Roles of E- and P-cadherin in the human skin

The Ca(2+)-dependent cell-cell adhesion molecules, termed cadherins, are subdivided into several subclasses. E (epithelial)- and P (placental)-cadherins are involved in the selective adhesion of epidermal cells. E-cadherin is expressed on the cell surfaces of all epidermal layers and P-cadherin is expressed only on the surfaces of basal cells. Ultrastructural studies have shown that E-cadherin is distributed on the plasma membranes of keratinocytes with a condensation in the intercellular space of the desmosomes. During human skin development P-cadherin expression is spatiotemporally controlled and closely related to the segregation of basal layers as well as to the arrangement of epidermal cells into eccrine ducts. In human skin diseases E-cadherin expression is markedly reduced on the acantholytic cells of tissues in pemphigus and Darier's disease. Cell adhesion molecules are now considered to play a significant role in the cellular connections of cancer and metastatic cells. Reduced expression of E-cadherin on invasive neoplastic cells has been demonstrated for cancers of the stomach, liver, breast, and several other organs. This reduced or unstable expression of E- and P-cadherin is observed in squamous cell carcinoma, malignant melanoma, and Paget's disease, but cadherin expression is conserved in basal cell carcinoma. Keratinocytes cultured in high calcium produce much more intense immunofluorescence of intercellular E- and P-cadherin than those cells grown in low calcium. E-cadherins on the plasma membrane of the keratinocytes are shifted to desmosomes under physiological conditions, and therein may express an adhesion function in association with other desmosomal cadherins. Soluble E-cadherins in sera are elevated in various skin diseases including bullous pemphigoid, pemphigus vulgaris, and psoriasis, but not in patients with burns. Markedly high levels in soluble E-cadherin are demonstrated in patients with metastatic cancers.

Regressive changes of astroglia in white matter lesions in cerebrovascular disease and Alzheimer's disease patients

The pathogenesis of white matter lesions, which are frequently found in ischemic cerebrovascular disease and Alzheimer's disease, remains unclear. Using light and electron microscopic immunohistochemistry for glial fibrillary acidic protein (GFAP) as a marker, the present study focused on the role of astroglia which show characteristic morphological alterations. Of 29 brains of patients with cerebrovascular disease and Alzheimer's disease, 4 brains showed extensive swelling and vacuolation of white matter astroglia with their processes disintegrated and beaded (termed clasmatodendrosis). No such cells were observed in 6 control patients. Clasmatodendritic astroglia were not intensely eosinophilic using hematoxylin and eosin staining and included large lipophilic granules in their perikarya. These astroglia were immunoreactive for serum proteins such as immunoglobulins, fibrinogen and complement C3, C1q and C3d, as well as for proteins which are known to increase in reactive astroglia, such as vimentin, alpha-B crystallin, apolipoprotein-E and laminin. Double labeling for GFAP and microglial cell markers indicated that these cells were of astroglial lineage. Immunoelectron microscopy for GFAP revealed that clasmatodendritic astroglia had condensed chromatin, lysosomes and large membrane-bound osmiophilic cytoplasmic inclusions, which corresponded to the lipophilic granules observed with light microscopy. These cytochemical features collectively suggest that clasmatodendritic astroglia incorporate edema fluid and phagocytose cellular debris, and eventually degenerate as a result of cerebral edema.

[White matter lesions after occlusion of the bilateral carotid arteries in the rat--temporal profile of cerebral blood flow (CBF), oligodendroglia and myelin]

In the present investigation, we examined cerebral blood flow (CBF), numerical density of oligodendroglia and extent of white matter lesions after bilateral ligation of common carotid arteries in Wistar rats. Doppler flow-meter revealed a reduction of CBF to 30-40% of that before operation after 1 and 3 days, however recovered to 50-60% after 7 and 14 days. Semiquantitative evaluation with immunohistochemistry for transferrin showed a numerical decrease of oligodendroglia in the medial corpus callosum after 14 and 30 days. Tissue rare-faction promptly occurred in the optic nerve and optic tract after 3 days, whereas it was delayed to 7 days after operation and increased in intensity gradually in the other white matter regions. These results indicate that bilateral occlusion of common carotid arteries in Wistar rats elicits a chronic cerebral hypoperfusion, which cumulatively leads to delayed appearance of white matter lesions.

Alterations in glia and axons in the brains of Binswanger's disease patients

BACKGROUND AND PURPOSE

Although increasing attention is being paid to Binswanger's disease, a form of vascular dementia characterized by diffuse white matter lesions, only limited information is available on the pathological changes that occur in the glia and axons in the white matter. We therefore investigated the brains of patients with Binswanger's disease to gain further insight into its pathophysiology.

METHODS

Autopsied brains from patients with Binswanger's disease (group 3; n = 17) were compared with those of nonneurological controls (group 1; n = 5) and controls with large cortical infarcts but without significant white matter lesions (group 2; n = 5). Glial fibrillary acidic protein (GFAP) was used as an immunohistochemical marker for astroglia, leukocyte common antigen (LCA) was used as a marker for microglia, and HLA-DR was used as a marker for activated microglia. Axonal damage was assessed by the accumulation of proteins, which are transported by fast axonal flow, amyloid protein precursor (APP), synaptophysin, and chromogranin A.

RESULTS

Although there was no difference in numerical density of GFAP-immunoreactive astroglia in each group, regressive astroglia were observed in 7 of 17 patients with Binswanger's disease. LCA-immunoreactive microglia were 1.7 times more numerous in Binswanger's disease than in group 1 (P < .05). HLA-DR-immunoreactive-activated microglia were 3.4 times and 2.1 times more numerous in Binswanger's disease as compared with group 1 (P < .01) and group 2 (P < .05), respectively. There was frequent perivascular lymphocyte cuffing, and clusters of macrophages with a decreased number of oligodendroglia were observed in the rarefied white matter. The grading scores for the number of axons immunoreactive for either APP, synaptophysin, or chromogranin A were significantly higher in Binswanger's disease than in group 1 or 2.

CONCLUSIONS

The pathological alterations in Binswanger's diseased brains include regressive changes in the astroglia and activation of the microglia with a decrease in the oligodendroglia, which were associated with the degradation of both myelin and axonal components. These results indicate that an inflammatory reaction and compromised axonal transport, mediated by chronic ischemia, may play an important role in the pathophysiology of Binswanger's disease.

Spontaneous hair follicle cycling may influence the development of murine contact photosensitivity by modulating keratinocyte cytokine production

The development of murine contact hypersensitivity is influenced by hair follicle cycling. Here, we have examined hair cycle-associated fluctuations of murine contact photosensitivity (CPS) to tetrachlorosalicylanilide (TCSA) and its immunologic mechanism(s). When the CPS outcome was monitored in correlation with their spontaneous, synchronized hair cycling, mice aged 8 and 14 weeks, with most of their hair follicles in telogen, exhibited strong CPS responses, whereas 4-, 11-, and 16-week-old mice with a predominance of anagen follicles in a large area of their integument exhibited lower responses. This suggests that the development of CPS is inhibited in mice with anagen hair follicles. Antigen-specific, T-cell receptor V beta 7+ suppressor T cells, which are recognized to down-regulate the CPS response to TCSA, were not generated in sensitized anagen mice. Culture supernatants of epidermal cells derived from mice with anagen hair follicles contained factor(s) that suppress in vivo the development of CPS. It was found that levels of mRNA for tumor necrosis factor alpha (TNF alpha) were markedly decreased in epidermal cells from early anagen to telogen mice, whereas message for IL-1 receptor antagonist (IL-1ra) was transcribed increasingly during this hair cycling. These findings suggest that altered keratinocyte production of these cytokines is involved in mediating the anagen-associated depression of CPS.

T-cell proliferation to superantigen-releasing Staphylococcus aureus by MHC class II-bearing keratinocytes under protection from bacterial cytolysin

Skin colonization with Staphylococcus aureus may exacerbate skin disorders by activation of lesional T cells with release of superantigens. Although T cells are effectively stimulated by staphylococcal superantigens in the presence of epidermal accessory cells, it remains to be elucidated whether in vivo cutaneous colonization with S. aureus can activate T cells. We examined how T cells are stimulated in the presence of keratinocytes by mitomycin C (MMC)-treated S. aureus that are unable to propagate but retain their ability to produce superantigens. Peripheral blood mononuclear cells (PBMCs) proliferated well in response to MMC-treated superantigen-producing S. aureus and bacterial supernatants. When purified T cells were cultured with MMC-treated S. aureus or supernatant in the presence of interferon-gamma-pre-treated keratinocytes, the supernatant, but not MMC-treated S. aureus, stimulated T cells. MMC-treated S. aureus had a cytotoxic effect on keratinocytes. Furthermore, keratinocytes were highly susceptible to alpha-toxin compared with monocytes and B cells functioning as accessory cells in PBMCs. This suggests that a lack of response of T cells to S. aureus plus keratinocytes is due to damage of superantigen-presenting function of keratinocytes by cytolysin. The activity of alpha-toxin was much less stable than that of superantigen during incubation. Given that S. aureus-colonized skin provides circumstances in which viable keratinocytes are exposed to superantigens but not to active cytolysin(s), skin-infiltrating T cells may be effectively stimulated by S. aureus.

Thrombin and trypsin induce granulocyte-macrophage colony-stimulating factor and interleukin-6 gene expression in cultured normal human keratinocytes

We studied the effects of serine proteases on cytokine gene expression by cultured normal human keratinocytes. In resting keratinocytes, steady-state mRNA levels for interleukins IL-1 alpha, IL-1 beta, IL-7, and IL-8, transforming growth factors alpha and beta, and tumor necrosis alpha were sufficient to be detected by our reverse transcriptase-polymerase clozin reaction method. Incubation of keratinocytes with 25 nM trypsin or 1 unit/ml thrombin for 24 hr selectively upregulated mRNA levels for granulocyte-macrophage colony-stimulating factor (GM-CSF) and Il-6 to detectable levels. Keratinocytes secreted GM-CSF and IL-6 protein in response to these proteases. Monensin did not inhibit the gene expression for the cytokines, thereby excluding the possibility of intervention by secreted molecules. Aprotinin and argatroban inhibited the effects of the proteases. SFLLRN and SLIGRL, tethered ligand receptor peptides for thrombin receptor and for proteinase-activated receptor 2 (PAR-2), respectively, duplicated the effects of the proteases on keratinocytes, which expressed mRNA for both receptors. Trypsin increased tyrosine phosphorylated proteins and intracellular free calcium concentrations. Tyrphostin, pertussis toxin, or H-7 suppressed trypsin- and thrombin-induced GM-CSF gene expression. Our results demonstrate that the serine proteases activate thrombin receptors and PAR-2 on keratinocytes, triggering intracellular signaling and then inducing the synthesis of GM-CSF. We speculate that serine proteases modulate the course of physiological and pathological processes in the skin by stimulating keratinocytes to produce the cytokines.

Patients in phase I trials of anti-cancer agents in Japan: motivation, comprehension and expectations

We attempted to characterize the motivation, comprehension and expectations of patients who had given informed consent to participate in phase I trials of anti-cancer agents at the National Cancer Center of Japan. Thirty-three patients were given a simple multiple-choice questionnaire and asked to return it at a later date. The completed survey was returned by 32 patients. The patients were surveyed before they had received any investigational phase I agents. Nineteen per cent of patients were motivated to participate in the phase I trials by the possibility of therapeutic benefit, 9% because participation seemed a better choice than no treatment and only 6% for altruistic reasons. Most patients comprehended the major features of a phase I trial, namely its investigational nature, the unknown effects of the agent investigated and the unclear benefit to the patients themselves. Fifty-nine per cent of the patients anticipated that they might suffer severe or life-threatening side-effects if they participated in the phase I trial, and 43% were able to indicate accurately the purpose of the phase I trial as a dose determination study. Although only a minority of the patients indicated that their motivation to participate was possible treatment benefit to themselves, when answering questions regarding expectations, more than half indicated that there might be personal benefits of varying degrees by participation.

Signalling defect in FMLP-induced neutrophil respiratory burst in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are clonal haematological disorders and MDS neutrophils have various abnormal functions which cause an increased risk of infective mortality. We examined luminol-dependent chemiluminescence and cytoplasmic Ca2+ increase in order to characterize the mechanisms of a signalling defect in MDS neutrophil respiratory burst. In MDS patients, chemiluminescence stimulated with N-formyl-L-methionyl-L-leucil-L-phenylalanine (FMLP) and calcium ionophore A23187 was defective (17.2 +/- 13.7 v 44.3 +/- 16.6, P = 0.001; 42.2 +/- 21.3 v 82.0 +/- 23.6, P < 0.05, respectively), but phorbol 12-myristate 13-acetate (PMA) chemiluminescence was normal (73.4 +/- 26.9 v 79.5 +/- 23.8, P = 0.52). There were no statistical significances in cytoplasmic Ca2+ increase stimulated with FMLP and recombinant human interleukin-8 (rhIL-8) compared with controls (251.1 +/- 104.3 v 272.7 +/- 41.2, P = 0.295; 238.6 +/- 65.0 v 253.9 +/- 38.3, P = 0.567, respectively). Flow cytometric analysis of MDS neutrophils disclosed that most MDS patients showed normal neutrophil cytoplasmic Ca2+ response to FMLP and rhIL-8. However, two patients with refractory anaemia with excess of blasts displayed a significant decrease of both chemiluminescence and cytoplasmic Ca2+ response to FMLP, and they also displayed low expression of FMLP receptor. These data suggest that most MDS patients have low FMLP chemiluminescence which is not due to a defect in the FMLP receptor. It is proposed that defective FMLP chemiluminescence in MDS results from a putative defect in protein kinase C- and Ca(2+)-independent cell-signalling mechanisms. Only a small group of patients have numerical or structural defects in the FMLP receptor, causing significant decrease of neutrophil respiratory burst.

Alterations of the blood-brain barrier and glial cells in white-matter lesions in cerebrovascular and Alzheimer's disease patients

BACKGROUND AND PURPOSE

The underlying cause of white-matter lesions, which are frequent findings in cerebrovascular disease (CVD) and Alzheimer's disease (AD), remains uncertain. We performed immunohistochemical analysis of serum protein extravasation to investigate the function of the blood-brain barrier in white-matter lesions.

METHODS

White-matter lesions were estimated by use of Kluver-Barrera staining in patients diagnosed clinicopathologically as having ischemic CVD (n = 14) and AD (n = 12) and from nonneurological control subjects (n = 6). Axonal damages were investigated by use of immunohistochemistry for amyloid protein precursor. Alteration of the blood-brain barrier was examined with fibrinogen and immunoglobulins used as markers. The numbers of HLA-DR-positive microglia and glial fibrillary acidic protein-positive astroglia were examined comparatively.

RESULTS

White-matter lesions were graded as normal (grade 0) in 14 of the 32 cases (44%), slight (grade I) in 10 cases (31%), moderate (grade II) in 6 cases (19%), and severe (grade III) in 2 cases (6%). Amyloid precursor protein was accumulated most frequently in grade II white-matter lesions. Immunohistochemistry for serum proteins labeled astroglial cell bodies and their processes, which seemed to have sequestered extravasated proteins. The groups with detectable white-matter lesions had significantly higher grading scores for fibrinogen and immunoglobulins than the control group (P < .05). Although the higher scores for serum protein extravasation were statistically significant in ischemic CVD cases (P < .05), there was no significant increase in AD cases. Activated microglia and astroglia were more numerous in the groups with white-matter lesions in both ischemic CVD and AD cases, although this increase in the number of astroglia was not evident in regions with clasmatodendrosis.

CONCLUSIONS

Dysfunction of the blood-brain barrier is more prominent in white-matter lesions seen in ischemic CVD than in AD and may have a role in the pathogenesis of cerebrovascular white-matter lesions.

E- and P-cadherin expression in tumor tissues and soluble E-cadherin levels in sera of patients with skin cancer

The expression pattern of epithelial (E)- and placental (P)-calcium-dependent cell-cell adhesion molecules was examined immunohistochemically in various skin tumors. E- and P-cadherin expression was preserved in nodular and superficial types of basal cell carcinoma (BCC). In well-differentiated squamous cell carcinoma (SCC), E-cadherin on the cell surface of the tumor was reduced but expression of P-cadherin was preserved more frequently at the peripheral sites of the tumor than in the central sites of the tumor. Paget's cells and melanoma cells did not express E- or P-cadherins in the nest of the epidermis. Immunoreactive E-cadherin levels in sera were significantly elevated in patients with invasive Paget's disease, metastatic malignant melanoma and severe types of psoriasis and atopic dermatitis when compared with those of normal controls. Reduced or loss of cadherin in localized tumor cells may be correlated with the proliferation, and the level of soluble E-cadherin in circulation may be a marker in the extent of damaged skin by tumor and/or inflammation.

Selective expansions of T cells expressing V beta 8 and V beta 13 in skin lesions of patients with chronic cutaneous lupus erythematosus

There are several clinical types of cutaneous lupus erythematosus (LE), including acute cutaneous LE (ACLE), which occurs in 50-60% of patients with systemic LE (SLE), chronic cutaneous LE (CCLE), which is almost the same as discoid LE (DLE), and subacute cutaneous LE (SCLE). Although several important hypotheses have been proposed to explain cutaneous LE, the pathomechanisms still remain complicated and obscure. Of special interest is whether and how the T cell receptor (TCR) repertoire of infiltrating lymphocytes is involved in the development of the different types. To address this issue, we immunohistochemically examined the V beta usage of infiltrating T cells in skin lesions, as well as in peripheral blood mononuclear cells (PBMC) of patients with cutaneous LE. The number of V beta 3.1 CD3+ cells in the PBMC of patients with ACLE and CCLE was significantly lower than in controls. In contrast, the number of V beta 3.1 CD3+ cells was elevated in the skin lesion of CCLE over that in psoriasis vulgaris or atopic dermatitis. Furthermore, skin lesions in CCLE patients showed a higher incidence of V beta 8.1 CD3+ and V beta 13.3 CD3+ cells than did those in ACLE patients. These results suggest that skin lesions of CCLE are oligoclonally associated with selective expansions of TCR V beta chains and may be induced by antigen stimuli, including superantigens.

Solvation of Copper(II) Ions in Liquid Ammonia

X-ray absorption fine structure (XAFS) measurements have been performed at -50 degrees C on a 0.4 mol dm(-)(3) copper(II) nitrate solution in liquid ammonia. Extended X-ray absorption fine structure (EXAFS) spectroscopy was used to determine the coordination number and bond distances for the solvated copper(II) ion in solution. The equatorial ammonia nitrogens are located 2.00 Å from the copper and the axial nitrogen 2.19 Å from the copper. However, it was not possible from the EXAFS analysis alone to conclude whether there was one or two axial nitrogens. Therefore, X-ray absorption near-edge structure (XANES) spectroscopy was combined with discrete variational Xalpha (DV-Xalpha) molecular orbital calculations for a series of five- and six-coordinated models to determine the coordination number and the geometry. The experimental XANES spectrum was best reproduced by a model where the copper(II) ion is pentacoordinated in liquid ammonia in a square pyramidal geometry with the copper(II) ion lifted above the average nitrogen plane.

Glial expression of cytokines in the brains of cerebrovascular disease patients

We examined the immunohistochemical localization of the proinflammatory cytokines tumor necrosis factor-alpha, lymphotoxin and interferon-gamma in 22 autopsy brains of patients with either cerebrovascular disease (CVD) or other neurological diseases as well as 2 non-neurological control brains. These cytokines were coexpressed mostly in the microglia/macrophages and in a few astroglia in the brains with acute cerebral infarction and cerebral hemorrhage. In cases with cerebral infarction, they were observed as early as 33 h after the onset of the illness and persisted for up to 40 days after the onset. In one patient with cerebral hemorrhage who survived for 4 h, the cytokine-immunoreactive glial cells were confined to the margins of the hematoma. In contrast, the cytokine-immunoreactive glia were distributed diffusely in one patient with cerebral hemorrhage who died 12 days after the onset of the illness. Labeling for these cytokines was weak in the glial cells of control brains and those with neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and multiple system atrophy, in so far as there were no concomitant acute CVD foci. The present results indicate that proinflammatory cytokines are up-regulated in the brains of patients with acute stroke, and suggest an early inflammatory response in human CVD.

Inhibitors of sphingolipid synthesis modulate interferon (IFN)-gamma-induced intercellular adhesion molecule (ICAM)-1 and human leukocyte antigen (HLA)-DR expression on cultured normal human keratinocytes: possible involvement of ceramide in biologic action of IFN-gamma

To elucidate the participation of sphingosine and ceramide in the biologic action of cytokines on epidermal keratinocytes, we studied whether inhibitors of sphingolipid synthesis modulate interferon (IFN)-gamma-induced intercellular adhesion molecule (ICAM)-1 and human leukocyte antigen (HLA)-DR expression on cultured normal human keratinocytes. Pretreatment of keratinocytes with L-cycloserine or fumonisin B1, but not 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), significantly suppressed both ICAM-1 and HLA-DR expression induced by IFN-gamma. Because the synthesis of all kinds of sphingolipids is blocked by L-cycloserine and all except that of sphinganine by fumonisin B1, whereas PDMP inhibits the synthesis of glucosylceramide and glycosphingolipids, the result suggests the participation of ceramide and/or sphingosine in IFN-gamma-induced ICAM-1 and HLA-DR expression. Exogenous C2-ceramide reversed the effects of L-cycloserine and fumonisin B1. On the other hand, sphingosine reversed the effect of L-cycloserine, but not of fumonisin B1. These results indicate that ceramide participates in this pathway, as fumonisin B1, but not L-cycloserine, inhibits the synthesis of ceramide from sphingosine. In addition, reverse transcriptase polymerase chain reaction showed that L-cycloserine reduced the mRNA for ICAM-1, HLA-DR alpha, and HLA-DR beta induced by IFN-gamma, and C2-ceramide and sphingosine antagonized the effect of L-cycloserine. Furthermore, the degradation rate of fluorescent sphingomyelin into ceramide in keratinocytes was increased by IFN-gamma, suggesting that IFN-gamma activates sphingomyelin hydrolysis in keratinocytes. These observations suggest the possible role of ceramide in IFN-gamma-induced ICAM-1 and HLA-DR expression on keratinocytes. Ceramide may function as an endogenous modulator mediating the cytokine signals in keratinocytes.

Th2 suppressor cells are more susceptible to sphingosine than Th1 cells in murine contact photosensitivity

Murine contact photosensitivity (CPS) to 3,3',4',5-tetrachlorosalicylanilide (TCSA) is a cutaneous delayed-type hypersensitivity reaction in which both positive and negative regulatory pathways exist. The latter pathway is mediated by antigen-specific, CD4+ suppressor T cells (CPS-Ts) that are Th2 cells. We examined the effects of sphingosine and synthetic cell-permeable analogs of ceramide on the cellular kinetics of CPS-Ts and immune lymph node cells from TCSA-photosensitized mice (CPS-LNC), along with other murine T-cell populations. The addition of sphingosine at 10 or 3 microM to in vitro cultures suppressed DNA synthesis of CPS-Ts and Th2 clones, including D10 cells and 24-2 cells, but not that of CPS-LNC or Thl clones, including 23-1-8 and 28-4 cells. This suggested that sphingosine exerts its inhibitory effects preferentially on the proliferation of Th2 cells. Although suppressing DNA synthesis, sphingosine augmented the production and mRNA expression of interleukin-4 (IL-4) and enhanced the expression of the IL-4 receptor in CPS-Ts. In addition, the ability of sphingosine to induce signal transduction of CPS-Ts was confirmed by elevation of the intracellular free Ca++ concentration. Because CPS-Ts exposed to sphingosine exhibited a lower G2M/G1 ratio than control, these seemingly ambivalent phenomena may be caused by retardation of the G1 to S phase progression, a cell-cycle dysregulation known to augment cytokine production. In contrast to sphingosine, cell-permeable ceramide did not affect the proliferation of these cells when stimulated with mitogen/antigen and did not augment IL-4 production by CPS-Ts. Our study suggests that sphingosine modifies the Th1/Th2 balance by preferentially affecting the cellular kinetics of Th2.

Spontaneous autoimmune skin lesions of MRL/n mice: autoimmune disease-prone genetic background in relation to Fas-defect MRL/1pr mice

The autoimmune-prone MRL/Mp-lpr/lpr (MRL/lpr) mouse is characterized by the lpr mutation, which is a defect in the Fas antigen. Since Fas mediates apoptosis, this defect results in CD4-CD8- double negative T-cell proliferation, lupus nephritis, and macroscopic lupus erythematosus-like skin lesions. The control counterpart of MRL/lpr mouse is the MRL/Mp-+/+ (MRL/n) mouse, which lacks the lpr mutation and is almost normal during the first 6 mo of life. The lpr mutation, however, accelerates autoimmune phenomena in MRL/lpr mice. Thus, it is important to investigate autoimmune diseases like systemic lupus erythematosis in relation to the autoimmune disease-prone genetic background of MRL/n mice. We found that skin lesions in aged MRL/n mice had unique characteristics. The first characteristic is spontaneous occurrence, and the second is epidermal cell nuclear immunostaining with IgGs by direct immunofluorescence. The skin lesions in aged MRL/n mice showed milder inflammation than in MRL/lpr mice. A homogeneous pattern of epidermal cell nuclear staining was always associated with nuclear staining in kidney cells and also correlated with the in vitro binding of sera to keratinocytes cultured from newborn MRL/n mice. These results suggest that the skin lesions of aged MRL/n mice are a good model for certain types of cutaneous lupus erythematosus and also can provide new insights into the long-standing controversy whether epidermal cell nuclear staining occurs in vivo.

Geochemical challenge to earthquake prediction

The current status of geochemical and groundwater observations for earthquake prediction in Japan is described. The development of the observations is discussed in relation to the progress of the earthquake prediction program in Japan. Three major findings obtained from our recent studies are outlined. (i) Long-term radon observation data over 18 years at the SKE (Suikoen) well indicate that the anomalous radon change before the 1978 Izu-Oshima-kinkai earthquake can with high probability be attributed to precursory changes. (ii) It is proposed that certain sensitive wells exist which have the potential to detect precursory changes. (iii) The appearance and nonappearance of coseismic radon drops at the KSM (Kashima) well reflect changes in the regional stress state of an observation area. In addition, some preliminary results of chemical changes of groundwater prior to the 1995 Kobe (Hyogo-ken nanbu) earthquake are presented.

Eosinophilic pustular folliculitis effectively treated with recombinant interferon-gamma: suppression of mRNA expression of interleukin 5 in peripheral blood mononuclear cells

Eosinophilic pustular folliculitis (EPF) is characterized clinically by pruritic grouped follicular papules and pustules on the trunk, limbs, and face, and, histologically, by follicular infiltration with eosinophils. The blood eosinophil count is elevated in most patients. Oral minocycline, nonsteroidal anti-inflammatory drugs, diaminodiphenylsulphone, and corticosteroids may induce remission. We report two Japanese men with EPF who responded poorly to the usual therapy. Intravenous injections of recombinant interferon-gamma (rIFN-gamma), 5 x 10(5) to 2 x 10(6) Japan Reference Unit (JRU) (1 JRU roughly corresponds to 4 NIH units) daily for 7 days, cleared the skin lesions and returned the peripheral eosinophil counts to normal in both patients. However, the lesions recurred 2-3 days after rIFN-gamma was stopped. Both patients have received intravenous rIFN-gamma once or twice a week for nearly 1 year without systemic side-effects. Reverse transcriptase-polymerase chain reaction revealed a decreased expression of interleukin 5 (IL-5) mRNA in peripheral mononuclear cells after the rIFN-gamma therapy. rIFN-gamma may become the treatment of choice in recalcitrant EPF, although further studies are needed. It may work by interfering with the immunological function of type 2 T-helper cells, including IL-5 production responsible for the growth and differentiation of eosinophils.