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Biomedical subjects

R Kaji

Publications and source records attributed to R Kaji.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Muscle afferent block for the treatment of writer's cramp].

A 29-year-old man suffered from dystonic writer's cramp for over three years. When he wrote, typed and did other tasks using right hand, dystonic involuntary movement triggered medial rotation of the arm, wrist extension and shoulder elevation. Medication, biofeedback, and botulinum injection were performed without much success. We tried to block the sensory input from muscles by using lidocaine and ethanol. We made injections of 0.5% lidocaine 50ml and 99% ethanol 5ml into muscles with abnormal activity at the frequency of twice a week for about six months. After the treatment, dystonic movement was remarkably improved and he was then able to write, type and perform other tasks with the right hand. Side effects included pain of the injection site, nausea and dizziness, which lasted for a few hours. This "muscle afferent block" did not cause muscle weakness. We speculate that muscle afferent plays a pivotal role in dystonia so that its blocking may be of clinical use.

Adult↗
PubMed1995

[Potassium channel dysfunction at the lesion site in multifocal motor neuropathy as revealed by threshold electrotonus].

Multifocal motor neuropathy presents as a treatable muscular atrophy and is characterized by persistent conduction block and fasciculations or myokymia. Although the pathological findings at the lesion site revealed perivascular demyelination with little evidence of remyelination, the mechanism of conduction block is still unknown. We explored the threshold electrotonus, which registers membrane potential changes through threshold variation, at the lesion site. The findings were consistent with focal potassium channel dysfunction, with some evidence of depolarization block. The disrupted blood-nerve barrier and lack of Schwann cell-mediated extracellular potassium regulation may predispose the membrane depolarization, thereby accounting for the conduction block and fasciculations. Sensory nerve fibers are known to have more inward rectifiers, which take up the extracellular potassium, than motor fibers, and this may explain the sparing of these fibers.

Humans↗
PubMed1994

Anti-GM1 antibodies and impaired blood-nerve barrier may interfere with remyelination in multifocal motor neuropathy.

Multifocal motor neuropathy has pure motor manifestation and nonremittent clinical courses. Antiganglioside antibodies, though variable in titers, are characteristically elevated in the majority of these patient. In our cases, pathological findings at the site of conduction block suggested impaired remyelination and disruption of blood-nerve barrier. These findings lead us to postulate that antibodies toward gangliosides or toward unknown antigens containing gangliosides initiate motor-specific demyelination. The lesion, once produced, may persist as a result of impaired remyelination caused by disrupted blood-nerve barrier. The antibodies bound to denuded axons may also interfere with a remyelinative process. If so, antibodies may not always be circulating, thus accounting for variable levels of titers.

Antibodies↗
PubMed1994

Immunohistochemical investigation of epidermal growth factor receptor expression in ameloblastomas.

Immunohistochemical analysis was performed to determine the localization of epidermal growth factor receptor (EGFR) in ameloblastomas. Ameloblastoma samples were classified into follicular, plexiform, and basal cell types. The number of cases in each category was 17, 19 and 3, respectively. Ameloblastomas, disregarding their histological type, consist of two cell forms: peripheral columnar cells and central stellate cells. The frequency of EGFR expression was much higher in the latter than in the former (P < 0.005). On analysis with respect to histological types, the frequency of EGFR expression in columnar cells was not significantly different between the follicular and the plexiform types, but was observed more frequently in the stellate cells in the follicular than in the plexiform ameloblastomas (P < 0.05). This pattern of EGFR expression was not consistent with the PCNA staining pattern, but was similar to that of keratin expression which we have reported previously. The present study suggests that EGFR expression in ameloblastomas is closely associated with tumour differentiation, and squamous differentiation in particular.

Ameloblastoma↗
PubMed1994

Dissociation between contingent negative variation and Bereitschaftspotential in a patient with cerebellar efferent lesion.

Contingent negative variation (CNV) and Bereitschaftspotential (BP) were from the scalp in a patient with a discrete infarct in the mesial tegmentum of the midbrain involving the decussation of the superior cerebellar peduncle. Bereitschaftspotential in association with hand movements was completely absent while CNV was normally present at the frontocentral midline. This indicates that CNV is, as opposed to BP, generated without cerebro-cerebellar interactivation, suggesting different generating mechanisms.

Cerebellar Diseases↗
PubMed1994

Ultra-high dose methylcobalamin promotes nerve regeneration in experimental acrylamide neuropathy.

Despite intensive searches for therapeutic agents, few substances have been convincingly shown to enhance nerve regeneration in patients with peripheral neuropathies. Recent biochemical evidence suggests that an ultra-high dose of methylcobalamin (methyl-B12) may up-regulate gene transcription and thereby protein synthesis. We examined the effects of ultra-high dose of methyl-B12 on the rate of nerve regeneration in rats with acrylamide neuropathy, using the amplitudes of compound muscle action potentials (CMAPs) after tibial nerve stimulation as an index of the number of regenerating motor fibers. After intoxication with acrylamide, all the rats showed equally decreased CMAP amplitudes. The animals were then divided into 3 groups; rats treated with ultra-high (500 micrograms/kg body weight, intraperitoneally) and low (50 micrograms/kg) doses of methyl-B12, and saline-treated control rats. Those treated with ultra-high dose showed significantly faster CMAP recovery than saline-treated control rats, whereas the low-dose group showed no difference from the control. Morphometric analysis revealed a similar difference in fiber density between these groups. Ultra-high doses of methyl-B12 may be of clinical use for patients with peripheral neuropathies.

Acrylamide↗
PubMed1994

Generator mechanism of pain-related evoked potentials following CO2 laser stimulation of the hand: scalp topography and effect of predictive warning signal.

In order to clarify the generator mechanism of pain-related evoked potentials (pain EPs), we studied the scalp topography of the pain EPs following CO2 laser stimulation of hand dorsum by using balanced sternovertebral electrodes as the noncephalic reference in 11 normal volunteers. We also examined the effects of predictive warning signal (light-emitting diode) on the pain EPs. In both the warned and unwarned conditions, all of the 22 hand stimulations showed a large negative component (N2) at the peak latency of about 213 ms followed by a large positive component (P2) at the peak latency of about 329 ms. A preceding small negative component (N1) at the peak latency of about 148 ms was detected in 12 of the 22 hand stimulations in the warned condition and in 13 of the 22 hand stimulations in the unwarned condition. P2 was significantly larger and occurred earlier in the warned condition than in the unwarned condition, whereas other components did not differ between the two conditions, suggesting that an increased attention of the subject to the stimulus influenced the generator mechanism of the P2 component. With regards to the scalp topography, N2 was maximal at Cz and widespread transversely to both sides, whereas P2 was maximal at Cz or Pz and spread more posteriorly than N2. These findings suggest that P2 is generated by a different mechanism from N2 and is most likely associated with pain-related cognitive function. N1 was localized to the contralateral central and midtemporal areas, confirming that the nociceptive inputs are perceived in the sensory cortex in humans. The question as to whether the N1 component is generated in the hand area of the primary somatosensory cortex or in the secondary somatosensory cortex, or in both areas, remains to be solved.

Adult↗
PubMed1994

Correlation of E- and P-cadherin expression with differentiation grade and mode of invasion in gingival carcinoma.

The expression pattern of two Ca(2+)-dependent cell-cell adhesion molecules, E- and P-cadherin (CD), in 25 primary gingival squamous cell carcinomas (SCC) was examined immunohistochemically. The occurrence of reduced-type expression of both E- and P-CD increased significantly with the grade of carcinoma differentiation, culminating in a complete loss of P-CD in poorly differentiated SCC. The occurrence of reduced-type P-CD expression also increased significantly with the mode of invasion, as was the case with E-CD. Furthermore, no P-CD molecules were detected in one of the six SCC having a diffuse, cord-like invasion and in three of the six having a diffuse type of invasion. These findings suggest that the down-regulation of these cell adhesion molecules closely correlates with the differentiation grade and mode of invasion of gingival SCC.

Cadherins↗
PubMed1994

Optimisation of botulinum treatment for cervical and axial dystonias: experience with a Japanese type A toxin.

Twenty two patients with cervical and axial dystonias were treated with Japanese type A botulinum toxin. Injections were given repeatedly at intervals of 28-30 days to carefully chosen muscles with increased activities, with a maximum dose per session of 300 units. The maximum improvements in subjective and objective ratings were obtained only after repeated injections. No anti-toxin antibodies were detected; nor did any muscle fail to respond to the toxin. During the treatment, previously "silent" muscles were activated to reproduce the original abnormal posture, as if driven by a central motor programme. This resistance to treatment was overcome by injecting the toxin into newly activated muscles. Repeated injections are thus required to override central mechanisms in dystonias or to maximise drug delivery to large muscles. Antibody development may be controlled by the use of a less immunogenic toxin.

Adolescent↗
PubMed1994

Brachial plexus injury with cough attack: case report.

Cough attacks elicited by movement of the neck and right arm are reported in a patient who had sustained several shoulder injuries and who had an anterior scalenectomy. The coughing was accompanied by weakness in the right upper limb. At exploration, the phrenic nerve was found adhered to the brachial plexus. The cough attacks disappeared, and the weakness of the right upper limb improved somewhat after lysis of the adhesions between the phrenic nerve and the plexus and after external neurolysis of the upper, middle, and lower trunks. Postoperatively, the patient could elevate his right arm without coughing.

Brachial Plexus↗
PubMed1994

[Electrodiagnosis of neuromuscular diseases--a syndrome of monomelic amyotrophy with spinal hemiatrophy, anti-GM1 antibodies and abnormal F-waves (MASH)].

Electrodiagnosis rests upon sound anatomical and physiological bases of the peripheral nervous system, which are utilized for the dynamic process of differential diagnosis. If clinical and electrophysiological findings do not conform to any of the previously known diseases, there may be a chance of identifying a new entity. As an example, we report nine Japanese patients with unilateral atrophy of the distal upper limb and the cervical cord. Symptoms typically began insideously in young adulthood, progressed for a few years and then stabilized. Distribution of the muscle weakness usually corresponded to the territories of a few peripheral nerves, although not accompanied by sensory deficits. Serum anti-GM1 IgG antibodies were elevated in 6 out of 9 patients. Electrophysiological testings disclosed absent or delayed F-waves in the nerve involved. No long tract signs of the cord were demonstrated, although the spinal cord atrophy was extensive in some patients. Three showed partial clinical improvement after cyclophosphamide therapy or intravenous immunoglobulin. These findings may suggest that this entity is immune-mediated as in multifocal motor neuropathy, with its blunt of immune attack directed not only to peripheral motor nerves but also to spinal motor neurons.

Adolescent↗
PubMed1994

Sleep bruxism as a manifestation of subclinical rapid eye movement sleep behavior disorder.

A 59-year-old man with temporomandibular joint pain/dysfunction syndrome presented with a long history of nocturnal bruxism. All-night polysomnographic recordings with video monitoring showed episodes of teeth grinding or clenching occurring exclusively during rapid eye movement (REM) sleep, which were often associated with movements of the hands and fingers and/or brief vocalization. Throughout REM sleep, there was excessive phasic chin electromyographic twitching, without increased tone, and also excessive phasic electromyographic twitching in multiple muscle sites. The patient maintained a normal nonrapid eye movement-REM cycle, but showed increased REM density. Polysomnographic characteristics suggested that there may be a common pathophysiology in a certain type of sleep bruxism and the REM sleep behavior disorder. Sleep bruxism seen in this case is concluded to be a manifestation of subclinical REM sleep behavior disorder.

Bruxism↗
PubMed1994

[Carpal tunnel syndrome: clinical experience of 61 cases].

Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy. Appropriate diagnosis and therapy contribute to obtaining good results. We performed carpal tunnel release in 61 patients including 8 cases with chronic renal failure. They included 18 males and 43 females. Age distribution was from 28 to 76 years of age among the males, and from 29 to 82 years of age among the female patients. Bilateral operations were performed in 13 cases (male 5, female 8). Operations were carried out with local anesthesia in all cases except one. The skin incision was about 5 cm on the palmar skin. Hypertrophy of the transverse carpal ligament was found in all cases, with a thickness of 4 mm on the average. Usually, the ligament was as hard as gum in consistency. There were also hypertrophy of the subcutaneous connective tissue and palmar aponeurosis or aberrant muscle in some cases. In CTS following long-term hemodialysis for chronic renal failure, the ligament was very hard and appeared to be partly calcified. All patients improved clinically after the operation. We should understand the characteristic clinical symptoms and signs of CTS. Clinical worsening was prominent at night and/or early in the morning. Definite diagnosis was performed by electrophysiological means. Operative indications are 1) cases whose daily activities are disturbed due to severe symptoms with progressive aggravation, 2) cases with muscle weakness in the distribution of the median nerve, 3) cases with thenar atrophy, 4) cases which, electrophysiologically, are suspected of demyelination of the median nerve. As there were many unpredictable anomalies and variations among the lesions, correct decompression of the median nerve under direct vision is necessary during surgery.

Adult↗
PubMed1994

[Intravenous immunoglobulin therapy in multifocal motor neuropathy].

We treated ten consecutive patients with multifocal motor neuropathy (MMN) with high-dose intravenous immunoglobulin. Ages ranged 18 to 58 years, with disease duration of 9 months to 8 years. We treated them with 0.2 g/kg of human immunoglobulin for 6 consecutive days. All but one showed a clinical improvement starting within a week after the first infusion. The functional improvement ranged from marked to mild degree. In six patients, the clinical effect abolished within 2 months. Improvement was persistent for more than 6 months in the other three. In only two patients conduction block improved after the treatment. The discrepancy may result from an increased threshold of remyelinated or chronically demyelinated fibers for excitation. Side effects were not documented. This pilot study indicates that immunoglobulin may be a safe and effective therapy for MMN.

Adolescent↗
PubMed1994

[Ictal electroencephalographic findings and clinical seizure types in postencephalitic epilepsy].

A prolonged video/electroencephalogram (EEG) monitoring was performed in two patients with intractable epilepsy after adult onset acute encephalitis. Clinically both patients were thought to have a localized epileptogenic focus because of the single stereotyped clinical seizures by history in two patients, and a well localized lesion shown by MRI in one patient. The video/EEG monitoring, however, revealed multiple EEG foci ictally as well as interictally in both patients. Moreover, both patients were found to have at least two different patterns of clinical seizures. In patients with adult onset postencephalitic epilepsy, therefore, it is necessary and important to evaluate enough number of seizures by prolonged video/EEG monitoring even if seizures are clinically stereotyped by history and localized lesions are present on brain imaging.

Acute Disease↗
PubMed1993

Purification and characterization of interferon-gamma-inducing molecule of OK-432, a penicillin-killed streptococcal preparation, by monoclonal antibody neutralizing interferon-gamma-inducing activity of OK-432.

An immunoglobulin M mouse monoclonal antibody (MAb) to streptococcal preparation OK-432, TS-2, was generated. The TS-2 MAb showed positive reaction with butanol extract of OK-432 and fungal, branched (1-->3)-gamma-glucans (lentinan and schizophyllan) as well as lipoteichoic acids. Moreover, the interferon (IFN)-gamma-inducing activity of OK-432 was neutralized by TS-2 MAb. The affinity column of butanol extract of OK-432 on CNBr-activated Sepharose 4B-bound TS-2 antibody was prepared and the fractions containing IFN-gamma-inducing activity were eluted. The polysaccharide sample carrying the IFN-gamma-inducing activity with a molecular weight of 700,000 was destroyed by treatment with acid or sodium metaperiodate, but was stable to treatment with heat, alkali, pronase, or neuraminidase. Survival time of human salivary adenocarcinoma-bearing animals given a combination of the polysaccharide sample purified from butanol extract of OK-432 and TS-2 MAb was significantly shorter compared with that of the tumor-bearing animals given only the purified polysaccharide sample of OK-432. Moreover, a high level of effector cell activity in natural killer (NK) and lymphokine-activated killer (LAK) assays and significant increase of IFN-gamma-positive cells or asialo-GM1-positive cells were detected in the spleen cells from the animals given the polysaccharide sample purified from butanol extract of OK-432. These findings indicate that the polysaccharide sample purified by the affinity chromatography of butanol extract of OK-432 on CNBr-activated Sepharose 4B-bound TS-2 MAb carries the IFN-gamma-inducing activity of OK-432 and marked antitumor activity.

Animals↗