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Biomedical subjects

H Shimada

Publications and source records attributed to H Shimada.

At least 721 records · Page 40Linked to original sources
PubMed1990

Effects of several dithiocarbamates on tissue distribution and excretion of inorganic mercury in rats.

The effects of various chelating agents, sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-methylbenzyl-D-glucamine dithiocarbamate (MBGD), sodium N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD), which were newly synthesized, and sodium N-methyl-D-glucamine dithiocarbamate (MGD), on the distribution and excretion of inorganic mercury were compared in rats exposed to HgCl2. Rats were injected i.p. with 203HgCl2 (300 micrograms of Hg and 74 kBq of 203Hg/kg) and 30 min or 24 h later, they were injected with a dithiocarbamate (1200 mumol/kg). At 30 min after mercury administration, BGD and MBGD significantly enhanced the biliary excretion of mercury, while CBGD, MGD, and HBGD enhanced the urinary excretion of mercury to a small extent. At 24 h after mercury injection, BGD was the most effective on the biliary excretion of the metal, while MGD and HBGD significantly enhanced the urinary excretion of the metal. All of these dithiocarbamates were effective in mobilizing mercury from the kidney at 30 min after mercury treatment. At 24 h after mercury treatment, HBGD and BGD effectively depressed mercury content in the kidney. These results show that the injection of BGD and HBGD at both 30 min and 24 h after mercury treatment can much more effectively mobilize mercury from the kidney without redistribution of mercury to other tissues, such as brain, heart, and lung, when compared with injection of other chelating agents. The pattern of mobilization and excretion of mercury following treatment with each chelating agent was related to the organic/aqueous partition coefficient of each dithiocarbamate-mercury complex.

Animals↗
PubMed1990

Effect of auditory presentation of words on color naming: the intermodal Stroop effect.

To verify two hypotheses (the automatic parallel-processing model vs the feature integration theory) using the Stroop effect, an intermodal presentation method was introduced. The intermodal presentation (auditory presentation of the distractor word and visual presentation of color patch) separates completely the color and word information. Subjects were required to name the color patch on the CRT and to ignore the auditory color-word in the present experiment. A 5 (stimulus onset asynchronies) x 4 (levels of congruency) analysis of variance with repeated measures was performed on the response times. Two main effects and an interactive effect were significant. The findings indicate that without the presentation of color and word component in the same spatial location the Stroop effect occurs. These results suggest that the feature-integration theory cannot explain the mechanisms underlying the Stroop effect.

Adult↗
PubMed1990

[Changes in the liver weight in the elderly].

To elucidate the effect of aging on liver weight in the elderly, 582 elderly cases (male 291, female 291), were selected from 2000 elderly autopsied cases on the basis of being free from pathological findings affecting liver weight. Both liver weight and its ratio to body weight decreased with age, and influenced by obesity; the former increased and the latter decreased in obese cases. Analysis according to the degree of obesity also showed decrease of liver weight and is ratio to body weight with age. Comparison between males and females of the same decade revealed the tendency that in females the liver weight was low, while liver weight.body weight ratio was high. The same results were obtained by analysis based on the degree of obesity.

Aged↗
PubMed1990

The presence of a novel protein in calf serum that recognizes beta amyloid in the formalin-fixed section.

Here we report on a monoclonal antibody, H6-33, that labels various beta-amyloid plaques, including diffuse plaques in the formalin-fixed, paraffin-embedded section from the brain affected with Alzheimer's disease (AD), without formic acid pretreatment. H6-33 also labels some neurofibrillary tangles and all kuru plaques in Gerstmann-Sträussler-Scheinker disease. In sharp contrast, H6-33 did not stain beta amyloid in the leptomeningeal vessel. For specific staining, H6-33 required the presence of fetal calf serum and it was necessary for beta amyloid to be formalin fixed. These results suggest that a novel protein in the calf serum, CSX, binds formalin-fixed beta amyloid, followed by H6-33 binding. The detection of beta amyloid by CSX was nullified by formic acid pretreatment of the tissue section. In accordance with this, CSX reacted only with a polymer form of synthetic beta peptide after fixation, but not with native beta-protein or beta-peptide monomer. These observations strongly suggest that 1) meningovascular beta amyloid should have a beta-pleated sheet structure somewhat dissimilar to that of beta-amyloid cores; and 2) most, if not all, of beta-protein immunoreactivities of diffuse plaques in AD sections are presumably derived from small amounts of amyloid fibrils scattered in the normal-looking neurohil.

Alzheimer Disease↗
PubMed1990

[Phagocytic activity of rat Kupffer cells--the measurement method in vitro and the effect of hepatocytes upon the phagocytic activity].

The measurement method of the phagocytic activity of Kupffer cells (=KC) was investigated and the effect of hepatocytes (=HC) upon the phagocytic activity of KC was studied in vitro. Phagocytic activity of KC was measured by the uptake rate of 59Fe by KC (2 x 10(6)) incubated with chondroitin sulfate 59Fe for 24 hours (=phagocytic activity rate:PAR). When KC were co-cultured with HC (2 x 10(5), 5 x 10(5), 1 x 10(6) cells) for 24 hours, the PAR increased in proportion to the increase in number of HC (4.13, 5.37, 6.28%), comparing with that of KC alone (3.36%). And when KC were cultured with the supernate of HC (5 x 10(5)) which were cultured for 24 hours, this PAR (4.15%) was superior to that of KC alone, but didn't exceed that of KC co-cultured with HC (5 x 10(5)). The PAR was remarkably suppressed by the inhibitor of glycolysis (NaF), but was not suppressed so much by the inhibitor of oxidative phosphorylation (NaN3). The measurement method of phagocytic activity of KC in vitro was established, and it was proved that the PAR was enhanced by co-cultured HC and the supernate of cultured HC, and depended on glycolytic metabolism.

Animals↗
PubMed1990

Immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine in haemodialysis patients.

The immune response of 32 haemodialysis patients vaccinated with a recombinant yeast-derived hepatitis B vaccine (YHB vaccine) was compared with that of healthy adults and of another haemodialysis patient group vaccinated with the plasma-derived vaccine (PHB vaccine). Twenty-two patients were immunized 3 times (months 0, 1 and 6) intramuscularly with a 20 micrograms dose, and ten patients with a 40 micrograms dose of the YHB vaccine. All members of the former group (100%) and nine of the latter group (90%) were anti-HBs positive after 3 vaccinations (months 7); anti-HBs concentrations with geometric mean titres (GMTs) of 82.3 mIU/ml and 242.1 mIU/ml, respectively, the difference being statistically in significant. The 87 healthy control group participants were vaccinated according to the same schedule but with 10 micrograms per dose, and 98% of them were anti-HBs positive by month 7, with a GMT of 198.3 mIU/ml. The patients responses were higher at each time point than those of 53 dialysis patients vaccinated in an earlier study with either 20 micrograms or 40 micrograms PHB vaccine. Two additional inoculations led to a substantial elevation of the anti-HBs titre in most of the haemodialysis patients; GMTs by month 12 being 506.8 mIU/ml and 979.5 mIU/ml for the 20 micrograms and the 40 micrograms dose respectively. No serious side-effects were observed over the one-year period of study. From these results, it was concluded that the YHB vaccine is highly immunogenic and could replace the PHB vaccine even in dialysis patients.

Adult↗
PubMed1990

[An autopsy case of postencephalitic parkinsonism: investigation on neurofibrillary tangles in comparison with those in progressive supranuclear palsy].

We report an autopsy case of postencephalitic parkinsonism (PEP). The distribution, histochemical, and immunohistochemical characteristics of neurofibrillary tangles (NFTs) in the case were studied and compared with NFTs in progressive supranuclear palsy (PSP). The patient was a 78-year-old woman who had suffered from "sleeping sickness" at age 27 and parkinsonism developed 13 years later. NFTs were found in the brainstem, basal ganglia, subthalamus, hypothalamus, thalamus and hippocampus in addition to marked degeneration of the substantia nigra. In the brainstem, NFTs were found not only in the amine-containing neurons but also in the pedunculopontine nucleus, which was recently reported to have cholinergic neurons. NFTs were immunostained by antibodies against tau and ubiquitin, both of which have been identified as antigenic components of NFTs in Alzheimer's disease and also those in PSP. Ultrastracturally, NFTs were composed of paired helical filaments. In serial sections with stained with Congo red and Bodian stains, all NFTs visible with Bodian stain in the brainstem of the case seemed to have Congo red birefringence which is produced by beta-sheet conformation of protein. In contrast, in three cases of PSP, less than half of NFTs seemed to have birefringence. These findings suggest that the protein components of NFTs in PEP and PSP are common to each other, but the conformation of the protein of some NFTs in PSP may be different from those in PPE.

Aged↗
PubMed1990

[Prevention of vitamin K deficiency in the early neonatal period--prophylactic oral administration of VK to the mother].

We studied the effect of vitamin K(MK-4) on the prevention of vitamin K deficiency in the early neonatal period. MK-4 (20 mg/day) was given orally for 1-7 days to 183 pregnant women at 37-39 weeks gestation. In the MK-4 treated group, there were no cases of melena neonatorum but there were 9 cases in the untreated group (9/757, 1.2%). To investigate the influence of MK-4 administration on liver function and the VK dependent coagulation system, maternal and umbilical venous blood were taken to measure T-Bil, GOT, GPT, gamma-GTP, LDH, and II, VII, X activity and HPT. There was no significant difference between these values in MK-treated and untreated groups. MK-4 concentrations were measured in the maternal and umbilical venous blood of 68 subjects. The level of MK-4 in umbilical venous blood was less than 0.1 ng/ml in 17 of 21 subjects not treated with MK-4 but it was over 0.1 ng/ml in 30 of 47 MK-4 treated subjects. However, no MK-4 was detected in 6 of 8 subjects who were treated for 1 day. The level of MK-4 in maternal blood was less than 0.1 ng/ml in 12 of 21 untreated subjects but it was 0.19-92.6 ng/ml in all of the 47 MK-4 treated subjects. The mean MK-4 concentration in cord blood as a percentage of that in maternal blood was 17.9%. These findings indicate that MK-4 is effectively transported from maternal to fetal blood through the placenta and its administration to pregnant women is useful in preventing melena neonatorum.

Administration, Oral↗
PubMed1990

[An erythremia with acquired HbH disease and chromosomal abnormality].

A 56-year-old male was admitted to the Nihon University Hospital because of general fatigue and anemia on September 21st, 1985. He had mild hepato-splenomegaly. Hematological findings showed RBC 286 x 10(4)/microliters, Hb 6.0/dl, reticulocyte count 2.5%, platelet count 9.3 x 10(4)/microliters and WBC 2,400/microliters. An erythroblast per 100 leukocytes counted in a blood film was found. Bone marrow was erythroid hyperplasia with megaloblasts. The erythroblasts were PAS positive but not ringed sideroblasts. Other laboratory data including hemolysis were all negative. This case seemed to be diagnosed as refractory anemia (RA) according to the FAB classification. Chromosomal analysis of marrow cells, however, all revealed 46, XY, 20q- at diagnosis and 46, XY, 7q- 20q- after 22 months. Furthermore, Hb electrophoresis ahd family study indicated the presence of acquired HbH disease. Neither erythroid bursts (BFU-e) nor late erythroid progenitors (CFU-e) were detected. He has had progressive anemia without proliferation of blasts for over 2 years. From these findings, we postulate that the entity of erythremia should be distinguished from RA including many heterogeneous diseases.

Chromosome Deletion↗
PubMed1990

Comparative effects of three dithiocarbamates on tissue distribution and excretion of cadmium in mice.

The effects of sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and sodium N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD), which were newly synthesized, on the distribution and excretion of cadmium were compared in mice exposed to cadmium. Mice were injected with 109CdCl2 (1 mg Cd/kg and 74 KBq of 109Cd/one animal) and 30 min or 24 h later, they were injected with the dithiocarbamates (400 mumols/kg). At 30 min after treatment with cadmium, these chelating agents significantly enhanced the biliary excretion of cadmium, and HBGD and CBGD significantly increased the urinary excretion of the metal. At 24 h after cadmium injection, BGD and HBGD significantly increased the biliary excretion of cadmium and HBGD was the most effective on the biliary excretion of the metal. These chelating agents were effective in mobilizing cadmium from the liver and kidney at 30 min after cadmium treatment. HBGD showed the largest effectiveness on the depression of cadmium contents in the liver and kidney. At 24 h after cadmium treatment, only HBGD among these chelating agents significantly reduced the cadmium contents in the liver and kidney. These results show that the injection of HBGD at both 30 min and 24 h after cadmium treatment can much more effectively mobilize cadmium from the body mainly through the bile without redistribution of cadmium to other tissues, such as brain, testes, and heart, than injection of BGD and CBGD.

Animals↗
PubMed1990

[Valvular regurgitation in patients with complete heart block by color Doppler echocardiography].

We studied valvular regurgitation (pulmonary, aortic, tricuspid and mitral regurgitation) in 30 patients with complete heart block by color Doppler echocardiography, pulse Doppler and continuous wave Doppler echocardiography. The prevalence rate of multivalvular regurgitation of these subjects was 83.3%. Regurgitation involving all four valves appeared in 30.0% of these patients. The prevalence rate of pulmonary, aortic, tricuspid and mitral regurgitation was 56.7%, 33.3%, 100%, and 76.7% respectively. Pulmonary regurgitation (PR) was observed in patients with complete heart block without pulmonary hypertension. PR velocity was slow and interrupted by atrial contraction. It might be possible to evaluate atrial pressure from the interruption of PR. Tricuspid regurgitation (TR) during systole was often present in patients with right ventricular endocardial pacing. Systolic TR was influenced by atrial contraction. When atrial contraction occurred during systole, TR was interrupted, or shortened. Diastolic TR and MR were easily detected by M mode color Doppler echocardiography. The diastolic TR and MR were of slow velocity and appeared 240-290 msec after P wave. These atypical valvular regurgitation in patients with complete heart block reflect of the inverse atrial-ventricular pressure gradient across the atrio-ventricular valve.

Adult↗
PubMed1990

A case of gallbladder carcinoma with infiltration into the muscular layer that resulted in relapse and death from metastasis to the liver and lymph nodes.

An eighty-six-year old woman was submitted to simple cholecystectomy and choledocholithotomy for acute obstructive cholangitis due to cholecysto-choledocholithiasis. At the operation, neither lymphogenic nor hematogenic metastasis was observed. Grossly, a protuberant lesion with an uneven surface and obscure borders was seen spread over the fundus and the body of the resected gallbladder. Histologically, it was a well-differentiated adenocarcinoma with slight invasion to the muscular layer. The patient died of recurrent carcinoma three years and eight months after the operation. At autopsy, multiple metastatic tumors were found in both lobes of the liver, and many lymph node metastases around the hilus of the liver, hepatoduodenal ligament and pancreas were also observed. It is strongly believed that gallbladder carcinomas that infiltrate the muscular layer should be classified as early-stage carcinomas with a fair prognosis, together with mucosal carcinomas. However, on the basis of the present case of relapse following simple cholecystectomy as described above, radical cholecystectomy including a wedge resection of the liver and dissection of the regional lymph nodes would seem necessary even for gallbladder carcinoma with infiltration into the muscular layer.

Adenocarcinoma↗
PubMed1990

[High field magnetic resonance imaging in Wilson's disease].

Magnetic resonance imaging studies on 3 cases with Wilson's disease were performed, using high field magnetic resonance system of 1.5 tesla. All patients had neurological findings of tremor, rigidity, dystonia or dysarthria at onset. Two patients had been treated with D-penicillamine for 14 years and 7 years respectively, and one patient was not treated then. T2-weighted images revealed abnormalities of signal intensity in lenticular nucleus, thalamus, pulvinar, superior colliculus, lateral portion of substantia nigra, midbrain and pontine tegmentum, and cerebral and cerebellar white-matter. Especially noted were following three hitherto undescribed abnormalities; high signal intensity of globus pallidus which normally shows very low signal intensity, restoration of signal intensity of lateral portion of substantia nigra, and marked low signal intensity of pulvinar and superior colliculus.

Adolescent↗
PubMed1990

[Morphological observation of the mitral annulus fibrosus in patients with mitral valve prolapse].

Sixteen cases of mitral valve prolapse (MVP) with mitral regurgitation (MR) in the aged (mainly in their eighth and ninth decades) with both clinical and pathological evidences were investigated. One hundred autopsy cases served as the control. The longitudinally-sectioned mitral annulus fibrosus was pathologically studied in all with special reference to the atrium-valve disjunction reported by Hutchins. Morphologically, the mitral annulus fibrosus was classified either as type A (the mitral valve attaches to the left ventricle), type B (the mitral valve attaches to the left atrium: Hutchins' disjunction), type C (the atrialis continues to the left atrium and the fibrosa to the left ventricle), or type D (mitral annulus calcification). Type B was observed in only 31% of the MVP cases, whereas it was seen in 43% of the control cases. It was concluded that Hutchins' observation could not be regarded as the characteristic pathological finding of MVP.

Aged↗
PubMed1989

Structure of sea-urchin arylsulfatase gene.

The gene encoding arylsulfatase (Ars; EC 3.1.6.1) as well as two Ars pseudogenes were isolated from sea urchin genomic libraries. The Ars gene was 20-kbp long and contained six exons interrupted by five introns. Four polypyrimidine repetitive sequences were dispersed in its upstream-flanking region. Comparison of the amino acid sequence of sea-urchin arylsulfatase with those of human sterol sulfatase, human arylsulfatase A and bacterial arylsulfatase revealed that they have two similar sequences in common. The position of the transcription-start site of the Ars gene was determined to be approximately 40-bp upstream from the 5' end of the protein-coding region, and the nucleotide sequence of the 5'-flanking region was determined up to 3.3 kbp upstream from the transcription start point. Putative TATAA box and CCAAT consensus sequences were located at positions -28 and -82, respectively. A highly conserved hexamer motif, CTCTTT, localized near the transcription-start site of the sea-urchin Ars gene, was also detected in similar regions of other sea urchin genes such as CyIIIa, Spec 1, Spec 2a, Spec 2c, Spec 2d, and SM50, but not in the histone genes.

Amino Acid Sequence↗
PubMed1989

Formation of directly mutagenic alpha-hydroxy-N-nitrosopiperidine phosphate ester by near-ultraviolet irradiation of N-nitrosopiperidine in phosphate buffer.

Previously we found that direct-acting mutagens can be formed from N-nitrosodialkylamines on exposure to near-ultraviolet light in the presence of phosphates. We have now isolated the mutagenic photoproduct formed from N-nitrosopiperidine and inorganic phosphate and identified its structure as the phosphate ester of alpha-hydroxy-N-nitrosopiperidine. This reaction represents a new, non-enzymatic activation of promutagenic N-nitrosodialkylamines.

Buffers↗