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Biomedical subjects

N Yasuda

Publications and source records attributed to N Yasuda.

At least 217 records · Page 12Linked to original sources
PubMed1989

Associations of health practices and social aspects of life with mortality among elderly people in a Japanese rural area.

A five-year study of persons aged 65 years and over in a Japanese rural area was conducted to examine associations of health practices and the social aspects of life with mortality. Age- and sex-related changes in the associations were examined. For health practices, constipation among men aged 75 years and over, and never or not annually receiving checkups among women aged 75 years and over were associated with increased mortality risk after adjustment for the initial subjective health status. In contrast to no associations between the social aspects of life and mortality among women aged 65-74 years, social aspects of life were more predictive of mortality than subjective health status and health practices among women aged 75 years and over. In this group, having neither a job nor a family role, membership in a group for the elderly while participating only in group tours and/or lecture meetings or without attending any of the regular activities, and infrequent contact with friends were associated with increased mortality. Among men, increased mortality risk was associated with membership in a group for the elderly while participating only in group tours and/or lecture meetings in the 65-74 year-old group.

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PubMed1989

[Nuclear DNA cytofluorometry of normal human laryngeal epithelia and squamous cell carcinoma].

Normal human laryngeal epithelia and laryngeal squamous cell carcinoma were assayed by Feulgen DNA cytofluorometry using free cell nuclei isolated from carnoy-fixed, paraffin-embedded specimens. In all of the 12 normal specimens, the epithelium showed typical diploid cell clones with low proliferative activity. Polyploid cells were seen in only two specimens from subjects aged 61 and 69 years respectively, and the number of polyploid cells seen in these two specimens was only two. Fifteen cancer cases were divided into three groups: an untreated group (5 cases), a chemotherapy group (5 cases) and a group of cases with recurrence after radiation therapy (5 cases). Among these three groups the DNA ploidy patterns were compared. In the untreated group, all cases showed a two-peak diploid pattern and a high proliferative activity, and polyploid cells were present. In the chemotherapy group, a wide one-peak histogram extending from 2C to about 5C was noted in 4 cases, and an aneuploid pattern in one case. Thus, the DNA ploidy pattern in the chemotherapy group differed from that in the untreated group. Of the 5 cases with recurrence after radiation therapy, one had a tetraploid pattern, but the remaining 4, a two-peak diploid pattern similar to that seen in the untreated group. Polyploid cells were observed in all these cancer cases. However, because they were also seen in some normal subjects, the finding of polyploid cells is not considered to be conclusive of cancer diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Synthesis and biological activity of 7 alpha-hydroxyethyl-1-oxacephem derivatives.

A series of 7 alpha-hydroxyethyl-1-oxacephems (1) was synthesized. The main focus of this study was to investigate biological activity relationships between 1-oxacephems (1) and the corresponding cephems (2). Replacement of the sulfur atom of 2 by the oxygen atom caused an enhancement of antibacterial activity, although the antibacterial activity of 1 was not high enough. Additionally 1 showed beta-lactamase inhibitory activity, especially against cephalosporinase. However, the potency was lower than that of 2.

Anti-Bacterial Agents↗
PubMed1989

Synthesis and structure-activity relationships of 3-(2-imidazolyl)thiomethyl cephalosporins.

The synthesis and structure-activity relationships of a series of 3-(2-imidazolyl)thiomethyl cephalosporins are described. Among the compounds, 7 beta-[2-(2-amino-1,3-thiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-3- [(4,5-dicarboxyimidazol-2-yl)thiomethyl]-3-cephem-4-carboxylic acid (1) exhibited potent activity against both Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa. We also estimated lipophilicity of the compounds from the chromatographic log k' value of reversed-phase HPLC. The relationship between lipophilicity and biological activity showed that compound 1 had the most suitable lipophilicity.

Cephalosporins↗
PubMed1989

Soluble interleukin-2 receptors in plasma cell dyscrasias.

Levels of the soluble form of the interleukin-2 receptor (sIL-2R) were evaluated in the peripheral blood of 69 patients with plasma cell dyscrasias. A close relationship was seen between serum sIL-2R levels and clinical features. Among patients with normal BUN and creatinine levels, the mean (+/- 1SD) level of sIL-2R in 44 patients with multiple myeloma (MM) was higher than that of normal controls (457 +/- 227 U/ml vs 288 +/- 124 U/ml, P = 0.01). The mean level of sIL-2R in eight patients with primary macroglobulinemia was 722 +/- 251 U/ml. In MM, those with active or refractory disease showed a significantly higher mean level of sIL-2R than those in the remission phase (577 +/- 240 U/ml vs 335 +/- 103 U/ml, P = 0.01). There was a negative correlation between sIL-2R and hemoglobin levels in MM patients (r = -0.45, P = 0.01). Five patients with complications of renal insufficiency had elevated levels of sIL-2R. In a longitudinal study of a patient with plasmacytoma and an extremely high sIL2-R level, the sIL-2R level showed a strong relationship with tumor burden. Patients with high sIL-2R levels generally had a poor prognosis than those with normal levels. Thus a high sIL-2R level may be an indicator of a poor prognosis in MM.

Aged↗
PubMed1989

Halogenation and anesthetic potency.

Previous studies have shown that the anesthetic potency of organic compounds increases as a given halogen is replaced with successively larger halogens. These studies often are limited in the accuracy of determination of potency, rarely correlate potency with physical properties, and usually fail to include ether compounds. Because establishing relationships between structure and activity may shed light on anesthetic action, we studied the new anesthetic, I-537 (CHF2-O-CHBr-CF3), relative to two other ether anesthetics, I-653 (CHF2-O-CHF-CF3) and isoflurane (CHF2-O-CHCl-CF3) for both of which MAC and oil/gas partition coefficients are accurately known. The oil/gas partition coefficient of I-537 at 37 degrees C was found to be 245 +/- 6 (mean +/- SD) and the MAC in Sprague-Dawley rats 0.52 +/- 0.07%. Increasing atomic weight of the 1-ethyl halogen (i.e., F in I-653, Cl in isoflurane, and Br in I-537) progressively decreases MAC (increases potency) and increases lipid solubility. Although potency and solubility change by more than 10-fold, the product of MAC and the oil/gas partition coefficient remains essentially constant (120 +/- 11). However, this product is significantly less than that for other inhaled anesthetics, a finding which either challenges the unitary theory of narcosis or suggests that the lipid solvent classically used to model the site of anesthetic action (olive oil) is inappropriate.

Anesthetics↗
PubMed1989

Solubility of I-653, sevoflurane, isoflurane, and halothane in plastics and rubber composing a conventional anesthetic circuit.

This study defines some characteristics of a standard anesthetic circuit that may impede anesthetic induction and recovery with I-653, sevoflurane, isoflurane, and halothane. Partition coefficients for anesthetic circuit components (masks, bellows, bags, airways, and circuit tubes) consistently ranked halothane greater than isoflurane greater than sevoflurane greater than I-653, suggesting a reverse order of washin and washout rates for an anesthetic circuit constructed from similar components. Consistent with this prediction, the concentrations of I-653 increased and decreased more rapidly than those of the other agents at any flow rate during washin (0.5, 1, or 2 L/min gas inflow rates) or washout (1, 3, or 5 L/min) in a conventional anesthetic circuit. The rates of change in I-653 concentration closely approximated the maximal possible theoretical rates. Our results suggest that absorption of I-653 by circuit components or soda lime should not hinder induction of or recovery from anesthesia.

Adsorption↗
PubMed1989

Solubility of I-653, sevoflurane, isoflurane, and halothane in human tissues.

Tissue/blood partition coefficients of anesthetics are important indicators of the rate of tissue wash-in and wash-out, and wash-in and wash-out are determinants of the rates of induction of and recovery from anesthesia. In the present study of human tissues, we found that the tissue/blood partition coefficients (for brain, heart, liver, kidney, muscle, and fat) for the new anesthetic I-653 were smaller than those for isoflurane, sevoflurane, and halothane (anesthetics listed in order of increasing tissue/blood partition coefficients). For example, the respective brain/blood partition coefficients were 1.29 +/- 0.05 (mean +/- SD); 1.57 +/- 0.10; 1.70 +/- 0.09; and 1.94 +/- 0.17. This indicates that induction of and recovery from anesthesia with I-653 should be more rapid than with the other agents. The finding of a lower tissue/blood partition coefficient for I-653 parallels the previous finding of a lower blood/gas partition coefficient.

Aged↗
PubMed1988

Activation of the adenovirus-2 E2a late promoter during inhibition of protein synthesis by cycloheximide.

The 5' termini of human adenovirus 2 (Ad2) E2a mRNA, which starts at two separate (early and late) promoter regions, were mapped on Ad2 nucleotide sequences with the aid of primer extension analysis and quantitated. In the early stage (6 h) of Ad2 infection of KB cells and 293 cells, E2a mRNA started mostly at the early (75.4 mp) promoter region. When these infected cells were cultured in the presence of cycloheximide from 1 to 6 h postinfection, the transcription from the late (72.2 mp) promoter region increased. Especially in 293 cells, approx. 50% of E2a mRNA started at the late promoter region. We conclude from the results that the activation of the late promoter during infection does not depend on viral DNA replication. Our results suggest the involvement of cellular protein(s) in this activation.

Adenoviruses, Human↗
PubMed1988

Suppression of gastric ulcer induced by stress and HCL-ethanol by intravenously administered metallothionein-II.

A metallothionein isoform metallothionein-II was isolated from the livers of zinc acetate-treated rats. Metallothionein-II, which showed a single band on polyacrylamide gel electrophoresis, was subjected to two kinds of anti-ulcer screening systems. It was shown that intravenously administered metallothionein-II suppressed the formation of rat water-immersion stress- and HCl-ethanol-induced gastric ulcer significantly. The effect may partly be derived from the zinc contained in the metallothionein-II. However, the effect of metallothionein-II was much stronger than that of an equivalent mole of zinc. Apparently, metallothionein-II had an anti-ulcerogenic activity not based on the effect of intrinsic zinc.

Acetates↗
PubMed1988

The piriform cortex is not a direct olfactory relay to the mediodorsal thalamic nucleus in cats and rabbits.

Following injections of horseradish peroxidase into the mediodorsal thalamic nucleus (MD), retrogradely labeled cells were found in various areas in the cat and rabbit. Among these, olfactory-related areas to which the olfactory bulb projects directly or indirectly via the piriform cortex were the olfactory tubercle, amygdala and insular cortex, while no labeled cells were detected in the piriform cortex and endopiriform nucleus in both species. These results indicate that the piriform cortex and endopiriform nucleus do not send their axons directly to the MD.

Amygdala↗
PubMed1988

[Trypanosoma cruzi antibodies in the cerebrospinal fluid: a search using complement fixation and immunofluorescence reactions].

Cerebrospinal fluid (CSF) samples of 200 patients who presented central nervous system (CNS) pathologies were evaluated for antibodies to Trypanosoma cruzi (T. cruzi). The evaluation was made through: complement fixation test (CFT) in 69 patients, indirect (IgG) immunofluorescence test (IFT) in 118, and by CFT and IFT in 13. In 50 cases the IFT has been made also in concentrated (20 X) CSF samples. Results were evaluated in report to CNS pathology, CSF cells and proteins, and tests in the CSF for other CNS infections (syphilis, cysticercosis, schistosomiasis, toxoplasmosis). These tests were based on techniques similar to those adopted for the search of antibodies to T. cruzi, and were conducted concomitantly to tests for T. cruzi in the same CSF sample for everyone of the cases. Antibodies to T. cruzi were found in three patients. The first was a patient committed by the acquired immunodeficiency syndrome (AIDS) in whom there occurred exacerbation of the acute stage of Chagas' disease. The second is a patient who is committed by epilepsy, and an acute stroke occurred in the third patient: Chagas' disease had been previously diagnosed in them through the demonstration of antibodies to T. cruzi in the blood serum.

Animals↗