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Biomedical subjects

Toshihide Harada

Publications and source records attributed to Toshihide Harada.

14 recordsLinked to original sources
PubMed2006

Parkinson disease patient with fibromyalgia: a case report.

Parkinson's disease (PD) is characterized by motor disturbances such as tremor, slow movement and rigidity. Also, pain is a common symptom in patients with PD. The prevalence of pain is 40-75% in patients with PD. Physicians should pay attention to pain in patient with PD. We report a PD patient who suffered from fibromyalgia (FM). If the amount of pain is not maximal in the side more affected by parkinsonism and pain is not markedly relieved when the patient is in the "on" state, the pain may be due to FM.

Aged↗
PubMed2006

Basal blood flow in complex regional pain syndrome does not necessarily indicate vasoconstrictor nerve activity.

OBJECTIVES: To quantitatively investigate simultaneous skin blood flow and sweating in a patient with complex regional pain syndrome. METHOD: Using one probe, skin blood flow and sweating were measured on the affected and non-affected sides at baseline and after activation of sympathetic system in a 47-year-old woman with complex regional pain syndrome type I of the left hand. RESULTS: Basal sweating, sympathetic sweat response, basal blood flow, sympathetic flow response, and attrition rate of blood flow (the ratio of sympathetic flow response to basal blood flow) of the affected side were greater than those on the non-affected side. CONCLUSIONS: Although sympathetic nerve activity (sympathetic flow response) appeared greater on one side, basal blood flow was also greater on that side. These contradictory results suggest that some factor or factors increase basal blood flow despite a higher sympathetic nerve tone on the side. Comparing basal blood flow on one side to the contralateral side does not necessarily indicate lesser vasoconstrictor nerve activity on that side. Advantages of simultaneous measurement of skin blood flow and sweating with a single probe may make the method useful.

Complex Regional Pain Syndromes↗
PubMed2005

Activation of human SII cortex during exploratory finger movement and hand clenching tasks.

We used electric median nerve stimuli to elucidate the functional properties of neurons in the human secondary somatosensory cortex during exploration of small objects and muscle contraction. Somatosensory evoked fields were recorded from nine healthy subjects with a 204-channel neuromagnetometer. Electrical stimuli were applied once every 3 s to the left median nerve at the wrist. The conditions during the stimulation were rest (control session), exploration of small objects (exploration session) and clenching the hand while the wrist was being electrically stimulated (clench session). The strengths of equivalent current dipoles of evoked fields from the secondary somatosensory cortex were increased during the exploration session, but those of evoked fields were decreased by the clench session.

Adult↗
PubMed2005

Difference in somatosensory evoked fields elicited by mechanical and electrical stimulations: Elucidation of the human homunculus by a noninvasive method.

We recently recorded somatosensory evoked fields (SEFs) elicited by compressing the glabrous skin of the finger and decompressing it by using a photosensor trigger. In that study, the equivalent current dipoles (ECDs) for these evoked fields appeared to be physiologically similar to the ECDs of P30m in median nerve stimulation. We sought to determine the relations of evoked fields elicited by mechanically stimulating the glabrous skin of the great toe and those of electrically produced P40m. We studied SEFs elicited by mechanical and electrical stimulations from the median and tibial nerves. The orientations of dipoles from the mechanical stimulations were from anterior-to-posterior, similar to the orientations of dipoles for P30m. The direction of the dipole around the peak of N20m from median nerve electrical stimulation was opposite to these directions. The orientations of dipoles around the peak of P40m by tibial nerve stimulation were transverse, whereas those by the compression and decompression stimulation of the toe were directed from anterior-to-posterior. The concordance of the orientations in ECDs for evoked fields elicited by mechanical and electrical stimulations suggests that the ECDs of P40m are physiologically similar to those of P30m but not to those of N20m. The discrepancy in orientations in ECDs for evoked field elicited by these stimulations in the lower extremity suggests that electrical and compression stimulations elicit evoked fields responding to fast surface rubbing stimuli and/or stimuli to the muscle and joint.

Adult↗
PubMed2005

Effects of high linear energy transfer radiation on the cochlea of C3H/He mouse during postnatal developmental course.

To investigate the biological effectiveness of neutrons at energies below 1MeV with regard to ear toxicity, we exposed mice to 1.0 Gy of monoenergetic neutrons (1.026 MeV) or 137Cs gamma rays at 7 days of age, and observed subsequent morphological changes in the inner ear with light and scanning electron microscopes. Monoenergetic neutrons, but not gamma rays, caused acute changes in the ear. The epithelium of the greater epithelial ridge in the organ of Corti showed degeneration around 6 hours and disappeared by 72 hours post-irradiation. The apoptotic cell death of the epithelium of the greater epithelial ridge was inducible by the radiation at 3 or 4 days of age. The hair cells formed the protrusion structures of the surface by 72 hours post-irradiation. Neutron-irradiation also caused acute otitis media until 10 weeks of age.

Aging↗
PubMed2005

Effect of monoenergetic neutron irradiation on the postnatal development of the cochlea in C3H/HeN mice.

To investigate the toxic effect of neutrons at energies of approximately 1MeV on the ear, we exposed 7-day-old mice to 1.0 Gy of monoenergetic neutrons (1.026 MeV) or (137)Cs gamma rays, and assessed subsequent morphological changes in the inner ear by light and scanning electron microscopy. Monoenergetic neutrons, but not gamma rays, caused acute changes in the ear. The epithelium of the greater epithelial ridge in the organ of Corti had disappeared by 72 hr post-irradiation, as a result of epithelial apoptosis observed 6 hr post-irradiation. Radiation could induce apoptotic cell death of the epithelium of the greater epithelial ridge at 3 or 4 days of age. Protruding structures were detected on the surface of the hair cells by 72 hr post-irradiation. The neutron-irradiation also caused the apoptotic cell death of epithelial cells at the nasal conchae, and subsequent acute otitis media continued until 10 weeks of age.

Age Factors↗
PubMed2004

Human reactions to physical stimulus and the removal of such stimulus as recorded by magnetoencephalography.

We studied the cortical evoked fields elicited by the examiner's touch on glabrous skin of the subject's index finger. Two main components of evoked fields were elicited, and these dipoles were located in the primary somatosensory cortex contralateral to the side of the subject's index finger touched by the examiner. When the timing of removal of the examiner's finger triggered the data acquisition using the photosensor, the strength of the dipole from early evoked fields was stronger than that from late ones. We showed that these evoked fields were elicited by removal and touch of the examiner's finger respectively in response to the mechanical compression and decompression of the skin.

Adult↗
PubMed2004

[Somatosensory evoked potentials/fields--exploration of brain function].

We have summarized the history of electroencephalography(EEG) since 1875, when a paper by Richard Caton was published describing the first EEG recordings in animals. Somatosensory evoked potentials (SEPs) were recorded by George Dawson in 1951. Thereafter, SEPs were developed for clinical use with other evoked potentials such as auditory evoked potentials(VEPs). To understand evoked potentials, related mechanism of induction of far-fields-potentials(FFP) following stimulation of the median nerve has been discussed. SEPs consisted of P9, N9, N10, P11, N11, N13, P13, P14, N18, N20 and P20/P22. Scalp recorded P9 FFP arises from the distal portion of the branchial plexus as reflected by N9 stationary negative potential recorded over the stimulated arm. Cervical N11 and N13 arise from the root entry zone and dorsal horn, respectively. Scalp recorded P13, P14 and N18 FFP originate from the brainstem. In this communication, magnetoencephalography(MEG) and results of one of our recent studies on somatosensory evoked fields(SEFs) are also discussed. One of the important features of MEG is that magnetic signals detected outside the head arise mainly from cortical currents tangential to the skull. Since the net postsynaptic current follows the orientation of cortical pyramidal cells, the MEG signals mainly reflect activity of the fissural cortex, whereas radial current may remain undetected. In our study, we demonstrated SEFs elicited by compression and decompression of a subject's glabrous skin by a human operator. Their dipoles were tangentially oriented from the frontal lobe to parietal lobe.

Animals↗
PubMed2003

A collaborative study on the malignant syndrome in Parkinson's disease and related disorders.

We report the results of a collaborative study on malignant syndrome (MS) that developed in patients being treated with levodopa and other anti-parkinsonian drugs. We analyzed clinical features, laboratory findings, precipitating events, and risk factors for poor outcome. The study was conducted in five centers in Japan. Patients who developed MS between January 1991 and December 1997 were included. The enrollment criteria used were the same as those for neuroleptic MS proposed by Levenson et al. (1985).A total of 99 episodes were encountered in 93 patients (72 with Parkinson's disease and 21 with secondary parkinsonism); one patient had four recurrences of MS and three patients had two recurrences. High fever was the most frequent clinical manifestation of MS followed by worsening of parkinsonism, and then altered levels of consciousness. Serum creatine kinase was abnormally elevated in all the patients studied. Life-threatening complications were rhabdomyolysis, disseminated intravascular coagulation, and acute renal failure. The most frequent precipitating event was discontinuation or dose reduction of anti-parkinsonian drugs, particularly levodopa. No drug was the exception in the precipitation of MS. Intercurrent infection was the next most common precipitating event. MS developed without drug withdrawal or infection in some patients. In five patients, severe "wearing off" phenomenon was the only event preceding the onset of MS. Hot weather and dehydration appeared to be the cause in three patients. Among the total of 99 episodes, patients recovered to the pre-MS state following 68 episodes (68.7%); in the remaining 31.3%, patients failed to recover to their previous state. Older age, higher Hoehn and Yahr stage during the symptomatic phase of MS, higher akinesia score, and the absence of wearing off phenomenon prior to developing MS were associated with poor outcome. The most frequently used treatments of MS were intravenous fluid, levodopa, dantrolene sodium, and intragastric bromocriptine. Early introduction of treatment is important. Any elevation of body temperature during the course of anti-parkinsonian drug treatment should be considered as MS until proved otherwise.

Aged↗
PubMed2003

Clinical features of malignant syndrome in Parkinson's disease and related neurological disorders.

INTRODUCTION: We elucidated the cause and clinical characteristics of malignant syndrome (MS) in patients with Parkinson's disease (PD), early-onset parkinsonism (EOP), and other neurological disorders. MATERIALS AND METHODS: Subjects were 260 patients with PD or EOP, and three patients with other neurological disorders associated with MS. We studied clinical symptoms before and after the onset of MS, and evaluated autonomic function particularly before the onset of MS. RESULTS: The overall incidence of MS accompanying PD and EOP in our department was eight of 260 patients (3.1%). The incidence of MS in EOP was significantly higher than that in PD. All patients with MS showed comparatively longer duration of illness and advanced stage of PD and EOP. Factors triggering MS included reduced dosage or discontinuation of anti-parkinsonian drugs, reduction of oral intake, dehydration, infectious disease, postoperative state, and treatment with major tranquilizers. Although patients demonstrated marked autonomic symptoms at the onset of MS, in many cases autonomic dysfunction developed before the onset of MS. Even EOP patients, who usually demonstrated milder autonomic dysfunction, showed abnormalities in the correlation between circadian rhythm of blood pressure and pulse rate, and/or abnormal gastric emptying test, suggesting that autonomic dysfunction plays an important role in the cause of MS. Cooling the body, fluid replacement, resumption or increasing the dosage of anti-parkinsonian drugs and administration of dantrolene sodium overcame MS in all cases. CONCLUSION: Autonomic dysfunction is related to the cause and clinical features of MS in PD, EOP and some other neurological disorders.

Adult↗
PubMed2002

Effects of movement on somatosensory N20m fields and high-frequency oscillations.

Somatosensory evoked fields were recorded to determine the effects of movement and attention on high-frequency oscillations during active finger movements of the ipsilateral and contralateral sides in response to electrical stimulation of the median nerve. A whole-scalp neuromagnetometer was used to record somatosensory evoked fields from eight subjects following electric median nerve stimulation at the wrist. The following three sessions were performed: (1). rest, (2). movement of fingers on the ipsilateral in response to stimulation and (3). movement of fingers on the contralateral in response to stimulation. The somatosensory evoked fields with a wide-bandpass (0.1-1000 Hz) were recorded. High-frequency oscillations and N20m were separated by subsequent high-pass (> 300 Hz) and low-pass (< 300 Hz) filtering. The maximum amplitude of high-frequency oscillations decreased during finger movements accompanying a decrease in somatosensory N20m dipole strength. Activation of the motor cortex appeared to suppress both the amplitude of high-frequency oscillations and the N20m dipole strength.

Adult↗
PubMed2002

Role of human SII cortices in sensorimotor integration.

OBJECTIVES: To elucidate the functional properties of neurons in the human primary (SI) and ipsilateral and contralateral secondary (iSII or cSII) cortices in response to stimuli during finger movement. METHODS: We measured somatosensory evoked fields (SEFs) produced by electric stimuli delivered to the median nerve at 0.2 Hz in 6 healthy subjects. RESULTS: The amplitudes of evoked fields from both iSII and cSII were gradually attenuated with time. Consecutive blocks of trials were obtained to assess the habituation of each evoked field. Complex finger movements with attention (gating session) increased the amplitude of evoked fields from the iSII cortices but reduced the amplitudes of evoked fields from the cSII cortices (P<0.01). In contrast, the amplitude of P30 m from the SI did not show habituation effects but decreased significantly in the gating session (P<0.01). CONCLUSIONS: The enhanced iSII as well as suppressed cSII cortices during complex finger movements with attention are not only considered to be result of gating effect but also attention.

Analysis of Variance↗
PubMed2002

[A sporadic case of late-onset familial amyloid polyneuropathy type I (transthyretin Met 30-associated familial amyloid polyneuropathy) inborn habitant of Ehime prefecture].

We reported a 62-year-old man of late-onset familial amyloid polyneuropathy type I(transthyretin Met 30-associated familial amyloid polyneuropathy) from Ehime Prefecture. There was no family history related to endemic Japanese foci (Nagano and Kumamoto foci). He demonstrated paraesthesia in the legs and mild autonomic symptoms at the age of 52. These symptoms gradually developed. Analysis of the transthyretin gene from his leucocytes demonstrated he had Met 30 transthyretin mutation. Therefore, he was diagnosed with late-onset familial amyloid polyneuropathy type I(FAP 1). In some families, asymptomatic carriers with the mutant transthyretin gene were diagnosed. In early stage, this patient's polyneuropathy and autonomic nervous system dysfunction were less serious than those of FAP 1 patients from endemic Japanese foci. These symptoms of this patient was slowly progressive. He hoped liver transplantation (brain death or living-related) treatment if possible. Now he became 68-year-old and bed-ridden.

Amyloid↗