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Biomedical subjects

A Iino

Publications and source records attributed to A Iino.

At least 19 recordsLinked to original sources
PubMed1997

Scanning and transmission electron-microscopic study of the development of the podocyte in the human fetus.

The metanephric kidneys of seven human fetuses at 11-17 weeks' gestation were examined by scanning and transmission electron microscopy in order to evaluate differentiation of glomerular podocytes. When glomeruli were in the stage of S-shaped bodies, the surface of the visceral epithelium of renal corpuscles was smooth, with indistinct cell borders. As the glomeruli developed, visceral epithelial cells of renal corpuscles became spherical and resembled clusters of grapes in dense aggregation. In this stage, processes and foot processes were simultaneously formed at the base of epithelial cells. As glomeruli further differentiated, visceral epithelial cells of renal corpuscles began to separate from one another and became flat with the development of vascular loops. Processes and foot processes were exposed for the first time in Bowman's space. In this stage, the degree of differentiation of epithelial cells varied widely among various sites of the glomerulus. As glomeruli developed further, projections became more complex and epithelial cells began to show structures similar to those of adult epithelial cells. The adjacent foot processes arose from different cells throughout the period of morphological differentiation.

Adult↗
PubMed1997

Suppression of glucose absorption by some fractions extracted from Gymnema sylvestre leaves.

Extracts containing gymnemic acids, which were extracted from the leaves of Gymnema sylvestre (GS) as nine fractions, were evaluated for their effects on a high K(+)-induced contraction of guinea-pig ileal longitudinal muscles, on glucose transport mediated by the difference of glucose-evoked transmural potential difference (delta PD) in the inverted intestine of guinea-pig and rat, and on blood glucose in rat. Among nine fractions obtained by high performance liquid chromatography from the extract, f-2 and f-4 strongly suppressed the high K(+)-induced contraction of the ileal muscle, f-3 and f-5 did so moderately, and f-8 and f-9 did so weakly, whereas the other fractions did not affect it. The degree of suppression of high K(+)-induced contraction by f-2 at 74% was almost the same as that of f-4 at 67%, at concentrations of 0.1 mg/ml. The suppressed contraction by f-2 or f-4 was recovered by adding 5.5 mM pyruvate. The delta PD increased by 5.5 mM glucose in the inverted intestines of guinea-pig and rat were equally suppressed by 0.1 mg/ml of f-2 or f-4 to 40%. In a rat sucrose tolerance test, f-2 and f-4 suppressed the elevation of blood glucose level. Both f-2 and f-4 suppressed the contraction of guinea-pig ileal longitudinal muscle, interfered with the increase in delta PD induced by glucose in the inverted intestines of guinea-pig and rat, and inhibited the elevation of blood glucose level. In conclusion, it is suggested that some of the extracts containing gymnemic acids from GS leaves suppress the elevation of blood glucose level by inhibiting glucose uptake in the intestine.

Administration, Oral↗
PubMed1995

Immunocytochemical localization of actin in the nucleolus of rat oocytes.

In order to determine the localization of actin, growing and fully grown rat oocytes were immunocytochemically examined using a post-embedding ultrastructural protein-A gold technique. In quiescent oocytes, the nucleoplasm showed slightly lower levels of actin signal when compared to the surrounding cytoplasm. The highest levels of labeling were found on nucleoli showing a reticular type morphology. In oocytes at the diakinesis stage in which nucleolar compaction had occurred, the levels of labeling increased by 5-6 times those found in quiescent oocytes. Except for conspicuous accumulation of actin under the plasma membrane, compact nucleoli had significantly higher levels of labeling when compared with those found on the general cytoplasm, while the nucleoplasm with homogeneously dispersed chromatin showed significantly lower levels of associated actin signal than the general cytoplasm. In oocytes at metaphase I, the cytoplasmic region had comparable or lower levels of labeling than the cytoplasm of oocytes at diakinesis. The meiotic spindle embedded in material with medium electron density showed a similar level of labeling as the surrounding cytoplasm. On the other hand, significantly higher levels of associated actin were observed on the chromosomes of metaphase I. The actin signals were dispersed over the chromosomes and not concentrated on a specific region. These results suggest that nuclear actin may be involved in the process of chromosome construction and also the formation of the compacted structure of the nucleolus.

Actins↗
PubMed1995

Diagnostic revolution of microhematuria by real time confocal scanning laser microscope: Hyodo-Iino-Miyagawa method, third report.

The real time confocal scanning laser microscope provides excellent three-dimensional images free of out-of-focus information. The objective of this study was to evaluate the usefulness of the laser microscope for the diagnosis of microhematuria. Characteristics of the test were evaluated in 81 patients with definite causes of hematuria. 30 erythrocytes in urinary sediments were examined for each patient, and those in whom less than 20% of the erythrocytes were poikilocytes were considered to have urological diseases and those in whom 80% or more of the erythrocytes were poikilocytes to have nephritis. According to these criteria, the sensitivity and the specificity of the examination to nephritis were 100 and 98.1%. 91.4% of the patients with urological disease had the nonglomerular type. The time required for the examination was less than 2-5 min in samples containing 1-3 erythrocytes in one field under an ordinary light microscope (x400).

Cell Size↗
PubMed1994

Confocal scanning laser microscopy of morphometric human sperm parameters: correlation with acrosin profiles and fertilizing capacity.

OBJECTIVES: To develop quantitative criteria for assessing sperm morphology and to determine the correlation between the percentage of morphologically normal spermatozoa and the outcome of the sperm hypo-osmotic swelling test, sperm acrosin profile, and sperm capacity for fertilization. DESIGN: The maximal length and width of the sperm head, the length of the midpiece and principal piece of the sperm tail, and the ratio of the surface of the acrosomal region to the total surface of the head were determined in specimens obtained from a group of infertile men and a group of fertile men using a confocal scanning laser microscope. Group A consisted of 53 infertile men who were participating in an IVF program, and group B consisted of 98 fertile men. The mean +/- 2 SD of the morphometric parameters in group B was established as representing the lowest and highest normal values in both groups. A normal spermatozoon was defined as one with morphometric parameters within normal levels. The lowest percentage of morphologically normal spermatozoa, hypo-osmotic swelling test result, and acrosin activity in group B were also taken as the lowest normal values in group A. SETTING: In vitro fertilization program at the Tottori University School of Medicine, Yonago, Japan. MAIN OUTCOME MEASURES: Sperm morphometric parameters, percentage of morphologically normal spermatozoa, hypo-osmotic swelling test, and acrosin activity. RESULTS: The length of the midpiece, ratio (x 100) of the surface of the acrosomal region to the total surface of the sperm head, percentage of morphologically normal spermatozoa, outcome of hypo-osmotic swelling test, and acrosin activity were significantly higher in group B than in group A. The maximal width of the head was significantly lower in group B than in group A. Strongly positive correlations were observed between percentage of morphologically normal spermatozoa or length of midpiece and the proportion of fertilized oocytes in group A and between ratio (x 100) of the surface of the acrosomal region to the total surface of the head and acrosin activity in groups A and B. Sperm morphology showed high positive and negative predictive values for acrosin activity (normal/abnormal) and fertility potential (present/absent). CONCLUSIONS: Using quantitative strict criteria, we found that sperm morphology was an important predictor of sperm fertilizing capacity. The confocal scanning laser microscope provided useful information about the sperm cytoskeleton and its importance in fertilization.

Acrosin↗
PubMed1993

The spatial distribution of spindle microtubules in anaphase 3Y1 cells.

The spatial distribution of the microtubules (MT) in the rat 3Y1 cells in mitosis was investigated by immunoelectron microscopy and computer-graphic reconstruction of serial thin sections. In anaphase the interzone-MT increased in number gradually with advancing phase, while the kinetochore-MT in half-spindles decreased. The interzone-MT overlapped with each other at the equatorial region of the cell, and they formed a specific structure called the 'stem bodies'. The ends of the interzone-MT opposite to the stem bodies often attached to chromosomes but not to the poles. The stem bodies were not labeled with immunogold particles of anti-alpha tubulin. Some of the stem bodies or MT which originate from stem bodies were found just beneath the plasma membrane in the equatorial region where abundant actin filaments appear showing the formation of the contractile ring and subsequently the cleavage furrow begins. On the basis of these observations it is assumed that the interzone-MT is involved both in the separation of chromosomes in anaphase and in the formation of the cleavage furrow in telophase.

Anaphase↗
PubMed1993

Structural changes of iliac cancellous bone in postmenopausal women: a scanning electron microscopic study.

The functional state of iliac cancellous bones in healthy postmenopausal women was investigated by scanning electron microscopy (SEM) using a modified organic preparation method. SEM analysis of the location, number, size and phase of the remodeling sites showed that normal iliac cancellous bone of postmenopausal women has high resorbing activity in the early stage of postmenopause in both the region near the cortico-endosteum and the midway region, while in the late stage of postmenopause there is a great difference in resorbing activity between the two regions; namely, the resorbing activity progressively decreases with age, but high resorbing activity is continuously present in the region near the cortico-endosteum. Our results suggest the possibility that at the region near the cortico-endosteum the bone volume loss occurs continuously throughout all the stages of post-menopause, while at the midway region it occurs only in the early stage and not in the late stage of postmenopause.

Aged↗
PubMed1992

Acrosin profiles of human spermatozoa recovered from the new Sperm Prep II filtration column.

Twenty semen samples were collected and two aliquots of 1.5 ml were prepared from each sample. One sample of each pair (fraction-one) was used for evaluation of semen parameters and total acrosin activity of spermatozoa. The other sample of each pair (fraction-two) was mixed with an equal volume of Ham's F-10 medium and filtered through the Sperm Prep II. At the end of the filtration, the filtrate was pooled, sperm parameters were evaluated and total acrosin activity was assessed. Percentage of normal spermatozoa, sperm motility, and total acrosin activity of spermatozoa were significantly higher in the postfiltered fraction-two than in the fresh fraction-one. Considering the great importance of acrosin for fertilization, it is suggested that Sperm Prep II filtration method may be beneficial in preparing spermatozoa from infertile men with low acrosin profiles for assisted reproduction programs. Further studies will be necessary, however, in order to confirm this, since the present study concerned men with known fertility.

Acrosin↗
PubMed1990

The tannin-osmium conductive staining after dehydration: an attempt to observe the chromosome structure by SEM without metal coating.

The tannin-osmium conductive staining method was modified in order to observe chromosomal structures without metal coating. The treatment with tannic acid and OsO4, which has been used in aqueous solution in the original method, was performed in acetone solution after dehydration in the present study. The usefulness of this method is discussed showing ultrastructural images of chromosomes of Drosophila and Tradescantia, which can be achieved by the method.

Animals↗
PubMed1989

Application of colour laser microscope for observing living biological specimens.

Pollen-mother cells from Lilium longiflorum, human metaphase chromosomes and human spermatozoa, were observed under a colour laser microscope. Helical mitochondrial strands were clearly evident in the middle piece of human spermatozoa. The technique enables living specimens to be conveniently and effectively examined.

Chromosomes↗
PubMed1986

New micro-glass-tube leukocyte adherence inhibition assay assessing cell adherence of mononuclear cell subpopulations defined by monoclonal antibodies.

A new micro-glass-tube leukocyte adherence inhibition (LAI) assay which is appropriate for detecting delayed type hypersensitivity in vitro has been developed for human leukocytes. Enumeration of adherent cells is replaced by a cellular radioimmunoassay determining antibody binding of the monoclonal reagents, OKT4, OKT8 and OKM1, to glass-adherent cells, fixed by glutaraldehyde or formaldehyde. An LAI reactivity to purified protein derivative of tuberculin (PPD) was detectable in donors giving a positive PPD skin test with OKT4 reagent, but not with the other two reagents.

Antibodies, Monoclonal↗