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Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 523 records · Page 29Linked to original sources
PubMed1994

[Amount of mercury from dental amalgam filling released into the atmosphere by cremation].

Mercury in dental amalgam filling is released into the atmosphere by cremation and is a suspected source of mercury pollution. The amount of mercury released was measured at three crematoriums. First, mercury levels in the atmosphere were measured. Mercury existed mainly in the gaseous form in ambient air. The concentration of atmospheric mercury at the three crematoriums (S, T and M) ranged from 4.3 to 19.7ng/m3, which was nearly identical to levels in our university surveyed as the control area and also to the levels of atmospheric mercury in general in Japan. Secondly, the amount of mercury release from T crematorium was estimated using official published statistical data in Japan and calculated as follows: sigma[(age specific number of dead that were cremated) x (the number of restored teeth by age category) x (mercury content per amalgam filling (0.6 g))] x (prevalence rate of restoration with amalgam). The amount of mercury released from this crematorium was estimated to be approximately 9.4 kg per year, or a daily release of 26 g into the ambient air. These results indicate that mercury release by cremation is similar to that from other man-made sources.

Air Pollutants↗
PubMed1994

[Intravenous pirenzepine reduces salivary secretion rapidly].

We evaluated the effects of pirenzepine on salivary secretion and heart rate, comparing them with those after atropine. Forty-two patients for gynecological operations were divided into three groups. P, A and C groups received pirenzepine 10 mg, atropine 0.5 mg and saline 1 ml intravenously 4 min before induction. Salivary secretion was aspirated at 30, 60 and 120 min after induction. Heart rate was recorded at 1, 30, 60 and 120 min after injection. In P and A groups, salivary secretion decreased significantly, but there was no significant difference between them. In A group, heart rate increased at 1, 30 and 60 min after injection, but at 120 min there was no difference among three groups. We conclude that intravenous pirenzepine as well as atropine reduces salivary secretion, but it does not increase heart rate as atropine.

Adult↗
PubMed1994

Oncogenicity studies of the cognition-enhancing agent nefiracetam in mice and rats.

Oncogenicity studies of nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide, DM-9384, CAS 77191-36-7), a new cognition-enhancing agent, were carried out in male and female mice and rats. The compound was administered in diet for 104 weeks at dosage levels of 30, 90 and 270 mg/kg/d for mice and of 200, 600 and 1800 ppm for rats. The administration of nefiracetam produced no effects on survival, appearance or behavior. Body weights of the high dose male mice and rats were occasionally significantly decreased when compared to the controls. When calculated on a g/animal/d basis, food consumption was sometimes decreased for these male groups. At necropsy, there was no evidence of treatment related changes, nor were these seen on histopathological examination. All microscopic changes seen in mice and rats were of the usual type commonly occurring in untreated aged B6C3F1 mice and F344 rats. In conclusion, the administration of nefiracetam for 24 months to B6C3F1 mice and F344/DuCrj rats produced only slight effects on body weight in the high dose males with a no-effect level of 90 mg/kg/d for mice or 600 ppm for rats. There was no evidence of an oncogenic effect of nefiracetam.

Animals↗
PubMed1994

[Coronary artery spasm after mitral valve replacement: a case report].

A 50-year-old female with a malfunctioning bioprosthetic mitral valve which was implanted 7 years earlier underwent reoperation. She had no history of angina pectoris. Calcium channel blockers and nitrates had not been taken by the patient. Coronary arteriograms were normal. About 2 hours after the reoperation, EKG monitor showed abrupt ST segment elevation which was immediately followed by ventricular tachycardias and fibrillations. This life threatening circulatory collapse recurred until a drip infusion of diltiazem was started. Maximum CPK-MB was 145 IU/l. Postoperative coronary arteriography, which was performed after 12 hours of withhold of diltiazem, showed a spasm in the proximal segment of the right coronary artery. Coronary artery spasm should be considered among the causes of abrupt and unexpected circulatory collapse after open heart surgery even in the absence of coronary artery disease.

Coronary Vasospasm↗
PubMed1994

Hyperphosphorylation of a novel 80 kDa protein-tyrosine kinase similar to Ltk in a human Ki-1 lymphoma cell line, AMS3.

Ki-1 lymphoma is a subtype of human malignant lymphoma characterized by the expression of CD30 (Ki-1) and a peculiar morphology. It is occasionally accompanied by a unique reciprocal chromosomal translocation t(2;5)(p23;q35). A Ki-1 lymphoma cell line, AMS3, was established by maintaining biopsied tumor cells in SCID (severe combined immunodeficiency) mice. To investigate abnormalities of the signal transduction in Ki-1 lymphomas, AMS3 lysate was immunoprecipitated with anti-phosphotyrosine monoclonal antibody, 25.2G4, and the immunoprecipitates were subjected to kinase assay and immuno-blotting with 25.2G4. A unique phosphotyrosine-containing protein of MW 80,000, designated p80, was found only in AMS3 cells and not in other cell lines or mononuclear cells from healthy donors. Subsequent amino acid sequence analysis of its tryptic digests showed that p80 was a hitherto undescribed tyrosine phosphoprotein similar to Ltk (leukocyte tyrosine kinase). Furthermore, physical interaction of p80 with CD30 was suggested from immunoprecipitation experiments with AMS3 lysates.

Animals↗
PubMed1994

[Two cases of pulmonary hypertrophic osteoarthropathy associated with primary lung cancer, in which symptoms were rapidly improved by resection of the primary lesions].

Pulmonary hypertrophic osteoarthropathy (PHO) is a syndrome of unknown etiology, presenting with osteitis of the long bones, arthritis, and clubbing of digits, associated with lung cancer or other chronic pulmonary or pleural diseases. Although about 3-10 percent of cases of lung cancer were reported to be associated with PHO in USA or Europe, reports of these cases are relatively rare in Japan. We report two cases of PHO associated with primary lung cancer, in which symptoms were rapidly improved by resection of the primary lesions. Both cases were poorly differentiated adenocarcinoma of the lung (pT2N0M0, Stage I). The bone and joint pain rapidly improved soon after the resection of the primary lesions. The abnormal findings of bone scan and bone X-ray film subsequently improved. In the 2nd case, radionuclide imaging more clearly revealed the presence and extent of subperiosteal activity than radiography. Radionuclide disclosure of PHO was considerably more sensitive than radiography.

Adenocarcinoma↗
PubMed1994

[Symbas's operation in a case of congenital fistula of the right coronary artery to left ventricle].

Congenital fistula between a coronary artery and the left cardiac ventricle are extremely rare. Since Blakeway (1918) first described this type of anomaly, only 72 cases have been reported up to the present, within our knowledge. A surgical correction of congenital fistula of the right coronary artery to left ventricle in a 36 year-old woman who suffered from easy fatigability is reported. This lesion was deduced after echocardiography identified a dilated right coronary artery and fluttering of the posterior cusp of the mitral valve throughout the diastole, the diagnosis was confirmed by retrograde aortography and coronary angiography. The fistula was closed by Symbas's operation under cardiopulmonary bypass with cardiac arrest and mild hypothermia. Postoperative recovery was uneventful. Coronary angiography one month after the operation revealed that the right coronary artery was still dilated with thrombus; there were no signs of myocardial ischemia or infarction. This diagnosis and successful treatment were based on careful study of the documentation of the 72 previously reported cases.

Adult↗
PubMed1994

[Planned combination therapy of coronary artery bypass and PTCA in ischemic heart disease].

Concomitant planned therapy consisting of a coronary artery bypass operation and percutaneous transluminal coronary angioplasty (PTCA) was attempted to shorten the period of cardiac arrest and make operations safer in patients undergoing emergency coronary artery bypass operations or coronary artery bypass operations in cases of significantly reduced left ventricle function or small perfusion lesions. The bypass operation was performed to treat only the main lesion and PTCA was undertaken 1-2 months later for coronary revascularization to treat secondary lesions. Finally, complete coronary revascularization was achieved. This concomitant method was performed on three cases. In all of these cases, two grafts were made and 1-2 lesions were dilated by PTCA. It was suggested that planned concomitant coronary artery bypass operations and PTCA provide a safer method of treatment in certain selected cases.

Angioplasty, Balloon, Coronary↗
PubMed1993

Engraftment of human non-Hodgkin lymphomas in mice with severe combined immunodeficiency.

BACKGROUND: Malignant non-Hodgkin lymphoma (NHL) is one of the most difficult neoplasms to transplant into nude mice. Mice with severe combined immunodeficiency (SCID) accept various human cancers much more efficiently than do nude mice. The authors investigated whether SCID mice could be used as convenient hosts in which to grow human NHL in vivo. METHODS: Fifty NHL specimens were engrafted into SCID mice. The original specimens and the tumors that developed in SCID mice were studied immunohistologically and by Southern blot analysis to clarify their clonal identity and to determine if they were Epstein-Barr virus (EBV)-transformed B cell proliferations. RESULTS: SCID tumors developed from 23 of 50 NHL specimens. Ten tumors were identical immunophenotypically and, partly, genotypically to the original NHL, showing that the original NHL grew in the SCID mice. B-cell NHL rather than T-cell NHL and high-grade rather than low-grade malignancy groups were much more easily heterotransplanted. Most of the heterotransplanted NHL were maintained by successive transplantation. In two other SCID tumors, the original NHL clones and a newly developed B-cell clone coexisted. The remaining 11 SCID tumors were composed of newly developed clones. The latter 13 tumors were shown to be human cells of B-cell lineage bearing EBV latent proteins--latent membrane protein 1 and EB nuclear antigen 2--suggesting that they originated from EBV-infected B-cells that were present in the original tumor tissues. CONCLUSION: SCID mice accept human NHL far more efficiently than do nude mice. However, frequent occurrence of spontaneous EBV-associated B-cell proliferation must be kept in mind.

Animals↗
PubMed1993

Alteration of the structural properties of starch components by the lack of an isoform of starch branching enzyme in rice seeds.

This study describes the effect of starch-synthesizing enzymes on biosynthesis of storage starch in rice amylose-extender mutants, which contain branched D-glucans with abnormal structures. Western blot analysis indicated that two out of five amylose-extender mutant lines lacked an isoform of starch branching enzyme, termed RBE3, although the levels of granule-bound starch synthase and a major form of branching enzyme, RBE1, were normal in these two mutants. Proteins corresponding to the 87-kDa RBE3 molecule were present in the three other amylose-extender mutants as well as in the wild type. However, the level of branching enzyme activity significantly decreased in all amylose-extender mutants, suggesting that the 87-kDa proteins in these three mutants are inactive forms of RBE3. Therefore, we conclude that formation of the abnormal branched glucans in the amylose-extender mutant of rice is due to the lack of the RBE3 activity. The cDNA clones encoding RBE3 have been identified from a normal rice seed cDNA library in lambda gt11, using a synthetic oligonucleotide as a probe. The deduced amino acid sequence of RBE3 indicates that this protein is initially synthesized as a precursor of 825 amino acids, including a 65-residue transit peptide at the NH2 terminus. The sequences of the catalytic regions in amylolytic enzymes are highly conserved in the sequence of RBE3. Thus, the branching enzyme isoform belongs to a family of the amylolytic enzymes. RBE3 also shares a noticeable degree of sequence identity with RBE1, especially at the central portion of the protein molecule. However, RBE3 possesses an approximately 70-residue extra sequence at the NH2 terminus and lacks a COOH-terminal sequence of almost 50 residues as compared with RBE1. The structural differences at both termini may explain the distinct role in starch synthesis for RBE1 and RBE3.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1993

Hyperpolarization-activated inward current in embryonic chick cardiac myocytes: developmental changes and modulation by isoproterenol and carbachol.

Modulation of the hyperpolarization-activated inward current (If) in embryonic chick ventricular myocytes was examined using whole-cell voltage-clamp. Long (3 s) hyperpolarizing pulses were applied from a holding potential of -30 mV to steps of -40 to -120 mV. If was marked in 3-day-old cells, diminished at 10 days, and was almost completely gone at 17 days. If current density (at -120 mV) was -6.7 +/- 1.3 (3 days), -3.3 +/- 1.0 (10 days), and -2.0 +/- 0.5 pA/pF (17 days). If reduction paralleled the decrease in spontaneous activity. In 3-day cells, the threshold potential was -50 to -60 mV, and the reversal potential was -13.4 +/- 1.3 mV. The time course of activation was fitted by a single exponential and was temperature dependent: tau was 1.3 +/- 0.4 s at 20 degrees C and 0.7 +/- 0.4 s at 30 degrees C (at -120 mV). If amplitude was enhanced by 12.1 +/- 1.8% at 30 degrees C compared with 20 degrees C. Cs+ (3 mM) blocked If and had a negative chronotropic effect (rate decreased by 61%). Isoproterenol (1 microM) caused a positive chronotropic effect (17.1 +/- 2.9%) and increased If by 65.2 +/- 5.6%. Carbachol (0.1 microM) had a negative chronotropic effect (26.3 +/- 3.4%), and decreased If by 41.2 +/- 1.3%; it also reversed the enhancement produced by isoproterenol. Intracellular application of 100 microM GTP-gamma S decreased basal If by 35.2 +/- 5.0%, but potentiated the stimulant effect of isoproterenol (by 37.8 +/- 4.7%) and the inhibitory effect of carbachol (21.2 +/- 4.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1993

Evaluation of truncated neuropeptide Y analogues with modifications of the tyrosine residue in position 1 on Y1, Y2 and Y3 receptor sub-types.

Substitutions of the tyrosine residue in position 1 of truncated neuropeptide Y (N-terminal fragment 1-4 linked to C-terminal fragment 18-36 by the epsilon-aminocaproic acid) produced analogues that compete for specific [125I]polypeptide YY (PYY) binding in the frontoparietal cortex (Y1-enriched) with a profile best fitted to a two site-model with KD values in the low and high nM range, respectively. In the hippocampal membrane preparations (Y2-enriched), halogen substitutions on the aromatic ring generated analogues with competition profiles best fitted to a one-site model, revealing differences between the two binding assays and the interaction of these analogues with the Y1 and Y2 receptor sub-types. In the rat vas deferens (Y2-enriched), all truncated analogues inhibited the twitch response with similar or slightly weaker potency than the native molecule. In contrast, these molecules were markedly less potent than neuropeptide Y (NPY) in the rabbit saphenous vein (Y1-enriched) and the rat distal colon (Y3-enriched). Some of the truncated analogues were inactive at up to microM concentrations in the rat distal colon, demonstrating the distinct structural requirement of the receptor sub-type present in this bioassay. These results revealed that amino acid residues between positions 5 and 17 are critical for the maintenance of optimal affinity for the NPY receptors present in the rabbit saphenous vein and the rat distal colon.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Inhibitory effects of capsazepine and SR 48968 on citric acid-induced bronchoconstriction in guinea-pigs.

We have examined the effects of capsazepine, a selective capsaicin antagonist, and SR 48968, a selective NK2 receptor antagonist, on citric acid inhalation-induced bronchoconstriction in guinea-pigs. Simultaneous inhalation of capsazepine (10 microM) significantly inhibited (by 85%) the bronchoconstriction induced by inhaled citric acid (0.4 M) but not that induced by histamine (2 mM). In capsaicin-pretreated (50 mg/kg s.c. 3 weeks earlier) guinea-pigs, citric acid failed to cause any bronchoconstriction, while the effect of histamine was uninfluenced. Furthermore, citric acid inhalation-induced bronchoconstriction was also markedly inhibited (by 65%) after pretreatment with SR 48968 (0.3 mg/kg i.v.). SR 48968 blocked the bronchoconstriction but not the hypotension evoked by neurokinin A. Therefore, these results suggest that inhalation of a low-pH solution such as citric acid can stimulate sensory neurons through a mechanism similar to that for capsaicin with regard to sensitivity to capsazepine. Tachykinins such as neurokinin A are then locally released from the terminals of sensory nerves and cause bronchoconstriction, mainly by NK2 receptor mechanisms.

Administration, Inhalation↗
PubMed1993

Copper-metallothionein distribution in the liver of Long-Evans cinnamon rats: studies on immunohistochemical staining, metal determination, gel filtration and electron spin resonance spectroscopy.

Distribution of metallothionein (MT) and copper ion (Cu) in the liver of LEC (Long-Evans Cinnamon) rats was investigated to examine the relationship between Cu-MT induction and the development of hepatitis followed by hepatocellular carcinomas. Immunohistochemical studies on MT in the liver of LEC rats indicated that MT is accumulated in nuclei and cytosols. Both MT and Cu, estimated by radioimmunoassay and flameless atomic absorption spectrometry, respectively, in subcellular fractions of the liver were found to be concentrated highest in cytosols, followed by nuclei, mitochondria and microsomal fractions. Gel-filtration (Sephadex G-75) studies demonstrated that MT is induced as the Cu-MT form. Furthermore, the Cu-MT fragment purified by the gel-filtration contains the Cu(I)-MT form, as demonstrated by ESR (electron spin resonance) measurements at 77K. These results will be important for understanding the development of hepatitis in LEC rats.

Animals↗