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Biomedical subjects

F Otsuka

Publications and source records attributed to F Otsuka.

At least 163 records · Page 9Linked to original sources
PubMed1993

Successful differentiation of Spitz naevus from malignant melanoma by microfluorometric analysis of cellular DNA content.

Two cases of presumed Spitz naevus, whose diagnosis on clinical and histological grounds was uncertain, were examined for cellular DNA content using the technique of DAPI-DNA microfluorometry. They were compared with 20 cases, respectively, of clinically and histologically confirmed, Spitz naevus, malignant melanoma and acquired pigmented naevus. The two Spitz naevi showed a diploid pattern in a distribution histogram of cellular DNA content. The pattern was similar to that of confirmed Spitz naevi and of acquired pigmented naevi but different from the aneuploid pattern of malignant melanomas. DNA index values of the two cases were within the range of confirmed Spitz naevi and different from those of malignant melanomas. The DAPI-DNA microfluorometric method thus provided confirmatory evidence for the diagnosis of Spitz naevus. The method appears to reflect sensitively the biological behaviour of tumour cells, and is a useful aid to the diagnosis of uncertain Spitz naevi.

Adult↗
PubMed1993

Cultured skin fibroblasts derived from three patients with disseminated superficial actinic porokeratosis (DSAP) are hypersensitive to the lethal effects of X-radiation but not to those of ultraviolet (UV) light.

Disseminated superficial actinic porokeratosis (DSAP), skin lesions of which are known to be induced by ultraviolet (UV) light, does not develop into skin cancer as frequently as other types of porokeratosis (PK). To establish the cellular basis of this characteristic of DSAP, we examined the colony-forming ability of UVC light- or X-ray-irradiated cultured fibroblasts derived from DSAP patients' skin. Sensitivity to the lethal effects of UV light was not significantly different between 3 DSAP and 5 control cell strains. In contrast, DSAP cell strains were significantly hypersensitive to the lethal effects of X-radiation, although the sensitivity was less than that of cell strains from other types of PK patients. The results indicate that the actinic character of DSAP is not reflected in the cellular response to the lethal effects of UV light, but suggest that DSAP shares X-ray sensitivity, which is probably associated with the cancer-prone nature of PK.

Aged↗
PubMed1993

Contact immunotherapy with squaric acid dibutylester for warts [corrected].

The efficacy of squaric acid dibutylester (SADBE), a topical allergen, was investigated in the treatment of 20 patients with warts. All patients had multiple or warts recalcitrant to other therapies or hesitated to have the painful cryotherapy. The patients with warts present for a mean of 15.3 months (range 1-36) were successfully sensitized with 2% SADBE in acetone. Then the warts were treated with a 0.1 or 0.01% SADBE application once a week or every other week, so as to maintain a mild contact dermatitis. Twelve of the 20 patients (60%) were completely cured after an average of 6 applications (range 2-12). Five patients (25%) showed either a poor or no response even after 9-18 applications. Three patients (15%) exhibited contact dermatitis either at the sensitization or the treatment site. Our study shows that this therapy, although not always safe, is effective in treating warts in some patients, who either hesitate at conventional cryotherapy or have warts resistant to other therapies. The safety of this method remains to be evaluated.

Administration, Cutaneous↗
PubMed1993

A human metal responsive element-binding protein interacts with a homologous element of the mouse metallothionein-I gene.

Metallothionein (MT) is thought to play a central role in the detoxification of heavy metals, and thus studies on its regulation are toxicologically important. Heavy metal-dependent induction of MT genes is mediated by metal responsive elements (MREs) located upstream of the genes. Zinc regulatory factor (ZRF) is a zinc-dependent MRE-binding protein that was originally detected in HeLa cell nuclear extracts using the most proximal MRE of the human MT-IIA gene (hMREa) as a probe. We show that ZRF in HeLa cell nuclear extracts can also bind to the most potent MRE of the mouse MT-I gene (mMREd). This finding was further confirmed by using partially purified ZRF. Moreover, cadmium could not promote complex formation between ZRF and mMREd at any concentration tested, as is also the case with ZRF and hMREa. These observations suggest that the transcriptional regulatory system of MT genes by zinc is conserved beyond species.

Animals↗
PubMed1992

Zinc-specific activation of a HeLa cell nuclear protein which interacts with a metal responsive element of the human metallothionein-IIA gene.

Transcription of metallothionein genes is activated by heavy metals such as zinc and cadmium, and a DNA element called metal responsive element (MRE) is essential for this process. By mobility-shift assay, we identified a HeLa-cell nuclear protein which specifically binds to MREa of human metallothionein-IIA gene. This protein, named ZRF (zinc-regulatory factor), is present in the cells untreated with heavy metals. Zinc is essential for, and increases in a dose-dependent manner, the binding of ZRF to MREa. Other heavy metals which can also induce metallothioneins, including cadmium, copper and mercury, do not activate ZRF. A MREa-containing oligonucleotide that can bind ZRF confers heavy metal-inducibility to a heterologous promoter, suggesting that ZRF is a zinc-dependent transcriptional activator. In addition to the MRE core sequence, the surrounding sequences are also important for both ZRF binding in vitro, and zinc-dependent transcriptional activation in vivo. MREa by itself responds not only to zinc but also to other metallothionein-inducing heavy metals, indicating that the ZRF protein, not the MREa sequence, is responsible for the zinc specificity.

Base Sequence↗
PubMed1992

A nuclear factor that recognizes the metal-responsive elements of human metallothionein IIA gene.

Expression of metallothionein (MT) genes is regulated by heavy metals mainly at the transcriptional level, via cis-acting elements called the metal-responsive elements (MREs). A HeLa cell nuclear factor that recognizes MREs of the human MTIIA (hMTIIA) gene, MREBP, was characterized. Mobility shift assay and DNase I footprinting experiments showed that MREBP binds specifically to several MREs present upstream of the hMTIIA gene. Cadmium and zinc ions inhibited binding of MREBP to a MRE at high concentrations, suggesting a role of MREBP in the negative regulation of the hMTIIA gene. MREBP was partially purified by passing the HeLa nuclear extract over heparin-agarose, Sephacryl S-300, and MRE-Sepharose affinity columns. Blotting experiments showed that a polypeptide with an M(r) of 112,000 is responsible for the MREBP activity.

Base Sequence↗
PubMed1992

Possible Werner syndrome. A unique association with spontaneous digital gangrene in infancy and decreased life span of cultured skin fibroblasts.

BACKGROUND: Werner syndrome is a hereditary disease characterized by several features generally associated with aging. However, the differences between Werner syndrome and the normal aging process are clear. Werner syndrome is usually diagnosed through the clinical signs and symptoms it presents. In recent years, however, the cultured skin fibroblasts of patients have grown slowly and patients have a short life span; these characteristics provide a useful diagnostic aid. OBSERVATIONS: We recently examined a 42-year-old single man who had short fingers, marked facial scars resulting from chilblain-like eruption in infancy, glaucoma caused by uveitis developed in his middle age, callosities on the soles, and immaturation of sexual glands. Repeated peripheral blood examinations showed a positive result for antinuclear factor, slight elevation of immunoglobulin levels, and a low leukocyte count. His family had repeated consanguineous marriages and his parents were cousins. We cultured skin fibroblasts from the patient's forearm and compared them with those of four normal control male subjects. The patient's skin fibroblasts showed a remarkably low population growth rate and a total replicative life span. CONCLUSION: The patients presented unique clinical features for Werner syndrome such as chilblain-like eruption in infancy and glaucoma caused by uveitis. Cell culture studies revealed cellular abnormalities compatible with Werner syndrome. We thus diagnosed the patients as possibly having Werner syndrome.

Adult↗
PubMed1992

Relationship between cholesterol sulfate and intercellular cohesion of the stratum corneum: demonstration using a push-pull meter and an improved high-performance thin-layer chromatographic separation system of all major stratum corneum lipids.

To investigate the role of cholesterol sulfate (CS) as an intercellular glue or cement in the stratum corneum, we compared the relationship between CS levels and magnitude of the intercellular cohesion of the stratum corneum between the palm and the upper arm. Using a push-pull meter, the palm displayed approximately seven times the magnitude of cohesion of the stratum corneum as the upper arm (n = 11). CS and other stratum corneum lipids were extracted from the palm and the upper arm (n = 22) by a cup method and determined by our improved high-performance thin-layer chromatography (HPTLC). Despite a great difference in the magnitude of cohesion (p less than 0.01), CS levels and ratios of CS to ceramides and CS to cholesterol in the stratum corneum showed no significant differences between the palm and the upper arm. Our results suggest that differences in CS cannot account for the differences in cohesion between palm and upper arm.

Adult↗
PubMed1992

The effects of interferon-beta on phorbol ester or calcium ionophore-induced intercellular adhesion molecule-I expression in epidermal carcinoma cells.

Keratinocyte intercellular adhesion molecule (ICAM)-I expression is induced by interferon (IFN)-gamma. It has been previously reported that IFN-beta suppresses IFN-gamma-induced ICAM-I expression in A431 cells, a human squamous cell carcinoma cell line. In this study, the suppression mechanisms were investigated at the post second messenger level. Both 12-O-tetradecanoylphorbol-13-acetate (TPA) and calcium ionophore (A23187) induce ICAM-I expression in A431 cells. ICAM-I expression induced by either was not suppressed with cotreatment with IFN-beta. Furthermore, IFN-beta did not inhibit the translocation of protein kinase C (PKC) by TPA. It appears that the pathways involved in ICAM-I expression induced by activation of PKC or increased in intracellular Ca++ are not affected by IFN-beta.

Calcimycin↗
PubMed1992

A case of neutrophilic dermatosis (ND) complicated by cryofibrinogenemia (CFGN) and myelodysplastic syndrome (MDS).

A case of neutrophilic dermatosis (ND) complicated by cryofibrinogenemia (CFGN) and myelodysplastic syndrome (MDS) is reported. Although the patient presented pancytopenia, the skin lesions were compatible with those of ND from the clinical and histopathological findings. Further, immunofluorescence technique revealed cryofibrinogen (CFG) deposits on the walls of the blood vessels in the skin lesion, and a high titer of CFG components was disclosed in the patient's peripheral blood. In this case, CFGN may have been associated with MDS; hence CFG deposits probably played a role, at least in part, in the skin lesion formation. This is probably the first case of ND complicated by CFGN. And careful examination of an underlying disease is recommended in association with ND and/or CFGN.

Cryoglobulins↗
PubMed1992

Effect of platelet-poor plasma from patients with neurofibromatosis on the growth of cultured neurofibroma-derived fibroblast-like cells.

The effect of platelet-poor plasma from patients with von Recklinghausen's disease (neurofibromatosis, NF) on the cell growth of cultured neurofibroma-derived fibroblast-like cells (NF fibroblast-like cells grown from explant cultures of cutaneous neurofibromas) was examined. Platelet-poor plasma and sera from nine NF patients and nine control individuals were examined. When comparing platelet-poor plasma from patients with NF with control individuals, the former stimulated the proliferation of fibroblast-like cells derived from neurofibromas, not that of normal fibroblasts.

Adult↗
PubMed1992

Pelgeroid-like anomalous cells in the diagnosis of neutrophilic dermatosis associated with myelodysplastic syndrome.

Neutrophilic dermatoses (ND), with or without accompanying myelodysplastic syndrome (MDS), were examined in terms of nuclear abnormality like pelgeroid anomaly of infiltrating cells into skin lesions. Six ND accompanying MDS showed 1.0 to 13.5% of such anomalous cells among infiltrating cells. In contrast, ND without accompanying myeloproliferative disorders rarely had such anomalous cells. Our findings suggest that pelgeroid-like anomalous cells infiltrating into ND are probably a good marker of underlying MDS.

Aged↗
PubMed1992

Phthalic acid dermatitis caused by an organostannic compound, tributyl tin phthalate.

We report a case of primary irritant contact dermatitis caused by an organostannic insecticide, tributyl tin phthalate, which has been thought to be stable and safe. A factory worker has been in contact with raw tributyl tin phthalate on one leg. Soon after taking a hot-water bath, he developed severely painful erythema on this leg. Patch tests and chemical analysis revealed that hot water hydrolyzed tributyl tin phthalate and produced concentrated phthalic acid. Since phthalic acid, a weak acid, was then concentrated, an acute irritant reaction appeared in this patient.

Accidents, Occupational↗
PubMed1992

Estimation of metallothionein synthesis in cadmium-exposed human lymphocytes by gel electrophoresis and silver staining.

Metallothionein (MT) is a low molecular weight metal-binding protein that is induced by a variety of heavy metals, and therefore is a candidate for an index in the biological monitoring of heavy metal exposure. As an approach to the establishment of a practical monitoring method, we estimated the MT levels in Cd-exposed cultures of human peripheral blood mononuclear cells as well as purified lymphocytes using a technique developed for the electrophoretic analysis of MTs. By this procedure, we could successfully detect the MTs induced by Cd in a dose-dependent manner. MTs were detectable even in cells exposed to as low as 0.5 microM Cd, which is close to the blood Cd levels of exposed workers. These results indicate the usefulness of this technique as a practical method for the monitoring of heavy metal exposure.

Cadmium↗
PubMed1992

Zinc status in proliferative response of T lymphocytes.

The in vitro proliferation of T lymphocytes are highly susceptible to Zn deprivation and Cd addition. In order to define Zn status in T cell proliferation, toxicological and biochemical situation of Zn in proliferative response of T cells was investigated by use of mouse spleen cell cultures stimulated by T cell-mitogen, Con A. The inhibitory effect of Cd on T cell proliferation was protected specifically by Zn. The protection by Zn was effective when Zn was added within 16 h after Con A stimulation. Zn addition affected neither Cd content in cells nor induction of Cd-thionein. These findings indicate that Zn-dependent processes expressed before the S phase of cell cycle are critical for T cell proliferation and are targets susceptible to Cd. Moreover, electrophoretical analysis showed two unknown Zn-binding proteins (49 and 100 KD) induced in spleen cells incubated with Con A and radioactive Zn. These Zn-binding proteins may be associated with the Zn-dependent processes critical for T cell proliferation.

Animals↗
PubMed1991

Chromosome abnormalities of porokeratosis-cultured epidermal keratinocytes. Comparison with those of cultured dermal fibroblasts.

Cultured epidermal keratinocytes and dermal fibroblasts derived from porokeratosis (PK) patients' skin lesions or normal-appearing skin had numerical and sometimes structural chromosomal abnormalities. Such abnormal cells were seen in 4.08% and 0.375% of all the studied epidermal keratinocytes derived from affected skin and normal-appearing skin, respectively. Similar abnormalities were present in 1.70% and 3.67% of the dermal fibroblasts from the patients' affected skin and normal-appearing skin, respectively. Chromosomal abnormalities were more frequent in keratinocytes and fibroblasts from the patients' skin than in keratinocytes (0.429%) or in fibroblasts (1.22%) derived from normal control donors. Clonal proliferation of such abnormal cells was frequently seen in keratinocytes from the patients' affected skin. The frequent appearance of chromosomal abnormalities and clonal proliferation in epidermal keratinocytes may explain skin lesion formation and skin cancer development in PK patients.

Cell Division↗
PubMed1991

Change in activity of nuclear poly(ADP-ribose) glycohydrolase during the HeLa S3 cell cycle.

The change in activity of nuclear poly(ADP-ribose) glycohydrolase during the cell cycle of HeLa S3 cells was investigated. The poly(ADP-ribose) glycohydrolase activity was solubilized from HeLa S3 cell nuclei and chromosomes only by sonication at high ionic strength. The enzyme hydrolyzed poly(ADP-ribose) exoglycosidically, producing ADP-ribose. After release from mitosis, the activity of the solubilized nuclear poly(ADP-ribose) glycohydrolase per nucleus or per unit protein, assayed with [3H]poly(ADP-ribose) (average chain length, n = 15) as substrate, was lowest in the early G1 phase and highest in the late G1 phase. The specific activity in the late G1 phase was about two times that in the early G1 phase. The high activity remained constant during the S-G2-M phase. A similar change during the cell cycle was observed after release from hydroxyurea block. These results suggest that the activity of poly(ADP-ribose) glycohydrolase doubled during the G1 phase of the cell cycle of HeLa S3 cells.

Cell Cycle↗