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Biomedical subjects

Y Sasai

Publications and source records attributed to Y Sasai.

At least 91 records · Page 5Linked to original sources
PubMed1993

Toxic pustuloderma induced by ofloxacin.

A patient with drug-induced toxic pustuloderma is presented. The patient, who was asthmatic and who was being treated with ofloxacin for bronchitis and pharyngitis, developed intense erythemas followed by subcorneal pustulation associated with fever and a neutrophil leukocytosis. The diagnosis was confirmed by oral readministration of ofloxacin, with the result that pustular eruptions were induced. This form of drug eruption had not previously been attributed to ofloxacin.

Bronchitis↗
PubMed1993

Cell cycle analyses of extramammary Paget's disease.

The cell cycle of Paget cells in extramammary Paget's disease was investigated using microscopic analysis of the DNA content, and using immunohistochemistry for 5-bromodeoxyuridine (BrdU) incorporation. Stripped skin was treated with tetrasodium ethylendiamine tetraacetate dihydrate (EDTA) and trypsin, and epidermal cells suspensions were obtained. Microscopic analysis of the DNA content in the cells was performed. The resulting DNA histogram was close to the normal ploidy. Specimens from the involved skin were incubated with BrdU, and sections were immunostained with anti-BrdU monoclonal antibody. A few nuclei showed positive staining for BrdU. The present study showed that the proliferative potential of Paget cells in extramammary Paget's disease was low. This may explain why lesions of extramammary Paget's disease enlarge rather slowly.

Aged↗
PubMed1992

Molecular characterization of a rat negative regulator with a basic helix-loop-helix structure predominantly expressed in the developing nervous system.

We report here the cDNA cloning and characterization of a rat basic helix-loop-helix (HLH) factor, designated HES-5. This factor has a distant sequence homology to Drosophila hairy and Enhancer-of-split proteins, both of which are required for normal neurogenesis. DNase I footprinting analyses show that HES-5 binds to the sequence CACNAG (called N box), a recognition sequence of Enhancer-of-split proteins. Although HES-5 does not bind to the sequence CANNTG (called E box) recognized by other HLH factors, it attenuates the binding of E47, an HLH activator, to E box by forming a hetero-oligomer. In cotransfection analyses using NIH 3T3 cells, HES-5 significantly represses transcription originating from the promoter containing the N box sequences. Furthermore, HES-5 also partially inhibits the E47-induced expression from the promoter containing E boxes. Northern blot, RNase protection, and in situ hybridization analyses demonstrate that the HES-5 mRNA is specifically expressed in the nervous system. Prominent expression is observed in the ventricular zones of the embryonal brain vesicles and the outer nuclear layer of the neural retina. These results suggest that the negative regulator HES-5 may play an important role in neural development.

3T3 Cells↗
PubMed1992

Histochemical analysis of sialomucin in Paget cells of mammary and extramammary Paget's disease.

The cytoplasmic sialomucin in Paget cells of both mammary and extramammary Paget's diseases was examined, using a new method proposed by Volz et al. (1987a, b). The staining methods used involved an electrolyte-Alcian Blue (pH = 5.8) and periodic acid Schiff. Oxidation was performed with 0.4 mmol/l periodate in 1 mol/l HCl at 4 degrees C or 50 mmol/l periodate in distilled water at room temperature for 1 h. Methylation, saponification, borohydride reduction, and digestion with diastase, neuraminidase (Vibrio cholerae) or chondroitinase ABC, were also employed. The cytoplasmic mucin was found to exhibit positive reaction for the above staining which were variously altered by the chemical modification procedures and diminished in intensity or abolished by digestion with neuraminidase. These results suggest that the cytoplasmic mucin in Paget cells is sialomucin without side-chain substituent in genital Paget's disease, and that with a substituent at C7 in mammary Paget's disease.

Breast Neoplasms↗
PubMed1992

Expression of ras proto-oncogene related protein p21 in normal human skin and cutaneous tumours.

The cellular proto-oncogene, ras, is known to play an important role in the regulation of cell growth and proliferation in normal and malignant conditions. The present study was undertaken to immunohistochemically examine the expression of ras protooncogene product p21 in normal human skin and some cutaneous tumours. In normal skin, the expression of p21 was found in sweat glands, sebaceous glands, capillary endothelium, and smooth muscles, while epidermis was devoid of reaction product. Keratoacanthoma and the granular cells of verruca vulgaris were immunoreactive to the antibody for p21. Bowen's disease and squamous cell carcinoma were positive for p21, but basal cell carcinoma and seborrheic keratosis were negative. In mammary and extramammary Paget's diseases, the immunoreactivity was inconsistent. The expression of p21 in malignant melanoma cells was intense, whereas normal melanocytes and nevus cells were devoid of the expression. These results suggest that the expression of p21 does not correlate with nuclear anaplasia and malignant behaviour of cutaneous tumours.

Bowen's Disease↗
PubMed1992

Two mammalian helix-loop-helix factors structurally related to Drosophila hairy and Enhancer of split.

We report the molecular characterization of two novel rat helix-loop-helix (HLH) proteins, designated HES-1 and HES-3, that show structural homology to the Drosophila hairy and Enhancer of split [E(spl)] proteins, both of which are required for normal neurogenesis. HES-1 mRNA, expressed in various tissues of both embryos and adults, is present at a high level in the epithelial cells, including the embryonal neuroepithelial cells, as well as in the mesoderm-derived tissues such as the embryonal muscle. In contrast, HES-3 mRNA is produced exclusively in cerebellar Purkinje cells. HES-1 represses transcription by binding to the N box, which is a recognition sequence of E(spl) proteins. Interestingly, neither HES-1 nor HES-3 alone interacts efficiently with the E box, but each protein decreases the transcription induced by E-box-binding HLH activators such as E47. Furthermore, HES-1 also inhibits the functions of MyoD and MASH1 and effectively diminishes the myogenic conversion of C3H10T1/2 cells induced by MyoD. These results suggest that HES-1 may play an important role in mammalian development by negatively acting on the two different sequences while HES-3 acts as a repressor in a specific type of neurons.

Amino Acid Sequence↗
PubMed1992

Epidermal keratinocytes of bullous pemphigoid express intercellular adhesion molecule-1 (ICAM-1).

Intercellular adhesion molecule-1 (ICAM-1) is the ligand for lymphocyte function associated antigen-1 (LFA-1), mediating the adhesion of lymphocytes to vascular endothelium. Keratinocytes are known to express ICAM-1 in some inflammatory dermatoses. Using an indirect immunofluorescence method, we examined the patterns of ICAM-1 and LFA-1 staining in bullous pemphigoid (BP) lesions and compared them to pemphigus vulgaris (PV) cases. ICAM-1 was expressed on the cell surface and in the cytoplasm of epidermal keratinocytes at the sites of erythematous and bullous lesions of BP. LFA-1 molecules were expressed on T cells at the basement membrane zone. In addition, HLA-DR-positive keratinocytes were observed in the basal layer. ICAM-1 was not, however, expressed on epidermal keratinocytes in uninvolved skin from BP patients, PV or normal control skin. It is known that ICAM-1 is expressed on keratinocytes at the site of lymphoid infiltration in cutaneous dermatoses and that LFA-1-positive T cells can bind to interferon gamma-induced ICAM-1-positive keratinocytes. Our results suggest that cellular immunity involving ICAM-1 and LFA-1 may play a part in the pathogenesis of bullous pemphigoid.

Cell Adhesion↗
PubMed1992

Eosinophil involvement in atopic dermatitis as reflected by elevated serum levels of eosinophil cationic protein.

Eosinophil cationic protein (ECP), one of the eosinophil granule proteins, is released during allergic reactions. We investigated the possibility of correlations among the serum levels of ECP, clinical activity, and eosinophil number in patients with atopic dermatitis (AD). Forty-four patients with AD and 25 normal, non-atopic subjects were studied. ECP was quantitated by a double antibody radioimmunoassay. The levels of serum ECP correlate with the grading of severity of clinical evaluations in AD. The patients with severe and moderate AD had significantly higher ECP concentrations than normal controls (p less than 0.001); mild AD had levels identical with those of control groups. A positive correlation was observed between the number of peripheral blood eosinophils and serum ECP levels in the severe cases (r = 0.67, p less than 0.05). Furthermore, these ECP levels significantly decreased in response to either improvement of clinical severity of AD or decreased numbers of blood hypodense eosinophils in anti-allergic drug-treated patients. No coefficient of correlation was observed between serum ECP and IgE levels. These findings indicate that eosinophils may release their granular contents, including ECP, into the peripheral circulation and/or inflammatory skin lesions and subsequently provoke a clinical exacerbation by stimulating allergic reactions.

Adolescent↗
PubMed1992

Eosinophil phenotypes in bullous pemphigoid.

Eosinophil phenotypes were investigated in peripheral blood and skin lesions from eight patients with bullous pemphigoid (BP). By Nycodenz density gradients fractionation, blood eosinophils were divided into two phenotypes; normodense (greater than 1.080 g/ml) and hypodense (less than or equal to 1.080 g/ml). Increased numbers of hypodense eosinophils were observed in the blood from all patients with BP. Immunocytochemical observations, using an EG2 monoclonal antibody to react with the secretion form of eosinophil cationic protein (ECP), revealed that EG2 was expressed in 86 +/- 3% of hypodense phenotypes and 3 +/- 2% of normodense phenotypes. Ultrastructurally, hypodense eosinophils were characterized by numerous spheroidal granules, each with a lytic crystalloid core. These indicate that the hypodense phenotype represents a cell in an activated state. Only eosinophils with immunocytochemical and morphological characteristics similar to hypodense phenotypes infiltrated around the basement membrane zone in involved skin of BP. Furthermore, direct adherence of eosinophils associated with degranulation into basal keratinocytes was seen at the sites of blistering lesions. Bullous fluids contained higher concentrations of ECP than sera as determined by a radioimmunosorbent assay; thus hypodense (activated) eosinophils may directly damage the basal keratinocytes by releasing their granule proteins, subsequently leading to dermo-epidermal separation.

Aged↗
PubMed1992

Ultrastructural aspects of infiltrated eosinophils in bullous pemphigoid.

By scanning (SEM) and transmission electron microscopy (TEM), we evaluated the infiltrated eosinophils in lesions at various stages of clinical development from patients with bullous pemphigoid (BP) and eosinophilia. Visualized by SEM, numerous inflammatory cells migrated through the cutaneous basement membrane into the cavity of newly formed blisters 12 to 24 hrs after formation. Many migrating cells attached to the reverse side of the bullous cavity, and some basal cells shed into the cavity. As the bullae developed 24 to 48 hrs after formation, the reverse surface of the bullous cavity became predominantly composed of these migrating cells and the exposed squamous cells. The migrating cells had villi, ruffles and ridge-like profiles on their surfaces, which were suggested eosinophils. By TEM in the same lesions, many morphologically activated eosinophils were seen to have passed through the basement membrane into the newly formed blisters; they exhibited spheroidal cytoplasmic granules with less dense crystalloid cores and intracellular channels. Eosinophils infiltrating in the developed bullous cavity directly adhered to basal cells and released their granule contents onto these target cells. These findings suggest that inflammatory cells, especially eosinophils, may amplify the formation of dermal-epidermal separation in BP lesions.

Eosinophils↗
PubMed1992

Surface charge of fractionated guinea pig keratinocytes measured by free-flow cell electrophoresis.

Keratinocytes differentiate from basal cells to spinous, granular, and horny layer cells. It is known that alterations in the surface charge of cell membranes in most cases reflect the processes of differentiation. By using a continuous colloidal silica (Percoll) density gradient, keratinocytes may be separated into three fractions which correspond to their arrangement in vivo. Using a free-flow cell electrophoretic technique, we measured the electrophoretic mobility of guinea pig keratinocytes. Electrophoretic mobility histograms of basal and granular cells showed slow and fast monophasic patterns, respectively. In spinous cells, a biphasic pattern of slow and fast electrophoretic mobility was present. The electrophoretic mobility level of guinea pig keratinocytes was slightly reduced with neuraminidase digestion. Those of human red blood cells and lymphocytes, however, were markedly decreased. These results indicate that membrane charge density is lower in basal cells and higher in granular cells and that the membrane charge density of guinea pig keratinocytes involves not only neuraminic acid residues but also other substance(s). Our results illustrate the alterations of cell membrane charge properties during epidermal cell differentiation.

Animals↗
PubMed1991

Molecular characterization of transcription factors that bind to the cAMP responsive region of the substance P precursor gene. cDNA cloning of a novel C/EBP-related factor.

A cAMP response element (CRE) plays an important role in the cAMP-mediated gene regulation. Several factors that recognize a CRE have been characterized, and it has been shown that they need either covalent modification by protein kinase A or a cofactor such as the adenovirus Ela to function as an activator. In this study we show that the substance P precursor gene expression is regulated by protein kinase A and identify the CRE sequence in its promoter region. We find that a novel factor and ATF2 bind to the region containing the CRE of the substance P precursor gene. The sequence analysis indicates that the novel protein, designated CELF, has a significant homology to C/EBP gene family proteins in the carboxyl-terminal part containing the basic region and the leucine zipper motif. Ubiquitous expression of CELF suggests that this factor is utilized by various genes. Cell-free transcription analyses indicate that CELF is a constitutive transcriptional activator without apparent phosphorylation by protein kinase A. These results demonstrate that multiple factors are responsible for transcriptional control of the substance P precursor gene through the CRE region.

Activating Transcription Factor 2↗
PubMed1991

Adenosine deaminase deficiency due to heterozygous abnormality consisting of a deletion of exon 7 and the absence of enzyme mRNA.

An adenosine deaminase (ADA;EC 3.5.4.4)-deficient B lymphoblastoid cell line BADO5 derived from a Japanese patient with severe combined immunodeficiency disease and two B lymphoblastoid cell lines, BAMO5 from his mother and BAFO5 from his father, were characterized. To identify mutations affecting ADA activity, we prepared cDNAs to ADA mRNAs of the BADO5 cell line for nucleotide sequencing. Sequence analysis of one of the BADO5 ADA cDNA clones revealed deletion of exon 7, and one point mutation of base 629 from G to A that did not affect the amino acid sequence. All clones of the BADO5 cell line so far examined showed the absence of exon 7 by Southern blotting analysis. Ribonuclease protection assay with an RNA probe spanning from exon 5 to exon 11 showed that the BADO5 ADA mRNA had a deletion of exon 7, the BAMO5 mRNA had normal length, and the BAFO5 mRNA had two species with a deletion of exon 7 and with normal length. Consequently, the patient's ADA genes resulted from one allele of the BAMO5 ADA gene that did not produce a detectable mRNA, and the other allele of the BAFO5 ADA gene producing an aberrant mRNA without exon 7.

Adenosine Deaminase↗
PubMed1991

Densitometric determination of human papillomavirus DNA quantities by chromato-scanning in the fluorescence mode.

The quantitation of human papillomavirus DNA isolated from warts by chromato-scanning (fluorescence mode) photographs of ethidium bromide-stained agarose gels is described. Excitation at 200 nm (with a cutoff filter at 400 nm) generates fluorescence from the white portion of the printing paper. The fluorescent intensity correlated with the quantities of DNA in the band of interest. The amounts of DNA were determined using calibration curves of approximately the same size as lambda phage DNA fragments. This general method of quantification is applicable to photographs of other types of polynucleotides capable of being separated and stained in a gel medium.

Bacteriophage lambda↗
PubMed1991

Bullous pemphigoid antigen expression in Pam 212 cells induced by the addition of platelet activating factor.

Platelet activating factor (Paf-acether) is a phospholipid which has various activities including platelet and neutrophil aggregation and eosinophil chemotaxis. We have previously reported that the blister fluids of bullous pemphigoid possess platelet aggregation activity and suggested that Paf-acether might be concerned with the accumulation and activation of neutrophils and eosinophils. In this study, we examined the influence of Paf-acether on BP antigen expression on Pam 212 cells. Paf-acether enhanced the expression of BP antigen on Pam 212 cells and this expression was blocked by Paf-acether antagonist. Our observations might suggest that Paf-acether contributes to the blister formation not only by the activation of inflammatory cells but the enhancement of BP antigen.

Animals↗
PubMed1991

Enzymatic regulation of glycolysis and gluconeogenesis in rabbit periodontal ligament under various physiological pH conditions.

Optimal concentrations of the essential components for analyzing the activity of each enzyme associated with glycolysis and gluconeogenesis in rabbit periodontal ligament were examined, and enzyme assay systems for 15 enzymes including 22 reactions were established using triethanolamine buffer. Specific activities of all the enzymes, except for the gluconeogenic reaction of phosphoglycerate kinase, were systematically evaluated using the optimum buffer for each enzyme, since the activity of each enzyme varied depending on the buffer used. For glycolysis, the activity levels of hexokinase and 6-phosphofructokinase were very low, and consequently these enzyme reactions were inferred to be the rate-limiting steps. For gluconeogenesis, fructose 1,6-bisphosphatase and aldolase activities were extremely low, and the activities of glucose 6-phosphatase, phosphoenolpyruvate carboxykinase and pyruvate carboxylase were undetectable. These results suggest that the periodontal ligament may have no gluconeogenesis capability. With a rise in pH, the activities of the key enzymes of glycolysis gradually increased, and a specific "crossover" point was found between the activities of glyceraldehyde-phosphate dehydrogenase and phosphoglyceromutase. In addition, the activity of fructose 1,6-bisphosphatase, one of the key enzymes of gluconeogenesis, was markedly increased with a rise in pH, although pH changes had no effect on aldolase activity. Consequently, alkaline pH appeared to result in overall stimulation of glycolysis.

Animals↗