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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 415 records · Page 23Linked to original sources
PubMed1991

Biological half-time and body burden of cadmium in dogs after a long-term oral administration of cadmium.

To investigate the kinetic behavior of cadmium, we conducted a long-term oral administration experiment, using beagle dogs. The experimental animals were given a commercial diet and pelleted food containing 1, 3, 10, 50, and 100 mg of cadmium per day in the form of cadmium chloride for 8 yr. A single injection of cadmium (as CdCl2) into dogs was also performed in order to obtain fundamental kinetic information for a dog. The kinetic behavior of cadmium in chronic experiment is described theoretically, using a two-compartment model. The model was selected based on the elimination pattern of cadmium from the blood in the single injection experiment. The parameters of the model were estimated from the acute and chronic experimental data. The theoretical value of the cumulative amount of cadmium excreted in urine agreed with the experimental one. This result suggests that the two-compartment model used in this study is useful to elucidate the kinetic behavior of cadmium after a long-term exposure to cadmium. The terminal biological half-time in the two-compartment model was estimated at about 1 to 2 yr for both male and female dogs given 1, 3, 10, and 50 mg of cadmium, and for the male dog given 100 mg of cadmium, but only 0.3 to 0.5 yr for the female dog given 100 mg of cadmium. The amount of cadmium in the central compartment and tissue compartment increased continuously and then gradually reached a steady state. The amount of tissue compartment was much higher than that of the central compartment for each beagle dog.

Administration, Oral↗
PubMed1991

Apodemus sylvaticus, a new host for Acanthocheilonema viteae (Nematoda: filarioidea).

Susceptibility of Apodemus sylvaticus and A. agrarius to infection with Acanthocheilonema viteae was compared with that of hamsters and jirds. Microfilaremia in A. sylvaticus was first noted on day 52 post-infection (p.i.) and lasted during the course of the study (up to day 150 p.i.). Maximum microfilaremic levels (female worm basis) of A. sylvaticus [mean +/- S.D. (n) = 690 +/- 1288(6)] were considerably higher than those of hamsters [16 +/- 18(6)] and jirds [51 +/- 25(5)]. Adult worm recovery in A. sylvaticus ranged from 2 to 40% of the number of infective larvae inoculated. Worm development in A. sylvaticus resembled that in hamsters and jirds. In contrast, microfilaremia was not detected in, nor adult worms recovered from A. agrarius throughout the study.

Animals↗
PubMed1991

Geotropic ocular deviation with skew and absence of saccade in Creutzfelt-Jakob disease.

Three patients with Creutzfelt-Jakob disease (CJD) showed characteristic ocular manifestations. The head was turned left or right with the eyes deviated downward and skewed. When the head was turned to one side, the eyes very slowly deviated to that side. In addition, spontaneous ocular movements were very slow with no saccadic component early in the apathetic stage. Caloric stimulation produced tonic deviation to the appropriate side without nystagmus. At autopsy one patient showed lesions compatible with the panencephalopathic type of CJD. Although bilateral pretectal areas had marked gliosis, other nuclei and structures associated with oculomotor system in the brainstem, including the oculomotor, trochlear, abducens, vestibular and perihypoglossal nuclei, medial longitudinal fasciculus and para-median pontine reticular formation were preserved. These patients had a supranuclear disorder, probably caused by combined disruption of the direct and indirect frontal eye field to the brainstem pathways plus impairment of the superior colliculus-mediated saccade pathways.

Creutzfeldt-Jakob Syndrome↗
PubMed1991

Application of mathematical model to multiple-dose experimental chemotherapy for fatal murine pneumonia.

Two beta-lactam antibiotics, cefazolin and cefmenoxime, were administered for 7 days to mice with pneumonia caused by Klebsiella pneumoniae by using dosage regimens that would simulate multiple dosing in usual clinical treatments at dosing intervals of 8 or 12 h. Viable numbers of the bacteria in the lungs were measured at 12- or 24-h intervals. The mathematical model established in a previous single-dose study was applied in this study to explain the time courses of the changes in bacterial count over 7 days. However, because the error in viable count measurements was larger than that in the previous study, the time course of the changes in mean viable count was not regular and the viable count reduction rate changed during multiple dosing, and therefore it was difficult to explain the time course by repeated application of the mathematical model described previously. This study suggests that the changes in pharmacokinetic and pharmacodynamic parameters during multiple dosing need to be considered.

Animals↗
PubMed1991

[Effects of ascorbic acid on the free radical formations of isoniazid and its metabolites].

By the use of electron spin resonance (ESR) spectroscopy and of spin-trapping technique, the effects of ascorbic acid on the formation of the free radical intermediates due to isoniazid (INAH) and its metabolites were investigated with a microsomal system. When alpha-(4-pyridyl 1-oxide)-N-tert butylnitrone (4-POBN) was used as a spin trapping agent, the ESR signal due to hydrazine (Hy) was formed to be most intensive among others. Therefore, it was presumed that Hy is a potent intermediate to cause an INAH-induced hepatic injury. In the presence of ascorbic acid (AA), the free radical formation of Hy, INAH and acetyl hydrazine was significantly inhibited, suggesting that AA may affect the INAH-hepatitis. By the addition of inhibitors of cytochrome P-450 like metyrapone and CO, the generation of the radical from Hy decreased, confirming that the radical is formed by the cytochrome P-450 dependent microsome systems. The 4-POBN-trapped radical species generated from Hy was presumed to be the hydrazyl radical by the results of mass spectrometry.

Animals↗
PubMed1991

Embolization with steel coils using a saline flush technique.

A method using saline flush to push Gianturco steel coils through catheters is described, and has been successfully used in 45 patients. The saline flush technique requires no precise matching of coils and catheters, solves problems associated with the conventional method and simplifies the coil embolization procedure.

Arteries↗
PubMed1991

[Predictive factors of etiologic agents of community-acquired pneumonia presenting at a district general hospital].

Community-acquired pneumonia is one of the major respiratory diseases causing hospital admission in previously healthy patients. Prompt and appropriate antibiotic selection is essential for recovery. The authors tried to determine the distribution of the etiologic agents of community-acquired pneumonias and to analyze predictive factors. Out of 188 cases of community-acquired pneumonia presenting to our hospital, etiologic agents were determined in 106 cases (56%). Twenty-nine cases were due to Streptococcus pneumoniae, 27 cases due to Mycoplasma, 17 cases due to Haemophilus influenzae and 21 cases due to Mycobacterium tuberculosis. M. tuberculosis was the cause in 11% of all cases and the importance of pulmonary tuberculosis must be emphasized as a community-acquired pneumonia. Out of 58 cases under 50 years old, Mycoplasma pneumoniae was the etiologic agent in 23 cases (40%) and S. pneumoniae in 7 cases (12%). Out of 62 cases not less than 70 years old. M. tuberculosis was the most common etiologic agent (15 cases, 24%). S. pneumoniae followed, being causative in 13 cases (21%). M. tuberculosis was the cause in 10 cases out of 31 cases who did not complain of fever at presentation. In 86 cases who did not show leukocytosis on admission, 21 cases were due to Mycoplasma (24%) and 15 cases were due to M. tuberculosis (17%). In particular 17 cases were due to Mycoplasma among 28 cases under 50 years old without leukocytosis (61%), and 11 cases were due to M. tuberculosis in the 27 cases no less than 70 years old without leukocytosis (41%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[A case of whole visual field visuomotor ataxia of bilateral hands associated with bilateral parietooccipital lesions in the white matter].

A 29-year-old male with visuomotor ataxia was reported. Visuomotor ataxia of bilateral upper extremities was noted in whole visual field including central visual field (optische Ataxie). Neither contraction nor depression of visual field was detected by the test using kinetic or static perimeter, respectively. Magnetic resonance imaging and computed tomography of the brain revealed bilateral parietooccipital lesions in the white matter, and pathological examination of brain biopsy specimen demonstrated demyelination. We considered that bilateral parietooccipital lesions in the white matter were responsible for visuomotor ataxia in this case.

Adult↗
PubMed1991

["Wrapping" method of the graft in repair of acute aortic dissection].

A simple method to wrap the graft in repair of acute aortic dissection was described. The diseased ascending aorta was excised and both ends of the aorta were trimmed with application of a Teflon felt inside and a preserved equine pericardium outside. The graft was anastomosed to the trimmed ends and the equine pericardiums were turned and sutured around the graft. Two additional sutures were tied around the equine pericardium to reinforce oppression. This simple technique is very useful to control oozing from the suture lines.

Acute Disease↗
PubMed1991

[Combined operation for left atrial myxoma, mitral regurgitation, coronary artery stenosis and abdominal aortic aneurysm].

A 68-year-old male patient with a left atrial myxoma, mitral regurgitation, ischemic heart disease and abdominal aortic aneurysm underwent resection of the myxoma, mitral valve replacement, 4 coronary artery bypass grafting and replacement of the aneurysm simultaneously. The aneurysm was replaced under partial cardiopulmonary bypass. Combined cardiac and abdominal aortic operation is useful in selected patients who require IABP support postoperatively or whose cardiac function is poor.

Aged↗
PubMed1991

[Successful emergency operation of a right atrial rupture due to a traffic accident].

A case of right atrial rupture with cardiac tamponade due to a traffic accident is reported. By thoracic CT, we diagnosed this condition and successfully repaired the ruptured site five hours after injury. Early diagnosis of cardiac rupture is always very difficult, but at any time in nonpenetrating injury, we must treat patient under suspicion of this disease.

Accidents, Traffic↗
PubMed1990

ESR analysis with long-chain alkyl spin labels in bovine blood platelets. Relationship between the increase in membrane fluidity by alcohols and phenolic compounds and their inhibitory effects on aggregation.

Four spin-labeled probes (5-doxylstearic acid (5-NS), its methyl ester (5-NMS), 16-doxylmethylstearate (16-NMS) and 4-(N,N-dimethyl-N-pentadecyl)ammonium-2,2,6,6-tetramethylpiperidine-1-ox yl (CAT-15)) were used to monitor membrane fluidity change in bovine platelets induced by three alkyl alcohols, benzyl alcohol and two phenolic compounds. The relationship between the increase in membrane fluidity induced by these compounds and their inhibitory effects on platelet aggregation was observed. Experiments with the four probes showed that n-hexyl alcohol induced decreases in the order parameter of 5-NS and apparent rotational correlation times of the other probes at the same minimal alcohol concentration. The decreases were observed in the concentration range that inhibited aggregation. n-Amyl alcohol and n-butyl alcohol decreased the values of the parameters of the above mentioned only at higher concentrations that were dependent on their hydrophobicities. Like alkyl alcohols, benzyl alcohol and phenolic compounds decreased the values of the parameters in the concentration ranges in which these compounds inhibited platelet aggregation. The concentration of these compounds causing 50% inhibition of platelet aggregation, the IC50 values, and data on 5-NS-labeled platelets indicated that they inhibited aggregation and decreased the value of the order parameter at lower concentrations relative to their Poct values in comparison to the effective concentrations of alcohols. Phenolic compounds also decreased the values of the apparent rotational correlation times of 5-NMS and 16-NMS. These results indicate that the inhibition of platelet aggregation by alcohols and phenolic compounds is due to membrane perturbation in wide range in depths within the lipid bilayer.

Alcohols↗
PubMed1990

[High-field MR findings of multiple system atrophy].

Magnetic resonance images obtained at 1.5T were reviewed in 23 patients with clinically diagnosed multiple system atrophy (MSA). The patient group consisted of 13 cases with olivoponto-cerebellar atrophy (OPCA), three with striatonigral degeneration (SND), and seven with Shy-Drager syndrome (SDS). In each disorder group, hypointensity of the pars compacta of the substantia nigra was frequently demonstrated as well as the atrophy of the brain stem and cerebellum. Although T2-weighted images depicted hypointensity of the putamen, which was prominent in its posterolateral part, in cases with SND and SDS, it was not encountered in cases with OPCA. Therefore, this finding was considered to facilitate differential diagnosis between OPCA and other two disorders. These hypointensities in the putamen and pars compacta of the substantia nigra may be due to excessive iron deposition and seem to correlate with extrapyramidal tract signs of MSA.

Corpus Striatum↗
PubMed1990

Unusual hyperporphyrin spectrum by bis(glutathione dimethyl ester)-hemin complex, a model of cytochrome P-450-thiolate complexes.

A bis(thiolato) complex of iron-porphyrin exhibiting a "split Soret band" with peaks at 374 and 466 nm, classified as a "hyperporphyrin (HP) spectrum", was prepared with Fe(III)protoporphyrin dimethyl ester (FePPIXDME), glutathione dimethyl ester (GSHDME) and tetrabutylammonium hydroxide in acetone solvent. The structure of the complex was characterized by comparing their electronic absorption and electron spin resonance (ESR) spectra with those of thiolate adducts of cytochrome P-450 and their chemical model complexes. Under the same conditions as those for the formation of the HP spectrum, the generation of the free superoxide anions was detectable by ESR spectrometry at 77K. On the basis of the results, the possible reaction mechanism generating the superoxide anions by the bis(GSHDME)-FePPIXDME complex was proposed.

Animals↗
PubMed1990

Isolation and characterization of extremely minor gangliosides, GM1b and GD1 alpha, in adult bovine brains as developmentally regulated antigens.

In addition to ganglioside GM1b, an unusual and extremely minor ganglioside, GD1 alpha, was efficiently isolated from bovine brain by combination of Q-Sepharose and Iatrobeads column chromatographies. In the course of purification steps, the presence of the sialidase-labile ganglioside was proved by a highly sensitive TLC/enzyme-immunostaining method. The structure was characterized by gas-liquid chromatography, permethylation study, sialidase degradation, immunostaining with specific antibodies, fast atom bombardment-mass spectrometry, and proton magnetic resonance spectrometry. The content of the ganglioside was very small (0.016%) in the total gangliosides. This finding suggests that a synthetic pathway of asialo GM1----GM1b----GD1 alpha may exist in mammalian brains. A monoclonal antibody NA-6 that was obtained by immunizing mice with purified GM1b reacted specifically with GM1b but showed no cross-reactivity with other structurally related gangliosides such as GM1a, GD1a, and so on. Using the method of TLC/immunostaining with NA-6, GM1b was found to be strongly expressed during embryonic days 14-17 in chick brains. Thus, it is assumed that extremely minor gangliosides like GM1b and GD1 alpha found in adult brains are characterized as embryonic molecules.

Animals↗
PubMed1990

Vitamin E deficiency in acquired fat malabsorption.

Thirteen patients with adult-onset vitamin E deficiency due to fat malabsorption were investigated clinically and electrophysiologically. These patients had slightly or moderately decreased serum vitamin E (1.7-4.8 micrograms/ml, normal less than 6.0) or vitamin E/cholesterol ratio (0.21-0.31 mg/g, normal less than 0.35). Only one patient had typical neurological manifestations of vitamin E deficiency, which improved with supplementary vitamin E. The pathological findings in this patient were also compatible with vitamin E deficiency. This patient had poorly controlled diabetes mellitus due to advanced chronic pancreatitis. Reviewing previously reported cases of vitamin E deficiency with diabetes mellitus in chronic pancreatitis, the duration of deficiency until the onset of symptoms was shorter than in those cases without complications. Although adult patients with early, slight deficiency of vitamin E are generally asymptomatic, patients with diabetes mellitus tend to have early neurological symptoms. The vitamin E tolerance test should be used, because even in some patients with vitamin E deficiency due to malabsorption, the deficiency can be overcome by large oral doses of vitamin E.

Adult↗
PubMed1990

Selective loss of nigral neurons in Pick's disease: a morphometric study.

Loss of neurons from the substantia nigra (SN), which is often encountered in Pick's disease, was quantitatively analyzed in 13 cases of Pick's disease and 19 age-matched controls. On sections from the upper and lower portions of the SN, the pigmented zone (zona compacta) and the non-pigmented zone (zona reticulata) were delineated, and these zones were partitioned into quarters: medial, mid-medial, mid-lateral and lateral. Neuronal loss was fairly severe and more evident in the upper section of the SN (-40%), especially in the mid-medial and lateral quarters. In the lower section (neuronal loss: -28%), the medial quarter was most severely affected. Non-pigmented neurons were preserved. Fibrillary gliosis was denser in the zona reticulata, where neuronal loss was minimal. These findings revealed a selective vulnerability of nigral neurons according to their topography and pigmentation and suggests the primary involvement of some neuronal groups (especially the pigmented neurons) of the SN in Pick's disease.

Aged↗