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Biomedical subjects

K Yamamura

Publications and source records attributed to K Yamamura.

At least 271 records · Page 15Linked to original sources
PubMed1986

Effect of lead on electrophoretic mobility of rat erythrocytes.

Lead often affects the erythrocyte membrane. The relationship between the changes in erythrocyte membrane and the anemia caused by lead is still unclear. Initially, the effect of lead injected intraperitoneally on the electrophoretic mobility of rat erythrocytes was investigated in order to study the relationship between them. As indices of lead exposure, hemoglobin (Hb) levels, hematocrits (Ht), delta-aminolevulinic acid dehydratase (ALA-D) activities and blood lead (blood Pb) levels in the injected rats were also examined. Exposure to lead significantly decreased the mobility of rat erythrocytes. The changes in mobility seemed to be less sensitive than those in ALA-D activity, however, the decreases in mobility were simultaneous with or prior to those in Hb level and Ht. The decreases in mobility were evident to some extent below a blood Pb level of 100 micrograms/100 ml and generally present at a level of 100 micrograms/100 ml and over. In the rats exposed to lead a significant negative correlation was found between the mobilities and the logarithms of blood Pb level.

Animals↗
PubMed1986

Cell-type-specific and regulated expression of a human gamma 1 heavy-chain immunoglobulin gene in transgenic mice.

A functionally rearranged human gamma 1 heavy-chain immunoglobulin gene was cloned from a human plasma cell leukemia cell line, ARH-77, into the phage lambda Charon 4A. The recombinant phage DNA was introduced into fertilized mouse eggs (about 200 copies of the human gene per egg). A total of 30 mice were born and were screened for the presence of the human gamma 1 gene by dot hybridization. Two of these 30 mice had integrated one or two copies of the gene. The gamma 1 mRNAs were detected only in spleen. Levels of gamma 1 mRNA and the percentage of spleen cells producing human gamma chain increased up to 50-fold after treatment with bacterial lipopolysaccharide (a B-cell mitogen) but not with concanavalin A (a T-cell mitogen), suggesting B-cell-specific and regulated expression of the human gamma 1 heavy-chain gene. Human gamma chain-producing cells were found only in the periphery of the germinal center of the white pulp in histological sections of the spleen but not in sections of other tissues. Human gamma chains appeared to be coupled with mouse light chains to form a complete IgG molecule and were secreted into the cell supernatant. The production and secretion of endogenous immunoglobulin heavy and light chains in transgenic mice appeared to be the same as in normal mice. About one-seventh of the spleen cells that produced endogenous mouse heavy chains also produced human gamma chains, but no cells that produced only human gamma chain were observed.

Animals↗
PubMed1985

High-performance liquid chromatographic assay of antiinflammatory drugs incorporated in gel ointments. Separation and stability testing.

High-performance liquid chromatographic determinations of gabexate mesilate (FOY), prostaglandin E1 (PGE1), PGE1-alpha-cyclodextrin (PGE1-CD), prednisolone (PD) and butyl flufenamate (BF) incorporated in gel ointment were investigated. The gel ointment is composed of a carboxy vinyl polymer (1.3%, w/w) and a large amount of an aqueous organic solvent. A methanol extraction system offered simultaneous advantages of the removal of the polymer and the recovery of active ingredients from the gel phase. The recoveries of the drugs were 100%. The stabilities of PGE1, PGE1-CD, FOY, PD and BF incorporated in gel ointment, stored at 5, 25 and 40 degrees C for up to 90 days, were investigated.

Alprostadil↗
PubMed1985

Cell fusion studies in the Werner syndrome.

The mechanism of retarded DNA synthesis was investigated by the cell fusion method. The [3H] TdR labeling index of young cells from patients with Werner syndrome (WS cells) X young normal human diploid fibroblast cells (NH cells) was considerably lower than that of NH homodikaryons, but was significantly higher than that of WS homodikaryons. The labeling index of old WS X young NH heterodikaryons was as low as that of WS homodikaryons. The labeling index of WS X HeLa heterodikaryons was the same as that of HeLa homodikaryons. These results indicate that WS cells are somewhat similar to senescent NH cells. The labeling indices in both WS karyoplast X NH heterodikaryons and WS cytoplast X NH cybrids were lower than those in normal karyoplast X NH heterodikaryons and normal cytoplast X NH cybrids, respectively. These results indicate that both nuclear and cytoplasmic environments are involved in the retarded DNA synthesis in WS cells. The most plausible interpretation of all our data is that the retarded DNA synthesis in WS cells could be caused by either the 'senescent factor(s)' or the deficiency of gene product(s) that is necessary for DNA synthesis and could be a secondary consequence of the genetic defect.

Adult↗
PubMed1985

Electrophoretic variants of blood proteins in Japanese. IV. Prevalence and enzymologic characteristics of glucose-6-phosphate dehydrogenase variants in Hiroshima and Nagasaki.

Electrophoretic screening of glucose-6-phosphate dehydrogenase (EC 1.1.1.49, G6PD) was conducted one sample of 9,260 children born to the atomic bomb survivors in Hiroshima (Honshu) and Nagasaki (Kyushu). The prevalence of electrophoretic variants was 0.11% in males and 0.42% in females in Hiroshima, and 0.16% in males and 0.31% in females in Nagasaki. Enzymologic characteristics of 10 variants obtained from three males and seven hemizygous fathers of heterozygous females were examined. As a result, three new types of G6PD variants were identified among five variants detected in Hiroshima, and three new types among five variants in Nagasaki. All the variants except one belonged to Class 3, as defined by Yoshida et al. (1971).

Adolescent↗
PubMed1985

A study of zinc distribution in erythrocytes of normal humans.

The assignment of zinc bound to carbonic anhydrase isoenzymes (CA-I and CA-II) and Cu2 Zn2 superoxide dismutase (SOD1) was investigated in the hemolysates from 21 normal male subjects. Sufficient care was taken to remove leukocytes and platelets. The following values of zinc distribution were obtained: total zinc, 113.8 +/- 22.7 (mean +/- S.E.) micrograms X 100 ml-1; CA-I-derived zinc, 866.6 +/- 26.2 micrograms X 100 ml-1; CA-II-derived zinc, 99.9 +/- 3.9 micrograms X 100 m-1; SOD1-derived zinc, 60.3 +/- 1.9 micrograms X 100 ml-1; the other zinc, 87.0 +/- 12.6 micrograms X 100 ml-1. Namely, 7.6% of the zinc in human erythrocytes is not bound to the carbonic anhydrases and Cu2Zn2 superoxide dismutase, but present in available form or attached to other enzymes.

Adult↗
PubMed1985

Introduction of mouse C epsilon genes into Cos-7 cells and fertilized mouse eggs.

A fragment of the cloned gene for the mouse C epsilon chain, coding for the first, second, third, and fourth domains, has been coupled to the SV40 promotor region (pSV2-mC epsilon). About 50 copies of pSV2-mC epsilon or its PvuII-EcoRI fragments were introduced into Cos-7 cells. Expression of PvuII-EcoRI fragments of pSV2-mC epsilon was observed in about 50% of the Cos-7 cells by indirect fluorescence staining. However, no expression of circular pSV2-mC epsilon was observed. About 200 copies of linearized pSV2-mC epsilon with EcoRI were introduced into fertilized mouse eggs. Two of 78 mice born from these eggs had integrated mouse C epsilon genes. Mouse C epsilon gene was shown to be integrated in a tandem array and as intact structures without undergoing gross deletions or rearrangements, judged from the Southern blotting patterns from several restriction enzymes. The first transgenic mouse was mated to a normal male to examine whether mouse C epsilon gene were stably transmitted to progeny. Among 5 mice to which the C epsilon gene had been transmitted, one deleted 5 copies of this gene and another deleted one junction fragment, thus demonstrating relatively unstable transmission. No C epsilon mRNA was detected in the liver, kidney, brain, lung, skeletal muscle, heart, testis, or spleen of a transgenic mouse.

Animals↗
PubMed1985

Exercise-induced changes in blood zinc and related proteins in humans.

Effects of cycle ergometer exercise (approximately 75% maximum ventilatory O2 consumption for 30 min) on the concentrations of zinc and related proteins in erythrocytes and/or plasma were studied on 11 sedentary male students. Lower concentrations of total zinc and of zinc derived from carbonic anhydrase I type (CA-I) in erythrocytes were observed immediately after exercise, but they disappeared after 30 min of rest. The change in total zinc concentration in erythrocytes correlated well with that in CA-I concentration immediately after exercise, as well as after rest. The concentration of carbonic anhydrase II type (CA-II)-derived zinc did not vary substantially at any time. On the other hand, there were significant increases in the plasma concentrations of total zinc and of alpha 2-macroglobulin (alpha 2-MG)-bound zinc immediately after exercise, whereas no such effect was noted in albumin-bound zinc. A positive correlation was found between total zinc and alpha 2-MG concentrations in plasma immediately after exercise. In addition, the change in the activity of alkaline phosphatase, a zinc metalloenzyme, correlated well with that in the total zinc concentration in plasma. These results suggest that a brief physical exercise induces the movement of zinc into plasma.

Adult↗
PubMed1984

High-performance liquid chromatographic assay for prostaglandin E1 in various ointment vehicles. Separation and stability testing.

A high-performance liquid chromatographic method for the determination of prostaglandin E1 (PGE1) incorporated in white petrolatum, white ointment, hydrophilic petrolatum and Plastibase was investigated. The prostaglandin was separated from the oleaginous vehicles with n-hexane-aqueous acetonitrile. Most of white petrolatum, which is a principal component in the vehicles, remained in the n-hexane layer, and the recovery of the drug from any vehicle attained 100%. The method was applied to stability studies of PGE1 in white petrolatum and macrogol ointment. In which pure PGE1 and PGE1-alpha-cyclodextrin complex (PGE1-CD) were incorporated. The drug remained intact for up to 6 months when stored at 5 degrees C. At 25 and 40 degrees C, pure PGE1 was more stable than PGE1-CD and both PGE1 species were more stable in white petrolatum than in macrogol ointment.

Alprostadil↗
PubMed1984

The levels of superoxide dismutase, catalase, and carbonic anhydrase in erythrocytes of patients with Down's syndrome.

The levels of cytoplasmic superoxide dismutase ( SOD1 ), catalase (CAT'ase), and carbonic anhydrase isoenzymes (CA-B and CA-C) were determined in the erythrocytes from 11 male patients with Down's syndrome. The levels of SOD1 and CAT'ase, as well as CA-B showed significant increases compared with those in normal controls, whereas the CA-C level did not change substantially. In addition, a positive correlation was noted between the levels of SOD1 and of CAT'ase (r = 0.764).

Adolescent↗
PubMed1984

Effects on cochlear microphonics in guinea pigs induced by prolonged exposure to low-frequency sound.

The effects on CM induced by 46.5 h exposure to low-frequency sound of 0.125 kHz at 115 dB (SPL) and 100 dB (SPL), which frequency is considered to be in the vicinity of the lowest limit of audiofrequency for guinea pigs, were investigated by the sound pressure levels at which CM output voltages produced 50 microV (50 microV isopotential responses) at test frequencies of 0.06, 0.08, 0.12, 0.18, 0.25, 0.5, 1, 2, and 4 kHz, and by the intensity function measured from 65 to 120 dB (SPL) at test frequencies of 0.06, 0.08, 0.12, 0.18, 0.25, 0.5, 1, and 2 kHz. The results obtained were as follows. In 50 microV isopotential responses measured at about 30 min after the termination of sound exposure, the mean dB in the 115 dB-exposed group tended to elevate at all test frequencies of 0.06 kHz to 4 kHz as compared with those in the control group. Significant dB elevations were especially observed at 0.06, 0.12, 1, 2, and 4 kHz. In the 100 dB-exposed group, however, no significant dB elevations were observed at any test frequencies as compared with those in the control group. In the intensity function measured at about 40-60 min after the termination of sound exposure, the mean output voltages in the 115 dB-exposed group induced by test stimuli of 0.18 kHz-2 kHz at higher intensities showed significant depression in comparison with those in the control group (by over 110 dB at 0.18 and 0.25 kHz, and by over 90 dB at 1 and 2 kHz).(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗