that ATP inhibits neuronal activity by enhancing neuronal GABA release via a P(2) receptor, perhaps a P2X receptor, thereby protecting against hypoxic/hypoglycemic perturbation of hippocampal neurotransmission.

Adenosine Triphosphate↗
PubMed2002

L-trans-PDC enhances hippocampal neuronal activity by stimulating glial glutamate release independently of blocking transporters.

The glutamate transporter inhibitor, L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) reversibly enhanced hippocampal neuronal activity in the rat and mouse dentate gyrus. The PDC action was still found in mice lacking the glial glutamate transporter GLT-1. PDC did not influence the rate of spontaneous miniature excitatory postsynaptic currents and spontaneous inhibitory postsynaptic currents, ionotropic glutamate receptor currents, or GABA-evoked currents in cultured rat hippocampal neurons. PDC increased glutamate released from cultured hippocampal astrocytes from normal rats, normal mice, and GLT-1 knock-out mice, that is not inhibited by deleting extracellular Na(+), while the drug had no effect on the release from cultured rat hippocampal neurons. The results of the present study thus suggest that PDC stimulates glial glutamate release by a mechanism independent of inhibiting glutamate transporters, which perhaps causes an increase in synaptic glutamate concentrations, in part responsible for the enhancement in hippocampal neuronal activity.

Animals↗