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Biomedical subjects

Y Wada

Publications and source records attributed to Y Wada.

At least 775 records · Page 43Linked to original sources
PubMed1991

Morphometric study of cervical anterior horn cells and pyramidal tracts in medulla oblongata and the spinal cord in patients with cerebrovascular diseases.

To clarify the effect of damage to the upper motor neurons on lower motor neurons, quantitative studies were made regarding the cross-sectional area and the number of the individual anterior horn cells in the lateral nuclear cell groups of the 5th segment of the cervical spinal cord (C5), and regarding the cross-sectional areas of the pyramidal tract in the medulla, and in the spinal cord at the C5 and L2 levels. The subjects included 45 patients with cerebrovascular disease (CVD), and 50 age-matched controls without neurological disease. The medullary pyramid (MP) and the ventral funiculus (VF), ipsilateral to the hemispheric lesion, were compared with the MP and VF of the other, unaffected, side. The ventro-lateral funiculus (VLF), anterior horn (AH) and C5 anterior horn cell (AHC), contralateral to the lesion, were also compared with the VLF, AH, and AHC of the other, unaffected, side. The AHC area (mean cross-sectional area of anterior horn cells) and the MP area, VF area, VLF area, AH area (mean cross-sectional areas of MP, VF, VLF and AH) associated with the hemispheric lesional side were significantly decreased, compared with those of the unaffected sides and the controls. However, there was no significant difference in AHC number between the affected and unaffected sides in patients with CVD, nor between the affected side and the controls. In order to examine the relationship between a decrease in AHC area and degree of paralysis, CVD patients were divided into two groups according to degree of muscle strength: the severe and mild paralysis groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Effect of left ventricular hypertrophy secondary to systemic hypertension on left coronary artery flow dynamics.

STUDY OBJECTIVE: The aim was to clarify the characteristics of the phasic blood velocity pattern and their possible causes in left ventricular hypertrophy secondary to systemic hypertension. DESIGN: Measurements of blood velocities in the left anterior descending coronary artery were made with a 20 MHz Doppler catheter with a top mounted annular crystal. All patients had normal coronary arteriograms. PATIENTS: 23 hypertensive patients [systolic/diastolic pressure: 181(SD 15)/100(4) mm Hg)] with left ventricular hypertrophy, and 13 atypical chest pain patients without left ventricular hypertrophy or any abnormal haemodynamic findings (normal controls) entered the study. MEASUREMENTS AND MAIN RESULTS: The left anterior descending coronary artery blood velocity waveform in pressure overloaded left ventricular hypertrophy was characterised by delayed early diastolic inflow. The diastolic rise time of coronary flow (TDR), ie, the time from the beginning of diastole to peak velocity, was higher in patients with hypertensive left ventricular hypertrophy than in normal controls, at 145(56) v 66(15) ms, p less than 0.001. In patients with hypertensive left ventricular hypertrophy, TDR correlated well with the degree of hypertrophy (r = 0.83, p less than 0.01) and also with peak left ventricular systolic pressure (r = 0.62, p less than 0.01). The coronary flow reserve, calculated from the ratio of the diastolic mean velocity after intracoronary injection of papaverine to the resting flow velocity, decreased with prolongation of TDR (r = 0.58, p less than 0.02). CONCLUSIONS: (1) Impairment of early diastolic coronary arterial inflow is the most remarkable characteristic in pressure overloaded left ventricular hypertrophy; (2) preceding systolic vascular compression and impaired left ventricular relaxation correlate with the delayed early diastolic inflow; (3) the delayed inflow is an important possible cause of the decreased coronary flow reserve in the hypertensive left ventricular hypertrophy.

Adult↗
PubMed1991

Stable Lyonization of X-linked pgk-1 gene during aging in normal tissues and tumors of mice carrying Searle's translocation.

We investigated whether age-dependent reactivation of a repressed X-linked gene occurs. Subjects were female mice, carrying the X-autosomal translocation, T(X;16)16H (Searle's translocation). The mice were also heterozygous, for the X-linked gene coding for phosphoglycerate kinase (T16H pgk-1b/+ pgk-1a and pgk-1a was selectively repressed in these mice (McMahon and Monk, 1983). An electrophoretic method was applied to determine the PGK-1 allozyme patterns in blood, bone marrow, brain, gastrointestinal tract, liver, heart, spleen, and uterus (including tumor tissues when found). Samples were collected from mice of three different ages: 2 months (n = 4), 11 to 12 months (n = 10), or 18 to 21 months (n = 15). The lowest detection limit of the relative cellular population expressing the PGK-1A allozyme was found to be 2%, which was sensitive enough to detect the reported reactivation ratio (more than 10% of cells in a lower power microscopic field). We could not detect PGK-1A activity in any organ, including tumors in any age group, leading to the conclusion that reactivation of the repressed pgk-1a gene did not occur during aging.

Aging↗
PubMed1991

A long-term outcome study of tardive dyskinesia in patients on antipsychotic medication.

We followed 28 patients with tardive dyskinesia (TD) (eight men and 20 women, mean age 55.1 years) for 11-12 years to elucidate the long-term outcome of TD. All the patients received their physicians' choice of therapy, mainly comprising antipsychotics. The severity of TD was assessed at 5 and 11-12 years after the baseline evaluation. TD did not disappear in any patient. The severity of TD was unchanged in 39.3%, and improved in 17.9% despite continuous treatment with low doses of antipsychotics (mean 221.4 mg chlorpromazine equivalent daily). TD fluctuated in 21.4% and worsened in only 21.4%. Outcome was not correlated with patient sex or age, duration of primary illness, dosage of antipsychotics, or changes in dosage. The initial severity of TD showed some relationship to outcome. The number of bodily areas affected by TD increased in some patients with unchanged TD severity.

Adult↗
PubMed1991

Comparison of kindling at short interstimulus intervals in acutely and chronically prepared rabbits.

For the purpose of contributing methodologically to experimental research on epilepsy, we investigated whether a difference exists in kindling development between acute and chronic preparations using identical species of animals, kindled brain tissues, stimulus intervals, and intensities. Seizure-threshold stimulations repeatedly applied at 5-min intervals to the unilateral visual cortex in rabbits completed the generalization of epileptiform discharge trains after the 11th-24th trials in the acute preparations concomitantly with an increase in the afterdischarge duration and the development of independent discharges, whereas they induced no kindling phenomena even with 50 trials in the chronic preparations. These results indicate that there is an extreme difference in kindling susceptibility between acute and chronic preparations, resulting, presumably, from multifactorial dissimilarities in these experimental conditions.

Animals↗
PubMed1991

Responses of neurons in the rat vestibular nuclei to static tilt stimulation.

The response properties of otolith afferent neurons have been analysed in the monkey and the cat. However, knowledge about the rat's responses to static tilt is scarce. To elucidate central information processing of the otolith system, responses to static tilt were analysed in the rat vestibular nuclei neurons.

Animals↗
PubMed1991

[Experimental study of the whole body response in rabbits by linear oscillatory acceleration and/or optokinetic stimulation].

Motion sickness may be defined as an abnormal body response caused to certain kinds of motion in normal subjects. Although we know etiologic factors and symptoms of motion sickness, the mechanism of motion sickness remains unknown. To clarify some characteristics of motion sickness in rabbits, we observed responses of the autonomic nervous system consisting of a change in heart rate (HR), coefficient of variation of R-R interval (CV-RR), and serum adrenaline (AD) -and free fatty acid (FFA) concentrations during linear oscillatory acceleration and/or optokinetic stimulation. The following results were obtained as 1. Although transverse and vertical linear oscillatory accelerations affected little the body responses, longitudinal linear oscillatory acceleration diminished HR and increased CV-RR and FFA. 2. Since injection of atropine or labyrinthectomy reduced the changes of HR and CV-RR induced by longitudinal linear oscillatory acceleration the responses may originate from the vestibulo-parasympathetic nerve reflex. 3. An increase of FFA during longitudinal linear oscillatory acceleration indicates that sympathetic nerve as well as parasympathetic nerve activities are elevated. 4. In this study optokinetic stimulation was not so influential as linear oscillatory acceleration for provoking motion sickness in rabbits. 5. Concomitant stimulations of optokinetic and vestibular inputs enlarged variations of these responses.

Acceleration↗
PubMed1991

Multiple bullae and paresis after drug-induced coma.

Two cases of bullous skin lesions and paresis following coma due to the ingestion of many antipsychotic drugs were reported. Histological examination showed an intra-epidermal blister in case 1 and degeneration of sweat glands in both cases. An immunofluorescence study showed massive deposits of IgM and C3 in the dermal vessels. As similar deposits of immunoglobulin and complement were not observed in patients with ordinary lesions such as decubitus, a different mechanism in the formation of the bullous skin lesion other than pressure is suggested.

Adult↗
PubMed1991

[A successful correction of common atrium with left atrial isomerism].

A successfully treated case of one-year-old girl of common atrium associated with bilateral superior vena cava and an interrupted inferior vena cava with hemiazygos continuation is reported. In addition to these anomalies of systemic venous connection, both atrial appendages show morphological characteristics of left type, and the final diagnosis of left atrial isomerism was made. In the corrective surgery, atrial septation was reconstructed using trimmed autogenous pericardial patch to allow the left superior vena cava to drain into the right side of the common atrium. The patient had been pointed out bradycardia (50-100/min) since her birth. Postoperative electrocardiogram also showed bradycardia (78-100/min). Especially in sleeping, her heart rate was 50-60/min, resulting in A-V junctional escaped rhythm and A-V dissociation. This fact suggests that her sinus node is absent or hypoplastic, one of the characteristics of left atrial isomerism. Since left atrial isomerism is reported to cause a decrease of atrial rhythm with aging, careful postoperative observation on specific arrhythmia is necessary.

Abnormalities, Multiple↗
PubMed1991

[Usefulness of ulinastatin as a radical scavenger for protection of reperfusion injury after myocardial ischemia in open heart surgery].

The usefulness of ulinastatin for protection of reperfusion injury after myocardial ischemia was evaluated in 25 patients undergone open heart surgery (18 cases with coronary artery bypass grafting and 7 with valve replacements). Twenty five patients were divided into two groups; U (+)-group consisted of 12 patients with ulinastatin (10,000 IU/kg) injected via the aortic root just before aortic declamping, and U (-)-group of 13 patients without ulinastatin. There were no significant differences between the two groups in age, body weight, total cardiopulmonary bypass (CPB) time, and aortic cross clamp time. Blood samples were obtained from coronary sinus before the start of CPB, just before the aortic cross clamp and immediately after reperfusion, and 1 and 3 hours later. Levels of thiobarbituric acid (TBA), alpha-tocopherol (alpha TOC), polymorphonuclear elastase (PMNE), creatine phosphokinase (CK) and creatine phosphokinase isoenzyme (CK-WB) release were measured, and myocardial aerobic metabolism was also evaluated. At each time point after reperfusion, TBA levels in U (+)-group were significantly less (p less than 0.05), and alpha TOC levels were significantly higher (p less than 0.05) than those in U (-)-group. PMNE increased progressively during CPB and showed a peak at 3 hours after reperfusion. And both groups showed increased lactate production and anaerobic metabolism immediately after reperfusion and 1 hour later, as evidenced by changes in excess lactate and redox potential of lactate and pyruvate. There was, however, no significant difference between the two groups with CK-MB as well as CK release.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1991

[Delayed finger opening caused by a midbrain lesion].

We report a 25 year-old woman with delayed finger opening caused by a midbrain lesion. Magnetic resonance imaging revealed an abnormal intensity area in the left midbrain in the vascular territory corresponding to the mesencephalic inferomedian branch and central posteromedian branch of posterior cerebral artery. Clinically, she suffered from Weber's syndrome, and in the course of recovery, she developed marked delayed finger opening. Her weakness was slight, this delayed finger opening was observed only after maximal grip, and she required about ten seconds to open her right fingers. She could open and grip her fingers easily and quickly in moderate contraction. In the electromyogram, the action potentials of flexor digitorum profundus muscle did not disappear promptly upon instruction to open her fingers, and they lasted for approximately six seconds with gradual decrease. On the other hand, the action potentials of extensor digitorum muscle were reciprocally inhibited and increased gradually after the decrease of the flexor muscle potentials. The abnormally continuing discharges in the flexor muscles were thought to be the cause of her delayed finger opening. The phenomenon of delayed finger opening caused by cervical root lesions, peripheral nerve lesions, or a brain stem (pons-medulla oblongata) lesion have been reported. But, the phenomenon caused by a midbrain lesion, like our case, has not been reported. The present case was different from the previously reported cases with this phenomenon showing simultaneous discharges from both agonistic and antagonistic muscles.

Adult↗
PubMed1991

[Left ventricular hypertrophy secondary to systemic hypertension: its effect on coronary hemodynamics].

To clarify the characteristics and possible causes of phasic blood velocity patterns in pressure overload hypertrophy, we measured blood flow velocities in the left anterior descending coronary arteries in 16 patients with left ventricular hypertrophy secondary to systemic hypertension. These measurements were made with a 20MHz Doppler catheter. All patients had normal coronary arteriograms. The blood flow velocity patterns were characterized by the decrease in the rise of early diastolic inflow velocity. Prolongation in the time from the onset of diastole to peak velocity (TDPV) correlated with the degree of left ventricular hypertrophy. TDPV was prolonged in proportion to the increase in the peak left ventricular systolic pressure and left ventricular ejection fraction. The flow reserve calculated from the ratio of the diastolic mean velocity after the intracoronary injection of papaverine to the resting flow showed a trend toward the decrease proportional to the prolongation in TDPV due to an increase of wall thickness. In conclusion, preceding systolic vascular compression and systolic vascular strain can be factors causing early diastolic inflow disturbance in left ventricular hypertrophy secondary to hypertension. The decrease of coronary reserve may partially be attributable to the decrease in the rise of early diastolic inflow velocity.

Adult↗
PubMed1991

[Sensitivity test of anti-tumor agents. 2. Application of MTT assay].

Mosmann's method for measuring the number of viable cells, examination of their growth and function by tetrazolium test, "MTT assay", is widely thought to be reliable. For the purpose to establish a rapid, accurate, in vitro drug sensitivity test, MTT assay was applied and evaluated for clinical application. Based on Mosmann's original MTT assay, optimal and adequate conditions for (1) the number of the cells examined at the starting of cultivation, (2) concentration of anti-tumor agents, doxorubicin, cisplatin, mitomycin C, L-phenylalanine mustard, (3) incubation time with anti-tumor agents, were determined using established cell lines, T-24, RMUG, HeLa, Vero, P 388, and Colon 26 in 96 well microplates. Conclusions are as below: (1) Number of the cells in each well of microplate is 1 x 10(3)-1 x 10(6) cells/ml, that seemed to be theoretically and technically adequate. (2) Anti-tumor agents should be added at the peak plasma concentration. (3) Incubation for 4 to 5 days is preferable. (4) HCl-isopropanol seemed to be advantageous compared to 10% sodium dodecyl sulfate for solubilization of MTT formazan crystal. (5) Results of MTT assay and colony assay were well correlated.

Antineoplastic Agents↗
PubMed1991

[Bone marrow transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia].

We reported the results of 6 allogenic bone marrow transplantation (BMT) and 3 autologous BMT for patients with Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL) by Nagoya BMT group. Two of six patients who received allogenic BMT have continued complete remission (CR) on +639 days and +1,597 days. Four of six patients relapsed on +134, +203, +216, and +267 days. Two patients with a disease-free survival for a long time had both acute and chronic GVHD. It is suggested that graft-versus-leukemia (GVL) effect might prevent the relapse. On the contrary, one patient who received with monoclonal antibodies plus complement-treated autologous bone marrow is free of leukemia on +439 days. Our results suggest the follows. 1) We do chromosomal analysis at initial diagnosis in all cases to do BMT in first CR. 2) We intensify the conditioning regimen for BMT. 3) We study on application of GVL effect to prevent the relapse. 4) We establish the best purging method to eradicate residual leukemic cells for autologous BMT. 5) We do allogenic BMT using HLA-matched unrelated donor for patients without related donor.

Adolescent↗
PubMed1991

[A case of chronic progressive radiation myelopathy--a diagnostic significance of gadolinium-DTPA enhancement MRI].

A 65-year-old man had a biopsy diagnosis of right cervical squamous cell carcinoma. Post operative irradiation (4000 rads) was given to the bilateral cervical areas. Twenty five months after completion of irradiation, the patient developed muscle weakness in the right upper and lower extremities, and sensory disturbance below the C2 level in the left side, which was considered as Brown-Séquard syndrome. MRI of T1 weighted images (T1W1) showed mild swelling of the spinal cord from C1 to C6, while T2 weighted images (T2W1) revealed high intensity area at the same level. Gadolinium (Gd)-DTPA injection revealed ring enhancement in the right side of the spinal cord from C1 to C2 on sagittal and axial images. The neurological symptoms improved after the administration of corticosteroid. Two weeks after the therapy, a follow-up study revealed disappearance of cervical cord swelling on T1W1 and high intensity area was remarkably diminished on T2W1. Gd-DTPA enhancement, however, showed unremarkable change. Gd-DTPA enhancement was suggested to be a sensitive and valuable diagnostic method of CPRM.

Aged↗