Showing papers by "University of Ioannina published in 1993"

Preliminary criteria for the classification of Sjögren's syndrome. Results of a prospective concerted action supported by the European Community.

Abstract: Objective. Different sets of diagnostic criteria have been proposed for Sjogren's syndrome (SS), but none have been validated with a large series of patients or in a multicenter study. We conducted the present study involving 26 centers from 12 countries (11 in Europe, plus Israel), with the goals of reaching a consensus on the diagnostic procedures for SS and defining classification criteria to be used in epidemiologic surveys and adopted by the scientific community. Methods. The study protocol was subdivided into two parts. For part I, questionnaires regarding both ocular and oral involvement were developed; they included 13 questions and 7 questions, respectively. For part II a limited set of diagnostic tests was selected, and the exact procedure to be followed in performing these tests was defined. Part I of the study ipcluded 240 patients with primary SS and 240 age- and sex-matched controls. Two hundred forty-six patients with primary SS, 201 with secondary SS, 113 with connective tissue diseases but without associated SS, and 133 control patients were studied in part II. Results. The study resulted in (a) the validation of a simple 6-item questionnaire for determination of dry eyes and dry mouth, which showed good discriminant power between patients and controls, to be used in the initial screening for sicca syndrome; and (b) the definition of a new set of criteria for the classification of SS. The sensitivity and specificity of the criteria in correctly identifying patients with either the primary or the secondary variant of SS were also determined. Conclusion. Using the findings of this prospective multicenter European study, general agreement can be reached on the diagnostic procedures to be used for patients with SS. Final validation of the preliminary classification criteria for SS is underway.

Systemic Lupus Erythematosus in Greece. Clinical Features, Evolution and Outcome: a Descriptive Analysis of 292 Patients

Abstract: The purpose of this study was the descriptive analysis of patients with systemic lupus erythematosus (SLE) with a particular focus on initial clinical features, evolution and outcome of disease, prevalence of clinical and serological manifestations and identification of clinicoserological associations indicative of renal and CNS involvement. The methodology applied was the following: retrospective analysis of the clinical charts of 292 unselected patients (246 female (84.2%) and 46 male (15.7%)) with SLE examined between 1982 and 1992. Multivariate analysis and hierarchical log linear models were used to examine for clinicoserological associations. Descriptive analysis was based on the prevalence of main clinicoserological features and disease outcome. The outcome was examined on the basis of the number of flares, the presence of chronic renal failure, the presence of central nervous system (CNS) involvement with subsequent disability and deaths. Flares were considered the severe alterations in disease status, requiring additional therapy to be controlled. The disease begins most frequently in the second and third decade of life with cutaneous and joint manifestations, while renal and CNS involvement developed later. The prevalence of serious renal, pulmonary and CNS involvement as well as the prevalence of RF, anti-Sm and anti-nRNP antibodies remain low. Multivariate analysis revealed the associations of renal involvement with leukopenia and serositis, of anti-Sm with leukopenia, of secondary Sjogren's syndrome with RF and of thromboembolic events with anticardiolipin antibodies. Patients with childhood onset SLE have a higher tendency for developing renal involvement than adult onset SLE patients. In addition, anti-Ro(SSA) antibodies were associated with anti-La(SSB) and RF, while anti-Sm antibodies were associated with anti-nRNP and RF. Flares occurred with a frequency of 0.07 per patient per year. Only 63.6% of flares were accompanied by positive anti-dsDNA reactivities. Reported deaths were 0.0047 per patient per year. Hierarchical log linear models indicated that the main variables of the disease were sufficient to describe our disease model and that the order of the interaction between the variables was insignificant. We conclude that the prevalence of various clinical features associated with SLE is similar, although the prevalence of CNS and pulmonary involvement as well as anti-Sm and anti-nRNP antibodies are less prominent in Greek SLE patients than that reported in the literature. The various clinicoserological associations detected do not appear to be of major significance as they are not powerful enough to subgroup the disease.

Geographical classification of Greek virgin olive oil by non‐parametric multivariate evaluation of fatty acid composition

Abstract: Fatty acid compositional data for Greek virgin olive oils from 24 years of harvest and various regions and cultivars were evaluated using chemometric methods. Non-parametric discriminant analysis after proper transformation of the data seems to be a suitable approach to characterise the oils according to the geographical origin and may produce a scientific basis for the assignment of an ‘appellation d'origine’ trade mark.

Patients with anticentromere antibodies, clinical features, diagnoses and evolution

Abstract: The sera of 1373 patients derived from a random population of 2627 individuals examined in a rheumatology outpatient clinic were found to be positive for antinuclear antibodies (ANA). Forty-seven of 1373 ANA positive patients (3.42%) presented a pattern of anticentromere antibodies (ACA), and of these 41 were followed-up. The predominant clinical features among ACA positive patients were Raynaud's phenomenon, arthralgias, scleroderma affecting the hands, feet, face and forearms, telangiectases and pulmonary involvement. There were 26 patients (64%) with limited cutaneous systemic sclerosis (lSSc), seven with primary Sjogren's syndrome (Ss) (17%), five with idiopathic Raynaud's phenomenon (IRPh) (12%) and three (7%) with other diseases. The lSSc subset was characterized by a significantly younger age for disease onset than for the IRPh patients. The Raynaud's phenomenon of lSSc patients lasted for many years before the onset of scleroderma, while their pulmonary involvement was mild and subclinical. The Ss patients with ACA were characterized by a lower incidence of parotid gland enlargement and anti-La (SSB) antibodies than described in the literature. Finally, the presence of ACA correlates with the clinical criteria proposed for the diagnosis of lSSc.

Soluble interleukin-2 receptors, antineutrophil cytoplasmic antibodies, and other autoantibodies in patients with ulcerative colitis.

Abstract: Ulcerative colitis (UC) is an inflammatory bowel disease of unknown aetiology. In this study, serum samples from 80 patients with UC were studied for the presence of various autoantibodies and soluble interleukin-2 receptor molecules (sIL-2Rs) in an attempt to determine the degree of activation of the immune system in this disease process. Autoantibodies detected included rheumatoid factors (in 5% of patients), antinuclear antibodies (in 51.3%), anti-Ro(SSA) (in 1.3%), anticardiolipin antibodies (IgG and/or IgM classes in 26.3%), anti-double stranded DNA (IgG or IgM classes in 45%), and antineutrophil cytoplasmic antibodies (ANCAs, in 30%). The ANCAs had a perinuclear pattern (p-ANCA) in 95.8%, without anti-myeloperoxidase activity, at least in an enzyme linked immunosorbent assay (ELISA) system. Raised concentrations of sIL-2R were found in 32.5% of patients (26/80, 18 with active and eight with inactive UC). The mean (SD) sIL-2R concentrations were significantly higher in patients with active UC (595 (219) u/ml v 406 (162) u/ml, p = 0.0001) and in patients with ANCAs (584 (177) u/ml in ANCA positive v 447 (212) u/ml in ANCA negative patients, p < 0.01). The sIL-2R concentrations were correlated with increased serum concentrations of C3c (r = 0.23, p < 0.05) or C4 (r = 0.4, p < 0.001) components of the complement system and erythrocyte sedimentation rate (ESR, r = 0.44, p = 0.0001). Platelets, ESR, and C3c were not associated with disease activity (p = 0.06, 0.33 and 0.86) whereas mean (SD) serum concentrations of C4 were higher in active disease (37.4 (11.9) mg/dl v 32.3 (10.3) mg/dl, p < 0.05). The sIL-2Rs had 53% sensitivity and 82.6% specificity for disease activity whereas platelet counts had 53% sensitivity and 58.7% specificity. To conclude, UC is accompanied by an autoimmune response that results in the production of several autoantibodies and cellular immune activation, as shown by the high sIL-2R concentration, is also present. The identification of the target antigen(s) of p-ANCA would possibly act as an indicator of disease activity if this distinct subset of ANCAs can be attributed to the pathogenesis of UC. The sIL-2R concentrations seem to be a useful laboratory marker for assessing activity of the disease.

Moisture adsorption behaviour of pasta products.

Abstract: The moisture sorption isotherms of conventional (from 100% durum wheat semolina) and diet (high protein) spaghetti were constructed at 22, 30, 37 and 45°C, using a computerized inverse gas chromatographic method (CIGC). Conventional spaghetti exhibited a higher sorption capacity than diet spaghetti. This is attributed to the higher carbohydrate content of conventional spaghetti as compared to diet spaghetti. Good agreement was observed between moisture sorption isotherms obtained from the CIGC method and the gravimetric static method. BET (Brunauer, Emmett and Teller), GAB (Guggenheim, Anderson and De Boer) and 'Local' isotherm models were tested to fit the experimental sorption data. Goodness of fit, standard deviation and the applicable range of water activity (a w ) indicated that GAB and 'Local' isotherm models could explain the data well over a wide a w range up to 0.80.

Localization in paired correlated random binary alloys.

Abstract: We study both analytically and numerically the electronic structure and the transport properties of binary chains, when the site energies (${\mathrm{\ensuremath{\epsilon}}}_{\mathit{A}}$ or ${\mathrm{\ensuremath{\epsilon}}}_{\mathit{B}}$) are random in pairs. We compute the density of states and the localization length versus energy for various strengths of disorder by considering products of 2\ifmmode\times\else\texttimes\fi{}2 random matrices in the microcanonical ensemble and also within the usual canonical-ensemble method. The limiting cases of AA,BB correlation, which favor delocalization and AB,BA anticorrelation, which favor localization, as well as intermediate cases involving all pairs AA,AB,BA,BB at random, are distinguished. In the former case, if \ensuremath{\delta}=\ensuremath{\Vert}${\mathrm{\ensuremath{\epsilon}}}_{\mathit{A}}$-${\mathrm{\ensuremath{\epsilon}}}_{\mathit{B}}$\ensuremath{\Vert} is less than a critical value ${\mathrm{\ensuremath{\delta}}}_{\mathit{c}}$=2, we demonstrate that the density of states has a smooth part and associated dominant 1/${\mathit{E}}^{2}$ divergencies of the localization length which for \ensuremath{\delta}=${\mathrm{\ensuremath{\delta}}}_{\mathit{c}}$ become 1/E. Our results are explained by considering scattering from single-impurity pairs. The microcanonical-ensemble method is discussed and its limitations are pointed out.

Contact metric manifolds

Abstract: In this paper we study contact metric manifoldsM2n+1(ϕ, η, ξ,g) with characteristic vector field ξ belonging to thek-nullity distribution. Moreover we prove that there exist i) nonK-contact, contact metric manifolds of dimension greater than 3 with Ricci operator commuting with ϕ and ii) 3-dimensional contact metric manifolds with non-zero constant ϕ-sectional curvature.

Is central nervous system involvement a systemic manifestation of primary Sjögren's syndrome?

Abstract: Central nervous system involvement in primary Sjogren's syndrome (pSS) is a controversial issue. Without an international criteria for the diagnosis of pSS, each research center must establish, publish, and strictly adhere to their own criteria. Therefore, patients should be made aware of professional uncertainties, particularly when therapeutic decisions are involved.

Immunologic and viral markers in the circulation of anti-HIV negative heroin addicts.

Abstract: . To assess the degree of immune system activation associated with addiction or hepatotropic viruses infection, we examined 60 HIV-negative heroin addicts for the presence of hepatitis B virus (HBV) infection markers, hepatitis C virus antibodies (anti-HCV), various auto-antibodies, and serum levels of soluble interleukin-2 receptors (sIL-2R). In addition, 28 anti-HCV positive patients comprising the disease control group, were also examined. Our results demonstrated a high prevalence of anti-HCV antibodies (61.7% and 90% with 1st and 2nd generation ELISA, respectively). Eighty-seven percent (87Yi) of the addicts positive for anti-HCV by the latter and 92.8% of the disease control patients, were also positive with 2nd generation recombinant immuno-blot assay (RIBA-II). In 88.9% of anti-HCV positive addicts, antibody to C22–3 was the predominant (anti-C33c in 81.5%). Antibodies to C33c and C22–3 polypeptides were also more frequent in disease control group (92.8% and 85.7%, respectively). Anti-HCV antibodies were associated with increased transaminases (ALT or AST, P<0.05), as well as with longer duration of addiction (P<0.005). HBV infection markers (HBsAg, anti-HBc only and anti-HBs) were also present in the addicts (5%, 28.3% and 26.7%, respectively). Rheumatoid factors (RF) were detected in 36.7%, antinuclear antibodies (ANA) in 11.7%, antibodies (IgG and/or IgM) against cardiolipin (anti-CL) and double stranded DNA (anti-ds DNA) in 20% and 50%, respectively. RF, ANA, anti-CL and anti-dsDNA antibodies were also detected in the disease control group (32.10/, 89.3%, 28.5% and 28.5% respectively). Auto-antibodies of at least one specificity, were found in 83.3% of addicts independently of anti-HCV antibodies, HBV infection markers, increased ALT or AST levels, and the duration of addiction. They were, on the other hand, associated in addicts with antibodies to the C22–3 polypeptide of HCV (P = 0.0001) and with both of the predominant antibodies (anti-C33c and anti-C22–3) of the HCV (P<0.01 and P<0.05 respectively) in the disease control group. Thirty-nine addicts (65%) and 50% of the disease control patients were found to have increased levels of sIL-2R. In contrast to the disease control group, serum sIL-2R levels of addicts were associated with RF (P<0.05), anti-dsDNA (P< 0.0005) and total auto-antibodies (P=0.0005), while there was a slight negative correlation with the duration of addiction (r= -0.26, P<0.05). However, sIL-2R levels, were not associated with HBV and HCV infection markers in both groups. We conclude that intravenous heroin addiction appears to be associated with an increased prevalence of HCV and non-organ specific auto-antibodies. The latter may be driven by C22–3 and C33c polypeptides of HCV. Increased sIL-2R levels attest to a cellular immune activation in addicts, which is slightly correlated with shorter duration of addiction, independently of HCV or HBV, but in association with auto-antibodies production.

Covariability and Climatic Changes of the Lower-Troposphere Temperatures over the Northern Hemisphere.

Abstract: The covariability and the long-term fluctuation of the lowertroposphere temperatures is studied, applying factor analysis on grid point (1000÷500) hPa thickness data for the Northern Hemisphere. About 30 factors were retained and rotated for each season and year, but only about half of them were found to be significant. The grouping of the grid points according to the factor loadings has been mainly influenced by the land and sea distribution. Three teleconnections were found only, one in winter and two in summer. The winter one is a see-saw phenomenon between West Asia and North-West Scandinavia. In summer, the British Isles were found to covary with East Canada and the same is the case for almost all the subtropical deserts. The study of the factor scores revealed that the recent warming of the Earth’s surface in the lower troposphere appears over the continents only.

Cortisol secretion in stressed babies during the neonatal period

Abstract: The present study investigates the developmental pattern of serum cortisol secretion in sick fullterm and preterm neonates in comparison to that of normal babies over the first 30 days of life. Four g

Structure and catalytic activity of perovskites La-Ni-O supported on alumina and zirconia

Abstract: Lanthanum nickelate binary oxidic species supported on alumina and zirconia were tested for their catalytic activity for the NO + CO reaction. The support took place by impregnation of Al2O3 or ZrO2 without any pretreatment or after addition of lanthana on the support surface. The zirconia based solids show a surface area (BET) of 5–7 m2 g−1, one order of magnitude smaller than those based on alumina (40–60 m2 g−1). The crystal phase developed on ZrO2 was only La2NiO4 while on Al2O3 the phases found by X-rays were LaNiO3 and LaAlO3. The solids La2NiO4/ZrO2 containing nickel in 2 + state, were more active than LaNiO3/Al2O3 containing Ni3+. The smaller activity of the La-Ni-O solids supported on Al2O3 is attributed to the stronger adsorption of oxygen, or oxygenated species, on Ni3+ as compared to the weaker adsorption on Ni2+ existed in the La-Ni-O solids supported on ZrO2. Especially the stronger adsorption of nitric oxide in the first case results in a reaction route where an excess of nitric oxide as large as 25–30% is eliminated as compared to the reacting carbon monoxide. The excess of eliminated nitric oxide undergoes disproportionation towards nitrous oxide and nitrogen, the former undergoing further decomposition towards nitrogen and oxygen. In the second case of ZrO2/La-Ni-O the weaker adsorption of nitric oxide results in a nearly equimolecular elimination of the two reactants and the excess of nitric oxide reacting does not exceed a 12–14% of carbon monoxide. The Arrhenius plots for the nitric oxide reduction on the alumina-based solids show a unique behaviour for the whole temperature range examined while similar plots for the zirconia-based solids show a two stage behaviour corresponding to different surface mechanism. The activation energies of nitric oxide elimination with carbon monoxide on the above solids are appreciably smaller than activation energies of nitrous oxide decomposition on the same materials, in accordance with previous observations. Finally the activity of La2NiO4/ZrO2 solids calculated per mass of perovskite is nearly five times that of La2NiO4 pure perovskites prepared through the nitrate or citrate routes although their surface areas are equal for the citrate and only double for the nitrate solids.

Singularity-free cosmological solutions of the superstring effective action

Abstract: We study the cosmological solutions of the one loop corrected superstring effective action, in a Friedmann-Robertson-Walker background, and in the presence of the dilaton and modulus fields. A particularly interesting class of solutions is found which avoid the initial singularity and are consistent with the perturbative treatment of the effective action.

High-resolution epitope mapping and fine antigenic characterization of the main immunogenic region of the acetylcholine receptor. Improving the binding activity of synthetic analogues of the region.

Abstract: The main immunogenic region (MIR) of the nicotinic acetylcholine receptor (AChR) is an immunodominant area of the molecule, both in human and in experimental autoimmune myasthenia gravis. Anti-MIR monoclonal antibody (mAb) binding has been earlier localized between amino acid residues 67 – 76 of the AChR α-subunit. A thorough study of the epitope(s) for anti-MIR mAbs, by the use of a large panel of overlapping synthetic peptides and multiple peptide analogues, is now presented and offers clues for potential therapeutic applications of the obtained data. Use of all possible overlapping hexapeptides within Torpedo and human α40 – 91 AChR and of selected peptides of various sizes, showed that the shortest peptide capable of significant antibody binding is the pentapeptide α67 – 71. Systematic screening of peptide analogues, where each amino acid residue within α67 – 76 and α67 – 74 of both Torpedo and human AChRs was substituted by various amino acids, was performed. Asn68 and Asp71 were found to be indispensable for anti-MIR mAb binding, whereas Pro69 and Ala/Asp70 were less but still significantly important. mAb binding to α67 – 76 from various AChR species further supported the significance of these results. An additional series of selected peptide analogues was then constructed, aiming at the identification of analogues with high antigenic activity. Many analogues with either single substitutions of α76 or combinations of two substitutions at α73 and α76 were tested. Several of these analogues (mainly His76, Arg76, Val73Ala76, His73Ala76, Val73Arg76) exhibited dramatic mAb binding enhancement. Some anti-MIR mAbs that do not bind to α67 – 76 bound significantly to certain analogues. Such analogues could find applications in studies of therapeutic models of myasthenia gravis.

Antibodies to phosphatidylethanolamine in antiphospholipid syndrome and systemic lupus erythematosus: their correlation with anticardiolipin antibodies and beta 2 glycoprotein-I plasma levels.

Abstract: The sera patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) were tested, by ELISA, for antibodies to phosphatidylethanolamine (aPE), as well as to cardiolipin (aCL) and compared to healthy blood donors (HBD). Both, SLE and APS patients presented a higher titre of IgM-aPE antibodies than normals, while the IgG and IgA aPE reactivity did not differ. APS patients were characterized by higher IgM-aPE antibody titres than SLE patients. In contrast, the predominant isotype of aCL antibodies in APS patients was IgG. The IgM aPE reactivity was correlated with IgM aCL reactivity, while no correlation was observed between the total IgM values and IgM-aPE binding units of sera tested. Since it was shown that β2-glycoprotein-I (β2-GPI) contributes to a complex antigen by binding to phospholipids and that this antigen is recognized by antiphospholipid antibodies from autoimmune patients, sera β2-GPI levels were measured and correlated to aCL and APE activity. Although APS patients had...

Orf. clinical and epidemiological study

Abstract: Summary Twenty eight human cases of orf were studied from clinical and epidemiological points of view. Most of the patients were shepherds who were inoculated from infected animals during all seasons of the year. Typical lesions of different stages of orf were located on the hands, and were accompanied by local symptoms such as pain, pruritus, lymphangitis and adenitis, or less frequently by systemic symptoms such as fever or malaise. Two cases developed erythema multiforme, one developed erysipelas and another a papulovesicular eruption. Tzanck test may contribute to the diagnosis. The course of the disease can not be influenced by antibiotics, and only measures of local hygiene are recommended, except in complicated cases.

A survey on the assessment of wind energy potential in Greece

Abstract: In the present paper a statistical study of the available wind data for Greece is carried out to assess its wind energy potential. It is essential to establish the available wind energy for any given region in order to assess the relative potential at different sites. The applicability of the Weibull distribution is examined and tables and plots of Weibull parameters are given. The analysis showed that in the interior lowland parts of Greece, low available annual wind power densities exist (less than 20 w·m−2). In the eastern parts, along the coasts, especially on the Aegean Sea islands, the annual average wind energy flux is found to be rather high (more than 600 w·m−2 may be gained) which makes these islands possible locations for wind power utilization. On the other hand, the annual wind energy on the western parts along the coast and on the lonian Sea islands, a wind power of over 200 w·m−2 may be extracted.

Effect of varying concentrations of follicle stimulating hormone on the production of gonadotrophin surge attenuating factor (GnSAF) in women

Abstract: Summary OBJECTIVE We studied the time-course of production of gonadotrophin surge attenuating factor (GnSAF) in relation to varying serum concentrations of FSH in women. DESIGN Normally cycling women were investigated in four cycles, i.e. a spontaneous cycle treated with placebo (cycle P) and three cycles treated with three different FSH dosages (1 ampoule, cycle 1; 3 ampoules, cycle 3 and 6 ampoules, cycle 6). Placebo or FSH were given as a single i.m. injection on cycle day 2 (0900 h). The response of LH to an i.v. injection of 10 μg GnRH (GnSAF bioactivity) was investigated 4, 8, 12 and 24 hours after the injection of placebo or FSH. PATIENTS Six normally ovulating women with long-standing unexplained infertility were studied. The women were used as their own controls during the cycle treated with placebo. MEASUREMENTS Pituitary response to GnRH was calculated as the net increase in LH at 30 minutes (ΔLH) above the basal value. RESULTS Serum FSH concentrations increased after the injection of FSH in a dose dependent manner. Compared with cycle P, Δ LH was significantly attenuated in cycle 3 and cycle 6 at 8,12 and 24 hours and in cycle 1 at 12 hours after the injection of FSH. Basal concentrations of oestra-diol (E2) and LH did not differ significantly among the four cycles at any point except in cycle 6 at 24 hours after the FSH injection when E2 values were significantly higher and LH values significantly lower than in cycle-P. CONCLUSIONS These results suggest that GnSAF bioactivity increases significantly as early as 8 hours from a single injection of FSH before any significant increase in serum E2 values. We conclude that in women the effect of FSH on the production of GnSAF in the early follicular phase is concentration dependent.

Liver involvement in hemorrhagic fever with renal syndrome.

Abstract: Hemorrhagic fever with renal syndrome is an acute febrile nephropathy caused by several viruses of the genus Hantavirus of the family Bunyaviridae. During the past 8 years, 32 cases of hemorrhagic fever with renal syndrome have been diagnosed. Nine out of the 32 patients (28%) had raised (twofold upper normal limits) transaminases during hospitalization. Four out of the nine patients (44%) died. In contrast, only three out of the 23 patients (13%) without raised transaminases died. Five patients had slightly increased serum alkaline phosphatase and gamma-glutamyl-transpeptidase, whereas six patients had prolonged prothrombin time. Liver histology showed midzonal necrosis in hepatic lobules with extravasation of red cells and mild mononuclear infiltrate. Liver involvement seems to be an ominous prognostic factor in such patients and is correlated with severe renal failure and thrombocytopenia.