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Biomedical subjects

H Tanabe

Publications and source records attributed to H Tanabe.

At least 19 recordsLinked to original sources
PubMed1992

Relationship between tissue content of TC-81 and relaxation of rat aorta.

This study dealt with the relationship between the relaxant action of TC-81, a new Ca2+ antagonist, and its distribution in rat aorta depolarized by high K+ (65.4 mM). The inhibitory effect by TC-81 on K(+)-induced contraction and 45Ca2+ uptake was strongly time-dependent. TC-81 and nicardipine, each 10(-9) M, produced gradual relaxation of high-K(+)-induced contraction. The tissue contents of TC-81 and nicardipine increased with time courses that reflected decreasing tension. Both the maximum tissue content of TC-81 and the maximum relaxation were significantly greater than those for nicardipine. Also, the relaxations produced by TC-81 and nicardipine were correlated with the logarithm of the content of each drug in muscle tissues. However, the dissociation of TC-81 from the tissues was slower than that of nicardipine. The data suggest that the action of TC-81 is closely related to a gradual distribution of drug into muscle tissue, resulting in a slow onset of action. Also, the saturation time of TC-81 was longer than that of nicardipine, thereby accounting for the greater relaxation with TC-81.

Animals↗
PubMed1992

Chemical modification of cysteinyl, lysyl and histidyl residues of mouse liver 17 beta-hydroxysteroid dehydrogenase.

Monomeric 17 beta-hydroxysteroid dehydrogenase from mouse liver was rapidly inactivated by 5,5'-dithiobis(2-nitrobenzoic acid) and 2,4,6-trinitrobenzene-1-sulfonate, and the absorption spectra of the inactivated enzymes indicated that cysteine and lysine residues were modified. The kinetics of inactivation and spectrophotometric quantification of the modified residues suggested that complete inactivation was caused by modification of two cysteine residues or one lysine residue per active site. The inactivation by the two reagents was protected by NADP+ and some coenzyme analogs, but not by a steroid substrate, testosterone. Moreover, chemical modification by diethyl pyrocarbonate also produced inactivation of the enzyme, and showed a difference spectrum with a peak at 242 nm characteristic of N-carbethoxyhistidine residues, which decreased with the addition of hydroxylamine. The inactivation by this reagent, following pseudo-first-order kinetics, was protected partially by either NADP+ or testosterone and completely in the presence of both the coenzyme and substrate. The results suggest the presence of essential cysteine and lysine residues at or near the coenzyme-binding site and that of essential histidine residue(s) in the catalytic region of the active site of mouse liver 17 beta-hydroxysteroid dehydrogenase.

17-Hydroxysteroid Dehydrogenases↗
PubMed1992

Spectral characteristics of rapid off-response in congenital deuteranomaly in one of monozygotic female twins.

The spectral sensitivity of the rapid off-response in the electroretinogram was studied in monozygotic female twins. One case was diagnosed as congenital deuteranomaly, and the other was normal. The log ratio of the sensitivity at 480 nm to the sensitivity at 620 nm (log S480/S620) was within the deutan range in the first case and within the normal range in the second. The two case were determined to be different at the retinal receptor level by study of the rapid off-response. This result of the rapid off-response was consistent with the results of the psychophysical examinations.

Adult↗
PubMed1992

Surface electromyographic study of idiopathic cranial dystonia focused on the orbicularis oculi muscles.

We studied 115 Japanese patients with idiopathic cranial dystonia (Meige disease), using surface electromyography (EMG) focused on the orbicularis oculi muscles to classify the findings of the abnormal involuntary movements of this disease and to evaluate the pathophysiology of blepharospasm (BS). Surface EMGs at rest and at voluntary eyelid opening after eyelid closing were investigated. We found 62 (53.9%) patients exhibiting the overblinking type, 37 (32.2%) the tonic BS type, and 16 (13.9%) the normal type of behavior, considering the frequency of spontaneous blinking and presence of spasms. The present results suggest that BS is not a summation of blinking but a spatial and temporal extension of the orbicularis oculi muscle activity engaging in blinking, and the classification of the present study can support the investigation of the temporal characteristics of patients with this disease.

Blepharospasm↗
PubMed1992

Melorheostosis of the hand: a report of two cases.

Two cases of melorheostosis of the hand are reported. Histopathologic examination confirmed the characteristic x-ray findings and excluded other skeletal dysplasias, such as osteopoikilosis and osteopathia striata.

Adult↗
PubMed1992

Identification of the promoter region of the Escherichia coli major cold shock gene, cspA.

The major cold shock protein of Escherichia coli, CS7.4, is produced at a level of 13% of total protein synthesis upon a temperature shift from 37 to 10 degrees C. The transcription of its gene (cspA) was found to be tightly regulated and induced only at low temperature. In addition, the cspA mRNA was extremely unstable at 37 degrees C, so that CS7.4 production was hardly detected when the culture temperature was shifted from 15 degrees C to 37 degrees C. The transcription initiation site (+1) was identified. In vivo footprinting demonstrated that the region from bases -35 to -73 was protected from chemical modification, and gel mobility shift analysis showed that a cold-shocked cell extract contained a factor(s) specifically bound to the fragment containing the sequence between bases -63 and -92. This factor was synthesized de novo only at low temperature, and its synthesis was inhibited by chloramphenicol. Possible functions of this factor are discussed.

Amino Acid Sequence↗
PubMed1992

Creutzfeldt-Jakob disease with congophilic kuru plaques: CT and pathological findings of the cerebral white matter.

In a patient whose Creutzfeldt-Jakob disease with congophilic kuru plaques that was proved at necropsy, the early brain CT showed low-density areas in the cerebral white matter before cortical atrophy and ventricular enlargement became apparent. Subsequently, there occurred diffuse white matter lucency and severe brain atrophy. At necropsy, there was severe white matter destruction which was more prominent than cortical neuronal loss. Serial CT scans were of great value for demonstrating the early and predominant changes in the cerebral white matter.

Animals↗
PubMed1992

Lidocaine unmasks silent demyelinative lesions in multiple sclerosis.

Blockage of a small number of sodium channels may prevent impulse conduction in some demyelinated segments of nerve fibers with low safety factors, thereby unmasking subclinical demyelinative lesions. On the basis of this hypothesis, lidocaine, a sodium channel blocker, was administered intravenously to 28 MS patients and to 19 normal subjects and seven patients with nondemyelinating diseases. As predicted, lidocaine (mean plasma level, 2.7 micrograms/ml) elicited reversible subclinical symptoms in 23 of the MS patients, but it had not effect on the control subjects. We made a quantitative study of the visual functions (visual acuity, color vision, visual evoked potential [VEP]) that were impaired in 15 MS patients. Of the 23 affected eyes, nine showed normal VEPs, indicative of the test's sensitivity to focal lesions. This test should be useful in the diagnosis of MS and in the evaluation of the subclinical activity of MS as well.

Adult↗
PubMed1992

Nicotine-sensitive paresis.

Immediately after a patient with myoclonus epilepsy smoked a nicotine-containing cigarette, tetraparesis and hyperreflexia with ankle clonus developed, but disappeared within several minutes. During paresis, the H-reflex size of the soleus muscle increased, EEG showed more slow waves than before smoking, and the cerebral perfusion increased around the motor cortex as shown by single photon emission CT. A similar effect occurred when the patient chewed nicotine gum, and smoking a cigarette with a high nicotine content induced severe positive and negative myoclonus after the development of tetraparesis. Administration of the C6-type nicotinic antagonist mecamylamine not only countered the smoking effect, but ameliorated the spontaneous positive and negative myoclonus. Mecamylamine may prove useful for the treatment of positive and negative myoclonus in myoclonus epilepsy.

Adult↗
PubMed1992

[Affected siblings with Alzheimer's disease had missense mutation of codon 717 in amyloid precursor protein gene].

Using reverse genetic techniques, the gene responsible for familial Alzheimer's disease (FAD) is one of the clues to identify the pathogenesis of Alzheimer's disease (AD). Recently a missense mutation in the APP (amyloid precursor protein) gene (generally this mutation was called APP717) was detected in 2 Caucasian AD families and the same mutation was found in 3 Japanese AD families. We experienced brother's cases who were diagnosed as AD. Both of them and one normal person of the next generation had APP717. The first symptom of the elder brother (case 1) was forgetfulness at 52 years old, then dementia was advanced. In his clinical course there were characteristic findings such as the mirror sign, pseudodialog and jargon which has been rarely described in the Japanese literature. Finally he died of pneumonia at 57 years old. He was diagnosed as AD pathologically and physical findings of brain CT, SPECT (single photon emission computed tomography) and EEG supported this diagnosis clinically. The first symptom of the younger brother (case 2) was also forgetfulness at 45 years old, then severe dementia was advanced, at last he died of pneumonia at age 53 old. On the other hand the mother of the brothers died of severe dementia, so it was suspected that brothers died of severe dementia, so it was suspected that she had had AD. The clinical courses and pathological findings were thought to be typical of AD, namely there were no significant differences in comparison with other cases of FAD and sporadic AD.(ABSTRACT TRUNCATED AT 250 WORDS)

Alzheimer Disease↗
PubMed1992

[A case of late-onset Pick's disease with polyuria].

A 72-year-old male was admitted to our hospital with a 2-year history of polyuria, prosopagnosia and aphasia. He showed characteristic clinical features of Pick's disease such as stereotyped verbal output and behavior and personality changes. CT and MRI scans showed marked atrophy in the bilateral anterior temporal lobes mild atrophy of the bilateral frontal lobes. SPECT scans revealed perfusion abnormalities in corresponding areas. A 6-hour-water deprivation test resulted in decrease in the urine volume and in concentration of the urine, suggesting abnormality of his secondary drinking behavior. Polyposia resulting in polyuria as a clinical manifestation may be due to stereotypic behavior which is often seen in Pick's disease.

Aged↗
PubMed1992

[Two kindreds with familial Alzheimer's disease--analysis of the APP717 mutation and the mutated genes for the prion protein].

Numerous Caucasian familial Alzheimer's disease (FAD) pedigrees have been described in the literature, while only 21 Japanese FAD families have been reported to date. Here we report the clinical findings and the result of molecular genetic analysis of 4 patients from two FAD kindreds, OS-2 and OS-3. The proband in OS-2 family has developed loss of recent memory and place disorientation age at 43. A brain CT showed severe diffuse cortical atrophy. Her younger brother had dementia at 42 years and her mother and other 3 siblings had also dementia symptoms suspected to be Alzheimer's disease. The proband in OS-3 family showed declining recent memory at 49 years and developed dysphagia, gait disturbance and emotional incontinent with cerebral atrophy at 52 years. His father and elder brother demonstrated dementia signs at 60 and 54 years old, respectively. Recently it was reported that affected members from 2 Caucasian kindreds with FAD had missense mutation in exon 17 of the gene for amyloid precursor protein (APP). Patients from three different Japanese kindreds with FAD also showed the same mutation on the APP gene. Amino acid substitution (Val-Ile) at codon 717 by this mutation is responsible for FAD in at least some kindreds. We used genomic DNA from 4 affected members of 2 families to determine whether the disease in these families is associated with a APP717 mutation and the mutated codons, 102, 117, 129, 178 and 200, on the gene for protease-resistance prion protein (PrP) which cause transmissible dementia, Creutzfelt-Jacob disease (CJD) and Gerstmann-Strausler syndrome (GSS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Preliminary clinical trial of intrathecal rt-PA (TD-2061) for the prevention of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage].

The results of preliminary clinical trial (a multicenter, open-label, dose escalation study) of intrathecal recombinant tissue plasminogen activator (rt-PA) for the prevention of cerebral vasospasm were reported. Seventeen patients admitted within 48 hours of subarachnoid hemorrhage (SAH) were enrolled in this study. Patients ranged from 42 to 69 years of age. All cases enrolled were classified in clinical grade II, III or IV according to the classification of Hunt and Kosnik and in group 3 or 4 according to Fisher's CT grading scale. Surgery for clipping the aneurysms were performed and a small silicone catheter was left in the subarachnoid space. Twenty four hours after the surgery intrathecal bolus infusion of rt-PA was started through the silicone catheter at 6-hour intervals for 3 days. Patients were divided into 4 groups based on the dosage of rt-PA for each infusion. The dosage of rt-PA for each infusion and a number of cases in each group was as follows; 25 KIU in 4 cases, 75 KIU in 6 cases, 200 KIU in 4 cases and 600 KIU in 3 cases. There was no significant difference in the clearance of subarachnoid clots between four groups. However, the occurrence of both symptomatic and angiographic vasospasm was less in the 75 KIU group than in other three groups. Intracranial bleeding complications were noted in 4 patients (1/6 in the 75 KIU group, 2/4 in the 200 KIU group and 1/3 in the 600 KIU group). Serial coagulation studies demonstrated no evidence of systemic fibrinolysis. Disorientation was noted in 2 out of 3 patients of the 600 KIU group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[A case of small epidermoid cyst in cauda equina with manifest regional hypesthesia].

This report concerns the 22-year-old female who has been suffering the paresthesia in the left buttock and thigh for three months. Neurological examination revealed nothing other than hypesthesia and hypalgesia which distributed in the third, fourth and fifth segments of left sacral region with the loss of anal reflex. Pain had not been noticed until when she came to our clinic. Myelography and MRI showed small irregular round mass occupying a third of the spinal canal behind the body of fourth lumbar spine. In the axial view of MRI, the mass was enhanced by the gadolinium (Gd) except for the small portion of its center. She underwent the surgical treatment which revealed the tumor entangling four nerves of cauda equina in its center as imaged in MRI. The tumor was epidermoid cyst which presumably caused the chemical meningitis and involved those nerves. That resulted in the sensory disturbance in the left sacral region, although the tumor was not large enough to compress the nerves.

Adult↗