Conditioning of Superconductive Properties in Graph-Shaped Reticles.

We report on phenomena observed in planar integrated networks obtained connecting superconducting island by Josephson tunnel junctions. These networks, identifiable as tree-like graphs, have branches consisting of series arrays of Josephson junctions which can be individually current biased and characterized. Both Josephson supercurrents and gap parameters of the arrays embedded in the graph structures display properties significantly different from those of "reference" arrays fabricated on the same chips and having identical geometrical shape. The temperature and magnetic field dependencies of the Josephson current of the embedded arrays both show a singular behavior when a critical value is reached by the Josephson characteristic energy. The gap parameter of the junctions generating the embedded arrays is higher than that of the junctions forming the reference geometrical arrays.

Experimental Study of Spectral Properties of a Frenkel-Kontorova System.

We report on microwave emission from linear parallel arrays of underdamped Josephson junctions, which are described by the Frenkel-Kontorova (FK) model. Electromagnetic radiation is detected from the arrays when biased on current singularities (steps) appearing at voltages V(n)=Φ(0)(nc̅/L), where Φ(0)=2.07×10(-15) Wb is the magnetic flux quantum, and c̅, L, and n are, respectively, the speed of light in the transmission line embedding the array, L its physical length, and n an integer. The radiation, detected at fundamental frequency c̅/2L when biased on different singularities, indicates shuttling of bunched 2π kinks (magnetic flux quanta). Resonance of flux-quanta motion with the small-amplitude oscillations induced in the arrays gives rise to fine structures in the radiation spectrum, which are interpreted on the basis of the FK model describing the resonance. The impact of our results on design and performances of new digital circuit families is discussed.

Reticular erythematous mucinosis: histopathological and immunohistochemical features of 25 patients compared with 25 cases of lupus erythematosus tumidus.

BACKGROUND AND OBJECTIVES: Reticular erythematous mucinosis (REM) and lupus erythematosus tumidus (LET) share similarities. However, to our knowledge no study extensively compared the histological features of these two conditions. The aim of this study is to compare the histological and immunohistochemical features of REM and LET. METHODS: We evaluated epidermal thickness, hyperkeratosis, dermo-epidermal junction changes, interstitial mucin deposition, vessel dilatation and pattern, type and density of the inflammatory infiltrate in 25 cases of REM and LET. Anti-CD3, anti-CD20, anti-CD68, anti-CD4, anti-CD8, anti-CD123, anti-CD2AP, anti-IgG and anti-C3 antibodies were tested in a subset of patients. RESULTS: Both diseases are characterized by perivascular dermal infiltrates of lymphocytes mainly CD4+ positive and increased dermal mucin. However, REM tended to show more scattered and more superficial lymphocytes with more superficial mucin and to have less frequent immunoglobulin and complement depositions along the dermo-epidermal junction. Plasmacytoid dendritic cells (PDCs) were less represented in REM, and were mainly found as single cells differently from LET. CONCLUSIONS: REM and LET present some differences in the infiltrate, including PDCs, the mucin deposition and the immunoreactant deposition at the dermo-epidermal junction that justify the distinction of the two diseases and suggest different pathogenetic mechanisms.

Characterization of anomalous pair currents in Josephson junction networks.

Measurements performed on superconductive networks shaped in the form of planar graphs display anomalously large currents when specific branches are biased. The temperature dependences of these currents evidence that their origin is due to Cooper pair hopping through the Josephson junctions connecting the superconductive islands of the array. The experimental data are discussed in terms of theoretical models which predict, for the system under consideration, an inhomogeneous Cooper pair distribution on the superconductive islands of the network as a consequence of a Bose-Einstein condensation phenomenon.

Reticular erythematous mucinosis: a review of patients' characteristics, associated conditions, therapy and outcome in 25 cases.

BACKGROUND: Reticular erythematous mucinosis (REM) is an uncommon disease, the nosology and specific characteristics of which are controversial because most reports deal with single cases or small series. OBJECTIVES: To describe the characteristics of patients with REM regarding demographics, clinical and pathological features, comorbidities, treatment and course. METHODS: A retrospective and prospective study was conducted on 25 patients diagnosed with REM in the setting of university-affiliated dermatology departments and dermatopathology centres. RESULTS: Of the 25 patients with REM, 16 were women (sex ratio 2 : 1) and the mean age was 46 years. The roles of sun exposure and oral contraceptives were ambiguous. Associated diseases included hypertension (n = 4), malignancies (n = 3), autoimmune diseases (n = 3) and Borrelia infection (n = 1). Immunological studies (including serology and direct immunofluorescence) were noncontributory. The response to antimalarial treatment was good in > 80% of cases. Worsening or recurrence of the lesion after treatment discontinuation, or in the course of the disease, occurred in 31% of patients. CONCLUSIONS: We present the largest REM case series to date. The reticular pattern with involvement of the midline of the chest and back, the predilection for middle-aged women, the controversial relationship with photosensitivity and the possible association with other conditions such as malignancies and thyroid dysfunctions are the main characteristics that makes REM a recognizable disease.

Herpes simplex virus infection and pemphigus.

Pemphigus is a group of autoimmune blistering diseases of the skin and/or mucous membranes caused by the presence of antibodies against adhesion molecules on the cell surface of keratinocytes. In genetically predisposed patients, several factors, including drugs, physical agents, neoplasms, hormones, and viruses, notably herpes simplex virus (HSV), have been hypothesized to trigger or exacerbate the disorder. To clarify whether HSV infection represents an aetiopathogenetic factor for pemphigus or a consequence of the immunosuppressive treatment, skin and/or mucosal swabs from 35 patients with pemphigus vulgaris or pemphigus foliaceus were tested for HSV by polymerase chain reaction. Twenty-three of these patients were newly diagnosed, while the remaining 12 had had a previous diagnosis and were under treatment with low-dosage oral corticosteroids. Repeat swabs were taken two weeks after starting intensive immunosuppressive therapy in 8 HSV-negative patients. All skin swabs (n=27) resulted negative for both HSV-1/2, while oral swabs (n=30) were positive for HSV-1 in 5 out of the 12 patients who were being treated with oral corticosteroids, but in none (n=19) of the non-treated group (p=0.0067, X2 test). Five out of the 8 patients with repeat swabs became positive for HSV-1, prompting us to start antiviral therapy. In conclusion, HSV is unlikely to be a triggering factor for pemphigus, but its presence in pemphigus lesions seems to be a frequent and early complication of immunosuppression.

The usefulness of clonality for the detection of cases clinically and/or histopathologically not recognized as cutaneous T-cell lymphoma.

BACKGROUND: The determination of clonality has proven to be a useful adjunct to the diagnosis of cutaneous lymphocytic infiltrates. It is considered particularly helpful for the distinction of mycosis fungoides (MF) and inflammatory dermatoses. OBJECTIVES: To verify the sensitivity of the polymerase chain reaction (PCR)-heteroduplex analysis of T-cell receptor gamma-chain gene (TCRgamma) rearrangements in patients with MF and to establish whether a clinicopathological re-evaluation of lesions previously unclassified or considered to be non-neoplastic entities but found to be monoclonal allowed the recognition of additional cases of MF. METHODS: Included in the study were 116 patients, seen at our Institute from April 2002 to September 2003 and tested for TCRgamma rearrangements. Thirty-six patients were affected by clinically and histopathologically proven MF, while the remaining 80 cases had not been classified or had been classified as non-neoplastic entities. The sensitivity of the molecular analysis was determined on the basis of the results obtained in the 36 patients with MF. The 29 cases of the second series of patients found to be monoclonal were clinically and histopathologically re-evaluated. RESULTS: Clonal rearrangements were found in 87.5% of patients with plaque stage MF and in 20% of those with patch stage MF. The clinicopathological re-evaluation allowed us to reclassify 15 of 29 monoclonal cases of the second series of patients as MF. CONCLUSIONS: The study showed that the PCR-heteroduplex technique can determine a high percentage of monoclonality only in plaque stage MF. However, in spite of the low sensitivity of the method, several cases previously unrecognized could be reclassified as MF when their clinical and histopathological features were re-evaluated taking into account the clonality of the lymphocytic infiltrate.

Recovery of distal nephron enzyme activity after release of unilateral ureteral obstruction.

PURPOSE: Unilateral ureteral obstruction (UUO) for 24 hours results in a severe compromise of distal tubular function. The acidification defect is believed to be localized in the collecting duct. To characterize distal tubular function recovery one month after junction release, clearance studies in whole animals and enzyme studies in microdissected segments were performed in an experimental model of unilateral ureteral obstruction. MATERIALS AND METHODS: Following release of ureteral obstruction of 24 hours duration, a significant decrease of whole kidney glomerular filtration rate was observed in the postobstructed kidney (POK) with a marked increase in urinary pH, fractional excretion of bicarbonate (FEHCO3-) and decrease in urinary osmolality. By orthograde stop flow experiment, bicarbonate excretion rate (Fr:Ff HCO3-/Fr:Ff Inutest) increased in the first and second urine fractions of 120 microl. corresponding to the collecting segment in the POK, one day after release. Decrease in U-P pCO2 (p<0.01) suggested an impaired H+ secretion on distal nephron in POK. Recovery of inulin clearance and values of urinary pH, FEHCO3- and urinary osmolality near contralateral and control kidneys were observed thirty days following ureteral release. The decline in enzyme activity in the distal nephron due to structural damage from high intratubular pressure was evaluated. Bafilomycin sensitive H+ -ATPase activity measurement in the medullary collecting duct segments of the POK showed an important decrease (68%), with lightly reduced activity (20%) in the cortical collecting duct, 24 hours after obstruction release. Localized in the connecting tubule cells and secreted into the tubular fluid in the late distal nephron, renal kallikrein has been involved in bicarbonate transport at cortical collecting duct segments. The renal kallikrein-like activity was reduced in POK (p<0.01). RESULTS: Recovery of enzyme activity was shown thirty days after unilateral ureteral obstruction. Our results show severe functional damage of the collecting duct after 24 hours of unilateral ureteral obstruction. H+ -ATPase activity was markedly decreased on medullary collecting duct segments. CONCLUSIONS: A correlation between the functional impairment of distal H+ secretion and decreased distal nephron enzyme activity has been shown. Recovery of both the functional and the enzyme activity at the distal nephron was demonstrated thirty days after obstruction release.