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Biomedical subjects

N Yasuda

Publications and source records attributed to N Yasuda.

At least 181 records · Page 10Linked to original sources
PubMed1991

[Immunohistochemical investigation on expression of cytokeratins in normal epithelium, precancerous lesions and carcinomas of the hypopharynx].

In order to obtain a more objective method to evaluate epithelial disorders and carcinomas of the hypopharynx, the expression pattern of cytokeratins (CKs) was investigated by ABC technique using several kinds of monoclonal antibodies that react monospecifically with each subclass of CKs. In normal epithelia, CK-19 was strongly positive in the basal layer but apparently reduced in suprabasal layers and completely negative in superficial layers, while CK-13 showed a striking contrast to CK-19, being expressed within the whole thickness of epithelia except only in the basal layer. These 2 subclasses were also observed in "abnormal" epithelia, and characteristic changes of their combination were demonstrated in proportion to the histological gradings. In invasive carcinomas, CK-19 was strongly positive in all carcinoma cells of poorly differentiated carcinomas. It was sporadically positive in moderately differentiated carcinomas, the more differentiated the more sporadic. It was completely negative in well differentiated carcinomas. CK-13, on the other hand, was negative in poorly differentiated carcinomas but positive in keratinized cells of moderately or well differentiated carcinomas. Strong expression of CK-1 was observed only in well keratinized cells of hyperkeratotic epithelia and well differentiated carcinomas. These characteristic findings are consistently observed in all samples and, then, may be useful in evaluating epithelial disorders and carcinomas of the hypopharynx, when used in conjunction with standard histological techniques. It seems most likely that these results play a part in investigating normal and abnormal processes of cell differentiation.

Carcinoma, Squamous Cell↗
PubMed1991

Abnormal structure of the canine oncogene, related to the human c-yes-1 oncogene, in canine mammary tumor tissue.

Cellular oncogenes of genomic DNA in 6 canine primary mammary tumors were screened by Southern blot analysis, using 7 oncogene probes. A canine genomic oncogene related to the human c-yes-1 oncogene was detected as abnormal bands in solid carcinoma genomic DNA digested with EcoRI, HindIII, HindIII-EcoRI, or HindIII-BamHI. Comparison was made between other tumor specimens and control specimens obtained from 4 clinically normal dogs--1 mixed breed and 3 Shiba Inu dogs (the same breed as the dog from which the solid carcinoma was obtained). These abnormal bands were 0.1 to 1 kilobase shorter than the normal gene. However, digestion of genomic DNA obtained from normal WBC of this dog also produced all of the abnormal bands as observed in digested DNA from the solid carcinoma tissue. Therefore, in this dog, the genomic DNA of all somatic cells from the ontogenic stage still had the abnormal sequences related to the human c-yes-1 oncogene, and it is possible that this abnormal structure may have some role (eg, as an initiator) in tumorigenesis or the progression of this tumor.

Animals↗
PubMed1991

[Detection of pulmonary tuberculosis. Special characteristics of patients detected while receiving treatment for other diseases].

Tuberculosis (TB) detection is mainly classified as being either passive case-finding, at a hospital, or positive case-finding through a mass screening. Pulmonary TB patients detected while being examined for other complaints at a hospital are classified as passive findings. It is suspected that these patients have special characteristics which separate them from patients that are detected only after the onset of TB symptoms. The aim of this study is to elucidate those special characteristics of patients where detection occurred while being examined for other diseases by comparing them with patients detected by the other means. A survey was conducted on 686 pulmonary TB patients, diagnosed between 1986 and 1988, from the area served by the Kochi Prefectural Chuo Health Center, with the following results. 1) Among the 533 patients who were detected at a hospital, and excluding those detected by mass screening, 331 patients were detected only after the onset of TB symptoms (group B), with 202 patients being treated for other diseases before being diagnosed as having TB (classified as group A). In group A, 130 patients were detected because of manifesting additional symptoms related to tuberculosis such as fever and cough (group A-1), while the remaining 72 patients were detected by chance while being examined for other diseases (group A-2). 2) The number of elderly people and relapse cases was higher in group A compared to B group and the group detected by mass screening. 3) Symptoms, the rate of tubercle bacillus positives, and the period from the onset of symptoms to diagnosis (defined delay) in group A-1, were similar to group B. In group A-2, symptoms and the rate of tubercle bacillus positives were less than those of the other groups. 4) From the above findings, it is concluded that passive case-findings should be classified into 3 distinct groups.

Adolescent↗
PubMed1991

Cardiovascular actions of desflurane in normocarbic volunteers.

The cardiovascular actions of three concentrations of desflurane (formerly I-653), a new inhalation anesthetic, were examined in 12 unmedicated normocapnic, normothermic male volunteers. We compared the effects of 0.83, 1.24, and 1.66 MAC desflurane with measurements obtained while the same men were conscious. Desflurane caused a dose-dependent increase in right-heart filling pressure and a decrease in systemic vascular resistance and mean systemic arterial blood pressure. As measured by echocardiography, left ventricular end-diastolic area did not change except for a small increase at 1.66 MAC desflurane, and systolic wall stress was less at all concentrations of desflurane than during the conscious state. Desflurane did not change cardiac index or left ventricular ejection fraction. Heart rate did not change at 0.83 MAC, but progressively increased with deeper desflurane anesthesia. Stroke volume index was less at all concentrations of desflurane than while the men were conscious, but desflurane did not alter the velocity of ventricular circumferential fiber shortening. Mixed venous blood PO2 and oxyhemoglobin saturation were higher during all concentrations of desflurane anesthesia than during the conscious state. No volunteer developed a metabolic acidosis. We conclude that desflurane with controlled ventilation and constant PaCO2 causes cardiovascular depression, as indicated by the increased cardiac filling pressure and decreased stroke volume index and by no change in the velocity of circumferential fiber shortening in the presence of decreased systolic wall stress. However, cardiac output is well maintained, and heart rate does not increase at light levels of anesthesia. The cardiovascular actions of 0.83 and 1.66 MAC desflurane were also reexamined in 6 of the 12 men during the seventh hour of anesthesia. Prolonged desflurane anesthesia resulted in lesser cardiovascular depression than was evidenced during the first 90 min. The measures of cardiac filling (central venous pressure and left ventricular end-diastolic cross-sectional area) did not differ between the early and late periods of anesthesia. Systemic vascular resistance decreased further during the late period, but systolic wall stress did not differ between the two time periods. During the seventh hour of desflurane anesthesia, heart rate and cardiac index were higher at both anesthetic concentrations than during the first 90 min of anesthesia. Left ventricular ejection fraction and velocity of fiber shortening did not change with duration of desflurane anesthesia. Oxygen consumption, oxygen transport, the ratio of the two, mixed venous PO2, and mixed venous oxyhemoglobin saturation (SO2) increased late in the anesthetic in comparison with the first 90 min.

Adult↗
PubMed1991

Cardiovascular actions of desflurane with and without nitrous oxide during spontaneous ventilation in humans.

We investigated the cardiovascular actions of desflurane (formerly I-653) during spontaneous ventilation. We gave 0.8-0.9, 1.2-1.3, and 1.6-1.7 MAC desflurane in oxygen (n = 6) and in 60% nitrous oxide, balance oxygen (n = 6) to unmedicated healthy male volunteers. Both anesthetic regimens decreased ventilation, increased partial pressure of arterial carbon dioxide, and produced similar cardiovascular changes. In comparison with values obtained when the volunteers were conscious, desflurane anesthesia with spontaneous ventilation decreased systemic vascular resistance and mean arterial blood pressure. Cardiac index, heart rate, stroke volume index, and central venous blood pressure increased. Left ventricular ejection fraction increased at 0.83 MAC desflurane in oxygen, and otherwise did not differ from the conscious value. The velocity of ventricular circumferential fiber shortening, estimated by echocardiography, increased with desflurane in oxygen but did not change with desflurane in nitrous oxide. Oxygen consumption increased during desflurane and oxygen anesthesia, but not when nitrous oxide plus oxygen was the background gas. Desflurane increased oxygen transport, the ratio of oxygen transport to oxygen consumption, mixed venous partial pressure of oxygen, and oxyhemoglobin saturation. The cardiovascular changes with desflurane during spontaneous ventilation differ from those during controlled ventilation. With both background gases, spontaneous ventilation, in comparison with controlled ventilation, increased cardiac index, stroke volume, central venous pressure, left ventricular ejection fraction, velocity of circumferential fiber shortening, oxygen transport, and the ratio of oxygen transport to oxygen consumption but did not change mean arterial blood pressure except at 1.66 MAC desflurane in oxygen (when it was higher with spontaneous than with controlled ventilation).

Administration, Inhalation↗
PubMed1991

[Increased polyamine levels of normal-appearing mucosa and cancers in DMH induced cancer-bearing colon in rats].

Polyamine levels (putrescine, spermidine, spermine) in normal-appearing colonic mucosa of DMH administrated rats were measured in order to assess their importance as markers of precancerous changes. Mean putrescine, spermidine and spermine levels of normal-appearing mucosa were more than three times mean putrescine, more than twice mean spermidine and more than 1.5 times mean spermine levels of normal colonic mucosa. Mean polyamine levels of colon cancers were higher than those of normal-appearing mucosa but only spermidine level was significantly different between them. The mucosal polyamine levels may be a good biochemical marker to detect precancerous changes. There was no correlation between the polyamine levels and the growth rate of the colon cancers.

Animals↗
PubMed1991

[Solubility of desflurane (I-653), sevoflurane, isoflurane, and halothane in human blood].

The blood/gas partition coefficients for the new volatile anesthetic agent desflurane (I-653), sevoflurane, isoflurane, and halothane were determined, simultaneously, in 8 human volunteers to compare the solubilities of these agents in blood. The blood/gas partition coefficient for desflurane [0.49 +/- 0.03 (mean +/- SD)] was smallest, followed by sevoflurane (0.62 +/- 0.04), isoflurane (1.27 +/- 0.06), and halothane (2.46 +/- 0.09). Differences among the anesthetic agents were significant (P less than 0.001). The results of this study confirm that among these agents the solubility of desflurane in human blood is the smallest. The results suggest that the washin and washout of desflurane will be more rapid than that of sevoflurane, isoflurane, and halothane, and the washin and washout of sevoflurane will be more rapid than that of isoflurane and halothane.

Adult↗
PubMed1991

[Raised polyamines in erythrocytes of DMH administrated rats with colonic cancers and those relationship to tumor volume].

The objective of this study was to assess, in a controlled experimental system, whether the concentrations of polyamines (Pa) in urine or erythrocytes increase during the process of colon carcinogenesis in rats, and whether such changes reflect tumor volume. Colon carcinoma was induced in Sprague-Dawley rats by subcutaneous injection of 1, -2 dimethylhydrazine (DMH). 24-hour urine and blood samples were collected and analysed for their Pa consent, with high pressure liquid chromatographic method. The levels of any Pa derivatives in either urine or erythrocytes at 32 weeks after the administration of DMH were not significantly high compared with the control group at the same week. However, certain increases of Pa in erythrocytes were observed in the levels of putrescine (1.3 times), spermidine (1.3 times), and spermine (1.5 times) respectively compared with the control group and there were high positive correlations between tumor volume and the levels of each Pa derivatives. On the ground of the results, Pa in erythrocytes seems to be the sensitive parameter for tumor volume compared with Pa in urine.

1,2-Dimethylhydrazine↗
PubMed1990

Characterization of an internal-surface reversed-phase silica support for liquid chromatography and its application to assays of drugs in serum.

Internal-surface reversed-phase (ISRP) silica supports having N-octanoylaminopropyl phases bound to the internal surfaces of the porous silica and N-(2,3-dihydroxypropyl)aminopropyl phases bound to the external surfaces were synthesized from silica particles differing in nominal pore diameters and specific surface areas. These ISRP supports were characterized with regard to physical and chromatographic properties. The support with an N-octanoylaminopropyl phase coverage of 485 mumol/g and an average pore diameter of 65 A was the most suitable for the direct-injection determination of hydrophilic or hydrophobic drugs in serum or plasma. Non-steroidal anti-inflammatory (acetylsalicylic acid and salicylic acid) and tricyclic antidepressant drugs (desipramine and nortriptyline) in serum were successfully determined with this support and an acidic eluent.

Aspirin↗
PubMed1990

An enzyme-linked immunosorbent assay for the detection of antitetanus toxoid antibody using aluminum-absorbed coating antigen.

An enzyme-linked immunosorbent assay (ELISA) for the detection of antitetanus antibodies was developed using aluminum-absorbed tetanus toxoid as the coating antigen. The assay was tested by measuring antitetanus antibody levels in serum obtained from subjects before and after immunization with the aluminum-absorbed tetanus suspension. The specificity of the antibodies for tetanus antigen was tested both before and after antitetanus activity was removed with tetanus antigen-coated beads. Also, the activities of the sera were compared with those of a commercially available test. Our results indicated that the aluminum-absorbed tetanus suspension can be coated onto standard polystyrene ELISA plates and used to measure antibody titers to tetanus toxoid.

Absorption↗
PubMed1990

Parapharyngeal meningioma extending from the intracranial space.

A 50-year old woman with a giant parapharyngeal meningioma extending from the intracranial cavity was admitted to our hospital. The parapharyngeal tumor was biopsied using the transoral approach and a histological section diagnosis suggested meningioma. Thereafter, further examination by magnetic resonance images (MRI) and contrast enhanced CT scans revealed a diffuse meningioma en plaque in the posterior fossa. Invasion extended from the clival dura to the right sigmoid sinus. The extracranial extension of a meningioma is very rare but a few cases have been reported. In almost all of the reported cases, a large intracranial meningioma was simultaneously or previously verified by CT scans. Our case was special in that the intracranial mass was not voluminous but showed en plaque extension, and also because the pathway of the extracranial extension through the jugular foramen was clearly visualized by CT and MRI. Obliteration and invasion of the right sigmoid sinus and the internal jugular vein by tumor were also demonstrated.

Female↗
PubMed1990

Absence of abundant binding sites for anesthetics in rabbit brain: an in vivo NMR study.

Using magnetic resonance spectroscopy, the authors tested whether cerebral concentrations of inhaled anesthetics do not increase proportionately at inspired concentrations exceeding 3% 1) because anesthetics bind to and saturate specific sites in the brain or 2) because anesthetic-induced depression of ventilation limits the increase in alveolar anesthetic partial pressure. New Zealand White rabbits were anesthetized with methohexital, 70% nitrous oxide, and local infiltration of 1% lidocaine. Cerebral concentrations of anesthetic were determined from 19F spectra acquired with nuclear magnetic resonance (NMR). Inspired, end-tidal, and arterial anesthetic concentrations, and end-tidal and arterial partial pressure of carbon dioxide were measured. Blood/gas partition coefficients were determined and used to convert arterial anesthetic concentration to partial pressures. In seven spontaneously breathing animals, halothane (1%; n = 5) or isoflurane (0.8%; n = 2) was administered at a constant inspired concentration for 20 min; NMR spectra were acquired between 10 and 20 min. Thereafter, the inspired concentration was increased and the process repeated until apnea occurred. Two additional rabbits were anesthetized with isoflurane and studied similarly but with higher inspired concentrations during mechanical ventilation. In spontaneously breathing animals, ventilatory depression occurred, documented by marked increases in PaCO2, and cerebral concentrations of anesthetic did not increase proportionately at inspired concentrations exceeding 3%. In contrast to an absence of a correlation of inspired and cerebral concentrations during spontaneous ventilation, arterial and cerebral concentrations correlated linearly during both spontaneous and mechanical ventilation (R2 greater than 0.969). These results are consistent with depression of ventilation, rather than binding to specific cerebral sites as an explanation for the nonlinear relationship between cerebral and inspired anesthetic concentrations.

Animals↗
PubMed1990

Cardiovascular actions of common anesthetic adjuvants during desflurane (I-653) and isoflurane anesthesia in swine.

To determine the cardiovascular actions of drugs commonly combined with inhalation anesthetics, we administered one drug from each of several classes of adjuvants to seven swine already anesthetized with equipotent concentrations (1.2 MAC) of desflurane, formerly I-653, a new inhaled anesthetic, or isoflurane. Succinylcholine (1 and 2 mg/kg), atracurium (0.6 mg/kg), and atropine (5 micrograms/kg) plus edrophonium (5 mg/kg) had no cardiovascular effects. Fentanyl was given in amounts that decreased MAC for the inhaled anesthetics by 25%-35%. A dose of 50 micrograms/kg IV had no cardiovascular effects during either anesthetic, whereas 100 micrograms/kg IV modestly increased systemic vascular resistance without changing other variables. Naloxone (100 micrograms/kg IV) during infusion of fentanyl decreased systemic vascular resistance and increased cardiac output during both desflurane and isoflurane anesthesia, increased heart rate during only isoflurane anesthesia, and did not affect mean arterial blood pressure during either anesthetic. Thiopental (2.5 and 5.0 mg/kg IV) decreased mean aortic blood pressure, cardiac output, stroke volume, and systemic vascular resistance during both anesthetics without altering heart rate or left- or right-sided cardiac filling pressures. The addition of 60% nitrous oxide caused no cardiovascular changes during desflurane anesthesia, but increased systemic vascular resistance and decreased cardiac output and stroke volume during isoflurane without altering heart rate or cardiac preload. We conclude that the usual clinical doses of adjuvants commonly administered during anesthesia have no untoward cardiovascular actions during 1.2 MAC desflurane or isoflurane anesthesia in swine.

Adjuvants, Anesthesia↗
PubMed1990

Pharmacokinetics of desflurane, sevoflurane, isoflurane, and halothane in pigs.

We tested the prediction that the alveolar washin and washout, tissue time constants, and pulmonary recovery (volume of agent recovered during washout relative to the volume taken up during washin) of desflurane, sevoflurane, isoflurane, and halothane would be defined primarily by their respective solubilities in blood, by their solubilities in tissues, and by their metabolism. We concurrently administered approximately one-third the MAC of each of these anesthetics to five young female swine and determined (separately) their solubilities in pig blood and tissues. The blood/gas partition coefficient of desflurane (0.35 +/- 0.02) was significantly smaller (P less than 0.01) than that of sevoflurane (0.45 +/- 0.02), isoflurane (0.94 +/- 0.05), and halothane (2.54 +/- 0.21). Tissue/blood partition coefficients of desflurane and halothane were smaller than those for the other two anesthetics (P less than 0.05) for all tissue groups. As predicted from their blood solubilities, the order of washin and washout was desflurane, sevoflurane, isoflurane, and halothane (most to least rapid). As predicted from tissue solubilities, the tissue time constants for desflurane were smaller than those for sevoflurane, isoflurane, and halothane. Recovery (normalized to that of isoflurane) of the volume of anesthetic taken up was significantly greater (P less than 0.05) for desflurane (93% +/- 7% [mean +/- SD]) than for halothane (77% +/- 6%), was not different from that of isoflurane (100%), but was less than that for sevoflurane (111% +/- 17%). The lower value for halothane is consistent with its known metabolism, but the lower (than sevoflurane) value for desflurane is at variance with other presently available data for their respective biodegradations.

Anesthetics↗
PubMed1990

[Prognostic significance of the DNA ploidy of the early glottic cancer].

The stage classification is most frequently used at the present in predicting the outcome of laryngeal carcinoma. Recently, DNA ploidy pattern as detected by DNA flow cytometry and cytofluorometry has been also shown to be predictive. In this study, DNA cytofluorometry was performed on formalin-fixed paraffin-embedded tissues from 18 patients with T1 and T2 glottic squamous cell carcinoma for whom long-term follow-up data were available. The DNA ploidy pattern was classified into three types, diploid, diploid + tetraploid and aneuploid according to the DNA content of Go/G1 cells and mitotic cells. In these 18 cases, 8 cases (44%) had diploid pattern, 3 cases (17%) had the diploid + tetraploid pattern and 7 cases (39%) had the aneuploid pattern. The ploidy pattern was significantly associated with the relapse-free rate, but did not correlate with the stage of the carcinoma and differentiation of the cancer cells. Distribution of the patients by histology, stage and therapy was almost equal among the diploid, diploid + tetraploid and aneuploid groups. All the patients were treated with irradiation (60Gy). In the group as a whole, no patient died of glottic carcinoma. Relapse-free survival rates for diploid, diploid + tetraploid and aneupoid were 88%, 33% and 29% respectively. This retrospective study of glottic cancer treated with radiation therapy suggests the possibility that the DNA ploidy pattern would significantly predict patient outcome and would be useful for selecting patients whose poor prognosis demands more aggressive therapy.

Aged↗