Motokazu Nakamura

Neuropeptides concentrations in the skin of a murine (NC/Nga mice) model of atopic dermatitis

BACKGROUND It has been reported that the expression of neuropeptides (NPs), and the density and structure of peripheral nerves in atopic dermatitis (AD) are different from those in normal skin. OBJECTIVE We investigated the role of NPs, in the development of AD with quantitative study of substance P (SP) and calcitonin gene-related peptide (CGRP) in the skin of AD-model mice. METHODS We measured the NPs in the skin of mice (NC/Nga as AD-model mice, BALB/c and C57BL/6 as control) by enzyme-linked immunosorbentassay (ELISA). Peripheral nerve fibers and SP in the skin were stained by immunohistochemical staining, using anti-PGP9.5 antibody and anti-SP antibody. RESULTS Under conventional condition, SP concentration in AD-like skin lesions of NC/Nga mice was higher than that in non-affected skin of the same mice. Under specific pathogen-free condition, SP concentration in the skin of NC/Nga mice was higher than that in the skin of BALB/c and C57BL/6 mice. In contrast, CGRP concentration in the skin lesions was lower than that in non-affected skin of NC/Nga mice. SP was detected not only in the nerve fibers in the dermis but also in mast cells in the inflammatory areas. CONCLUSIONS The skin of NC/Nga mice contains more SP congenitally, and environmental factors may aggravate this abnormal condition. We hypothesize that increase of SP accompanied with a decrease of CGRP in the skin may play important roles in the pathogenesis and development of AD.

Ultrastructural characterization of microvasculature in photoaging.

The cutaneous microvasculature was examined by electron microscopy in order to compare its characteristics in photodamaged preauricular skin and in sun-protected postauricular sites of 15 Japanese women aged 58-81 years. The characteristic ultrastructural features of the microvasculature in photodamaged skin compared with those in sun-protected skin included dilated vessels embedded in elastin which depressed endothelial cells, vessels surrounded by a thick amorphous material composed of multiple laminations of a basement membrane-like material, and activated endothelial cells which had increased numbers of cytoplasmic organelles and pinocytotic vesicles. A novel finding of this study in photodamaged vessels was an increased formation of new vessels (angiogenesis) via two distinct pathways. In severe elastosis, activated endothelial cells with densely packed intracytoplasmic microfilaments extended large pseudopods into the elastotic material. In contrast, isolated mesenchymal cells, which possessed immature Weibel-Palade bodies, were scattered around pre-existing vessels within the Grenz zone. In some cases, many mesenchymal cells with electron-lucent cytoplasms aggregated and interconnected by cytoplasmic processes, which was followed by the formation of vascular structures. These results suggest that there are significant ultrastructural differences in vessels between photoaged and intrinsically aged facial skin and that the photodamaged microvascular system is characterized by the co-existence of regressive changes and angiogenesis.

Propionibacterium acnes biotypes and susceptibility to minocycline and Keigai‐rengyo‐to

Background  Propionibacterium acnes is the predominant organism in acne lesions, but the sensitivity of different biotypes of P. acnes to therapeutic agents has seldom been reported.

Anti-lipase activity of Kampo formulations, coptidis rhizoma and its alkaloids against Propionibacterium acnes.

Anti‐lipase activity of Kampo formulations, Coptidis Rhizoma (CR), and its alkaloids against Propionibacterium. acnes were examined in vitro. The amounts of propionic and butyric acids in the medium were measured as growth and lipase activity of P. acnes, respectively. In tributyrin‐PYG medium with each concentration of Kampo formulation, CR, or the alkaloids added, the production of propionic acid was suppressed remarkably more than that of butyric acid. The suppression of production of these acids by CR was higher than that of the alkaloids. Furthermore, no lipase‐negative colonies were found on the medium to which Kampo formulations were added.

Activity of Eleven Kampo Formulations and Eight Kampo Crude Drugs against Propionibacterium acnes Isolated from Acne Patients: Retrospective Evaluation in 1990 and 1995

We reviewed the susceptibility of Propionibacterium acnes to eleven Kampo formulations and to eight Kampo crude drugs that had been studied by examining their minimum inhibitory concentrations (MIC) in 1990 and 1995. P. acnes strains were most sensitive to Oren‐gedoku‐to (OGT) among these Kampo formulations. Coptidis Rhizoma (CR) and Phellodendri Cortex (PC) inhibited the growth of P. acnes significantly among the eight Kampo crude drugs examined. The patterns of distribution of MIC of Kampo formulations and Kampo crude drugs to P. acnes in this study were almost the same as in our previous report in 1990. No significant increases in MIC of Kampo formulations and Kampo crude drugs to P. acnes were observed.

Morphological analysis of skin in senescence-accelerated mouse P10

Senescence-accelerated mice (SAM) were established as a kind of group of related inbred strains that have been used as animal models for accelerated senescence and age-associated disorders. To analyze the characteristics of skin in SAM, the present study examined its morphology at the histological and ultrastructural levels. Histologic comparison of skin from senescence-accelerated-prone (SAM P10) and -resistant (SAM R1) mice revealed that the most characteristic features of SAM P10 were remarkable increases in the number of mast cells and in the density of collagen fibers in the dermis. Therefore, cutaneous allergic responsiveness and the proliferative activity of fibroblasts were also examined. Ultrastructurally, mast cells in the skin of SAM P10 possessed specific granules which exhibited considerable heterogeneity in electron density and various degrees of degranulation. In contrast, mast cells in the skin of control SAM R1 possessed a population of stable granules. Mast cell granules were frequently in contact with fibroblasts and were in close apposition to collagen fibers in the dermis of SAM P10. The collagen bundles were disorganized, and various diameters of collagen fibers were observed. SAM P10 demonstrated a significantly reduced wheal-and-flare reaction to histamine and tachykinins such as substance P, which suggests that skin aging may cause reduced sensitivity of mast cells and/or blood vessels to extrinsic stimuli. An in-vitro study using organ and monolayer culture demonstrated that the proliferative capacity of fibroblasts in the skin of SAM P10 was reduced in comparison with SAM R1. This is the first report that demonstrates the detailed morphological characteristics of skin in SAM P10. The findings obtained suggest that SAM P10 is a useful animal model of aged human skin, because of its many similar morphological features, including the reduction of the cutaneous allergic response, represented by neurogenic inflammation via the axon reflex, and its decreased fibroblast proliferation.

Distribution to the skin of epinastine hydrochloride in atopic dermatitis patients.

Auteur(s) : Remi Letestu1, Florence Nguyen-Khac2, Frederic Davi2 1Service d’hematologie biologique, hopital Avicenne, 125, route de Stalingrad, 93000 Bobigny 2Service d’hematologie biologique, hopital Pitie-Salpetriere, 47-83, bd de l’Hopital, 75013 Paris La leucemie lymphoide chronique (LLC) est caracterisee par une evolution remarquablement heterogene. Alors que certains patients ont une maladie totalement indolente pendant des dizaines d’annees, d’autres meurent [...]

Ultrastructural characteristics of trichilemmal cysts : report of two cases

Two trichilemmal cysts (TC) on the scalps of two Japanese women were examined at the electron microscopic level. The ultrastructural characteristics of the TC included an abrupt transition from nucleate to anucleate cells, a few oval, small, keratohyaline granules mixed with increasing numbers of tonofibrils from the peripheral layer towards the center, spherical particles with lipid droplets, desmosomal structures in keratinized cells, and the interdigitation of keratin in the uppermost keratinizing cells. The keratinization pattern of the TC was unique in that typical soft or hard keratinization processes did not occur. Trichilemmal keratinization is observed in the trichilemmal sacs that surround the lower ends of catagen or telogen hairs, as well as in the outer root sheaths in the follicular isthmus of anagen hairs. Comparison of the ultrastructure of these two known types of trichilemmal keratinization with the keratinization pattern of the TC in our patients indicates that TC may differentiate into, or originate from, the proliferation of the outer root sheath in the follicular isthmus of anagen hairs.

Ultrastructural characterization of the distribution of melanin and epidermal macrophages in photodamaged skin

We examined the characteristics of melanin distribution, the possible mechanisms underlying the histological incontinence of pigment, and the significance of epidermal macrophages in photodamaged skin. We used electron microscopy to compare and quantitate melanin distribution in various types of cells and structures, to qualitatively observe associations of melanin granules with melanophages, and to examine morphological differences of epidermal macrophages in sun-exposed versus sun-protected facial skin. Melanin-containing cells (such as Langerhans’ cells) and melanin-containing structures (such as colloid bodies) in photodamaged skin were more numerous than in sun-protected skin, in proportion to differences in melanocyte density and in epidermal melanin content. Although the precise mechanism(s) of histological incontinence of pigment in photoaging skin appear to be very complicated, it is certainly one of the morphological hallmarks of photodamaged facial skin, and the degeneration of keratinocytes (noted by their electron-lucent properties), a feature characteristic of photoaging, contributes to that process. Furthermore, the increased numbers of epidermal macrophages in sun-exposed skin may be associated with photoaging processes (probably through their phagocytic function) as well as alterations of the cutaneous immune system.

Merkel cell carcinoma.

A 77-year-old woman had noticed a red papule on her head about 2 years before. The eruption gradually increased in size. So she visited our clinic on June 19th, 1995. Clinically, it consisted of the firm, nodular, reddish lesion, the size of which was 25×20mm in diameter. Total resection was carried out 1cm apart from the margin of the lesion. Histologically, tumor cells showed a trabecular pattern or bands with a rather uniform appearance, which extended from the dermis into subcutis. The tumor cells had oval, vesicular nuclei and scanty cytoplasm. Numerous mitotic figures were also present. Ultrastructurally, there were observed paranuclear aggregation of intermediate filaments and dense core neurosecretory granules which were located in the cytolasmic processes or near the Golgi apparatus. Immunohistochemically, cytokeratin 8, 18, 19, 20 and epithelial membrane antigen were positively stained within tumor cells. Tumor cells showed partially positive labeling against chromogranin A, neurofilament and neuron specific elorase. S-100 and HMB-45 were negative. From the findings above, this case was diagnosed as Merkel cell carcinoma. It was suggested that perinuclear bandles were related to the partial positive staining of neurofilament.