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Biomedical subjects

M Aihara

Publications and source records attributed to M Aihara.

At least 217 records · Page 12Linked to original sources
PubMed1985

Short term disposition of soluble vs. insoluble forms of cadmium in rat lung after intratracheal administration: an autoradiographic assessment.

An autoradiographic study was undertaken to compare the initial distribution patterns of soluble and less soluble forms of cadmium in the rat lung after intratracheal (i.t.) instillation. Male Sprague--Dawley rats were divided into 2 groups, each group received either soluble or a less soluble cadmium (109Cd) i.t. in 0.1 ml buffered saline. At 5, 30 and 90 min post-instillation, rats were sacrificed and processed for autoradiography, and radioactivity estimation of lung sections. 109Cd was unevenly distributed in the lungs at 5 min for both forms of Cd. At 90 min post-instillation, 109Cd was almost evenly distributed in the lung instilled with the soluble form; in case of the less soluble form a spotty distribution of 109Cd in the bronchi was observed. 109Cd was mainly translocated to the liver and stomach, followed by the kidney and intestine. It is apparent that the initial translocation of instilled 109Cd from the lung is relatively slow in the case of less soluble form as compared with the soluble form.

Animals↗
PubMed1985

[Basic and clinical studies on cefminox in obstetrics and gynecology].

Fundamental and clinical studies on cefminox (CMNX, MT-141), a new cephamycin antibiotic, were carried out and the results were as follows. After the intravenous one shot administration of 1 g CMNX to 17 cases, serum concentrations, tissue concentrations in pelvic organs and protein binding capacities in serum were measured. Blood concentrations ranged between 100-200 micrograms/immediately after the injection and declined gradually. Half-life (T1/2) was 75 minutes. Tissue concentrations were 30-70 micrograms/g (tissue weight) 10 minutes after injection and declined. Half-life was 90 minutes. The average serum protein binding rate was 66.3 +/- 8.4%. Correlation between tissue concentration (Y) and free serum concentration (X) was expressed as Y = 0.42 + 7.14X. Correlation coefficient (r) was 0.80 (r = 0.80). Correlation coefficient in serum concentrations between HPLC and bioassay was 0.83 and that in free concentration was 0.97. In clinical studies, CMNX was administered to 19 cases of obstetric and gynecological infections. The patients were constituted of 3 with puerperal endometritis, 3 with pyometra, 3 with pelvic peritonitis, 3 with parametritis, 3 with adnexitis, 2 with BARTHOLIN's abscess and 1 with retroperitoneal abscess and vulva abscess. Overall clinical efficacy was 89.5% (17/19). Bacteriologically 26 strains were isolated, 6 strains of E. coli, 4 strains of B. fragilis, 2 strains of P. anaerobius and P. asaccharolyticus and each one of E. faecalis, S. epidermidis, N. gonorrhoeae, S. marcescens, P. maltophilia, A. calcoaceticus, K. pneumoniae, P. mirabilis, H. influenzae, S. intermedius, E. lentum and F. varium. Twenty of these 24 strains were eliminated after the administration, K. pneumoniae was decreased, E. faecalis, S. marcescens and P. maltophilia remained unaffected. No side effects were observed but 1 case showed mild elevation of transaminases which normalized 1 week after CMNX was stopped.

Adolescent↗
PubMed1984

Platelet-collagen interactions: increase in rate of adhesion of fixed washed platelets by factor VIII-related antigen.

A simple technique using an aggregometer and fixed washed human platelets (FWP) and fibrillar collagen has been used to evaluate the contribution of the two components of the factor VIII (FVIII) complex to platelet-collagen interactions. FWP bound individually to collagen fibrils in suspension, and both the total number of FWP bound and the rate of adhesion increased with increasing collagen concentration. Von Willebrand's disease (vWD) type I or normal plasma immunoadsorbed with anti-factor VIII-related antigen (anti-FVIIIR:Ag) antiserum gave 20% and vWD type IIa gave 50% of the rate of adhesion obtained with normal, hemophilia A, or hemophilia A with inhibitor plasma, but the same percent adhesion was found with all plasmas. The rate of adhesion of both vWD type I and type IIa was corrected by the addition of purified FVIII complex. These results indicated that the FVIIIR:Ag and not the factor VIII coagulant activity (FVIII:C) in normal plasma or purified FVIII complex caused an accelerating effect on the rate at which FWP bound to collagen. Collagen fibrils not only bound FWP, but also adsorbed the FVIII complex with preferential adsorption of the forms of FVIIIR:Ag with the greatest ristocetin cofactor (FVIIIR:RCoF) activity. Saturation of collagen with FWP did not change the adsorption pattern of the FVIII complex. Also anti-FVIIIR:Ag blocked the accelerating effect of the FVIII complex but not the adhesion of FWP. Thus, FWP and FVIIIR:Ag appeared to bind to separate sites on collagen.

Adult↗
PubMed1984

A quantitative method for studying platelet adhesion to collagen.

A simple turbidimetric method is described that permits quantitation of both the number and the rate at which human fixed washed platelets adhere to fibrillar collagen in suspension. Fixed washed platelets were mixed with buffer or test sample in an aggregometer cuvette. Collagen was added, and the change in light transmission was recorded at 37 degrees C. Percent adhesion was obtained from the maximum change in light transmission within 5 minutes, and the adhesion rate was calculated from the initial slope of the adhesion curve. In this system, the percent adhesion was optimal at ionic strengths of 0.1 to 0.15 in a pH range of 7.0 to 8.0. Percent adhesion could be increased either by lowering the platelet number or by increasing the collagen concentration. No adherence of fixed washed platelets to heat-denatured collagen or Cytodex 3 beads was observed. Adhesion rate increased with greater stirring speed, but decreased with increasing concentrations of bovine serum albumin or normal human plasma, but the percent adhesion remained relatively constant. The rate of adhesion in 20% normal human plasma was greater than that in 1% to 4% bovine serum albumin buffer. This suggests that normal plasma contains some factor(s) that can overcome the inhibitory effect of protein on the rate of adhesion of fixed washed platelets to fibrillar collagen.

Blood Platelets↗
PubMed1983

Oligodendroglioma-like cells (clear cells) in ependymoma.

A brain tumor of a 22-year-old man was composed mostly of round cells with perinuclear halos (clear cells), forming clusters intersected by small blood vessels. In some areas, the tumor cells showed perivascular arrangement and epithelial pattern. Phosphotungstic-acid hematoxylin stain and immunoperoxidase stain for glial fibrillary acidic protein (GFAP) technique failed to stain the clear cells. Electron microscopy of the clear cells revealed them to be classical ependymoma cells with well developed intercellular junctions, microvilli and cilia. As no reporters in the past showed the evidence to clarify the nature of the clear cells, this case is considered a good example to support the viewpoint that the clear cells (oligodendroglioma-like cells) commonly observed in ependymomas are in reality ependymoma cells. It is stressed that the diagnosis of "mixed glioma" or "oligoependymoma" should be made with sufficient caution despite the recent advances of GFAP technique.

Adult↗
PubMed1983

Misincorporation in DNA synthesis after modification of template or polymerase by MNNG, MMS and UV radiation.

The synthetic DNA polymers, poly(dG-dC), poly(dC), poly(dA-dT), poly(dA) and poly(dT), were treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), methyl methanesulfonate (MMS) and UV irradiation. The modified polymers were used as templates to examine the incorporation of non-complementary nucleotides by E. coli DNA polymerase I. Methylation of poly(dG-dC) by MNNG predominantly induced the misincorporation of dTMP, whereas methylation by MMS induced that of dAMP. Treatment of poly(dT) with MNNG caused the misincorporation of dGMP to a considerable extent, but MMS did not enhance the error on poly(dT). The misincorporation of dAMP on poly(dC) and that of dGMP on poly(dA) were also increased by these chemicals. UV irradiation of poly(dT) and poly(dC) induced the error of dGMP and dAMP, respectively. These data on MNNG and MMS in vitro were in fair agreement with the directions of mutation in vivo. But the predominant induction of transitions by UV in vitro did not agree with the UV-induced transversions in E. coli. This inconsistency suggested the participation of other factors than direct mispairing in UV-induced transversion. Modification of DNA polymerase I by MNNG changed the ratio of polymerase to 3' leads to 5' exonuclease activity altering the fidelity of this enzyme, whereas MMS and UV-irradiation did not alter the fidelity of the enzyme.

DNA↗
PubMed1980

Dynamics of the estrogen receptor in the uteri of mice treated neonatally with estrogen.

Experiments were performed to examine the uterine response to estrogen and the dynamics of uterine estrogen neonatally. Uterine tissue of neonatally estrogenized mice showed a markedly reduced response to estrogen in the adult. The concentration of cytoplasmic estrogen receptor in the uteri of such mice was markedly lower than that of neonatally vehicle-injected control mice. Nuclear and cytoplasmic estrogen receptors of uteri in both groups were determined by the exchange assay at various intervals after injection of estradiol. Nuclear translocation of estrogen receptor complexes in neonatally estrogenized mice was similar to that in control mice. The concentration of cytoplasmic receptor decreased to low levels by 1 h and began a gradual increase from 1-16 h after injection in both groups. Between 16-24 h after injection, however, the level of cytoplasmic receptor continued to increase in control mice but almost ceased to increase in neonatally estrogenized mice. Ten daily injections of estradiol continued to increase the concentration of cytoplasmic estrogen receptor in control mice. On the other hand, in neonatally estrogenized mice treated daily with estradiol, the receptor level reached a plateau on day 5. These data suggest that the induction of new uterine estrogen receptor under the influence of estrogen may be altered by neonatal estrogen treatment.

Aging↗