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Notes: Basal cell carcinoma (BCC) is a frequent skin cancer with low metastalic potential. Expression of the anchoring filament proteins, native laminin-5 and its individual α3, β3 and γ2 chains, uncein, and linear IgA antigen was examined by immunostaining in 17 BCC with different histological subtypes. Immunoreactivity of the hemidesmosomal proteins, integrin α6β4. 230-kDa bullous pemphigoid antigen (BP-230 Ag) and plectin/HD-1, and that of dermal-epidermal junction (DEJ) components, integrin α2β1, laminin-1, collagen IV, and collagen VII was also analysed. Around tumour nests, the labelling of laminin-5 was absent or markedly reduced in 12 BCC (comprising eight solid BCC, three adenoid BCC and one keratotic BCC) and strong in five BCC (comprising three adenoid BCC, one keratotic BCC and one adenoid and keratotic BCC). Intriguingly, in tumour cells of 12 BCC including laminin-5 negative tumours, a cytoplasmic reactivity of the laminin 72 chain was detected, but not that of the α3 and β3 chains. In the basement membrane of the epidermis overlying tumour nests, the labelling of laminin-5 was always strong. Uncein, linear IgA disease antigen, and integrin α6β4 were absent in solid BCC and weakly expressed in adenoid or keratotic BCC. For plectin/HD-1 and BP-230 Ag, a cytoplasmic reactivity was detected in the majority of the tumour cells. The labelling of integrin α2β1, laminin-1, collagen IV and collagen VII indicated no alteration in the synthesis of these proteins. In peritumoral lacunae, immunoreactivity of hemidesmosome and anchoring filament proteins was absent, except for plectin/HD-1 on the tumour side and sometimes for laminin-5 on the stromal side, while laminin-1, collagen IV and collagen VII were detected on the stromal side. These findings suggest that the components of the hemidesmosome-anchoring filament complex are not synthetized or assembled properly in BCC, and that the alteration of these adhesion structures may be the cause of peritumoral lacunae.

Notes: To report the results of a prospective, open-label, uncontrolled study in 13 patients affected by Crohn’s disease with resistance to steroids.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:The patients were treated long-term with oral tacrolimus, aiming to both resolve acute attacks and maintain remission. Tacrolimus was administered at the dose of 0.1–0.2 mg.day/kg and adjusted in order to achieve levels of 5–10 ng/mL; only mesalazine was continued concomitantly. Steroids and total parenteral nutrition were tapered when appropriate.〈section xml:id="abs1-3"〉〈title type="main"〉Results:Median treatment was 27.3 months. Only one patient dropped out due to adverse events. Crohn’s disease activity index score significantly decreased after 6 months in 11 patients; for 1 year in nine of them, and 7 years in two of them. The inflammatory bowel disease life-quality questionnaire score significantly increased over the same periods. A marked drop in hospitalizations was recorded. In three out of six patients complete closure of fistulas occurred. Tacrolimus allowed total parenteral nutrition to be withdrawn in three out of five patients. Supplementation with low-dose steroids was required in five patients. Two patients underwent surgery.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusions:Tacrolimus therapy appears to be associated with both short- and long-term benefits, and may represent a therapeutic option in Crohn’s disease when conventional therapies fail. This study encourages its use in controlled trials.

Notes: Summary The aim of this study was to characterize cell-cell and cell-matrix interaction by evaluating the expression of different integrins in the nail matrix.Nail biopsies were obtained from two cadaver lingers, and eight patients with ingrowing toenails. Frozen sections were stained by indirect immunofluorescence using anti-α, anti-α2, anti-α3 anti-α4, anti-α5, anti-α6, anti-αv, anti-β. anti-β4 and anti-ICAM-1 monoclonal antibodies. Biopsies from normal human foreskin were evaluated as controls, α. α4 and α5 subunits were absent from both nail matrix and normal human skin. α2, α3 and β1 subunits were expressed in the basal and suprabasal layers of nail matrix, but only in the basal layer of skin epidermis, α6 and β4 subunits were strongly expressed in the basement membrane zone and in the basal layer of both nail matrix and epidermis. The αv subunit was expressed in the basal layer of nail matrix. ICAM-1 was not expressed in nail matrix epidermis.Our findings show that despite the distinctive features of the nail apparatus, compared with the epidermis, the pattern of integrin expression Is similar, although some differences in the distribution of α2. α3 and β1 subunits are detectable. These are probably related to the peculiar differentiation and keratinization of the nail.

Notes: Summary The expression of tenascin, a recently discovered extracellular matrix protein, was studied by immunohistochemical techniques in scleroderma skin and compared with its distribution in normal skin. In progressive systemic sclerosis, a marked increase in tenascin content was observed in the superficial reticular dermis. In localized scleroderma, the deposition of tenascin was increased both in the superficial and deep dermis of involved skin, whereas in clinically uninvolved skin the distribution of tenascin was the same as in normal control skin, i.e. the papillary dermis and periappendageal zone. The distribution of tenascin did not strictly parallel that of fibronectin. These findings and the current knowledge of tenascin biology suggest that the overproduction of tenascin in scleroderma dermis could be secondary to stimulation of fibroblasts by immune cell-derived cytokines, or could be due to abnormal fibroblasts, or a subpopulation of fibroblasts, producing high levels of this extracellular matrix protein.

Notes: We have studied the effects of tetanic stimulation of the corticostriatal pathway on the amplitude of striatal excitatory synaptic potentials. Recordings were obtained from a corticostriatal slice preparation by utilizing both extracellular and intracellular techniques. Under the control condition (1.2 mM external Mg2+), excitatory postsynaptic potentials (EPSPs) evoked by cortical stimulation were reversibly blocked by 10 μM 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), an antagonist of dl-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) ionotropic glutamate receptors, while they were not affected by 30–50 μM 2-amino-5-phosphonovalerate (APV), an antagonist of N-methyl-d-aspartate (NMDA) glutamate receptors. In the presence of 1.2 mM external Mg2+, tetanic activation of cortical inputs produced long-term depression (LTD) of both extracellularly and intracellularly recorded synaptic potentials. When Mg2+ was removed from the external medium, EPSP amplitude and duration increased. In Mg2+-free medium, cortically evoked EPSPs revealed an APV-sensitive component; in this condition tetanic stimulation produced long-term potentiation (LTP) of synaptic transmission. Incubation of the slices in 30–50 μM APV blocked striatal LTP, while it did not affect LTD. In Mg2+-free medium, incubation of the slices in 10 μM CNQX did not block the expression of striatal LTP. Intrinsic membrane properties (membrane potential, input resistance and firing pattern) of striatal neurons were altered neither by tetanic stimuli inducing LTD and LTP, nor by removal of Mg2+ from the external medium. These findings show that repetitive activation of cortical inputs can induce long-term changes of synaptic transmission in the striatum. Under control conditions NMDA receptor channels are inactivated by the voltage-dependent Mg2+ block and repetitive cortical stimulation induces LTD which does not require activation of NMDA channels. Removal of external Mg2+ deinactivates these channels and reveals a component of the EPSP which is potentiated by repetitive activation. Since the striatum has been involved in memory and in the storage of motor skills, LTD and LTP of synaptic transmission in this structure may provide the cellular substrate for motor learning and underlie the physiopathology of some movement disorders.

Notes: Immunohistological expression of VLA1–5 and α6β4 integrins have been studied in 21 cases of primary neuroendocrine carcinomas of the skin (NECS), three xenografts on nude mice and one NECS cell culture. The phenotypic properties of NECS cells were largely maintained in NECS grafted on athymic nude-mice and in the corresponding cell line. Our results indicate that α1β1 and to a lesser extent α3β1,α5βl are the main integrins expressed in NECS. In addition, VLA2,4 and α6β4 are heteroge-neously expressed in the same group of tumors and very sparsely present. These data suggest that like neuroblastoma and primitive peripheral neuroectodermal tumor (pPNET) the absence or the heterogeneous distribution of such integrins is correlated with the aggressive behaviour of NECS although long-term follow-up was not available for our cases. On the other hand, the α1 expression could be regarded as a novel marker for differential diagnosis between NECS (α1+) and pPNET (α1−). The α1β1, α2β1, α3β1, α5βl heterodimers in the 21 NECS studied showed an uniform pericellular staining of both the peripheral cells and central cells of the tumor islands. The predominant expression of α1β1 is consistent with the hypothesis of a primitive epithelial totipotential origin in NECS.

Notes: Sera from five patients with clinically and immunopathologically proven herpes gestationis were studied by complement fixing tmmunofluorescence and complement fixing immunoelectron microscopy using specimens of skin, amniochorion and placenta. The resutts demonstrated that the complement fixation antibody (herpes gestationis factor) could bind to the basement membrane zone of skin, amnion and chorion laeve but not to that of the placental syncytiotrophoblast. These data suggest that the herpes gestationis factor may be induced by the basement membrane zone antigens of extra-villous cytotrophoblasts.

Notes: A fully differentiated epithelium displaying features of human epidermis was obtained in vitro by culturing second-passage normal human keratinocytes for 14 days in defined medium and on an inert polycarbonate filter substratum at the air-liquid interface.Vertical sections stained for histology and indirect immunofluorescene studies showed that the‘basal’cells synthesize and secrete all major markers of hemidesmosomes and the lamina lucida. Components of the lamina densa are also expressed. Collagen VII is synthesized, but not secreted. Ultrastructural studies showed the presence of hemidesmosomes with major dense plaques and anchoring filaments, and a basement membrane-like structure was clearly identified.These results show that epidermal cells are able to produce hemidesmosomes and to secrete the major components of the dermo-epidermal junction in the absence of serum and dermal factors, suggesting that basement membrane synthesis and hemidesmosome assembly are not dependent on the presence of dermis.