Toshio Demitsu

Phagocytosis and bactericidal action of mouse peritoneal macrophages treated with leukotriene B4

The effects of exogenous leukotriene B4 (LTB4) on the resistance of mouse peritoneal macrophages against Salmonella (S.) typhimurium and Pseudomonas (P.) aeruginosa infections were studied. In vitro, LTB4 added to macrophage monolayers at final concentrations of 10(-12)-10(-8) M, enhanced their phagocytosis of S. typhimurium to 2.3 times the control level and that of P. aeruginosa to 1.8 times the control level. The intracellular killing rates were also elevated by the addition of LTB4: for S. typhimurium, 83.3% (LTB4) vs 59.1% (control) and for P. aeruginosa, 46.5% (LTB4) vs 9.2% (control). In vivo, intraperitoneally injected LTB4 (5 ng) enhanced the clearance at 24 h of intraperitoneally injected S. typhimurium from the mouse peritoneal cavity (2.38 x 10(3) +/- 0.94 x 10(3) cells [LTB4] vs 5.73 x 10(5) +/- 1.90 x 10(5) [control]) and spleen (5.00 x 10(2) +/- 0.94 x 10(2) [LTB4] vs 2.47 x 10(4) +/- 0.84 x 10(4) [control]), but this effect disappeared by 48 h. In contrast, in beige mice, an experimental model of the Chédiak-Higashi syndrome that is characterized by susceptibility to bacterial infection, there was no induction of the eliminating effect by intraperitoneal injection of LTB4. Activation of macrophages by exogenous LTB4 seemed to have contributed to such an augmented resistance of macrophages to bacterial infection. This study suggested a possible use of LTB4 in bacterial infectious diseases whereby phagocytes are able to play a key role in host defense.

Spontaneous regression of Merkel cell carcinoma: a comparative study of TUNEL index and tumor-infiltrating lymphocytes between spontaneous regression and non-regression group

Some Merkel cell carcinomas (MCC) have been reported to regress spontaneously. To clarify the mechanisms of spontaneous regression (SR) of MCC, we analyzed the TUNEL index, the labeling index of proliferating cell nuclear antigen (PCNA), the labeling index of bcl-2 protein, and the expression of p53 of the tumor cells. We also evaluated the number of infiltrating lymphocytes surrounding the tumor in the tissue specimens. Among seven patients with MCC (SR: n=4; non-regression (NR): n=3), the TUNEL index in the SR group was significantly higher than that in NR group (5.2 and 2.0%, respectively). In addition, the number of lymphocytes around the tumor nests was also significantly increased in the SR group compared to NR group (1576 and 663 cells/mm(2), respectively). Most of the infiltrating lymphocytes were UCHL-1 positive T-cells. There were no significant differences of the PCNA labeling index, the bcl-2 protein labeling index, and the expression p53 between SR and NR group. These results indicate that apoptosis and local T-cell mediated immune response might be involved in spontaneous regression of MCC.

Acute Generalized Exanthematous Pustulosis Induced by Dexamethasone Injection

A 52-year-old woman, without a history of psoriasis, developed a widespread, sterile pustular eruption on the trunk and extremities 2 days after subcutaneous injection of dexamethasone solution. Skin biopsy revealed subcorneal pustules filled with neutrophils and moderate lymphohistiocytic infiltrate with a few eosinophils in the dermis. There was no evidence of vasculitis. Patch testing showed positive pustular reactions to dexamethasone solution. Histology of this pustule also resembled that of the original eruption. To our knowledge, acute generalized exanthematous pustulosis due to corticosteroid has not been previously reported.

Melanoma in situ of the penis

Melanoma of the penis is rare and the prognosis is very poor. We report a case of melanoma in situ localized on the penile shaft. Melanoma in situ of the penis is extremely rare. We emphasize that early diagnosis of melanoma in situ will improve the prognosis of melanoma of the penis.

Activation of mast cells by silver particles in a patient with localized argyria due to implantation of acupuncture needles

An 83-year-old Japanese woman presented with multiple bluish-black macules and nodules with intense pruritus on the lower back (Fig. 1). She had received acupuncture therapy 20 years previously because of lower back pain. Histology showed a foreign body reaction and brownish pigmented particles in the dermis. Numerous mast cells were found around the pigmented particles. In electron microscopy, mast cells containing electron-dense silver particles in their cytoplasm showed focal or partial loss of granule contents, suggesting piecemeal degranulation (Fig. 2). Mast cells around free silver particles also showed piecemeal degranulation. These activated mast cells probably contributed to the development of pruritus and inflammatory reaction in the present case.

A case of anti-p200 pemphigoid clinically mimicking inflammatory epidermolysis bullosa acquisita.

SIR, Anti-p200 pemphigoid is a new disease entity, which was first described in 1996 by Hashimoto’s group. They described an unusual case with autoimmune subepidermal bullous lesions that clinically resembled bullous pemphigoid and a case with psoriasis vulgaris that developed extensive blister formation. Both the nonpsoriatic patient and the psoriatic patient were characterized by immunoglobulin (Ig)G autoantibodies against a novel 200-kDa lower lamina lucida component. To date, anti-p200 pemphigoid has been shown to present various clinical features. This new autoimmune bullous disease seems to be classified into three clinical forms: (i) coexistence with psoriasis, (ii) presenting the clinical features of vesicular pemphigoid, and (iii) presenting clinically atypical blistering features. In this report, we describe a new patient with anti-p200 pemphigoid clinically mimicking inflammatory epidermolysis bullosa acquisita (EBA). A 28-year-old Japanese male was referred to us because of numerous pruritic bullous skin lesions on the entire body of 2 weeks’ duration. Neither he nor his family had a past history of psoriasis. On physical examination, large, tense bullae and vesicles with erythema, and erosions similar to the skin lesions of bullous pemphigoid were found on his entire body (Fig. 1). The blisters tended to form in an annular arrangement resembling linear IgA bullous dermatosis or dermatitis herpetiformis. Oral and genital mucosae were not involved. Laboratory examinations revealed marked leukocytosis (21Æ8 · 10 L mm) and eosinophilia (37%). Because of the severe skin lesions, systemic prednisolone 100 mg daily was commenced; the dose was tapered down to 60 mg daily within 1 week. Because new blisters still appeared, the patient was treated with the combination therapy of prednisolone 60 mg and azathioprine 100 mg daily. Subsequently, no new bullae developed. The lesions healed, leaving mild scarring or milia formation. The prednisolone and azathioprine were gradually tapered down to 12Æ5 mg and 50 mg daily, respectively, and maintained at that dosage thereafter. Histology of lesional skin taken during the acute phase showed subepidermal blistering with abundant neutrophils, eosinophils and fibrin. Lymphocytes and eosinophils were found in the upper dermis. Direct immunofluorescence showed linear deposits of IgG and C3 at the dermo–epidermal junction. Indirect immunofluorescence using normal human skin sections as a substrate showed circulating IgG autoantibodies against the basement membrane zone (> 1 : 160), which were reactive exclusively with dermal side of 1 mol L NaCl-split human skin (> 1 : 40). Immunoblotting with epidermal and dermal extracts of normal human skin was performed using methods described elsewhere. The patient’s serum reacted with a 200-kDa protein of dermal extract (Fig. 2). The 290-kDa EBA antigen was not detected. Autoimmune subepidermal blistering disorders include bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, linear IgA bullous dermatosis, cicatricial pemphigoid, anti-p200 pemphigoid, anti-p105 pemphigoid, autoanti-p450 pemphigoid, EBA and bullous systemic lupus erythematosus. Anti-p200 pemphigoid has been identified as a new distinct entity and named by Zillikens et al. They identified IgG autoantibodies against a novel 200-kDa lower lamina lucida target antigen in nonpsoriatic bullous disease and a patient with coexisting bullous skin disease and psoriasis. They also described a predominance of neutrophils in the dermal infiltrate in the histology. Several other basement membrane zone components have been suggested as target antigens of autoimmune bullous dermatoses; however, the 200-kDa autoantigen seems to be different from laminins 1, 5 and 6, and type VII collagen. It has not been clearly suggested

A case of multiple subungual glomus tumors associated with neurofibromatosis type 1.

Glomus tumor is a distinctive neoplasm characterized by the presence of cells that resemble the modified smooth muscle cells of the normal glomus body, which is a specialized form of arteriovenous anastomosis. We report a case of multiple subungual glomus tumors associated with neurofibromatosis and review the literature on the pathophysiology of this association.

Paraneoplastic pemphigus mimicking erosive mucosal lichen planus associated with primary hepatocellular carcinoma

A 58‐year‐old Japanese male visited us with painful lesions on the lower lip, oral mucosa and genital region of an 8‐month duration. Histological features of the genital lesion were almost consistent with lichenoid tissue reaction. A few intraepidermal acantholytic keratinocytes were also seen in the suprabasal clefts. Direct immunofluorescence exhibited cell surface immunoglobulin (Ig)G deposition and linear deposition of fibrinogen at the dermoepidermal junction. IgG anti‐desmoglein (Dsg)3 antibody, but not anti‐Dsg1 antibody, was detected in the patients serum by enzyme‐linked immunosorbent assay. Immunoblotting using normal human epidermal extract detected the 210‐kD envoplakin, 190‐kD periplakin and 130‐kD Dsg3. The diagnosis of paraneoplastic pemphigus (PNP) was made. Subsequent investigation revealed a large space‐occupying lesion in the liver. Histological findings from liver biopsy specimen were consistent with hepatocellular carcinoma. The patient has been alive 38 months after the diagnosis of PNP was made, although the liver mass has slowly enlarged. Our case is clinically and histologically similar to erosive mucosal lichen planus. Immunological studies confirmed the diagnosis of PNP. The results of negative Dsg1 and positive Dsg3 were consistent with clinical features showing severe mucosal involvement without cutaneous erosion. In PNP, the association with non‐hematological solid tumor is extremely rare.

Interaction of the profilaggrin N-terminal domain with loricrin in human cultured keratinocytes and epidermis.

The relationship between the two coexpressed differentiation markers, profilaggrin and loricrin, is not clear right now. In this study, we explored the interaction of profilaggrin N-terminal domain (PND) with loricrin in keratinocytes and epidermis. Confocal immunofluorescence microscopic analysis of human epidermis showed that PND colocalized with loricrin. Loricrin nucleofected into HaCaT cells colocalized with PND in the nucleus and cytoplasm. The PND localizes to both the nucleus and cytoplasm of epidermal granular layer cells. Nucleofected PND also colocalized with keratin 10 (K10) in the nucleus and cytoplasm. Immunoelectron microscopic analysis of human epidermis confirmed the findings in nucleofected keratinocytes. Yeast two-hybrid assays showed that the B domain of human and mouse PND interacted with loricrin. The glutathione S-transferase (GST) pull-down analysis using recombinant GST-PND revealed that PND interacted with loricrin and K10. Knockdown of PND in an organotypic skin culture model caused loss of filaggrin expression and a reduction in both the size and number of keratohyalin granules, as well as markedly reduced expression of loricrin. Considering that expression of PND is closely linked to keratinocyte terminal differentiation, we conclude that PND interacts with loricrin and K10 in vivo and that these interactions are likely to be relevant for cornified envelope assembly and subsequent epidermal barrier formation.

Serum levels of vasoactive intestinal peptide are elevated in patients with atopic dermatitis

Vasoactive intestinal peptide (VIP) has been suggested to play some roles in atopic dermatitis. Tissue of VIP levels has been reported to increase in chronic lichenified lesions of atopic dermatitis (AD). To analyze whether serum levels of VIP in AD patients are elevated compared with normal controls and correlated with the disease severity, we measured serum levels of VIP using enzyme-linked immunosorbent assay in 53 patients with AD and 21 healthy individuals. The results showed that serum levels of VIP in AD patients (345.8+/-71.5 microg/ml) were significantly higher than those in healthy individuals (307.1+/-42.6 microg/ml). However, a correlation was not found between serum VIP levels and disease severity, other markers including serum LDH levels, total serum IgE levels, and peripheral blood eosinophil counts in patients with AD. This indicates that VIP levels in AD patients were elevated not only in the skin but also in the serum, suggesting that increased serum VIP levels in the patients with AD might be involved in its pathogenesis.