Biomedical subjects

C Kadoya

Publications and source records attributed to C Kadoya.

At least 19 recordsLinked to original sources

PubMed2000

Intraosseous microcystic meningioma.

Extradural ectopic meningioma is a rare tumor. We report on an example of microcystic meningioma arising in the skull of an elderly woman. Radiological examination revealed a localized osteolytic lesion in the left parietal bone. At surgery, it was discovered that the tumor was located within the skull without any evidence of extraosseous extension. The light microscopic, immunohistochemical and ultrastructural features were consistent with a microcystic variant of meningioma. To our knowledge, this is the first case of an intraosseous microcystic meningioma, and we believe that this type of meningioma should be considered in the differential diagnoses of myxoid bone tumors of the calvarium.

Aged↗

PubMed1998

Attenuation of ischemic inflammatory response in mouse brain using an adenoviral vector to induce overexpression of interleukin-1 receptor antagonist.

It has been demonstrated that administration of an interleukin-1 receptor antagonist protein (IL-1ra) reduces ischemic brain injury; however, the detrimental mechanism initiated by interleukin-1 (IL-1) in ischemic brain injury is unclear. In this study, we used mice that were transfected to overexpress human IL-1ra to elucidate the role of IL-1 in the activation of the inflammatory response after middle cerebral artery occlusion (MCAO). Myeloperoxidase (MPO) activity and immunohistostaining were used as a marker of polymorphonuclear leukocytes (PMNL) infiltration. Adenoviral vector (1 x 10(9) particles) was administered by injection into the right lateral ventricle in mice. Five days later, MCAO was performed on the mice using a suture technique. Permanent MCAO was achieved for 24 hours in the Ad.RSVIL-1ra-transfected. Ad.RSVlacZ-transfected, and saline (control) mice. Myeloperoxidase activity was quantified in each region and localization of MPO was determined by immunohistochemistry. After 2 hours of MCAO, the surface cerebral blood flow was reduced to 13.5% +/- 3.4%, 10.75% +/- 2.6%, and 10.9% +/- 2.6% of baseline in the ischemic hemisphere in Ad.RSVIL-1ra-transfected, Ad.RSVlacZ-transfected, and saline-treated mice, respectively. The MPO activity in the ischemic hemisphere in the Ad.RSVlacZ group was similar to that in the saline control group (cortex: 0.40 +/- 0.22 versus 0.33 +/- 0.11; basal ganglia: 0.46 +/- 0.23 versus 0.49 +/- 0.17; P > 0.05); however, it was significantly reduced in the Ad.RSVIL-1ra group (cortex: 0.18 +/- 0.07; basal ganglia: 0.26 +/- 0.15; P < 0.05). Myeloperoxidase immunohistochemistry showed that the massive accumulation of MPO-positive cells in the ischemic cortex, striatum, and corpus callosum regions was greatly attenuated in Ad.RSVIL-1ra-transfected mice. Our results indicate that Ad.RSVIL-1ra-transfected mice provide a useful tool to study the mechanism of action of IL-1. The MPO activity assay and immunostaining after 24 hours of focal ischemia were significantly reduced in IL-1ra gene-transfected mice, suggesting that IL-1 may play an important role in the activation of inflammatory cells during focal cerebral ischemia.

Adenoviridae↗

PubMed1995

Topographic electroencephalogram of propofol-induced conscious sedation.

OBJECTIVES: To determine the effects of increasing doses of propofol that induce conscious sedation on the topographic electroencephalogram (EEG) of human volunteers and to test the hypothesis that more frontal brain areas are affected by low doses of propofol. METHODS: The scalp EEG was recorded monopolarly from 16 different sites based on the 10-20 International System. Microcomputer-based hardware and RHYTHM 7.1 software were used to obtain quantitative power frequency topographic EEG data. A total of 10 normal adult volunteers were given incremental doses of propofol targeted to plasma concentrations of 0 to 1200 ng/ml. RESULTS: Sedative concentrations of propofol produced a dramatic increase in beta 1, an increase in alpha 2 and beta 2, and an increase in delta activity at the largest concentration, with almost no change in theta activity. The increase in beta 1 activity had a linear correlation with plasma propofol levels (r = 0.9). Topographic mapping indicated that beta 1 activation was primarily in the frontal and central regions, with focal changes more in the left hemisphere. CONCLUSIONS: Topographic brain EEG mapping techniques indicate that frontal brain beta 1 EEG activity may be useful as an objective brain index of propofol conscious sedation.

Adult↗

PubMed1995

Preischemic but not postischemic zinc protoporphyrin treatment reduces infarct size and edema accumulation after temporary focal cerebral ischemia in rats.

BACKGROUND AND PURPOSE: Zinc protoporphyrin (ZnPP) has multiple actions. It is an interleukin-1 antagonist as well as a hemeoxygenase inhibitor. Interleukin-1 is produced in ischemic brain and probably contributes to ischemic injury, although the role of heme oxygenase during ischemia is unknown. Whether ZnPP treatment is more effective before or after ischemia, as well as whether it is more protective in permanent or temporary cerebral ischemia, is also unknown. Therefore, we investigated the effect of ZnPP on infarction size and edema in a rodent model of temporary and permanent focal cerebral ischemia. METHODS: Two groups of adult male Sprague-Dawley rats were pretreated with either 50 mg/kg ZnPP IP or saline and subjected to permanent middle cerebral artery occlusion 30 minutes later. Four additional groups of animals were subjected to 2 hours of temporary middle cerebral artery occlusion followed by 22 hours of reperfusion. Two of these groups were pretreated 30 minutes before middle cerebral artery occlusion with either 50 mg/kg ZnPP IP or saline. The other groups received ZnPP at either 2 or 4 hours after middle cerebral artery occlusion. Regional cerebral blood flow in the ischemic cortex was monitored with laser Doppler flowmetry. Cerebral infarct size and brain water were measured 24 hours after the onset of either form of ischemia. RESULTS: Regional cerebral blood flow after occlusion was approximately 13% to 20% of baseline after either permanent or temporary ischemia. ZnPP had no effect on regional cerebral blood flow, infarct size, or edema formation in permanent ischemia. In contrast, pretreatment significantly reduced infarct size (17.2 +/- 6.6% in controls versus 6.2 +/- 2.9% in pretreated rats) and edema formation (center zone, 4.00 +/- 0.71% water in controls versus 1.18 +/- 0.26% water in pretreated rats) in the model of temporary ischemia, but treatment after occlusion had no effect. CONCLUSIONS: ZnPP treatment protected the brain when administered early in the temporary ischemia model.

Animals↗

PubMed1994

Recovery cycle of the Hoffmann reflex of tobacco smokers and nonsmokers: relationship to plasma nicotine and cotinine levels.

Ten normal adult tobacco smokers and 10 nonsmoking volunteers 20-31 years of age were the subjects of this study. The tobacco smokers all had a history of daily tobacco smoking. They were asked to stop smoking for 12 hours prior to testing. The Hoffmann (H) reflex and its recovery cycle were measured on different days before and just after smoking one nonfiltered 0 mg, low (0.27 mg), or high (2.16 mg) nicotine containing cigarette in a randomized order. Blood samples were drawn immediately after the H reflex recordings in the tobacco smokers. The blood samples were centrifuged, the plasma removed, frozen, and later assayed for nicotine and cotinine levels. Nonsmokers compared to tobacco smokers before smoking only had a tendency for enhanced amplitude of the recovery cycle. After smoking the nicotine containing cigarettes, the tobacco smokers had a depression of the amplitude of the H reflex recovery cycle. The amplitude of the H reflex recovery cycle at 160 ms was reduced. This decreased significantly with increasing plasma nicotine and cotinine concentrations. Individual differences were marked. The data obtained are consistent with evidence in animals that nicotine and tobacco smoke stimulate Renshaw inhibitory neurons in the spinal cord, either directly or indirectly which leads to a skeletal muscle relaxant effect.

Adult↗

PubMed1994

Central nervous system arteriovenous malformations with hereditary hemorrhagic telangiectasia: report of a family with three cases.

A family with central nervous system (CNS) arteriovenous malformations (AVMs) and hereditary hemorrhagic telangiectasia (HHT) is reported. A 46-year-old man had an intracerebral hemorrhage. Cerebral angiography showed one AVM and two angiomas. The HHT was diagnosed because of the concomitant existence of cutaneous telangiectasia. The patient's brother had HHT and paraplegia since the age of 21. Magnetic resonance imaging revealed an old spinal cord hemorrhage. The patient's son with HHT had an intracerebral hemorrhage at age 6. Angiograms showed two AVMs and one angioma. Familial CNS AVMs with HHT are extremely rare. The loci for human leukocyte antigen of the affected cases with HHT were evaluated, and the management of CNS AVMs with HHT is discussed.

Adult↗

PubMed1994

Relationship of electroencephalographic and cardiovascular changes to plasma nicotine levels in tobacco smokers.

OBJECTIVE: The effects of smoking one tobacco or placebo cigarette on the mean change in voltage of the electroencephalogram (EEG), arterial blood pressure, heart, and eye blink rates were correlated with the increase in plasma nicotine, exhaled carbon monoxide, and carboxyhemoglobin levels. METHODS: Twenty nonsmokers (age range, 19 to 42 years; mean age +/- SE, 27.0 +/- 1.9 years) and 65 regular tobacco smokers (age range, 20 to 48 years; mean age +/- SE, 27.7 +/- 0.8 years) were studied about 10 to 12 hours after overnight tobacco deprivation and immediately after inhaling air through a straw or after smoking one of their own brands of cigarettes, respectively. RESULTS: An increase of at least 10 ng/ml plasma nicotine was needed to obtain a statistically significant decrease in alpha 1 and an increase in beta EEG activity. An increase of at least 15 ng/ml plasma nicotine was needed to obtain a statistically significant decrease in delta EEG activity. The mean dominant alpha frequency, heart rate, systolic and diastolic blood pressure, exhaled carbon monoxide, and carboxyhemoglobin levels increased significantly with increasing plasma nicotine concentrations. CONCLUSIONS: Measurement of plasma nicotine levels is especially important to quantify the relationship between tobacco smoking, mean EEG activity, and cardiovascular changes. Nicotine plasma concentrations greater than 10 micrograms/ml produce consistent and statistically significant changes in brain wave activity. Smaller increments in plasma nicotine produce less consistent EEG changes.

Adult↗

PubMed1994

Electrophysiologic effects of propofol sedation.

The scalp electroencephalogram (EEG), the long latency cognitive P300 auditory evoked response (AER), and reaction times were recorded in 10 volunteers sedated with a computer-controlled infusion of propofol to target plasma concentrations of 0.3, 0.6, 0.9, and 1.2 micrograms/mL. The observed mean +/- SE venous plasma concentrations were 0.152 +/- 0.042, 0.372 +/- 0.078, 0.679 +/- 0.104, and 1.065 +/- 0.112 micrograms/mL, respectively. Scalp EEG topographic mapping revealed that beta 1 activation was primarily frontal and central with relative sparing of the temporal lobes. The P300 response was dramatically reduced by propofol in a concentration-dependent manner, even though the subjects were conscious but clearly sedated. Mean +/- SE reaction times were increased by propofol sedation from 347 +/- 35 ms (control) to 391 +/- 48, 460 +/- 70, 549 +/- 64, and 622 +/- 120 ms at increasing mean venous plasma propofol concentrations. The mean percentage +/- SE of correct responses decreased from 98.1 +/- 2.0 (control) to 99.1 +/- 1.7, 87.4 +/- 9.2, 82.8 +/- 12.9, and 69.8 +/- 20.9 at increasing propofol concentrations. Dramatic alterations in the EEG, P300 response, and reaction times were observed, especially with the higher plasma concentrations which produced conscious sedation.

Adult↗

PubMed1994

Double bilateral symmetrical aneurysms--case report.

A 52-year-old female admitted for subarachnoid hemorrhage and preoperative angiography revealed bilateral symmetrical middle cerebral artery aneurysms, which were successfully clipped. Post-operative angiography revealed bilateral symmetrical aneurysms in the distal anterior cerebral arteries, which were not identified on the preoperative angiograms, and were also clipped successfully. Such multiple aneurysms should not be treated by bilateral approaches in a one-stage operation.

Aneurysm, Ruptured↗

PubMed1993

Effects of tobacco smoking on the Hoffmann reflex.

Ten normal adult tobacco smoking volunteers 21 to 32 years of age were the subjects of this study. They were asked not to smoke for 12 hours prior to testing. The Hoffmann (H) reflex and its recovery cycle were measured before and just after smoking (on different days) one nonfiltered, zero, low (0.27 mg), or high (2.16 mg) nicotine tobacco cigarette. After smoking the nicotine-containing cigarettes, the subjects showed a reduction of the H reflex recovery cycle. Individual differences were marked. Nevertheless, the data obtained are consistent with evidence in animals that nicotine and tobacco smoke stimulate Renshaw inhibitory neurons in the spinal cord, either directly or indirectly. This technique provides another objective measure of the effects of tobacco smoking in human volunteers.

Adult↗

PubMed1993

Pachymeningoencephalitis: case report.

Hypertrophic cranial pachymeningitis is uncommon. We report the first case of pachymeningitis extending to the cerebral parenchyma (pachymeningoencephalitis) and involving the bone and extracranial soft tissue. The clinical features and pathogenesis are discussed.

Adult↗

PubMed1993

Clival chordoma associated with pathological laughter. Case report.

The case of a 40-year-old man with a clival chordoma who presented with symptoms of pathological laughter and left sixth cranial nerve paresis is reported. Laughing and talking during sleep were noted on polygraphic and videotape recordings of nocturnal sleep. Selective disorganization of sleep was observed, with laughing facial expressions and a lack of muscular atonia. The tumor developed in the prepontine cistern, compressing the pontomesencephalic structures backward and involving the upper clivus and the left cavernous sinus. No recurrence of laughter attacks were noted after total removal of the tumor. The sleep patterns observed were similar to those of experimental animals with lesions of the peri-alpha locus ceruleus. The importance of uncontrolled laughter as a sign of a ventral brain-stem mass is emphasized.

Adult↗

PubMed1991

Effects of hyperbaric environment on the P300 component of event-related potentials.

Hyperbaric chamber dives at 19 ATA with helium-oxygen were performed at the Japan Marine Science Technology Center, Yokosuka, from January 31 to February 2 in 1990. During simulated underwater experiments, event-related potentials were recorded in 2 divers for assessment of the cognitive function. Although the P300 amplitude of the potentials did not show any significant change, its latency was clearly prolongated and this prolongation continued to when the decompression reached to 70 m below sea level. These findings indicated that the hyperbaric environment corresponding to 180 m below sea level or less must cause some cognitive dysfunctions and that P300 is useful for early detection of those dysfunctions or HPNS.

Cognition↗

PubMed1991

[Arteriovenous malformation associated with meningioma].

A case of arteriovenous malformation (AVM) associated with a meningioma is reported. A 28-year-old woman was hospitalized for generalized convulsion. CT scan and right carotid angiogram revealed AVM in the right parietal lobe extending to the wall of the lateral ventricle. At the time of surgery an intraventricular meningioma attached to the choroid plexus was found in the excised cavity of the AVM. It is suggested that the meningioma might have been caused by chronic irritation due to an increased blood flow in the arteries supplying the AVM, because the AVM and the meningioma exist in the same lesion and share the same blood supply.

Adult↗

PubMed1991

[Successful treatment of huge arteriovenous malformation in the basal ganglia].

This report describes successful therapeutic results of a huge and high flow arteriovenous malformation (AVM) in the left basal ganglionic region. A 39-year-old female was admitted to our hospital presenting recent progression of aphasia, hemianopsia, hemiparesis, hemisensory disturbance on the right side. Progression of disturbance in consciousness was rapid, and the patient became comatose shortly after admission. A CT scan revealed a densely enhanced lesion in the left basal ganglia which caused aqueductal obstruction and hydrocephalus. Angiography demonstrated a huge and high flow AVM that was supplied by the anterior and posterior choroidal arteries, the lateral striate arteries and the insular branches of the middle cerebral arteries. This AVM drained into the vein of Galen via the inferior ventricular and basal vein. The draining vein was markedly dilated at the level of midbrain by a prominent stenosis of the junction between the vein of Galen and straight sinus, and it severely compressed the midbrain. Superselective embolization of the feeding arteries was done in two sessions. This was followed by surgical intervention for the embolized AVM one month after the second session. Embolization and surgery were carried out under barbiturate protection to reduce the risk of normal perfusion pressure break-through. The patient recovered well from these interventions without any hemodynamic changes and showed dramatic improvement of all focal neurological abnormalities. Postoperative angiography showed only a small residue of AVM.

Adult↗

PubMed1990

Skin and epidural recording of spinal somatosensory evoked potentials following median nerve stimulation: correlation between the absence of spinal N13 and impaired pain sense.

A clinical lesion study and intraoperative epidural recordings were made to test the origin and clinical significance of the spinal N13 and P13 of somatosensory evoked potentials (SEP) that follow median nerve stimulation. Intraoperatively, the respective peak latencies of spinal P13 and N13 coincided with those of the N1 component of the dorsal cord potential and its phase reversed positivity. On both the ventral and dorsal sides of the cervical epidural space, maximal amplitude was at the C5 vertebral level to which nerve input from the C6 dermatome is the main contributor. The modality of sensory impairment in the hand dermatome was examined in selected patients with cervical lesions, who showed such normal conventional SEP components as Erb N9, far-field P9, P11, P14, N18 and cortical N20, with or without loss of spinal N13. Statistically, the loss of spinal N13 was associated with decrease of pain sensation in the C6 dermatome. This was interpreted as being due to damage to the central grey matter of the cord, including the dorsal horn. Our results suggest the spinal N13 and P13 originate from the same source in the C6 spinal cord segment and that they are good indicators for the detection of centromedullary cervical cord damage.

Adult↗

PubMed1989

Effects of hyperbaric environment on human auditory middle latency response (MLR) and short latency somatosensory evoked potential (SSEP).

Hyperbaric chamber dives at 19 ATA with helium-oxygen were performed at the Japan Marine Science Technology Center from November 15 to December 3 in 1988 and from January 25 to February 4 in 1989. During simulated underwater experiments, auditory middle latency responses (MLRs) and short latency somatosensory evoked potentials (SSEPs) were recorded in 3 professional divers (2 divers in each dive) for assessment of brain function. During the saturation dive (180 m below sea level) component Pa on MLR was lost, while component Po remarkably increased in amplitude. These MLR changes rapidly recovered between the beginning of decompression and at about 90 m below sea level. On the other hand, N9-N20 interpeak latency on SSEP slightly or moderately increased in the both divers, but N9-N14 interpeak latency was not affected by the 19 ATA saturation dive. These results suggest that the hyperbaric environment corresponding to 180 m below sea level cause some cerebral dysfunctions, probably between the brainstem and the cortex, but these dysfunctions are only transient.

Adult↗

PubMed1988

Effects of a hyperbaric environment on human brain stem function with specific reference to auditory brain stem responses.

Hyperbaric chamber dives at 31 ATA with helium-oxygen were performed at the Japan Marine Science and Technology Center in 1987. During simulated underwater experiments, auditory brain stem responses were recorded in 4 professional divers for assessment of brain stem function. All divers had no clinical symptoms at 150 m below sea level, and their ABRs also showed no significant changes. During the 150-250 m depth saturation dives, all divers complained of various symptoms such as euphoria, ataxia, joint pain, tremor and dyspnea, while, I-III and I-V interpeak latencies on their ABRs increased with a tendency of recovery. Furthermore, the changes of both interpeak latency were independent of each other. These results indicate that transient dysfunction clinically or subclinically occurred at the processes between 150-300 m below sea level. Moreover, independent changes of I-III and I-V interpeak latencies in this study may mean that the pathways reached to the generation sites of wave III and V were different.

Adult↗