Showing papers by "University of Ioannina published in 1995"

Transgenic mice expressing the human heat shock protein 70 have improved post-ischemic myocardial recovery.

Abstract: Heat shock treatment induces expression of several heat shock proteins and subsequent post-ischemic myocardial protection. Correlations exist between the degree of stress used to induce the heat shock proteins, the amount of the inducible heat shock protein 70 (HSP70) and the level of myocardial protection. The inducible HSP70 has also been shown to be protective in transfected myogenic cells. Here we examined the role of human inducible HSP70 in transgenic mouse hearts. Overexpression of the human HSP70 does not appear to affect normal protein synthesis or the stress response in transgenic mice compared with nontransgenic mice. After 30 min of ischemia, upon reperfusion, transgenic hearts versus nontransgenic hearts showed significantly improved recovery of contractile force (0.35 +/- 0.08 versus 0.16 +/- 0.05 g, respectively, P < 0.05), rate of contraction, and rate of relaxation. Creatine kinase, an indicator of cellular injury, was released at a high level (67.7 +/- 23.0 U/ml) upon reperfusion from nontransgenic hearts, but not transgenic hearts (1.6 +/- 0.8 U/ml). We conclude that high level constitutive expression of the human inducible HSP70 plays a direct role in the protection of the myocardium from ischemia and reperfusion injury.

Contact metric manifolds satisfying a nullity condition

Abstract: This paper presents a study of contact metric manifolds for which the characteristic vector field of the contact structure satisfies a nullity type condition, condition (*) below. There are a number of reasons for studying this condition and results concerning it given in the paper: There exist examples in all dimensions; the condition is invariant underD-homothetic deformations; in dimensions>5 the condition determines the curvature completely; and in dimension 3 a complete, classification is given, in particular these include the 3-dimensional unimodular Lie groups with a left invariant metric.

Hypersurfaces in E4 with Harmonic Mean Curvature Vector Field

Abstract: The minimal hypersurfaces in E4 are the only hypersurfaces possessing the following property: Its mean curvature vector field is harmonic.

PAF-Degrading Acetylhydrolase Is Preferentially Associated With Dense LDL and VHDL-1 in Human Plasma Catalytic Characteristics and Relation to the Monocyte-Derived Enzyme

Abstract: In human plasma, platelet activating factor (PAF)–degrading acetylhydrolase (acetylhydrolase) is principally transported in association with LDLs and HDLs; this enzyme hydrolyzes PAF and s...

CYTOKINE mRNA EXPRESSION IN THE LABIAL SALIVARY GLAND TISSUES FROM PATIENTS WITH PRIMARY SJöGREN'S SYNDROME

Abstract: The pattern of cytokine mRNA expression in frozen minor salivary gland tissues from patients with primary Sjogren's syndrome (pSS) (n = 12) and controls (n = 8) using an in situ hybridization technique and oligonucleotide probes of interleukin-1 beta (IL-1 beta), tumour necrosis factor alpha and beta (TNF-alpha and TNF-beta), interleukin-6 (IL-6), interleukin-2 (IL-2) and its receptor (IL-2R), interleukin-4 (IL-4), interleukin-10 (IL-10), interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) was examined. In addition to in situ hybridization, immunohistochemistry was used to identify the subset of cells expressing IL-2 and IL-4 mRNA. Mononuclear cells involved in the minor salivary gland lesions of pSS patients were found to express mRNA for pro-inflammatory cytokines such as TNF-alpha and IL-1 beta, and cytokines involved in the regulation of B- and T-cell function (IL-2 and IL-6). In contrast, only three biopsies from patients with pSS express mRNA of inhibitory cytokines such as IFN-gamma and TGF-beta. Furthermore mRNA for IL-6 and IL-1 beta was also detected in the glandular epithelial cells suggesting that these cells may play a role in the pathogenesis of autoimmune lesion in Sjogren's syndrome. IL-10 mRNA was not detected while IL-4 mRNA was primarily detected in naive T-lymphocytes of patients with a mild and early lesion. These results suggest that local production of cytokines by both mononuclear and epithelial cells may be involved in the immune-mediated destruction of exocrine glands in patients with pSS.

Incidence, Complications, and Management of Meckel's Diverticulum

Abstract: Objectives: To elucidate the incidence of Meckel's diverticulum; to determine the correlation between the histologic type of the diverticulum's mucosa and its clinical presentation; and to review our experience with Meckel's diverticulum. Design: Case-control study. Setting: University hospital in loannina, Greece. Patients: A total of 2074 patients undergoing an appendectomy were examined intraoperatively for Meckel's diverticulum (subgroup A 1 ). In addition, Meckel's diverticulum was found incidentally in 15 patients who were undergoing intra-abdominal surgery (subgroup A 2 ). An operation for a complicated Meckel diverticulum was performed in an additional 15 patients (group B). Results: Thirty-three (1.59%) Meckel diverticulae were found incidentally among 2074 patients in subgroup A 1 . A positive correlation between Meckel's diverticulum and male sex was found ( P 1 ( P P Conclusion: Resection of the unexpected Meckel diverticulum can be performed safely with a low complication rate, regardless of the patient's age. (Arch Surg. 1995;130:143-146)

Reaction of Aniline with FeOCl. Formation and Ordering of Conducting Polyaniline in a Crystalline Layered Host

Abstract: A detailed study of the intercalative polymerization reaction of aniline with FeOCl, an extensive physicochemical and spectroscopic characterization of the products, and their oxidative behavior in air is presented. FeOCl reacts with excess aniline in CH3CN at 25 “C, in air, to form black microcrystalline products containing polyaniline (PANI) of the general formula (PANI),FeOCl (I). X-ray diffraction from a single crystal of (PANI),FeOCl shows that the polymer is intercalated in an ordered fashion that is commensurate with the FeOCl lattice. This ordering causes a doubling of the unit cell in the two in-plane directions (aand c-) forming a 2a x 2c superlattice. The PANI can be extracted from (I) by FeOCl framework dissolution in acid. Molecular weight studies of extracted PANI via gel permeation chromatography (GPC) analysis suggest a, 6100 and M,, 3500 versus M, 69 000 and M, 7700 observed for bulk PANI. Chain lengths of PANI in the intralamellar space are shorter than those of bulk PANI but show narrower length distribution. Variable temperature 2H-wide-line NMR of (PANI),FeOCl shows that the polymer chains are significantly confined with respect to phenyl ring rotation, but the spectra are influenced by the electron paramagnetism of the host. The (PAN1)PeOCl was also characterized by infrared spectroscopy, Mossbauer spectroscopy, electron paramagnetic resonance spectroscopy, thermal gravimetric analysis, magnetic susceptibility measurements, and charge-transport measurements. Mossbauer spectroscopy suggests a mixedvalent FeOCl with a Fe2+/Fe3+ ratio in the material -1:9. Aerial oxidation of (PANI),FeOCl yields an intimate mixture of PANI and P-FeOOH. The PANI after oxidation shows a molecular weight intermediate between that extracted from fresh (PANI),FeOCl and bulk PANI. The electrical conductivity of single crystals is 1.5 x S/cm and features a thermally activated temperature dependence consistent with a semiconductor. Thermoelectric power measurements show a positive Seebeck coefficient (-10 pV/K) at room temperature which increases steadily with decreasing temperature, reaching the value of 100-400 pV/K at 150 K, consistent with a p-type semiconductor. The charge transport data suggest that in (PANI),FeOCl the reduced FeOCl framework dominates the electronic conduction.

Quantitation and distribution of altered fatty acids in frying fats

Abstract: The distribution and quantity of polar compounds and altered fatty acids in used frying oils, collected by Food Inspection Services of the Junta de Andalucia in Spain, was measured. Additional samples evaluated were sunflower oil, high-oleic sunflower oil, and palm olein that were subjected to thermoxidation and frying in laboratory experiments. A combination of adsorption and high-performance size-exclusion chromatography was applied to the oil samples both before and after transesterification. Through analysis of fatty acid methyl ester derivatives, differentiation of four groups of altered fatty acids (oxidized monomers, nonpolar dimers, oxidized dimers, and polymers) could be attained. Evaluation of real frying samples with polar compound levels around the limit for fat rejection (21.1–27.6% polar compounds) gave values of total altered fatty acids ranging from 8.1 to 11.3%, and levels higher than 20% were found in the most degradated samples. The results obtained clearly support the need for control and improvement of the quality of used fats in fried-food outlets.

Inner ear involvement in rheumatoid arthritis: a prospective clinical study.

Abstract: Sensorineural hearing loss in rheumatoid arthritis (RA) has been reported to be the result of the extra-articular manifestation of the disease (rheumatoid nodular vasculitis) or due to drug ototoxicity. In an attempt to investigate the presence of sensorineural hearing loss and the possible causes for it we investigated prospectively 45 RA patients (42 female; three male) with a mean age of 52.5 +/- 10.7 years and a mean disease duration of 8.5 +/- 7.3 years. All patients underwent a complete physical examination and audiological evaluation which included pure tone audiometry and impedance audiometry (tympanogram, static compliance, acoustic reflex, reflex decay, acoustic reflex latency test. We found a sensorineural hearing loss > 20 dB HL in 44.4 per cent (40/90) ears. In all cases the site of hearing loss was the cochlea and in most of them it was bilateral and symmetric (16 patients out of 45 had bilateral sensorineural hearing loss i.e. 35.5 per cent. There was no correlation between sensorineural hearing loss and age, sex, disease duration, articular and extra-articular manifestations and the presence of autoantibodies in our patients. In addition, no correlation was found between sensorineural hearing loss and drug therapy for one at least of the following drugs: NSAIDs, D-penicillamine, plaquenil and methotrexate. We noticed a prologation of acoustic reflex latency in five patients (10 per cent) which was found to be correlated with the temporomandibular joint involvement and the presence of rheumatoid factor (RF). We conclude that inner ear involvement in RA is expressed by: (1) mild symmetric, bilateral sensorineural hearing loss of cochlear type in 35.5 per cent of patients; (2) normal acoustic reflex thresholds; (3) nondecay; and (4) prologation of acoustic reflex latency which appeared in a small number of patients (10 per cent).

Osteonecrosis of the femoral head. Hip salvaging with implantation of a vascularized fibular graft.

Abstract: The authors tried to save the hip joint by implanting a vascularized fibular graft, augmented with cancellous bone, into the curetted core of the femoral head that was affected by aseptic necrosis. Forty of 66 hips were observed for a minimum of 20 months and for as long as 66 months (average, 32 months). Clinical assessment according to the cause and severity of the disease was done using the Harris Hip Score. Twenty-eight hips (70%) were rated excellent, 7 (17.5%) were good, 2 (5%) were fair, and 3 (7.5%) failed and were replaced with an artificial joint. Clinically satisfactory results, including good and excellent, were obtained in 35 hips (87.5%). Radiographic evaluation showed improved appearance of the femoral head core in all 15 patients (37.5%) operated on at a precollapse stage of the disease. In 20 hips, the deformity of the femoral head was unchanged (50%), 2 (5%) became worse, and 3 (7.5%) failed. The number of hips with improved appearance as shown on radiographs and those in which the process was unchanged equaled the number of hips with satisfactory clinical results. These data show that the procedure can induce new bone formation that fuses with the affected subchondral bone, thus preventing the articular surface from collapse. This suggests that vascularized fibular grafting is an excellent alternative for hip salvaging when treating femoral head osteonecrosis.

Oscillations of Delay Difference Equations

Abstract: Consider the delay difference equation χn+1−χn+pnχn−k=0, n-0,1,2,… where {pn} is a sequence of real numbers and k is a positive integer. New oscillation criteria for this equation are established. An extension of the results to difference equations with several delays is also presented.

Lipid parameters including lipoprotein (a) in patients undergoing CAPD and hemodialysis

Abstract: ObjectiveOyslipidemia possibly contributes to the vascular complications commonly afflicting uremic patients. Lipoprotein (a) [Lp(a)] has been identified as an independent risk factor for atheroscl...

Anderson transition, scaling, and level statistics in the presence of spin orbit coupling.

Abstract: The effect of spin-orbit coupling (SOC) on the localization properties of electrons in two-dimensional disordered systems is investigated by numerical scaling techniques. The Anderson metal-insulator transition in the presence of random SOC is demonstrated by the scaling of the corresponding Lyapunov exponents, and the critical exponents are estimated. At the transition we obtain new universal scale invariant distribution functions for the nearest level spacing distribution function $P(S)$ and the two point correlation function ${K}_{2}(\ensuremath{\epsilon})$ describing the critical spectral density fluctuations.

Fractional excretion of potassium in normal subjects and in patients with hypokalaemia.

Abstract: The aim of our study was the determination of fractional excretion of potassium (FEK+) in both normal subjects and hypokalaemic patients. Three hundred and twelve normal subjects aged 21-69 years and 84 hypokalaemic patients aged 36-72 years were studied. The mean FEK+ in normal subjects was 8% (range 4-16%). FEK+ was positively correlated with serum potassium (r = 0.74, p < 0.0001) and inversely with serum creatinine (r = -0.51, p < 0.001). The mean FEK+ in patients with hypokalaemia of external origin was 2.8% (range 1.5-6.4%). On the contrary, the mean FEK+ in hypokalaemic patients in whom renal potassium loss was the main aetiologic factor for the pathogenesis of hypokalaemia was 15% (range 9.5-24%).

Hidradenitis suppurativa in Crohn's disease. A further support to this association.

Abstract: A patient with Crohn's disease (CD) subsequently developed the clinical and histological features of hidradenitis suppurativa (HS). So far, only five cases with such an association have been reported. Azathioprinc (150 mg/d) and methylprednisolone (16 mg/d) for CD combined with isotretinoin (0.7 mg/

The Chen-Type of the Spiral Surfaces

Abstract: We show that a spiral surface M in E3 is of finite type if and only if M is minimal Also, the plane is the only spiral surface in E3 whose the Gauss map G is of finite type, or satisfies the condition ΔG = ΛG, where Λ ∈ R3×3.

Factor Analysis of some climatological elements in Athens, 1931–1992: covariability and climatic change

Abstract: The climatological parameters of a station are, in general, intercorrelated to various degrees (e.g. cloudiness with sunshine duration or possibly rainfall with temperature). In this work, 15 climatological parameters of the National Observatory of Athens are distributed in groups where the contained parameters are highly covariant. This classification is achieved using P-mode Factor Analysis, based on the monthly values for the period 1931–1992. Using several known criteria, we found up to four significant factors. The first two are the most important ones including the “temperature” and the “precipitation” parameters, respectively, with loading values above 0.85. The other two are weaker and variable, depending on the month. Finally, climatic trends of the grouped parameters (factors) are examined and the result compared with those of studies using classical methods.

Catalytic activity and selectivity of perovskites La1−xSrxV1−x3+Vx4+O3 for the transformation of isopropanol

Abstract: The catalytic decomposition of isopropyl-alcohol (IPA) was studied over the perovskite series La 1− x Sr x V 1− x 3+ V x 4+ O 3 ( x=0.0, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 0.9, 0.95, 1.0 ) in the range 200–300°C. Catalyst characterization by XRD shows that gradual substitution of La 3+ by Sr 2+ transforms the LaVO 3 structure to SrVO 3 , both of cubic symmetry. ESR spectra at 13 K shows that the V 4+ (d 1 ) centers are localized in the form of vanadyl groups up to x≈0.6 , while thereafter they become delocalized. The catalytic transformation of IPA over these solids shows that the products obtained are propene and acetone. The selectivity of the reaction for x=0.0 is ca. 15% for acetone (85% propene) and increases linearly with the substitution of La by Sr reaching at x=1.0 the value of 40% (60% propene). The total reaction rate was maximum at x=0.0 and drops up to x=0.2 , thereafter remaining almost steady. The apparent activation energies calculated for the total conversion of IPA ( E tot ) according to the first order kinetics are clustered around 120 kJ/mol. These values are almost similar to those found for the acetone formation ( E acet ) while those estimated for the propene formation ( E prop ) are lower by an amount of 10–15 kJ/mol on average. A common compensation effect observed for the production of propene and acetone is explained by the variation of the heats of adsorption of the product. The reaction route seems negligibly influenced by electronic effects of the solids and it is mainly controlled by the acid/base function of the solid surface.

Osteoid osteoma in the differential diagnosis of persistent joint pain

Abstract: We report 20 cases (13 male and 7 female), mean age 21 years) of juxta-articular osteoid osteoma. The distribution of affected joints was as follows: hip joint (7 cases), knee joint (2 cases), ankle joint (2 cases); iliosacral joint (2 cases), lumbar spine (2 cases), carpus (2 cases), shoulder (1 case), second metacarpal (MCP; 1 case) and first metatarsal (MTP; 1 case). The duration between the onset of symptoms and diagnosis varied from 8 months to approximately 4 years. In juxta-articular osteoid osteoma, the clinical picture and the radiographic findings are often atypical, and this may lead to misdiagnosis and delayed definitive treatment. In young patients with persistent undiagnosed pain, the possibility of an osteoid osteoma should be considered. When the clinical picture is suggestive but radiological findings are negative, we must proceed to further investigation with bone scintigraphy and computed tomography. These examinations should be repeated 1 year after the onset of symptoms because initially negative findings may become positive at a later date. When the diagnosis of an osteoid osteoma is confirmed, surgical excision leads to complete relief of the symptoms.