Search PubMed⌕ Search

Biomedical subjects

K Yoshioka

Publications and source records attributed to K Yoshioka.

At least 235 records · Page 13Linked to original sources
PubMed1996

[A case of thoracic meningioma presenting paraplegia at 4.5 years after removal of a falx meningioma].

A case of a thoracic meningioma presenting paraplegia 4.5 years after removal of a falx meningioma is reported. A 73-year-old woman, complaining of diplopia, was admitted to our department. Neurological examination revealed right abducens palsy. CT demonstrated a well-enhanced right frontal mass beneath the falx. The mass was totally removed under right frontal craniotomy. Its histology was transitional meningioma with rich fibroblasts. 4.5 years after craniotomy, she complained of progressing gait disturbance and nocturnal leg pain. Neurological examination revealed paraplegia, complete loss of leg sensation, loss of patellar and ankle reflex, bilateral positive Babinski reflex and urinary disturbance. Rectal function and anal reflex were preserved. Thoracic MRI demonstrated an intradural extramedullary mass which was well enhanced with Gd-DTPA at Th6-7. Under laminectomy, the mass was totally removed. Its histology was transitional meningioma with rich psammoma bodies and whirl formations. 4 months after removal, her palsy and sensory loss were almost completely recovered. We were able to find 15 cases of combined intracranial and spinal meningiomas in the literature. A young woman of neurofibromatosis suffered from tentorial, intraventricular and C1-2 meningiomas. Of 15 cases without neurofibromatosis including our case, 4 cases were of young boys and 11 cases were of women. Their initial symptoms originated from intracranial meningiomas in 8 cases. Multiple intracranial meningiomas were revealed in only 4 cases. In 9 cases, one case presented a combination of one intracranial meningioma and one spinal meningioma. Histology of intracranial meningioma was almost the same that of spinal meningioma in almost half of the 10 cases. These findings suggest the multi sentricity theory of multiple meningiomas originating in other neuroaxial compartments. Severe spinal dysfunction was recovered after removal in our case. Rectal function and anal reflex were preserved. These anorectal findings suggest that spinal dysfunction is either complete or incomplete. Motor evoked potentials are hopeful tools which can select reversible spinal motor dysfunctions.

Aged↗
PubMed1996

[A case of pituitary adenoma progressing to pituitary apoplexy on the occasion of cerebral angiography].

A case of pituitary adenoma which had progressed from subclinical pituitary apoplexy to subacute pituitary apoplexy on the occasion of cerebral angiography is reported. A 29-year-old man, complaining of bitemporal hemianopsia, was admitted to our department. Plain skull X-p revealed enlargement and double floor of the sella turcica. No abnormal calcification was revealed. CT demonstrated an isodensity mass with a diameter of 4 x 4 cm, and with ring enhancement in the suprasellar region. The mass extended from the intrasellar region to the suprasellar region and had a signal of high intensity on T1-weighted images. Endocrinological examination revealed hyperprolactinemia with a serum level of 422 ng/ml and normal reaction of anterior pituitary hormones. On 3rd March, digital subtraction angiography with 5F catheter was performed with the patient under sedation. The contrast medium was ioxaglic acid (Hexabrix 320). A volume of 6 ml with a speed of 4 ml per second was injected for the internal carotid angiogram. A total volume of 60 ml was used. Serum saline with 10 unit per ml of heparin sodium was also used for flushing. During angiography, the patient's blood pressure was 125/60-115/60mm Hg. DSA revealed upward displacement of the proximal portion of the anterior cerebral artery, pocket formation, and staining of the tumor capsule. Six hours later, he complained of retroorbital headache. Next morning, he noticed complete lack of left visual acuity. On 7th March, right visual acuity degenerated to blindness. CT revealed that the mass had increased its density. With bifrontal osteoplastic craniotomy, the tumor with marked intratumoral hemorrhage was resected. Its histology was chromophobe adenoma. The patient's right visual acuity improved rapidly. On the occasion of cerebral angiography, we could observe that subclinical pituitary apoplexy deteriorated to subacute pituitary apoplexy. Rosenbaum postulated that injection of contrast media increased intravascular pressure leading to pituitary apoplexy. At present, we cannot postulate increased intravascular pressure with 5F catheter and DSA. We cannot rule out that, with underlying subclinical pituitary apoplexy, hemorrhagic infarction due to contrast media and the anti-coagulate effect of heparin sodium accelerated the intratumoral bleeding. Subclinical pituitary apoplexy is a vulnerable state because of its aggravation to symptomatic apoplexy under mild stress. We emphasize that an operation should be performed as early as possible in the case of subclinical pituitary apoplexy.

Adenoma↗
PubMed1996

Expression of tenascin in normal and diseased human kidneys.

Expression of tenascin was studied in normal human adult and fetal kidney specimens, and in renal tissues biopsied from patients with several types of glomerulonephritis. Immunofluorescent staining of the normal kidneys showed that tenascin was present weakly in the mesangial area and interstitium, but was absent from the glomerular capillaries. In the fetal kidney, tenascin was detected in the interstitium, but not in the immature glomeruli. In kidney tissues biopsied from patients with various renal diseases, expression of tenascin was associated with increased mesangial expansion and tubulointerstitial changes. In situ hybridization showed that tenascin mRNA was expressed in the renal tissues, but tenascin mRNA and tenascin protein were occasionally dissociated. These findings indicate that expression of tenascin is associated with mesangial expansion and also with tubulointerstitial changes in human glomerulonephritis. Tenascin expression may contribute to repair of injured glomeruli and interstitium.

Adult↗
PubMed1996

Hydrogen peroxide in the regulation of erythropoietin (Epo) gene expression in hepatocellular carcinoma cells.

The present studies were designed and carried out to determine if hydrogen peroxide (H2O2) is involved in the regulation of erythropoietin (Epo) gene expression and stimulation of Epo production in the hepatocellular (Hep 3B) cells. Hep 3B cells were incubated with varying concentrations of H2O2 for periods of 6 hours or 24 hours. In other experiments Hep 3B cells were incubated for 24 hours with or without increasing concentrations of catalase and in the presence of H2O2. Culture medium levels of Epo were determined and quantitation of Epo mRNA was also made. The results indicate that H2O2 increases the levels of Epo mRNA and Epo hormone production in Hep 3B cells, and that catalase, the specific scavenger of hydrogen peroxide, inhibits Epo production in these cells. Based on these findings, it is concluded that H2O2 takes part in the signal transduction mechanisms in Epo production. It is recommended that further studies be undertaken to find out the source of the hydrogen peroxide in the hepatocellular carcinoma cells.

Carcinoma, Hepatocellular↗
PubMed1996

[A case of acromegaly associated with variegated spinal disorders].

A case of acromegaly associated with variegated spinal disorders was reported. The spinal disorders were multiple cervical disc herniations, spinal epidural cavernous angioma, multiple ossification of the spinal ligament and lumbar canal stenosis. A 51-year-old woman with acromegaly, complaining of disturbances of delicate hand movement and gate, consulted our department. Her past history included diabetes mellitus, hypertension and progressing enlargement of her extremities. Serum growth hormone level was 65.7 ng/ml and somatomedin-c level was 746 ng/ml. Brain MRI showed a pituitary tumor extending to the right cavernous sinus. Cervical MRI revealed disc herniations at C5/6 and C6/7. Thoracic MRI revealed osteoporosis, ossification of the posterior longitudinal ligament and multiple ossification of yellow ligament. Lumbar MRI disclosed ossification of yellow ligament and canal stenosis. Anterior fusion of C5-C7 and an intracapsular removal of the pituitary tumor were performed. Its pathology was that of eosinophilic adenoma. After 3 months, she suffered from paraparesis. On repeating MRI examination with Gd-DTPA, a spinal epidural mass was found at T4. Under laminectomy of Th3-5 and Th8-11, the epidural mass and ossified yellow ligament were removed. The epidural mass was cavernous angioma. She was able to walk without any assistance. An association of spinal canal stenosis with acromegaly is well known. But the association of disc herniation and with the ossification of spinal ligaments is rather rare in the literature. Spinal epidural cavernous angioma is very rare. We discussed the etiological aspects and the management of spinal disorders with acromegaly.

Acromegaly↗
PubMed1996

[A case of acute occlusion of left middle cerebral artery due to an embolus treated successfully with percutaneous transluminal angioplasty].

The acute occlusion of cerebral artery by embolism causes severe cerebral infarction. In cases with poor colateral circulation, cerebral infarction develops more severely. In these cases, quick recanalization of the occluded cerebral artery is necessary to prevent severe hemorrhagic infarction and brain edema. We report a case where interventional techniques were used to bring about quick recanalization of occluded cerebral artery. We encountered a case of a sixty-year-old male who experienced complete occlusion of the left middle cerebral artery due to an embolus. It was very hard to pass a guide wire through the embolic lesion. At first, we tried mild local fibrinolysis therapy using tissue plasminogen activator, but we could not get any recanalization. However, after mild local fibrinolysis therapy, the guide wire could be passed through the occlusion point. Secondly, we tried percutaneous transluminal angioplasty (PTA) with 2.0mm diameter angioplastic balloon using up to five atomic pressures, after which we obtained partial recanalization. Finally we achieved total recanalization of the middle cerebral artery by PTA with a 2.5mm diameter angioplastic balloon. We crushed this embolus using the angioplastic balloon with up to six atomic pressures. The point of the techniques is to press the embolus against the arterial wall. After this angioplasty, there was an occlusion of the common trunk of the posterior parietal artery and the angular artery. However there was neither massive hemorrhagic infarction nor massive brain edema on follow up CT. In the treatment of acute occlusion of the cerebral artery due to embolism, we found PTA is very effective against the embolus. In the future, we need to develop a retrieving device and a balloon that will prevent the production of small emboli during the crush process involved when bringing about recanalization using PTA.

Acute Disease↗
PubMed1996

[A case of Iotrolan encephalopathy].

A case of Iotrolan encephalopathy is reported. A 66-year-old woman, suffering from subarachnoid hemorrhage, was admitted to our department on January 17th, 1995. After an operation for aneurysmal clipping and ventriculo-peritoneal shunt, she was discharged with no neurological deficiency. CT scan revealed ventricular enlargement and slight periventricular lucency. She was re-admitted on January 4th, 1996. She was suffering from nausea, vomiting, right hemiparesis, right hemi-hypesthesia and disturbance of consciousness. CT scan demonstrated right thalamic bleeding and bilateral ventricular hemorrhage. Further ventricular enlargement was also revealed. With medical treatment, her symptoms were relieved gradually. But disorientation and memory disturbance continued. Shuntography with Iotrolan was performed on February 2nd, 1996. The ventriculo-peritoneal shunt was demonstrated to be occluded on the abdominal side. The volume of Iotrolan used was about 8cc. She became very restless on the night of the examination. Her temperature was up to 38. CT on February 4th demonstrated brain penetration of the Iotrolan. Revision of ventriculo-peritoneal shunt, administration of steroids and hydration was performed. CSF findings demonstrated no abnormalities. Her symptoms were relieved gradually. Iotrolan is a non-ionic contrast media of dimer type, composed of C37 H48 I6 N6 O18. Its distinctive features are low distributing coefficient and high affinity with water. Contrasting several reports of Metrizamide encephalopathy, only 2 cases of Iotrolan encephalopathy were reported. Iotrolan is reported to be much safer than Metrizamide. We were able to find brain penetration by Iotrolan. It is expected to be a characteristic radiological finding of encephalopathy induced by contrast media. The mechanism of Iotrolan encephalopathy is obscure. Several theories concerning Metrizamide encephalopathy are proposed. These are (1) inhibition of hexokinase, (2) inhibition of acethylcholinesterase, (3) immunological mechanism and (4) vascular disturbance. Iotrolan has no 2-deoxy-glucose structure. The inhibition theory of hexokinase is least expected. Related matters are circulatory disturbance of liquor, dehydration, excessive contrast media, advanced age, diabetes mellitus, hypertension, epileptic patients and patients taking phenothiazines. Prompt therapy is important. Removal of contrast media, hydration and administration of steroids should be performed as early as possible.

Aged↗
PubMed1996

[Acute thrombocytopenic purpura following rubella vaccination].

A case of acute thrombocytopenic purpura following rubella vaccination is reported. A 3-year-old boy developed purpura on the 22nd days after rubella vaccination. His platelet count was 34 x 10(3)/microliter. Platelet-associated IgG was elevated, but the amount of megakaryocytes in bone marrow aspirates was within the normal range, suggesting immune mechanism-associated thrombocytopenia. He recovered spontaneously within one month. Thrombocytopenic purpura is a well-documented complication of natural rubella infection. Attention should be paid rubella vaccination-associated thrombocytopenia, though it seems to be less frequent than after natural infections.

Acute Disease↗
PubMed1996

[A case of acute occlusion of the cervical portion of the right internal carotid artery with successful stepwise vascular dilatation by rescue PTA and deferred PTA].

A case is reported of acute occlusion of the cervical portion of the internal carotid artery, which was recanalized and dilated by steps through rescue percutaneous transluminal angioplasty (PTA) and deferred PTA. A 53-year-old man, complaining of progressive disturbance of consciousness and hemiplegia, was admitted to our department at about 7 hours after onset. CT demonstrated no abnormality. Digital subtraction angiography revealed an occlusion of the right cervical internal carotid artery. After intra-arterial injection of t-PA, a guide wire was able to be passed through the artery. Recanalization of internal carotid artery was performed by rescue PTA with Stealth FS angioplastic balloons of small diameter. Residual stenosis ratio was about 80%. After rescue PTA, his symptoms improved. On the following day, deferred PTA with Stealth FS angioplastic balloons of larger diameter was performed. Stenosis ratio was 30%. After the procedure, his palsy was relieved. DSA in the 3rd week after the PTA revealed that the stenosis ratio had changed from 30% to 13%. Rescue PTA is very effective for prompt recanalization. Stepwise vascular dilatation by rescue PTA with small balloons followed by deferred PTA can improve symptoms and prevent fatal hemorrhagic infarction. This method is especially useful for high risk patients of cervical internal carotid artery occlusion.

Acute Disease↗
PubMed1995

Cell-cycle-dependent invasion in vitro by rat ascites hepatoma cells.

The relationship between cell cycle and experimental metastasis of tumor cells in vivo has been investigated, but it remains to be elucidate which step of metastasis, or whether tumor-cell invasion in particular, depends on cell cycle. We previously reported an in vitro cell-monolayer invasion (transcellular migration) assay system, in which the invasive capacity of tumor cells is measured by counting tumor cells penetrating beneath a cultured mesothelial cell monolayer after tumor-cell seeding. Using our invasion assay system, the relationship between invasive capacity and cell-cycle distribution of MMI cells, a highly invasive clone of rat ascites hepatoma AHI30, was investigated. Invasive capacity of aphidicolin- or hydroxyurea-synchronized tumor cells enriched in G1/S-early S-phase cells was about 2 to 6 times higher than that of asynchronous cells. According to time-course experiments to examine the relationship between invasive capacity and the size of fraction of cells in each phase after release from an aphidicolin or a nocodazole block, it was suggested that MMI cells are most invasive in G1/S-S phase. Phagokinetic assay using colloidal gold particles showed that one possible reason for the enhanced invasiveness might be the increased cell motility in such phases, as suggested by the in vitro invasion assay.

Animals↗
PubMed1995

Participation of rhop21 in serum-dependent invasion by rat ascites hepatoma cells.

Rat ascites hepatoma cells (MM1 cells) penetrate through a cultured mesothelial cell monolayer (MCL) in the presence of fetal calf serum (FCS), but scarcely do so in its absence. Inactivation of rhop21 of MM1 cells by ADP-ribosyltransferase C3 resulted in the suppression of this serum effect on the penetration, suggesting that the serum effect was mediated by rhop21. To ascertain this assumption MM1 cells were transfected with an activated (Val14) human rhoA cDNA (Neo/RhoA 1-7). The transfectants penetrated MCL extensively even in the absence of FCS and became largely independent of serum for the penetration. These results suggest that serum-induced invasion by MM1 cells is mainly mediated by rhop21.

ADP Ribose Transferases↗
PubMed1995

Pharmacological characterization of GR82334, a tachykinin NK1 receptor antagonist, in the isolated spinal cord of the neonatal rat.

Pharmacological characteristics of [D-Pro9,[spiro-gamma-lactam]Leu10,Trp11]physalaemin-(1-11) (GR82334), a tachykinin NK1 receptor antagonist, and its effects on slow depolarizing responses of lumbar ventral roots evoked by primary afferent stimulation were examined in isolated spinal cord preparations of neonatal rats. GR82334 (1-3 microM) caused dose-dependent rightward shifts of the concentration-response curves for substance P, substance P methyl ester, delta-aminovaleryl [Pro9,N-Me-Leu10]substance P-(7-11) (GR73632) and neurokinin A in normal artificial cerebrospinal fluid and those for substance P methyl ester, GR73632 and neurokinin A in the presence of tetrodotoxin. GR82334 (10 microM) did not evoke gamma-aminobutyric acid (GABA) release from spinal cords of neonatal rats, whereas [D-Pro9,[spiro-gamma-lactam] Leu10,Trp11]substance P (GR71251), another tachykinin NK1 receptor antagonist, induced a significant increase in GABA release. GR82334 (1-3 microM) markedly depressed the slow depolarizing response of ventral roots, referred to as slow ventral root potential, evoked by the stimulation of the contralateral dorsal root or the ipsilateral saphenous nerve. In contrast, cyclo[Gln,Trp,Phe,Gly,Leu,Met] (L-659,877, 1 microM), a selective tachykinin NK2 receptor antagonist, did not depress the saphenous nerve-evoked slow ventral root potential and did not antagonize the action of neurokinin A to induce ventral root depolarization. The present results provide further evidence for the involvement of substance P, neurokinin A and tachykinin NK1 receptors in the primary afferent-evoked slow ventral root potentials.

Amino Acid Sequence↗
PubMed1995

Tachykininergic slow depolarization of motoneurones evoked by descending fibres in the neonatal rat spinal cord.

1. In the isolated spinal cord of the neonatal rat, repetitive electrical stimulation of the upper cervical region elicited a prolonged depolarization of lumbar motoneurones (L3-5) lasting 1-2 min, which was recorded extracellularly from ventral roots, or intracellularly. 2. This depolarizing response was markedly depressed by the excitatory amino acid receptor antagonists D-(-)-2-amino-5-phosphonovaleric acid (D-APV, 30 microM) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM). The remaining response was further depressed by a 5-hydroxytryptamine (5-HT) receptor antagonist, ketanserin (3 microM). 3. In the presence of these antagonists, a small part of the depolarizing response of slow time course remained, and this response was partially blocked by the tachykinin NK1 receptor antagonists GR71251 (0.3-5 microM) and RP67580 (0.3-1 microM). In contrast, RP68651 (0.3-1 microM), the inactive enantiomer of RP67580, had no effect on the depolarizing response. 4. The slow depolarizing response in the presence of D-APV, CNQX and ketanserin was markedly potentiated by a peptidase inhibitor, thiorphan (1 microM). 5. This descending fibre-evoked slow depolarization became smaller after prolonged treatment (5-7 h) with 5,7-dihydroxytryptamine (10 microM), a neurotoxin for 5-HT neurones. Under such conditions, the effects of thiorphan and GR71251 on the slow depolarization were virtually absent. 6. Under the action of D-APV, CNQX and ketanserin, applications of tachykinins, substance P and neurokinin A produced depolarizing responses of lumbar motoneurones, and the responses were depressed by GR71251 and potentiated by thiorphan. 7. These results suggest that tachykinins contained in serotonergic fibres serve as neurotransmitters mediating the descending fibre-evoked slow excitatory postsynaptic potentials in motoneurones.

5,7-Dihydroxytryptamine↗
PubMed1995

Antitumor promotion by phenolic antioxidants: inhibition of AP-1 activity through induction of Fra expression.

Induction of phase 2 detoxification enzymes by phenolic antioxidants can account for prevention of tumor initiation but cannot explain why these compounds inhibit tumor promotion. Phase 2 genes are induced through an antioxidant response element (ARE). Although the ARE resembles an AP-1 binding site, we show that the major ARE binding and activating protein is not AP-1. Interestingly, AP-1 DNA binding activity was induced by the phenolic antioxidant tert-butylhydroquinone (BHQ), but the induction of AP-1 transcriptional activity by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA) was inhibited by this compound. BHQ induced expression of c-jun, junB, fra-1, and fra-2, which encode AP-1 components, but was a poor inducer of c-fos and had no effect on fosB. Like c-Fos and FosB, the Fra proteins heterodimerize with Jun proteins to form stable AP-1 complexes. However, Fra-containing AP-1 complexes have low transactivation potential. Furthermore, Fra-1 repressed AP-1 activity induced by either TPA or expression of c-Jun and c-Fos. We therefore conclude that inhibitory AP-1 complexes composed of Jun-Fra heterodimers, induced by BHQ, antagonize the transcriptional effects of the tumor promoter TPA, which are mediated by Jun-Fos heterodimers. Since AP-1 is an important mediator of tumor promoter action, these findings may explain the anti-tumor-promoting activity of phenolic antioxidants.

Animals↗