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Biomedical subjects

N Nagao

Publications and source records attributed to N Nagao.

At least 55 records · Page 3Linked to original sources
PubMed1992

The Kaike triathletes' hematocrit values. With relation to their competition results.

The subjects were 20 male triathletes in the 4th Kaike Triathlon, held in Tottori during 1984. The competitors' hemogram values were estimated at rest, during, and after the competition. The results were related to their competition order by methods of rank correlations and cluster analysis, using the average distance method. The first cluster, including an competition order is composed of hematocrit at rest, after swimming, after bicycling, and after the finish. The rank correlation coefficients between competition order and hematocrit values were significant (p less than 0.05) at each of the four periods, especially after swimming, though the probability is the same. We found that lower hematocrit values correlate with excellent competition results, as the competitors' hematocrit values could be elevated during exercise if their hematocrit values are in the low normal density whilst at rest.

Adult↗
PubMed1991

[Sulfuric acid submicron aerosols induce morphological changes in the central airways in the guinea pig].

We examined the airway injury of the guinea pig exposed to sulfuric acid submicron aerosols (1 mg/m3). The animals were exposed to filtered air (sham control) or to submicrometer-sized sulfuric acid aerosols for 4 hr/day, 6 days/week, with sacrifices after 4 hours, 3 days, 1, 2, and 4 weeks of acid exposure. Light and electron microscopic examinations revealed that epithelial injury such as disappearance of cilia in the central airways was observed and the severity of the injury increased with exposure duration. This experimental study shows that submicrometer particles of sulfuric acid induces significant alterations in the central airways and may be involved in the incidence of asthma attack.

Aerosols↗
PubMed1991

Energy intake profile in the triathlon competition by means of cluster analysis.

The subjects were 18 male triathletes competing in the 4th Kaike Triathlon held at Tottori in 1984. Answers to a questionnaire on dietary and water intake before and during the competition were analysed. Cluster analysis using the average distance method was applied to 21 variables relating to order, age, stature, body weight, total calorie intake and each nutrient element ingested during three periods: after swimming, during cycling and during the marathon. The arrival order was clustered with stature and weight, and its similarity showed 69.7 when the first cluster formed. Age along with carbohydrate, protein or water intake during the marathon formed secondary clusters with order, stature, and weight (similarity: 60.0). In the upper place group, breakfast calories occupied the largest portion of 26.1% and the smallest portion of 17.2% during the marathon running. Furthermore the group ingested more energy than the other groups during cycling.

Adult↗
PubMed1990

[HIV isolation and clinical markers on the seropositive subjects].

We investigated 18 anti-HIV seropositive subjects with respect to the isolation of HIV from peripheral blood mononuclear cells (PBMC) and cellular and serologic markers for progression to AIDS. The subjects included homosexuals and recipients of blood products. Three had AIDS, an asymptomatic subject developed AIDS during the study and 14 of the remaining have remained asymptomatic. HIV was isolated from all AIDS patients and 7 asymptomatic subjects. Moreover HIV was detected significantly sooner in symptomatic patients than in asymptomatic subjects. The reductions in CD4 lymphocytes number and CD4/CD8 ratio, as well as anti-HIV core (p24, p17) antigens negativity correlated with deterioration of clinical symptoms and successful HIV isolation. The isolates from AIDS patients and from an asymptomatic subject who 9 months later developed AIDS were infective and cytotoxic to MT-4 cells, however isolates from asymptomatic subjects were not infective. These findings indicate that disease progression correlates with the appearance of variant viruses that are more infective and cytopathic.

Biomarkers↗
PubMed1990

Epidermal growth factor (EGF) receptors in human chorionic gonadotropin-producing tumor: transplantation in nude mice and the effect of EGF on tumor growth.

We examined the presence and characteristics of epidermal growth factor (EGF) receptors in hCG producing tumors (CC-2-JCK) transplanted in female nude mice. We also examined the in vivo effects of EGF on tumor growth. Specific receptors with apparent dissociation constants of 3.89 x 10(-10) and 1.0 x 10(-9) M and binding capacities of 5.96 x 10(-10) and 1.52 x 10(-9) M/mg protein for EGF have been identified in the hCG-producing tumor. [125I]EGF binding to the tumor tissues was time, temperature, and tissue weight dependent and specific. EGF and transforming growth factor-alpha (TGF alpha) competed for [125I]EGF binding, with 50% of the bound [125I]EGF displaced by approximately 0.52 nM EGF and 3.10 nM TGF alpha. TGF beta competed for [125I]EGF binding slightly. Five micrograms of EGF caused an increase in the rate of tumor growth, while 50 micrograms EGF strongly inhibited tumor growth. The concentration of [125I]EGF binding in the tumor treated with low doses of EGF was high, and that in the tumor treated with high doses of EGF was low. These changes in EGF binding were attributable to the changes in the number of high affinity EGF receptors with no significant alteration in binding affinity. In conclusion, the existence of high concentrations of EGF receptors with high affinity and specificity to EGF was demonstrated in an hCG-producing tumor transplanted in nude mice and appeared to be correlated with tumor growth.

Animals↗
PubMed1990

[The relationship between alveolar apertures and alveolar size and smoking history in humans, and experimental studies on air pollutants].

Using surgical specimens from patients with lung tumor, alveolar apertures and alveolar sizes were quantitatively assessed using scanning electron microscopy. Compared with smoking habits, increased apertures, defined as alveolar destruction were observed in patients smoking more than 35 years, whereas alveolar size was increased in patients, with a 15-year smoking history. Experimental studies with exposure to NO2, O3 and H2SO4 mist showed that exposure of NO2 and H2SO4 could induce epithelial injury such as disappearance of cilia in the central airways.

Adult↗
PubMed1989

N-acetylation in chitosan and the rate of its enzymic hydrolysis.

Partially N-acetylated derivatives (degree of substitution (d.s.) 0.2, 0.4, 0.6 and 0.8 for N-acetyl) of chitosan were prepared from prawn shell chitosan, and their susceptibility towards a lysozyme from hen egg-white, three microbial chitinases and a chitinase from potato skins was examined. The partially N-acetylated derivatives (d.s. 0.4-0.8 for N-acetyl) were 1.5-4.0 times more digestible than N-acetylchitosan (d.s. 1.0 for N-acetyl), and their enzymic hydrolysis rate is controlled by the d.s. for N-acetyl group. These data suggest that chitosan is usable as a digestible material in the biomedical and biotechnological fields.

Acetylation↗
PubMed1989

New approach to eliminate HLA class I antigens from platelet surface without cell damage: acid treatment at pH 3.0.

A new method was studied for eliminating HLA class I antigens from the surface of platelets without damaging the cells. Platelets were exposed to an acid solution (pH 3.0) to eliminate the antigenicity of HLA class I antigens. The reduction in antigenicities of HLA class I common antigen and individual HLA class I antigens by acid treatment was marked. Patients' sera which contained multispecific HLA antibodies reacted with PBS-treated platelets, but not with acid-treated platelets. No changes were observed in the antigenicities of glycoprotein Ib or glycoprotein IIb/IIIa. The viability of acid-treated platelets was 83%. Ultrastructural investigations revealed no significant difference between the PBS-treated platelets and acid-treated platelets. The platelet function studies showed that the aggregation of acid-treated platelets induced by various agonists was only slightly reduced compared with PBS-treated platelets. We propose that acid-treated platelets are promising for clinical use in patients refractory to platelet transfusions and may be superior to chloroquine-treated platelets for analysis of the specificity of antiplatelet antibodies.

Blood Platelets↗
PubMed1988

[Cases of severe methyl bromide poisoning residing above a warehouse].

Methyl bromide has been widely used in Japan to fumigate grains and wood. One death and 3 cases of hospitalization resulted from exposure to methyl bromide at place of residence. These 4 cases were not employed and were members of one family living above a warehouse, the ground level of this building was a warehouse where herbs were stored and the second floor was their living area. On the 13th of May 1978 at 7:00 p.m., the herbs were fumigated with methyl bromide gas. The fumigator used 15 kg of methyl bromide (2 cylinders), a quantity far greater than usual. It is assumed that the concentration in the warehouse was between 10,000-15,000 ppm. Early in the morning on the 16th of May (3 days later), one of the family members, a 12-year-old girl, developed severe convulsions, and later 2 others also had severe convulsions, while the other suffered from marked mental confusion. The serum or plasma bromide ion level ranged from 280 to 600 ppm. The results of the clinical laboratory test showed that GOT exceeded the normal level in 3 out of the 4 cases. Moreover, LDH activity was above the normal range in 3 cases and CPK activity was increased in all the cases.

Adult↗
PubMed1987

Serum activity of C1 inactivator in Duchenne-type progressive muscular dystrophy.

We previously found that the level of the immunoreactive activity of C1 inactivator in the plasma Duchenne-type patients with progressive muscular dystrophy was lower than that in normal boys. Therefore, we investigated the level of the C1 inactivator inhibiting activity against C1 esterase in the serum from PMD patients. The mean level of anti-esterase activity of C1 inactivator against C1 esterase in the serum from PMD was 50% lower than that of the control group (P less than 0.05).

Adolescent↗
PubMed1987

[A simple determination method of bromide ion in plasma of methyl bromide workers by head space gas chromatography].

An improved method for the simple determination of bromide ion in plasma is described. It was modified from the method by Kawai, Sugiyama et al. (1985). In the improved method, 200 microliters of plasma and 800 microliters of distilled water were placed in a reaction vial to which 100 microliters of dimethyl sulfate was added. The reaction vial was immediately sealed, placed in an incubator at 85 degrees C, and shaken for 10 min. At the end of the reaction, a gas-tight syringe was used to draw out the head space gas of 1 ml. The methyl bromide gas was then injected into a gas chromatograph and methyl bromide was determined with F.I.D. A good linear relationship was obtained between the peak area of methyl bromide and the concentration of bromide ion within the range of 0.5 to 500 ppm. Bromide ion in the range of 0.5 to 500 ppm in standard solution was added to the plasma samples. After 10 repeated measurements, the relative standard deviation was found to be in the range of 2.8-3.6% and recovery was over 96%. The analytical results of this method were compared with those obtained by spectrophotometry. The analytical results obtained by the two methods were in good agreement (r = 0.9669) in plasma samples of 10 methyl bromide workers. A study to determine bromide ion concentration in 39 methyl bromide workers was made and the results were compared with those observed in 100 workers (control group) not exposed to methyl bromide.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromides↗