Animal models for retinitis pigmentosa induced by MNU; disease progression, mechanisms and therapeutic trials.

Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases in humans characterized by loss of photoreceptor cells leading to visual disturbance and eventually to blindness. A single systemic administration of N-methyl-N-nitrosourea (MNU) causes retinal degeneration in various animal species. The retinal degeneration is highly reproducible, and the photoreceptor cell loss occurs within seven days after MNU administration via apoptosis resembling human RP. Here, we describe the disease progression, disease mechanisms, and therapeutic trials of MNU-induced retinal degeneration.

IL-4/IL-13 antagonist DNA vaccination successfully suppresses Th2 type chronic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic disease with a Th2-type-cytokine dominant profile. Several cytokines and related peptides have been used for the treatment of AD but they were ineffective because of their limited biological half-life. We have recently developed a highly efficient mouse dominant negative interleukin (IL)-4/IL-13 antagonist (IL-4DM), which blocks both IL-4 and IL-13 signal transductions. OBJECTIVE: To examine the effects of IL-4DM in vivo in an AD model induced by the repeated exhibition of oxazolone (OX). METHODS: Plasmid DNA was injected intraperitoneally to cause an experimental AD-like dermatitis. The effect was evaluated by ear thickness, histological findings, and mast cells counts in the inflamed skin. The plasma IgE and histamine levels were measured. Cytokine production in skin and splenocytes were also analysed. RESULTS: Mice treated with control plasmid developed marked dermatitis with mast cells and eosinophil infiltration, and had increased plasma IgE and histamine levels with a Th2 type splenocyte cytokine profile. Treatment with mouse IL-4 DNA augmented the ear swelling and thickness with an increased dermal eosinophil count, plasma histamine level, and production of splenocyte IL-4. However, IL-4DM treatment successfully controlled the dermatitis, decreased the mast cell and eosinophil count, and suppressed plasma IgE and histamine levels. Splenocytes produced an increased level of IFN-gamma. CONCLUSION: These data showed that the simultaneous suppression of IL-4/IL-13 signals successfully controlled Th2-type chronic dermatitis. IL-4DM DNA treatment is a potent therapy for AD and related diseases.

Role of fatty acids in malignancy and visual impairment: epidemiological evidence and experimental studies.

International variation in breast and colon cancer incidence is positively related to total fat intake. However, total fat consists of different fatty acid families, e.g., saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and n-3 and n-6 polyunsaturated fatty acids (PUFAs). Epidemiological evidence and experimental studies suggest that these fatty acid families have different effects on breast and colon carcinogenesis. Therefore the action of each fatty acid on carcinogenesis should be evaluated separately. Although it is difficult to establish firm conclusions on the effect of each fatty acid in human epidemiological studies, experimental studies on animals and cultured cells suggest that n-6 PUFAs (linoleic acid and arachidonic acid) may have a tumor promoting effect, while n-3 PUFAs (eicosapentaenoic acid, docosahexaenoic acid and alpha-linolenic acid) and conjugated fatty acids (CFAs; a mixture of positional and geometric isomers of PUFAs with conjugated double bonds) exert an inhibitory effect on tumor growth. SFAs such as palmitic acid and stearic acid show little or no tumor promoting effect, and the action of oleic acid, a MUFA, is inconclusive. In addition to regulation of abnormal cell growth seen in cancers, fatty acids also control cell loss seen in degenerative eye diseases, such as degeneration of lens material in cataract and degeneration of photoreceptor cells in retinitis pigmentosa. Experiments suggest that n-6 PUFAs cause deleterious effects, while n-3 PUFAs result in beneficial effects on the lens and retina. In particular, docosahexaenoic acid is known to be effective in rescuing photoreceptor cells from damage. Thus, understanding the function of each fatty acid is likely to be important for making progress in treating these and other diseases.

Cytokeratin expression in subungual squamous cell carcinoma.

Cytokeratin expression in subungual squamous cell carcinoma was investigated in order to evaluate the origin and state of differentiation of the tumour. The tumour nests contained cytokeratin 14, 16 and 17, which were also expressed in the nail bed. Therefore, cytokeratin expression in subungual squamous cell carcinoma may reflect its indolent clinical prognosis.

Keratinizing squamous epithelium associated with Syringocystadenoma papilliferum differentiates towards infrainfundibulum: case report with immunohistochemical study of cytokeratins.

We describe a case of Syringocystadenoma papilliferum (SCAP) with keratinizing squamous epithelium in a 26-year-old female presenting with a dark brown to black nodule on her forehead. After surgical excision, the specimen was examined immunohistochemically using antibodies against cytokeratin (CK) 1, 8, 10, 14, 17, 18 and 19. Within the keratinizing squamous epithelium, CK1, 10, 14 and 17 were present, whereas the other CKs were absent. Based on CK expression, keratinizing squamous epithelium in SCAP seems to differentiate towards the infrainfundibulum.

Trichilemmoma: an immunohistochemical study of cytokeratins.

BACKGROUND: The histogenesis of trichilemmoma remains unclear. OBJECTIVES: To clarify the histogenesis of trichilemmoma by evaluating its cytokeratin (CK) expression. METHODS: In three cases of trichilemmoma, CK expression was studied immunohistochemically using seven antikeratin antibodies against CK1, 10, 14-17 and 19, respectively. RESULTS: CK1 and CK10 were present in keratinizing ductal epithelium. CK14 was present in the whole layer. CK15 was present in suprabasal layers in two cases. CK16 was present in the suprabasal layer, but was absent in keratinizing ductal epithelium. CK17 was present in suprabasal layers and the sebaceous duct-like structure. CK19 was totally absent. CONCLUSIONS: These results showed that trichilemmoma may differentiate mainly towards two directions: infundibular keratinization and proliferation of the outer root sheath with undifferentiated and pluripotent characteristics.

Immunohistochemical study of cytokeratins in hidradenitis suppurativa (acne inversa).

In 14 cases of hidradenitis suppurativa, cytokeratin (CK) expression was studied immunohistochemically, using six antikeratin antibodies against CK1, CK10, CK14, CK16, CK17 and CK19, respectively. The draining sinus tract epithelium of hidradenitis suppurativa lesions was divided into three components: infundibular-like keratinized epithelium (type A), non-infundibular keratinized epithelium (type B), and non-keratinized epithelium (type C). In type A samples, CK17 (which is found in normal infundibulum) was not detected, suggesting fragility of this epithelial type. Keratin expression in types B and C epithelia was similar to that observed in the outer root sheath in normal hair follicles. Our results suggest that the draining sinus epithelium may possess characteristics of fragility, undifferentiation and hyperproliferation, as shown with CK expression.

Cytokeratin expression in pilonidal sinus.

BACKGROUND: Pilonidal sinus (PS) is considered to belong in the category of follicular occlusion diseases (acne triad). OBJECTIVES: The aim of our study was to elucidate the pathogenesis of PS by evaluating its cytokeratin (CK) expression. METHODS: CK expression in nine cases of PS was studied immunohistochemically using six antikeratin antibodies. RESULTS: Infundibular-like epithelium contained CK1, 10 and 14 similar to normal infundibulum, but it did not contain CK17. In non-infundibular-like epithelium, CK14, 16 and 17 were detected similar to that in normal outer root sheath. CK expression in PS was similar to that in hidradenitis suppurativa, suggesting that sinus epithelium may be fragile, hyperproliferative and undifferentiated. CONCLUSIONS: PS can be classified in the same entity as follicular occlusion diseases based on CK expression.

Cytologic features of a primary myxoid malignant fibrous histiocytoma arising in the uterus: a case report.

BACKGROUND: Primary malignant fibrous histiocytoma (MFH) of the uterus is extremely rare. The 10 cases reported in the literature all involved the pleomorphic variant, and to the best of our knowledge, the myxoid variant has not been reported before. We describe the cytologic findings of primary uterine myxoid MFH in relation to the myxoid component, potentially leading to an incorrect diagnosis. CASE: A 68-year-old woman presented with a primary uterine tumor. Endometrial cytology showed numerous loosely arranged, spindle-shaped fibroblastlike cells; atypical histiocytelike cells; and giant cells with a necrotic background. The overall cytologic picture was of a degenerated pleomorphic leiomyosarcoma with an inconclusive diagnosis. A diagnosis of myxoid MFH was established after electron microscopic and immunohistochemical studies of the primary tumor and tumor transplanted, as primary cultured cells, in nude mice. The patient underwent an exploratory laparotomy and died of tumor progression 38 days after the initial consultation, without treatment. CONCLUSION: Because of overlapping cytologic features among uterine sarcomas with myxoid stroma, it is important to recognize the histiocytic lineage of tumor cells by immunohistochemistry and electron microscopy in various presentations of fresh samples.

Bone morphogenetic protein-2 and type IV collagen expression in psammoma body forming ovarian cancer.

Psammoma bodies (PBs), characterized as calco-spherules with concentric laminations, are common in serous tumors of the ovary. However, there is no agreements as to how the PBs are formed. Bone morphogenetic protein-2 (BMP-2) has recently been proposed to be involved in the calcification of tumor cells and recent electron microscopic studies demonstrated the presence of type IV collagen in PBs. Based on this evidence, we postulated a possibe role for BMP-2 and type IV collagen in the formation of PBs in ovarian cancer. We examined the expression of BMP-2 and typle IV collagen by immunohistochemistry and reverse transcription PCR (RT-PCR) in PBs-forming (NK-211) and -non-forming (SHIN-3, KF-1, A2780, KK-92, KOC-2S, SKOV-3, OMC-3, MN-1, EC, and KEN-3) ovarian cancer cell lines in vitro and in surgical specimens of serous adenocarcinoma (SA) with/without PBs and mucinous adenocarcinoma (MA) of the ovary. Cellular growth of cell lines was also evaluated by their doubling time in vitro. Transcripts for BMP-2 mRNA were detected by RT-PCR in all cell lines. By immunohistochemistry, BMP-2 protein expression was positive in 45% (5 out of 11) of cell lines. 36.4% (4 out of 11) were positive for type IV collagen. PBs-forming NK-211 was intensively positive for both BMP-2 and type IV collagen. In addition, NK-211 demonstrated extremely slow growth with a doubling time of 450 hours. In surgical specimens, BMP-2 vs. type IV collagen positivities in tumor cells were 100% (20 out of 20) vs. 40% (8 out of 20) in SA with PBs, 61.1% (11 out of 18) vs. 0% (0 out of 18) in SA without PBs and 75% (9 out of 12) vs. 0% (0 out of 12) in MA. In PBs themselves, 100% (20 out of 20) positivity for BMP-2 and 80% (16 out of 20) for type IV collagen was shown. These results raise the possibility that BMP-2 and type IV collagen-producing slow growing tumor cells form PBs in ovarian cancer.

Myxoid malignant fibrous histiocytoma of the uterus: a case with immunohistochemical, ultrastructural and tumor cell culture studies.

The clinical and pathological features, including ultrastructural and immunohistochemical findings, of a primary myxoid malignant fibrous histiocytoma of the uterus in a 60-year-old woman are reported. Microscopically, the principal feature of the tumor was a hypocellular area with diffuse degeneration, containing thin-walled curvilinear vessels, in which hyperchromatic small spindle and stellate cells, sometimes with vacuolated cytoplasm, were found. The transplanted tumor of primary cultured cells in nude mice presented as a prominent myxoid stroma confirming the histological structure of the primary tumor. Immunohistochemically, the presence of epithelial or heterogenous mesenchymal tumor components or cells of smooth muscle derivation were excluded and the tumor cells were positive for vimentin, CD 68, alpha 1-antitrypsin and alpha 1-antichymotrypsin. Ultrastracturally, pseudopodia and filopodia at the cell membrane and intracytoplasmic lysosomal granules were common. The patient had debulking surgery but died 38 days after the primary onset with the tumor occupying the entire abdomen and the pelvis.

Clear suppression of Th1 responses but marginal amelioration of autoimmune manifestations by IL-12p40 transgene in MRL-FAS(lprcg)/FAS(lprcg) mice.

To investigate the effects of overproduction of IL-12p40, a potent antagonist against IL-12, on lupus-like autoimmune disease in vivo, we generated p40 transgenic MRL-Fas(lprcg)/Fas(lprcg) mice. Serum p40 and IL-12 levels were 600- to 8000-fold and 3- to 20-fold higher in transgenic (p40-lpr(cg)) than nontransgenic (lpr(cg)) mice, respectively. Serum IFN-gamma levels increased after 3 months of age in lpr(cg) and this age-related increase was completely abrogated in p40-lpr(cg). Serum IL-4 levels were the same in both mice. Production of IgM and IgG anti-double-stranded DNA (dsDNA) antibodies was significantly lower in p40-lpr(cg). Anti-dsDNA antibodies decreased in Th1-dependent IgG2a but increased in the Th2-dependent IgG1 subclass significantly in p40-lpr(cg). Proteinuria, glomerulonephritis, and survival were only marginally ameliorated in p40-lpr(cg). The results suggest that excess p40 production in vivo may suppress Th1 responses in autoantibody and IFN-gamma production but lead to minimal improvement of clinical manifestations of autoimmune disease in this mouse model.