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Biomedical subjects

S Imayama

Publications and source records attributed to S Imayama.

At least 37 records · Page 2Linked to original sources
PubMed1998

Purification and characterization of a novel ceramidase from Pseudomonas aeruginosa.

We report here a novel type of ceramidase of Pseudomonas aeruginosa AN17 isolated from the skin of a patient with atopic dermatitis. The enzyme was purified 83,400-fold with an overall yield of 21.1% from a culture supernatant of strain AN17. After being stained with a silver staining solution, the purified enzyme showed a single protein band, and its molecular mass was estimated to be 70 kDa on SDS-polyacrylamide gel electrophoresis. The enzyme showed quite wide specificity for various ceramides, i.e. it hydrolyzed ceramides containing C12:0-C18:0 fatty acids and 7-nitrobenz-2-oxa-1, 3-diazole-labeled dodecanoic acid, and not only ceramide containing sphingosine (d18:1) or sphinganine (d18:0) but also phytosphingosine (t18:0) as the long-chain base. However, the enzyme did not hydrolyze galactosylceramide, sulfatide, GM1, or sphingomyelin, and thus was clearly distinguished from a Pseudomonas sphingolipid ceramide N-deacylase (Ito, M., Kurita, T., and Kita, K. (1995) J. Biol. Chem. 270, 24370-24374). This bacterial ceramidase had a pH optimum of 8.0-9.0, an apparent Km of 139 microM, and a Vmax of 5.3 micromol/min/mg using N-palmitoylsphingosine as the substrate. The enzyme appears to require Ca2+ for expression of the activity. Interestingly, the 70-kDa protein catalyzed a reversible reaction in which the N-acyl linkage of ceramide was either cleaved or synthesized. Our study demonstrated that ceramidase is widely distributed from bacteria to mammals.

Adult↗
PubMed1998

Intradermal administration of viral vaccines.

Intradermal administration maybe useful in lowering the cost of vaccination against hepatitis B significantly, and may also be helpful for the rapid induction of antibodies, reversing non-responsiveness, improving postexposure prophylaxis and immunising immunocompromised people. In addition, delayed type hypersensitivity skin reaction to the vaccine could serve as a useful marker for the acquisition of T helper type 1 immunoreactivity in vivo. However, there are some disadvantages when using intradermal vaccinations, including the requirement for skilful administration, the absence of approval from licensing authorities, the development of local skin reactions and a lower antibody response when 1/10 of the standard vaccine dose is used. This requires that appropriate vaccination regimens, including the correct vaccine dosage, and vaccination schedule are followed. In the future, a similar vaccination strategy might also be applied for the prevention and control of other infectious diseases. Copyright 1998 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1998

The proliferative properties of tumor cells differentially correlate with the host immune responses in anogenital Bowen's disease.

Bowen's disease is a squamous cell carcinoma in situ that rarely invades into the underlying dermis. In order to evaluate the relationship between the cytological properties of the tumor cells and the host immune response, we have examined the expression of p53 and proliferating cell nuclear antigen (PCNA), and the number of mitotic cells, clumping cells, koilocytes, Langerhans cells (LCs) and dermal lymphoid cell infiltration in 18 cases of anogenital Bowen's disease. When compared with normal anogenital skins (n = 10), a statistically significant number of p53-positive cells, PCNA-positive cells, mitotic cells, clumping cells, koilocytes and dermal lymphoid cells was observed in the cases of Bowen's disease. Importantly, there existed a very strong correlation between the number of PCNA-positive tumor cells and the number of infiltrated dermal lymphoid cells. Moreover, the number of mitotic cells significantly correlated with the number of intratumoral LCs. The in situ hybridization technique for human papilloma virus (HPV) demonstrated that the HPV-infected Bowen's disease showed a similar histological and immunohistological pattern as the HPV-non-infected counterparts, except for increased koilocyte formation and decreased p53 positivity. The present data suggest that the proliferative activity of Bowen's disease significantly correlates with the host immune reaction, and that the host immune system may differentially recognize the different cytological properties of tumor cells in the Bowen's disease.

Adult↗
PubMed1998

A case of episodic angioedema associated with blood eosinophilia: upregulated C5a receptor expression on eosinophils.

A 47-year-old woman was admitted to hospital complaining of swelling and pain of the extremities, accompanied by high fever and generalized erythema. Laboratory examination showed marked blood eosinophilia with elevation of IgM, IgE, and C-reactive protein. All autoantibodies examined were negative. The heart and lungs showed no untoward findings. Biopsies of the skin and muscle revealed cellular infiltration of eosinophils around small blood vessels. Quantitation of C5a receptor (C5aR) expression by flow cytometry using anti-C5aR antibody showed upregulated expression of C5aR on blood eosinophils but downregulated expression on neutrophils. The abnormal C5aR expression on eosinophils and neutrophils became normal after spontaneous resolution of symptoms and blood eosinophilia. The possibility that C5aR expression on granulocytes is related to the pathogenesis of this syndrome may be considered.

Angioedema↗
PubMed1997

Leser-Trélat sign with anaplastic ependymoma--an autopsy case.

A 36-year-old Japanese male, who 7 years previously had been diagnosed as having an ependymoma in the left parietal region, had received surgery, chemotherapy and radiotherapy. He later developed a rapid growth of multiple skin lesions on his back and extremities, which coincided with a regrowth of the tumor. Postmortem examination revealed that the ependymoma showed anaplastic transformation and necrosis; however, no malignancy was observed in the extracranial organs. The skin lesions were histologically diagnosed as seborrheic keratoses. We have, therefore, diagnosed the patient as having Leser-Trélat sign associated with anaplastic ependymoma.

Adult↗
PubMed1997

Increased number of IgE positive Langerhans cells in the conjunctiva of patients with atopic dermatitis.

AIM: To determine the role of Langerhans cells (LCs) found to bear IgE in patients with atopic dermatitis (AD) by evaluating the surface distribution of these cells in the conjunctival epithelium and epidermis of skin lesions in patients with AD. METHODS: The double labelling method was used to evaluate IgE positive cells that were positive for anti-CD1a or anti-CD23 antibody in an epithelial sheet of the conjunctival limbus. Specimens of conjunctiva were obtained from 12 men, six of whom had AD and ocular complications. Five patients without atopic disease served as controls, plus one additional patient with asthma but no AD. A similar study was conducted using epidermal sheets obtained from two patients with AD and from one without AD. RESULTS: The number of CD1a+ cells present in the conjunctival epithelium of the patients with AD significantly exceeded that of the patients without AD. Most CD1a+ cells in the conjunctival epithelium and epidermis from the patients with AD bore IgE on their surfaces. Few such cells from patients without AD bore IgE. No CD23+ cells were found in the patients with or without AD. CONCLUSIONS: The presence of an increased number of LCs bearing IgE on their surfaces in the conjunctival epithelium of patients with AD suggests that these cells may be involved in eliciting the hypersensitivity reaction and participate in ocular inflammation.

Adolescent↗
PubMed1997

Sulfidoleukotriene release test (CAST) in hypersensitivity to nonsteroidal anti-inflammatory drugs.

There is a great need to develop a method for making an accurate and reliable in vitro diagnosis of adverse hypersensitivity reactions to drugs. We measured the amount of sulfidoleukotriene (sLT) released from the peripheral blood leukocytes obtained from 25 patients who developed hypersensitivity reactions following the administration of nonsteroidal anti-inflammatory drugs (NSAIDs); 12 patients demonstrated reactions to Voltaren, 8 patients to Bufferin, and 5 patients to Sedes G. The stimulation index, the ratio of the amounts of sLT (pg/ml) incubated with and without drugs, was considerably higher in the patients than in the controls, which consisted of 5 nonallergic healthy subjects. The sensitivity of the CAST (cellular antigen stimulation test) was evaluated to range from 62.5 to 80%, while the specificity was 70-100%. The CAST may thus be useful as a novel in vitro test system in order to screen for possible hypersensitive reactions to NSAIDs with both reliability and safety.

Adult↗
PubMed1997

Normal-mode ruby laser for treating congenital nevi.

BACKGROUND: Q-switched laser therapy is known to be highly effective in treating dermal melanocytosis and pigmented epidermal lesions. However, to our knowledge, there are no reports on the effectiveness of laser therapy for congenital nevi. We evaluated the clinical efficacy and side effects of normal-mode ruby laser therapy for congenital pigmented lesions containing abundant melanin. OBSERVATIONS: A normal-mode ruby laser (pulse duration, 0.3-1.0 x 10(-3) seconds; energy fluence, 10-30 J/cm2; and spot size, 10 x 10 or 15 x 15 mm) (Toshiba Corp, Tokyo, Japan) was used to treat 3 patients with congenital nevi at intervals of 1 to 4 months. In all 3 cases, the pigmented lesions were significantly reduced almost to the level of the surrounding normal skin after 4 laser treatments. The treated areas were virtually free of scarring, and the skin texture resembled that of the surrounding normal skin. Unsightly hair growth was also reduced. CONCLUSIONS: The normal-mode ruby laser was effective in treating congenital nevi and produced good cosmetic results. The risk of recurrence is unknown, but the 3 patients in our study did not have any recurrences during the 18- to 39-month study period.

Child↗
PubMed1996

Presence of elevated carcinoembryonic antigen on absorbent disks applied to nipple area of breast carcinoma patients.

BACKGROUND: Carcinoembryonic antigen (CEA) is used as a serum marker to detect and monitor the status of various kinds of malignant tumors. To determine whether CEA might be detected in secretions collected topically from around the nipple area, and whether its secretion might differ in a cancerous versus a noncancerous breast, we developed a simple method for collecting and measuring CEA, using a small cellulose membrane disk and an enzyme immunoassay. METHODS: We measured the amount of CEA excreted from the nipple area of 22 healthy control women and 32 women with unilateral breast carcinoma confirmed histologically. Secretions were collected from the nipple area by affixing a small (20 mm diameter) absorbent disk made of nitrocellulose membrane backed with filter paper to that area for 24 hours. Substances absorbed by the membrane were then subjected to an immunoassay for CEA using anti-CEA antibodies. RESULTS: In the 22 healthy subjects, a small amount of CEA (0.6 +/- 0.9 units) was secreted from each nipple, which was equally low regardless of the phase of the menstrual cycle. In contrast, 30 of the 32 women with breast carcinoma secreted significantly greater amounts of CEA from the cancerous (16.1 +/- 8.2) than the noncancerous (2.0 +/- 2.2) breast. Such a difference (14.1 +/- 8.0) in CEA excretion was not observed in the healthy controls (0 +/- 0). CONCLUSIONS: These findings suggest that such disks may provide a simple and noninvasive method of collecting trace molecules, including CEA, in skin secretions around the nipple to evaluate functional disorders of the mammary glands, particularly breast carcinoma. Additional studies are indicated in larger groups of women with various stages of breast carcinoma as well as with benign breast diseases.

Absorption↗
PubMed1996

Hair cortex comedo.

We report two cases of skin lesions that clinically resemble a comedo. Both lesions demonstrated a firm black papule which was histopathologically reminiscent of a dilated hair follicle associated with an abnormality of the hair cortex. These findings are thus considered to represent a unique and peculiar variant of the dilated pore of Winer, and the term "hair cortex comedo" is therefore believed to be suitable for such lesions.

Acne Vulgaris↗
PubMed1996

Spontaneous architectural organization of mammalian epidermis from random cell packing.

The cells of the stratum corneum in the epidermis of some mammalian species are precisely stacked in columns in a honeycomb fashion. The epidermis constantly loses surface cells, which are replaced by basal cells that have differentiated during migration to the surface. The path of this migration is seen as precisely defined columns of cells that are in compressed Kelvin's tetrakaidecahedral form. We present a computer simulation of this architectural organization based on the assumption that the cells that migrate upward occupy less crowded regions. The simulation not only explained the mechanism by which the architecture is maintained during the process of cell replacement, but also showed that the architecture was spontaneously organized from initial cells supplied at random. Living organisms consist of self-organizing systems at various levels; however, self-organizing systems have been investigated mostly at the molecular level. The present computer simulation clarified the self-organizing system at the cellular level.

Animals↗
PubMed1996

Case report: Gianotti-Crosti syndrome associated with human herpesvirus-6 infection.

We report a case of Gianotti-Crosti syndrome associated with human herpesvirus-6 (HHV-6) infection. An eight-month-old girl developed monomorphous papules on her cheeks, buttocks, and extremities after the subsidence of exanthema subitum. Viral antibody analysis confirmed primary HHV-6 infection. HHV-6 may be added to the list of causative agents of Gianotti-Crosti syndrome.

Acrodermatitis↗