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Biomedical subjects

I Aoki

Publications and source records attributed to I Aoki.

At least 91 records · Page 5Linked to original sources
PubMed1995

Effects of exercise and amenorrhea on bone mineral density in teenage runners.

In order to elucidate whether exercise and calcium intake can offset bone loss due to hypoestrogenemia in teenage girls, the lumbar and femoral bone mineral density (BMD) in elite amenorrheic runners (group 1 (n = 8)) was compared with those in eumenorrheic athletes (group 2 (n = 15)) and two groups of eumenorrheic non-athletic subjects, group 3 (n = 14), and group 4 (n = 15). BMD was measured by dual energy x-ray absorptiometry. The subjects in group 1 lived in the dormitory, and their calcium intake was controlled to > 1400 mg/day. The subjects in groups 1, 2 and 3 were age matched (16-17 years old), but the body weight of those in group 2 was significantly greater than that of others. The subjects in groups 1, 3 and 4 were weight matched, but group 4 subjects were older by 5 years (21.0 +/- 0.2 years old). The lumbar BMD of group 1 was 1.0460 +/- 0.0259, which was not statistically different from those in the other groups, while the femoral BMD of group 1 was significantly higher than those of groups 3 and 4 at trochanter. The lumbar and femoral BMD of group 2 was significantly higher than in groups 3 and 4, but was not statistically different from group 1. There were no significant differences in serum parathyroid hormone levels, but osteocalcin and calcitonin levels of group 1 were significantly lower than those of groups 2 and 3, and groups 2, 3 and 4, respectively, suggesting that the rate of bone formation is suppressed in amenorrheic runners.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Effects of rhIL-1 alpha, rhIL-1 beta, and rhIL-1 receptor antagonist on erythroid progenitors (CFU-E and BFU-E) in human bone marrow.

Interleukin-1 (IL-1) is known to promote the production of colony-stimulating factor (CSF) and to possess the ability to protect the bone marrow suppression in granulocyte-macrophage (GM) series associated with radiotherapy or chemotherapy. There are conflicting reports concerning the action of IL-1 on erythroid progenitors, however, and no consensus has been established. In the present study, the influences of recombinant human IL-1 alpha (rhIL-1 alpha), rhIL-1 beta, and rhIL-1 receptor antagonist (rhIL-1ra) on erythroid progenitors (colony-forming units-erythroid, CFU-E; and burst-forming units-erythroid, BFU-E) in human bone marrow were studied. rhIL-1 alpha and rhIL-1 beta (1-1000 pg/mL) enhanced the CFU-E and BFU-E growth in human nonadherent (NA) bone marrow cells. rhIL-1 alpha and rhIL-1 beta also stimulated the formation of CFU-E and BFU-E in the NA and T cell-depleted bone marrow fraction. Moreover, rhIL-1 alpha and rhIL-1 beta enhanced the CFU-E and BFU-E in the CD34+ bone marrow cell fraction. These data and the results of limiting dilution analysis indicate that the stimulatory effect of IL-1 may consist of direct actions on erythroid progenitors. The enhancing effect of rhIL-1 alpha and rhIL-1 beta on erythroid progenitors was inhibited by rhIL-1ra. These data suggest that the stimulatory effect of IL-1 on CFU-E and BFU-E is mediated via the IL-1 receptor.

Antigens, CD↗
PubMed1995

[Analysis of T cell subsets in autoimmune hemolytic anemia patients].

To clarify a role of immunoregulatory T cells in the pathophysiology of autoimmune hemolytic anemia (AIHA), we investigated T cell subsets in the peripheral blood of 15 patients with AIHA by two color analysis using flow cytometry. Consequently both CD4+ cells and CD4+CD45RA+ cells decreased in proportion, irrespective of the disease activity (active or remission phase). CD4+CD45RA+ cells are regarded as naive T cells. Incidentally the ratio of CD45RA+ cells in CD4+ cells also fell in the low level in active phase, but it recovered to the normal ratio in remission. On the other hand, CD8+ cells and CD8+ +S6F1+ cells that may represent activated cytotoxic T lymphocytes increased in active phase and then both entered the normal range in remission. These findings suggest that AIHA could be caused partly by the alternative balance of CD4+CD45RA+ cells probably constituting a member of IRT and moreover by the activation of CTL.

Anemia, Hemolytic, Autoimmune↗
PubMed1995

[High resolution MR imaging of the inner ear apparatus using 3D-Fast spin echo sequence].

To evaluate the efficacy of high resolution MR imaging of the inner ear with 3D-Fast spin echo sequence, one volunteer and 12 patients were imaged with a 1.5 T MR scanner. High resolution T2-weighted images were obtained with a head coil in 13 minutes, and the voxel size was 0.39mm x 0.45mm x 1.2mm in most subjects. Original images and maximum intensity projection (MIP) images of the inner ear were evaluated. On original images, the endolymphatic duct was visualized in 72% of subjects, the cochlear aqueduct in 96%, three branches of the cranial nerves in the internal auditory canal in 100%, and flow void of the vessel in the cerebellopontine angle in 100%. On MIP images, more than two cochlear turns were visualized in 92% of subjects, three semicircular canals in 100%, and the anterior and posterior ampulla in 100%. MR imaging of the inner ear with 3D-Fast Spin Echo sequence provides a variety of useful information regarding the anatomy around the inner ear.

Ear, Inner↗
PubMed1994

Sensitive determination of methotrexate in monkey plasma by high-performance liquid chromatography using on-line solid-phase extraction.

A high-performance liquid chromatographic method was developed for the sensitive determination of methotrexate (MTX) in monkey plasma using direct injection and on-line solid-phase extraction. After application of a 100-microliters aliquot of plasma to a pre-treatment column, the column was washed with 0.02 M phosphate buffer (pH 7) to eliminate plasma proteins and endogenous substances, and subsequently the adsorbed MTX was eluted. The MTX fraction was transferred to an analytical column by a column-switching (heart-cutting) technique, and MTX was analyzed using ion-pair chromatography with tetrabutylammonium bromide. More than 50 injections could be performed onto one pretreatment column. The accuracy, precision, reproducibility and linearity were satisfactory over a wide range of MTX concentrations (5-1000 ng/ml). The quantitation limit was 5 ng/ml with a signal-to-noise ratio of 5. The method was suitable for the pharmacokinetic study of MTX in monkey.

Animals↗
PubMed1994

High-performance liquid chromatographic determination of phenylephrine in human serum using column switching with fluorescence detection.

A method for the determination of total phenylephrine (free plus conjugated) in human serum was developed using column-switching high-performance liquid chromatography (HPLC) with fluorescence detection. After serum was deproteinized with acetonitrile, the conjugated phenylephrine was hydrolyzed with diluted hydrochloric acid. The solution was evaporated to dryness. The reconstituted residue was analyzed with HPLC using a heart-cut technique. Good recoveries of the analytes from spiked human serum samples were obtained with small coefficients of variation. A good linear response was obtained for the concentration range 5-500 ng/ml. The lower limit of quantitation for phenylephrine in human serum was 5 ng/ml. The method was applied to the determination of phenylephrine in human serum after oral administration of phenylephrine hydrochloride.

Chromatography, High Pressure Liquid↗
PubMed1994

Sensitive high-performance liquid chromatographic determination of chlorpheniramine in human serum using column switching.

A sensitive method for the determination of chlorpheniramine in human serum was developed using column-switching high-performance liquid chromatography (HPLC) with ultraviolet detection at 210 nm. The analyte was extracted with diethyl ether from alkalinized serum. After evaporation of the organic layer, the reconstituted residue was analyzed by HPLC using a heart-cut technique. Good recoveries of the analyte from spiked human serum samples were obtained with a coefficient of variation below 7%. A good linear response was obtained for the concentration range 0.5-50 ng/ml, with a correlation coefficient higher than 0.999. The lower limit of quantitation for chlorpheniramine in human serum was 0.5 ng/ml. The method was satisfactorily applied to the determination of chlorpheniramine in human serum after oral administration of chlorpheniramine maleate.

Administration, Oral↗
PubMed1994

Treatment with dextran-conjugated anti-IgD delays the development of autoimmunity in MRL-lpr/lpr mice.

The onset of clinical disease in autoimmune MRL-lpr/lpr mice is preceded by a switch from predominantly IgM production to IgG production. Previous studies have shown that IgG autoantibodies play a central role in the development of life-threatening glomerulonephritis in this strain. Delaying or preventing the switch from IgM to IgG production might therefore be of therapeutic benefit. We previously documented similarities in the B cell repertoire expressed by young MRL-lpr/lpr mice and normal mice treated with the polyclonal activator LPS. Recent in vivo studies indicate that cross-linking membrane IgM or IgD can suppress LPS-dependent IgG production in normal animals. These observations led us to examine whether membrane cross-linking could also lower serum IgG levels in MRL-lpr/lpr mice. Lupus-prone animals were treated with multivalent anti-IgD conjugated to high m.w. dextran. This anti-IgD dextran conjugate was previously shown to reduce IgG production in LPS-stimulated normal animals. Treatment of young lupus-prone MRL-lpr/lpr mice resulted in a significant reduction in the total number of B cells secreting IgG and lower serum titers of IgG anti-DNA and IgG anti-histone autoantibodies. Anti-IgD dextran treatment also delayed the development of glomerulonephritis and improved survival. Thus, anti-IgD dextran interfered with autoantibody-dependent disease progression, perhaps by inhibiting the switch from IgM to IgG autoantibody production.

Age Factors↗
PubMed1994

Stimulatory effect of human insulin on erythroid progenitors (CFU-E and BFU-E) in human CD34+ separated bone marrow cells and the relationship between insulin and erythropoietin.

Erythropoietin is known to be effective for the treatment of anemia in chronic renal failure, but the efficacy of erythropoietin for anemia in other diseases is not so great. Insulin exerts a growth promoting activity in various kinds of cells. In the present study, the effects of insulin on erythroid progenitors (colony forming units-erythroid, CFU-E; and burst forming units-erythroid, BFU-E) in human bone marrow were examined at various concentrations of recombinant human erythropoietin (rh-Epo) to clarify the relationship between erythropoietin and insulin. Human insulin stimulated the formation of CFU-E and BFU-E in the presence of three concentrations (0.25, 5, and 100 U/ml) of rh-Epo. Stimulatory effects of human insulin on CFU-E and BFU-E were also observed in the nonphagocytic and nonadherent bone marrow fraction (NP-NA fraction) and in the NP-NA and T cell-depleted fraction at each concentration of rh-Epo. Human insulin further stimulated the CFU-E and BFU-E growth in CD34+ separated bone marrow cells. These results indicate that the enhancing effect of human insulin on erythroid progenitors is not mediated through monocytes and macrophages or T cells, suggesting a direct action on erythroid progenitors.

Animals↗
PubMed1994

Cross-reactivity of IgM- and IgG-secreting B cells in murine chronic graft-versus-host reaction.

A chamber ELISpot assay was used to measure the frequency with which in vivo activated B cells secreted cross-reactive antibodies during a chronic graft-versus-host reaction in mice. Both normal (C57BL/10 x DBA/2)F1 mice and F1 recipients of syngeneic spleen cells (SynF1) expressed repertoires in which 13-17% of IgM and 3-5% of IgG-secreting cells were cross-reactive. By comparison, 43-55% of IgM and 9-40% of IgG-secreting cells from F1 recipients of parental DBA/2 spleen cells (GVHF1) were cross-reactive (P < 0.01, GVHF1 versus F1 or SynF1). The cross-reactivity of the GVHF1 IgM secreting cells remained elevated for > 2 months following cell transfer. In contrast, the cross-reactivity of IgG-secreting cells, which was significantly high at Week 3 post-transfer, declined to nearly normal levels by Week 9. These findings demonstrate that cross-reactive B cells constitute an abnormally large fraction of the repertoire expressed by mice with chronic GVHR in a period when B cell hyperstimulation was occurring.

Animals↗
PubMed1994

Acute abdominal symptoms caused by hemorrhagic necrosis of a pheochromocytoma: report of a case.

The diagnosis of pheochromocytoma is often difficult in a patient presenting with acute illness but without the classical constitutional symptoms. We report herein the case of a woman who developed acute abdominal symptoms following hemorrhagic necrosis of a previously unsuspected pheochromocytoma. This patient underwent successful emergency resuscitation followed later by elective surgical resection of a right adrenal pheochromocytoma. A review of 27 other cases indicates that a fatal outcome is likely to result without the initiation of prompt and appropriate emergency treatment, followed later by removal of the tumor. Thus, early diagnosis is important not only for controlling hypertension, but also because performing a laparotomy on a patient with unrecognized hemorrhagic necrosis of pheochromocytoma can create a potentially lethal situation.

Abdomen, Acute↗
PubMed1994

Establishment and characterization of a malignant melanoma cell line (YP-MEL) derived from a patient with neurocutaneous melanosis.

A cell line, YP-MEL, was established from an intracranial malignant melanoma occurring in a neurocutaneous melanosis (NCMsis) patient. The established cell line was successfully cultured in serum-free medium with a doubling time of 41 h. The cells were refractile and small in size, with occasional pigmented giant cells. Histochemical and immunohistochemical features were compatible with common malignant melanoma and its cell line. Chromosome analysis revealed many supernumerary chromosomes and marker chromosomes including double minutes (DMs). When transplanted into nude mice, YP-MEL formed tumors histologically consistent with the original tumor. Addition of sera to the medium caused cellular spreading and elongation of cytoplasmic processes with an increase of melanin contents and tyrosinase activity. Because there was no melanoma cell line derived from a NCMsis patient, YP-MEL might be a beneficial tool for study on NCMsis.

Biopsy↗
PubMed1994

Establishment of three rat soft tissue tumor cell lines with different degrees of myogenic differentiation.

Soft tissue malignancies often show divergent differentiation, including myogenic lineage. Five rat tumors induced with 20-hydroxymethylcholanthrene (20-OH-MCA), were cultured in vitro, and three cell lines (YMC-1, YMC-2, YMC-3) were established from them. YMC-2 and -3 cells were spindle-shaped, and YMS-1 cells round and epithelioid. In confluency, YMC-3 cells formed myotubes. The nude mouse xenotransplants showed morphological features consistent with their myogenic phenotypes. Muscle-specific enzyme activities were highest in YMC-3 cells. These lines may be useful in the investigation of the myogenic differentiation of undifferentiated mesenchymal cells.

Animals↗
PubMed1994

cDNA cloning and mRNA expression of a serine proteinase inhibitor secreted by cancer cells: identification as placental protein 5 and tissue factor pathway inhibitor-2.

A serine proteinase inhibitor was purified from conditioned medium of the human glioblastoma cell line T98G. Analysis of its partial amino acid sequences indicated that this protein was identical to placental protein 5 (PP5), a placenta-derived glycoprotein with serine proteinase inhibitor activity, the amino acid sequence of which had been partially determined. cDNA cloning of PP5 demonstrated that it belonged to the Kunitz-type serine proteinase inhibitor family, having three putative Kunitz-type inhibitor domains, and that it was identical to a recently reported inhibitor, tissue factor pathway inhibitor-2 (TFPI-2) [Sprecher et al. (1994) Proc. Natl. Acad. Sci. USA 91, 3353-3357]. PP5/TFPI-2 transcripts were highly abundant in the full-term placenta and widely expressed in various adult human tissues, such as the liver, skeletal muscle, heart, kidney, and pancreas. Several ovarian carcinoma cells as well as T98G also contained significant amounts of the transcripts.

Amino Acid Sequence↗
PubMed1994

Pruritic papular eruption of the acquired immunodeficiency syndrome.

We report a case of acquired immunodeficiency syndrome with pruritic papular eruption. The patient, a hemophiliac, presented with generalized pruritic, skin-colored papules and nodules. The chronic lesions were excoriated and hyper-pigmented. The eosinophil count was elevated, but IgE was normal. The lesions and pruritus responded only to ultraviolet B phototherapy. While the mechanism is not known, ultraviolet B phototherapy may provide relief of AIDS-related pruritus.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Chromophobe renal cell carcinoma: a report of two cases.

Chromophobe renal cell carcinoma (RCC) is a recently established subtype of RCC, which has rarely been reported in Japan. In this communication, the authors report two Japanese cases of chromophobe RCC together with the immunohistochemical findings. The tumors were composed of sheets and cribriform glands formed by tumor cells with cloudy and reticular cytoplasm. Ultrastructurally, the cytoplasm was filled with numerous microvesicles. The tumor cells were positive for cytokeratin, epithelial membrane antigen, and Tamm-Horsfall protein. Occasionally, LeuM1-positive cells were also noted. Vimentin was negative, unlike the usual RCC. Reactivity for peanut agglutinin was more frequent than that to Lotus tetragonolobus agglutinin. The results of this study suggest that the tumor cells possessed phenotypes similar to the distal nephron rather than to the proximal tubular cells.

Adult↗
PubMed1993

Sensitive high-performance liquid chromatographic determination of 2,2'-[(2-aminoethyl)imino]diethanol bis(butylcarbamate) and its metabolites in human serum following pre-column derivatization with o-phthalaldehyde and stabilization of the derivatives.

A high-performance liquid chromatographic method for the sensitive determination of 2,2'-[(2-aminoethyl)imino]diethanol bis(butylcarbamate) (I) and its metabolites in human serum has been developed. The method was based on a pre-column derivatization with o-phthalaldehyde. The derivatives were stabilized at least for 24 h at 4 degrees C by using N-acetyl-L-cysteine as a thiol and by eliminating the excess o-phthalaldehyde in the reaction mixture by solvent extraction and the addition of an ammonium salt after the reaction. The recoveries and reproducibilities in human serum spiked with I and its two metabolites were satisfactory, and the responses were linear over a wide range of analyte concentrations. The detection limits of I and its metabolites, II and III, in serum were 0.5, 4 and 2 ng/ml, respectively, at a signal-to-noise ratio of 5. The method was satisfactorily applied to the clinical study of I.

3-Mercaptopropionic Acid↗