Biomedical subjects

M Takeda

Publications and source records attributed to M Takeda.

At least 667 records · Page 37Linked to original sources

PubMed1992

Tyraminelike action of succinylcholine in the isolated, blood-perfused canine atrium.

The mechanisms of succinylcholine-induced cardiac effects have not been fully elucidated. Accordingly, we studied the effects of succinylcholine on atrial rate and contractile force in the isolated canine atrium perfused with donor blood. The sinus node artery was perfused with heparinized blood from the common carotid artery of the donor dog at a constant pressure of 100 mm Hg. When succinylcholine in a dose range of 30-1000 micrograms was injected directly into the sinus node artery of the isolated atrium, increases in atrial rate and contractile force were observed in a dose-related manner. The atrial rate and contractile force were increased to 10.5% +/- 1.8% (mean +/- SEM) and 56.8% +/- 8.5% above the control values after the administration of 1000 micrograms of succinylcholine, respectively. After treatment with propranolol, the positive chronotropic and inotropic effects of succinylcholine and norepinephrine were significantly suppressed. Hexamethonium or tetrodotoxin pretreatment inhibited the cardiac effects of nicotine but did not modify the succinylcholine-induced cardiac effects. The succinylcholine-induced effects were significantly inhibited by treatment with imipramine, which also suppressed the tyramine-induced effects. We conclude that succinylcholine has cardioexcitatory properties mediated by release of catecholamine due to a tyraminelike action.

Animals↗

PubMed1992

Synthesis of N-substituted C-normorphinans and their pharmacological properties.

Several N-substituted C-normorphinans (VIII and IX) were synthesized and tested for their analgetic and narcotic antagonist activities and physical dependence capacity. Treatment of N-formyl- octahydro-2-pyrindine (IIIc) with polyphosphoric acid readily gave N-formyl-C-normorphinan (IV). The N-nor bases (V and VII) obtained from IV were converted to VIII and IX. The N-methyl derivative (I), which was previously reported to be inactive by Haffner's method, exhibited potent analgetic activity by the hot plate method and the AcOH-induced writhing test. Compounds VIII and IX showed pharmacological properties similar to those of N-substituted morphinans and exhibited agonist (analgetic) and/or narcotic antagonist activities. The C-nor analogue (IXa) of cyclorphan (IIc) exhibited potent analgetic and antagonist activities with no physical dependence capacity in the single-dose suppression tests both in rats and monkeys.

Analgesics↗

PubMed1992

Synthesis of the optically active trans-isomers of diltiazem and their cardiovascular effects and Ca-antagonistic activity.

Optically active trans-isomers of diltiazem were synthesized and their cardiovascular effects were evaluated in anesthetized dogs and in isolated guinea pig hearts. Both (+)-2 (2R,3S) and (-)-2 (2S,3R) were much less active than diltiazem (1, 2S,3S) with short duration of action. No substantial enantiomeric difference in activity was seen between them. Their Ca-antagonistic activities on Ca(2+)-induced contractions in K(+)-depolarized canine basilar arteries were also examined. Absolute stereochemistry of (+)-2 was determined to be 2R,3S by X-ray crystallographic analysis.

Animals↗

PubMed1992

3-anilino-L-alanine, structural determination of UV-5, a contaminant in EMS-associated L-tryptophan samples.

An aniline derivative which corresponds to UV-5 in the preceding paper was isolated from the case L-tryptophan sample associated with eosinophilia-myalgia syndrome (EMS). By spectroscopic analyses, the structure was identified as 3-anilinoalanine. The compound was optically active, and the stereochemistry of alanine moiety was determined as L, by comparing the specific rotation with a synthesized 3-anilino-L-alanine.

Alanine↗

PubMed1992

[Effects of the new cardiotonic agent loprinone hydrochloride (E-1020) on left ventricular diameter in normal and experimental heart failure dogs and its action potential characteristics in isolated guinea pig cardiac muscles and sinus nodes].

In anesthetized dogs, loprinone hydrochloride (LP, 10 approximately 100 micrograms/kg, i.v.) dose-relatedly increased cardiac contractility (LV dP/dt max), enhanced cardiac index and decreased systemic vascular resistance with relatively small reduction in mean aortic pressure (MAP) and a mild increase in heart rate (HR). LP also decreased left ventricular internal diameter (ID), increased fractional shortening (LVFS) and caused a leftward shift and an increase in the slope of the LV end-systolic pressure-ID relation. In the heart failure models induced by propranolol, LP rapidly reversed the cardiac depression and the enlargement in cardiac size. The extent of changes in MAP and HR by LP was smaller than those observed with several other cardiotonic agents. In guinea pig cardiac muscles, LP (10(-6)-10(-4) M) produced a concentration-related increase in contractile force and the maximum rate of rise of Ca(2+)-action potential. In the sinus nodes, LP induced a concentration-related decrease in action potential duration and increase in the slope of slow diastolic depolarization, resulting in an increase in beating rate. These influences of LP on sinus nodes were smaller than those of milrinone. These results indicate that LP increases LVFS, reduces cardiac size and improves the heart failure due to its cardiotonic and vasodilating properties. Moreover, electrophysiological studies suggest that at least a part of the lower chronotropic effects of LP may be due to the mildness of its direct stimulating effects on sinus nodes.

Action Potentials↗

PubMed1992

Encephalomyocarditis (EMC) virus-induced myocarditis by different virus variants and mouse strains.

The mode of occurrence of encephalomyocarditis (EMC) virus-induced myocarditis in mice was pathologically and virologically investigated using 2 virus variants (highly diabetogenic EMC-D and non-diabetogenic EMC-B) and 2 mouse strains (diabetes-susceptible BALB/c and diabetes-resistant C57BL/6). Mice were inoculated with 10(5) PFU/head of the virus intraperitoneally and observed up to 7 days post inoculation (7DPI). As compared with EMC-B-infected BALB/c and EMC-D-infected C57BL/6 mice, EMC-D-infected BALB/c mice developed marked myocarditis and exhibited a heart virus titer of more than 100 times above that of the others after 4DPI. Electron microscopically, small aggregations of virus-like particles, with 20-25 nm in diameter, were found in the cytoplasm of degenerated cardiomyocytes showing mitochondrial and myofibrillar degeneration in EMC-D-infected BALB/c mice.

Animals↗

PubMed1992

Biosynthesis of guanidinoacetic acid in isolated renal tubules.

Guanidinoacetic acid, a precursor of creatine, is an essential substrate for muscle energy metabolism. Since guanidinoacetic acid has been reported to be synthesized from arginine and glycine by glycine amidinotransferase (transamidinase) in kidney homogenates or slices, the purpose of this study was to provide evidence of guanidinoacetic acid synthesis in isolated tubules from rat kidneys, and to clarify the mechanism regulating it. Isolated rat tubules were incubated with various substrates. Guanidinoacetic acid was separated by high performance liquid chromatography and measured fluorometrically. Results obtained were as follows: (1) Guanidinoacetic acid was synthesized from arginine or canavanine and glycine in isolated rat tubules. (2) D,L-Norvaline, ornithine and methionine suppressed guanidinoacetic acid synthesis. (3) Creatine suppressed guanidinoacetic acid synthesis, i.e. creatine was a negative feedback inhibitor of guanidinoacetic acid synthesis in this in vitro system. (4) Guanidinoacetic acid was not synthesized from hydroxyurea, citrulline, argininosuccinic acid or canaline. These data demonstrate that guanidinoacetic acid is synthesized only from arginine or canavanine and glycine, and that the guanidine cycle may not function fully in the rat renal tubule.

Animals↗

PubMed1992

Calcitonin gene-related peptide (CGRP)-immunoreactive nerve terminals in the whole mount preparations of the dog urethra.

To visualize the entire shape of the intraepithelial nerve fibers, whole mount preparations of the dog urethra were produced and immunostained with an antiserum against CGRP, one of the predominant substances contained in the nerves. The immunoreactive nerves in the lamina propria were smooth (non-beaded) in appearance and weak in immunoreaction. Within the epithelium, they displayed typical beaded profiles and were intense in immunoreaction. The intraepithelial fibers branched and wound into an extensive network with wide meshes ("reticular terminal"). The bead-like swellings included large ones resembling Herring bodies in hypophyseal neurosecretory fibers. Another type of nerve terminal, consisting of fine and weakly immunopositive fibers, was also found in the epithelium. These branched in dendritic or in dense bouquet-like fashion, occupying smaller areas ("bouquet-like terminals). Vesicular swellings often characterized these terminals, though they were smaller and more uniform in size and far less in their amount of immunoreactive substance than were the swellings in the reticular terminals. Both types of nerve terminals originated from the same nerve trunk. The connection between the reticular and bouquet-like terminals, which may presumably represent secretory and receptive parts, respectively, morphologically supports the possible occurrence of an axon reflex in the urethral CGRP neurons. Our whole mount preparations, when doubly stained with CGRP and serotonin antibodies, further revealed the CGRP-positive reticular terminals being closely associated with serotonin- or CGRP-immunoreactive paraneurons dispersed in the epithelium.

Animals↗

PubMed1992

Remarkable improvement of growth and developmental retardation in Crohn's disease by parenteral and enteral nutrition therapy.

The patient, an 18-yr-old male (admission ht 153 cm, wt 30 kg), had been suffering from growth arrest and intermittent abdominal pain since he was 13 yr old, which was left untreated. Examinations on admission disclosed almost normal pituitary function, while levels of testosterone and somatomedin C were low. Roentgenological examination revealed extensive skip-stenotic lesions and longitudinal ulcers in the ileum, diagnostic of Crohn's disease. Therapy involving high-caloric parenteral and enteral alimentation resulted in a marked increase in both ht and wt, and improvement in roentgenological and colonoscopical findings. The interrelation between Crohn's disease and malnutrition with reference to some reports in the literature is discussed.

Adolescent↗

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

[Correlation of visual evoked potentials with dementia in Parkinson's disease].

There has been some debate regarding abnormalities in visual evoked potentials (VEP) in Parkinson's disease (PD). To elucidate the mechanism causing abnormal VEP, we investigated the relationship between VEP and mental function in PD patients. Pattern reversal VEP was recorded in PD patients (n = 27) and age-matched control subjects (n = 14). PD patients consisted of two subgroups; PD without dementia (nD-PD; n = 17) and PD with dementia (D-PD; n = 10). Dementia was evaluated according to the criteria for dementia assigned in DSM III-R, and mental faculties were estimated by using the mini-mental state examination (MMSE). In pattern VEP recordings, P100 latency and amplitude were measured for each eye stimulated. No patient or control subject had impairment of corrected visual acuity or ophthalmological disease. There was no significant difference in age among the three groups (D-PD, nD-PD and control subjects). D-PD patients showed significantly prolonged P100 latency compared to nD-PD patients and control subjects (p less than 0.05). With respect to P100 amplitude, no significant difference was shown among the three groups. In PD patients, there was a rough correlation between P100 latency and MMSE score. No correlation was found between P100 amplitude and MMSE score. In control subjects, P100 latency did not correlate with advancing age. In PD patients, nD-PD patients showed a significant correlation between P100 latency and age, whereas D-PD patients presented no correlation. Abnormal VEP in PD has been mostly ascribed to dopaminergic deficiency in the retina.(ABSTRACT TRUNCATED AT 250 WORDS)

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

[Endoscopic operation of congenital anterior urethral valve. Application of flexible renoureteroscope for antegrade urethroscopy].

4 children with anterior urethral valve were treated by TUR-Valve. Before TUR, valve anatomy could be easily seen by antegrade urethroscopy through cystostomy using a 10.8Fr caliber flexible renoureteroscope and destruction of the valve could be recognized after TUR. Antegrade urethroscopy with a flexible fiberscope was so helpful to TUR-Valve and the findings of voiding cystourethrography and micturition have remarkably improved. This technique is not so difficult to apply and thought to be one of the best methods to recognize valve anatomy and degree of resection. This technique is also applicable to other lower urinary tract lesions in children.

Adolescent↗

PubMed1992

[MRI of pheochromocytoma--comparison with CT, 131I-MIBG, urinary catecholamine level and operative findings].

16 patients (7 male, 9 female) ranging in age from 13 to 71 (44.1 +/- 18.4) years old with clinically diagnosed pheochromocytoma were prospectively evaluated with CT (N = 16), MRI (N = 16), 131I-MIBG (N = 10) and operative findings in order to evaluate their diagnostic efficacy. 1. Normal adrenal glands appeared less intense than the liver on T1-weighted image (T1WI), less intense than or isointense with the liver on both proton density image (PDI) and T2-weighted image (T2WI). 2. Pheochromocytomas with high urinary noradrenaline level appeared less intense than the liver on T1WI, more intense on T2W1 and showed accumulation of radioisotope on 131I-MIBG scintigraphy. In cases with normal urinary noradrenaline level, they appeared less intense than or isointense with the liver on all pulse sequences (T1WI, PDI and T2WI). 3. Although diagnostic accuracy of localization was 81.3% (13/16) by CT, 93.8% (15/16) by MRI and 90% (9/10) by 131I-MIBG scintigraphy, MIBG scintigraphy showed higher diagnostic ability in cases with multiple lesions or recurrent tumors.

3-Iodobenzylguanidine↗

PubMed1992

[Supralevator pelvic exenteration with simultaneous bowel and urinary reconstruction. Two case reports].

Two male patients underwent supralevator pelvic exenteration, preserving their normal voiding and evacuating function. Case 1 was a 19-year-old man with pineal region tumor, and a metastatic lesion in the bottom of the rectovesical pouch, possibly through the ventriculo-peritoneal shunt. Following supralevator pelvic exenteration, the construction of double pouches, a colonic J pouch and Mainz pouch to the urethra, were performed. Case 2 was a 39-year-old man with bulky retrovesical tumor. He underwent supralevator pelvic exenteration by sigmoid colo-proctostomy and U-pouch to the urethra. Both patients achieved continent except for urinary leakage at night and were able to defecate and urinate voluntarily. Urodynamic study revealed that the pressure in their urinary pouches was low.

Adult↗

PubMed1992

[The effect of intra-urethral catheter for prostatic hypertrophy patients who are unfit for operation and suffer from urinary retention].

The effect of double Malecot type polyurethane intraurethral catheter (IUC) was examined in 17 benign prostatic hypertrophy patients who were unfit for operation and suffered from urinary retention. Patients were aged 68 to 90 (mean 80.5) years old and the causes of IUC insertion were cardiac, cerebrovascular, respiratory and gastrointestinal diseases, diabetes mellitus and aging. IUC was selected among three types (55, 60, 65 mm) according to the length of prostatic urethra. Insertion of IUC was carried out easily under fluoroscopic guidance without endoscopy. All patients could void by themselves just after insertion of IUC and the longest indwelling period was 10 months. The length of IUC need not be longer than that of prostatic urethra and patients with normal or hypertonic bladder could void better than those with atonic bladder. Urinary tract infection did not get worse in any patients with indwelling IUC. Double Malecot type polyurethane IUC is a safe and an effective alternative method in place of urethral balloon catheter for inoperable prostatic hypertrophy patients in urinary retention.

Aged↗

PubMed1992

[Three-dimensional surface display with 123I-IMP in corticobasal degeneration].

A 65-year-old right-handed woman was admitted due to gait disturbance. She had suffered from progressive motor clumsiness in the left-sided limbs for four years. On admission, she was mildly demented, but not aphasic. Neurological examination disclosed constructional disability, limb-kinetic apraxia on the left side, and parkinsonism. Brain CT and MRI showed no responsible lesion. Three-dimensional surface display with 123I-IMP demonstrated decreased cerebral blood flow mainly in the right angular gyrus, and mildly in the right central region. She was clinically diagnosed as having corticobasal degeneration. Hypoperfusion in the angular gyrus and central region may account for constructional disability and limb-kinetic apraxia, respectively. Three-dimensional surface display with 123I-IMP appears to be useful for detecting the cortical region.

Aged↗

PubMed1992

[Food hygienic indexes on biodegradable polymers].

Current specifications for food packaging made of polyolefine plastics were applied to biodegradable plastics. No lead and cadmium were detected in any biodegradable plastic samples with the exception of bacterial cellulose, which contained trace amounts of lead and cadmium. Potassium permanganate consumption amount was less than the current specification level for polyofines. Sugars leached from bacterial cellulose was 22 +/- 1 microgram per 100 cm2 as glucose, and amino acids leached from poly-gamma-methylglutamate films was 8 +/- 3 micrograms per 100 cm2 as glutamic acid.

Amino Acids↗