Showing papers by "University of Udine published in 1994"

Structural basis of end-stage failure in ischemic cardiomyopathy in humans.

Abstract: BACKGROUNDIschemic cardiomyopathy is characterized by myocyte loss, reactive cellular hypertrophy, and ventricular scarring. However, the relative contribution of these tissue and cellular processes to late failure remains to be determined.METHODS AND RESULTSTen hearts were obtained from individuals undergoing cardiac transplantation as a result of chronic coronary artery disease in its terminal stage. An identical number of control hearts were collected at autopsy from patients who died from causes other than cardiovascular disease, and morphometric methodologies were applied to the analysis of the left and right ventricular myocardium. Left ventricular hypertrophy evaluated as a change in organ weight, aggregate myocyte mass, and myocyte cell volume per nucleus showed increases of 85%, 47%, and 103%, respectively. Corresponding increases in the right ventricle were 75%, 74%, and 112%. Myocyte loss, which accounted for 28% and 30% in the left and right ventricles, was responsible for the difference in th...

Laminar comparison of somatosensory cortical plasticity

Abstract: During tactile learning there is a transformation in the way the primary somatosensory cortex integrates, represents, and distributes information from the skin. To define this transformation, the site of earliest modification has been identified in rat somatosensory cortex after a change in sensory experience. Afferent activity was manipulated by clipping all except two whiskers on one side of the snout ("whisker pairing"), and the receptive fields of neurons at different cortical depths were mapped 24 hours later. Neurons in layer IV, the target of the primary thalamic pathway, were unaltered, whereas neurons located above and below layer IV showed significant changes. These changes were similar to those that occur in layer IV after longer periods of whisker pairing. The findings support the hypothesis that the layers of cortex contribute differently to plasticity. Neurons in the supragranular and infragranular layers respond rapidly to changes in sensory experience and may contribute to subsequent modification in layer IV.

Expression of Thyroid-specific Transcription Factors TTF-1 and PAX-8 in Human Thyroid Neoplasms

Abstract: TTF-1 and PAX-8 are tissue-specific transcription factors expressed in the thyroid follicular cells, contributing to the maintenance of the differentiated phenotype. In fact, it has been demonstrated that TTF-1 and PAX-8 are able to activate transcription from thyroglobulin and thyroperoxidase (TPO) promoters, the transcriptional activity of which is in vivo restricted only to the thyroid follicular cell. In order to gain insight into how these transcription factors control in vivo the differentiation of the thyroid cell and to have a better molecular characterization of human thyroid tumors, TTF-1, PAX-8, thyroglobulin, and TPO mRNA levels were measured in nonmalignant and malignant human thyroid tissues. Results indicate that the expression of TTF-1 and PAX-8 is not sufficient per se for the expression of the thyroid-differentiated phenotype. Furthermore, in follicular adenomas, PAX-8 mRNA levels are strictly related to TPO mRNA levels, suggesting that the amount of PAX-8 could play a role in the modulation of TPO gene expression. TTF-1 mRNA is always well detectable in papillary carcinomas and, in contrast, always absent in anaplastic carcinomas. Identical results were obtained when the expression of TTF-1 protein was investigated using immunohistochemistry. Thus, TTF-1 gene expression could be a molecular marker in order to distinguish these two types of thyroid neoplasms.

A lambda calculus of objects and method specialization

Abstract: This paper presents an untyped lambda calculus, extended with object primitives that reflect the capabilities of so-called delegation-based object-oriented languages A type inference system allows static detection of errors, such as message not understood, while at the same time allowing the type of an inherited method to be specialized to the type of the inheriting object Type soundness is proved using operational semantics and examples illustrating the expressiveness of the pure calculus are presented

Simulated Annealing for Multi Objective Optimization Problems

Abstract: In the last decade some large scale combinatorial optimization problems have been tackled by way of a stochastic technique called ‘simulated annealing’ first proposed by Kirkpatrick et al. (1983). This technique has proved to be a valid tool to find acceptable solutions for problems whose size makes impossible any exact solution method.

Genetic mapping and variability of seven soybean simple sequence repeat loci.

Abstract: Microsatellites or simple sequence repeats are stretches of short tandemly repeated DNA sequence motifs, dispersed throughout the genomes of most eukaryotes. Simple sequence repeat polymorphisms (S...

Sequence-specific DNA recognition by the thyroid transcription factor-1 homeodomain

Abstract: The molecular basis for the DNA binding specificity of the thyroid transcription factor 1 homeodomain (TTF-1HD) has been investigated. Methylation and ethylation interference experiments show that the TTF-1HD alone recapitulates the DNA binding properties of the entire protein. Studies carried out with mutant derivatives of TTF-1HD indicate a precise correspondence of some of its amino acid residues with specific bases in its binding site, allowing a crude orientation of the TTF-1HD within the protein-DNA complex. TTF-1HD shows an overall geometry of interaction with DNA similar to that previously observed for Antennapedia class HDs, even though the binding specificities of these two types of HDs are distinct. We demonstrate that the crucial difference between the binding sites of Antennapedia class and TTF-1 HDs is in the motifs 5'-TAAT-3', recognized by Antennapedia, and 5'-CAAG-3', preferentially bound by TTF-1. Furthermore, the binding of wild type and mutants TTF-1 HD to oligonucleotides containing either 5'-TAAT-3' or 5'-CAAG-3' indicate that only in the presence of the latter motif the Gln50 in TTF-1 HD is utilized for DNA recognition. Since the Gln at position 50 is an essential determinant for DNA binding specificity for several other HDs that bind to 5'-TAAT-3' containing sequences, we suggest that utilization by different HDs of key residues may depend on the sequence context and probably follows a precise hierarchy of contacts.

The Cardiac Renin-Angiotensin System in STZ-Induced Diabetes

Abstract: To determine the effect of diabetes on the cardiac renin-angiotensin system, we compared angiotensin II binding density and renin, angiotensinogen, and type 1 angiotensin II (AT1) receptor mRNA levels in hearts of Sprague-Dawley rats 14 days after the administration of streptozotocin (STZ), in vehicle-treated control rats, and in STZ-administered rats made euglycemic with insulin. Myocardial angiotensin II receptor density, determined using an in situ autoradiographic technique, was increased significantly in hyperglycemic diabetic rats in comparison with control rats and euglycemic diabetic rats ( P P −1 · min −1 i.p. for 7 days) or vehicle. Plasma renin concentration decreased significantly, whereas no significant changes occurred in cardiac renin or angiotensinogen steady-state mRNA levels. As in the first experiment, levels of AT1 receptor mRNA were significantly greater in the diabetic rats. Thus, myocardial angiotensin II receptor density is increased in diabetic rats in association with an increase in steady-state AT1 receptor mRNA levels, an abnormality that appears to be independent of changes in the circulating renin-angiotensin system.

A shell for developing non-monotonic user modeling systems

Abstract: This paper first presents a general structured framework for user modeling, which includes a set of basic user modeling purposes exploited by a user modeling system when providing a set of services to other components of an application. At a higher level of abstraction such an application may perform a generic user modeling task , which results from an appropriate combination of some basic user modeling purposes. The central aim of the paper is to present, within the proposed framework, a flexible general-purpose shell, called UMT (User Modeling Tool), which supports the development of user modeling applications. UMT features a non-monotonic approach for performing the modeling activity: more specifically, it utilizes a modeling approach called assumption-based user modeling, which exploits a truth maintenance mechanism for maintaining the consistency of the user model. The modeling task is divided into two separate activities, one devoted to user classification and user model management, and the other devoted to consistency maintenance of the model. The modeling knowledge exploited by UMT is represented by means of stereotypes and production rules. UMT is capable of identifying, at any given moment during an interaction, all the possible alternative models which adequately describe the user and are internally consistent. The choice of the most plausible one among them is then performed using an explicit programmable preference criterion. UMT is also characterized by a very well defined and simple interface with the hosting application, and by a specialized development interface which supports the developer during the construction of specific applications. This paper includes an example application in the field of information-providing systems. UMT has been developed in Common LISP.

Long-term culture and functional characterization of follicular cells from adult normal human thyroids

Abstract: We have obtained long-term cultures of differentiated proliferating follicular cells from normal adult human thyroid glands. In vitro growth of such human cells has been sustained by a modified F-12 medium, supplemented with bovine hypothalamus and pituitary extracts and no added thyrotropin. Cultures have been expanded, cloned, frozen, successfully retrieved, and characterized. Functional characterization of these cells shows constitutive thyroglobulin production and release and thyrotropin-dependent adenosine 3',5'-cyclic monophosphate production, the latter apparently not associated with significant increases in DNA synthesis or cell proliferation. Genetic characterization of these cells by chromosome counting showed the normal diploid chromosome number. The ability to cultivate differentiated human thyroid follicular cells in long-term culture opens possibilities for investigating the transduction pathways of thyrotropin stimulation in normal and pathological human tissues, developing clinically relevant in vitro assays, and considering cellular and molecular therapies.

Combined effects in preventing enzymatic browning reactions in minimally processed fruit

Abstract: Fresh sliced apples were dipped in ethanol or cysteine solutions and/or packaged in air or modified atmosphere in order to retard oxidative browning. Modified atmosphere packaging was effective in inhibiting darkening for at least nine days at refrigerated storage conditions. The combination ethanol dip/modified atmosphere packaging resulted as a suitable method in maintaining the original color in apple slices even after exposure to air.

Fibrinogen Plasma Levels as a Marker of Thrombin Activation in Diabetes

Abstract: This study attempted to verify the existence of a correlation between fibrinogen, a major cardiovascular risk factor in diabetes, and indexes of thrombin generation and action, prothrombin fragment 1 + 2 (F1 + 2), and D-dimer (D-D), in a group of diabetic subjects compared with a matched control group. Forty insulin-dependent diabetes mellitus patients and 30 matched healthy control subjects participated in this study. The subjects were tested for the following parameters: fibrinogen, prothrombin F1 + 2, D-D, fasting glycemia, and HbA1c. In addition, 5 diabetic subjects who maintained stable fibrinogen plasma levels > 300 mg/dl for at least 6 months before the study were treated with 12,500 U/day subcutaneous heparin for 7 days. Diabetic subjects showed increased levels of fibrinogen, prothrombin F1 + 2, and D-D plasma levels. Simple linear regression analysis detected a positive correlation between fibrinogen and prothrombin F1 + 2, D-D, and glycosylated HbA1c. In the five diabetic subjects treated with heparin fibrinogen, prothrombin F1 + 2 and D-D levels decreased at the end of the treatment. All these parameters returned to baseline after 7 days of washout. These data indicate that fibrinogen plasma levels are correlated to parameters of thrombin activation in plasma in diabetic patients and suggest that high fibrinogen plasma levels might be a risk marker for cardiovascular disease in diabetes because it is an expression of an existing thrombophilia.

The effects of intraperitoneal local anesthetic on analgesic requirements and endocrine response after laparoscopic cholecystectomy: a randomized double-blind controlled study.

Abstract: This randomized double-blind placebo-controlled study was designed to evaluate the effects on postoperative pain of the local anesthetic, 0.5% bupivacaine with epinephrine, sprayed hepatodiaphragmatically under the surgeon's direct view during laparoscopic cholecystectomy. Metabolic endocrine responses to surgery (glucose and cortisol) and nonsteroidal anti-inflammatory drug requirements were investigated, as well as the presence of nausea, vomiting, and sweating. Local anesthetics or placebo solutions were given as follows. Immediately following the creation of a pneumoperitoneum, surgeons sprayed the first 20 mL of solution (SI), and an additional 20 mL of solution (S2) was sprayed at the end of the operation. Patients were classified into three groups (14 patients per group). Group A received 20 mL of saline during both SI and S2, group B received 20 mL of saline during SI and 20 mL of bupivacaine during S2, and group C received 20 mL of bupivacaine during both SI and S2. The degree of postope...

Alcohol and cancers of the upper aerodigestive tract in men and women.

Abstract: In order to explore the potential differences in the effect of alcohol in men and women we took advantage of a case-control study of upper aerodigestive tract tumors conducted between 1986 and 1991 in Northern Italy Five hundred forty-six incidence cases of cancer of the oral cavity and pharynx (of whom 81 were women), 410 of cancer of the esophagus (of whom 67 were women), and 388 with cancer of the larynx, (of whom 19 were women) were interviewed. The control group included 2263 inpatients (of whom 557 were women) with acute conditions unrelated to alcohol and tobacco consumption. Among alcohol drinkers, similar odds ratios were detected in men and women. In the highest, well comparable intake category (i.e., > or = 42 drinks/week in women and 42-55 drinks/week in men), odds ratios were 4.5 and 3.8 for cancer of the oral cavity and pharynx, 3.0 and 4.7 for cancer of the esophagus, and 2.6 and 2.0 for cancer of the larynx in women and men, respectively, as compared to light drinkers. However, for all cancer sites a reduced risk was found among abstaining women but not in abstaining men, when compared with light-to-moderate drinkers. The present study, therefore, does not support the hypothesis that women may be substantially more vulnerable than men to alcohol carcinogenesis, at least at the level of the upper aerodigestive tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Mild sialoadenitis: a common finding in patients with hepatitis C virus infection.

Abstract: Pirisi M, Scott C, Fabris C, Ferraccioli G, Soardo G, Ricci R, Toniutto P, Avellini C, Vitulli D, Miotti AM, Beltrami CA, Bartoli E. Mild sialoadenitis: a common finding in patients with hepatitis C virus infection. Scand I Gastroenterol 1994;29:940-942.Background: Sjogren's syndrome (SS) is an autoimmune disease of presumed viral origin; sialoadenitis has been reported to occur in hepatitis C virus (HCV) infection. Methods: Lip biopsy specimens were graded in 32 consecutive patients with either HCV-related chronic liver disease or SS. Results: Seventeen of 22 HCV-positive patients had sialoadenitis, although generally mild (15 of 17, grades I-II). Severe inflammation (grades III–IV) was observed in 8 of 10 patients with SS (chi-square = 12.6; P < 0.0005). Moreover, HCV-positive patients with sialoadenitis differed from patients with SS in female sex prevalence (6 of 17 versus 10 of 10; chi-square = 10.9; p = 0.0001) and presence of serum antinuclear autoantibodies (0 of 17 versus 9 of 10; chi-square = 23...

New Trends in the Supply Environment

Abstract: Present‐day competitiveness has brought about a marked evolution in supply management, imposing on firms an increasingly close interaction with suppliers. The achievement of high‐level performances in terms of cost, quality and time to market appears ever more dependent on the quality and effectiveness of the supply network. This transformation modifies the traditional adversarial model of the buyer‐supplier relationship and fosters the reconfiguration and integrated management of the supply chain. At the same time, competitive dynamics and current global competing models encourage the extension of traditional sourcing areas. Analyses these evolutionary aspects of the current supply environment and examines the new role of the purchasing function.

Fibrinogen plasma levels as a marker of thrombin activation: new insights on the role of fibrinogen as a cardiovascular risk factor.

Abstract: Fibrinogen has recently emerged as a major risk factor for atherothrombosis. However, the pathophysiologic mechanism linking high fibrinogen concentration to cardiovascular disease is unclear. In this study 136 subjects (75 males, 61 females, age 51.7 +/- 14.4 years, mean +/- standard deviation, range 17-82) were tested for total and HDL-cholesterol, total triglycerides, apolipoprotein AI, apolipoprotein B, fibrinogen, prothrombin fragment and D-dimer. Moreover, 5 subjects who had hyperfibrinogenemia (range 450 to 950 mg/dl) for at least 6 months by repeated measurements, were treated with a short 7-day course of heparin 12,500 U/day subcutaneously. The effect of heparin on all the above mentioned parameters was observed at the end of treatment and after 7 days of wash-out. Simple regression analysis detected a positive correlation between fibrinogen and age, prothrombin fragment and D-dimer, and a negative correlation between fibrinogen and HDL-cholesterol and apolipoprotein AI. A direct correlation between age and both prothrombin fragment and D-dimer was also demonstrated. Multivariate analysis showed a persistent correlation between fibrinogen and prothrombin fragment, D-dimer and age, that was not influenced by sex, smoking habit and body mass index. In the 5 hyperfibrinogenemic subjects, heparin administration significantly reduced fibrinogen (625.4 +/- 211.1 vs 455.2 +/- 112.3 mg/dl, p < 0.03), prothrombin fragment (0.97 +/- 0.1 vs 0.63 +/- 0.2 nM, p < 0.002) and D-dimer (336 +/- 101.8 vs 275.2 +/- 78.5 ng/ml, p < 0.03). All these parameters returned to baseline after 7 days of wash-out (fibrinogen 632.5 +/- 198.2 mg/dl, prothrombin fragment 0.96 +/- 0.2 nM, D-dimer 325.8 +/- 98.65 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Design and Development of Knowledge-Based Systems: From Life Cycle to Methodology

Abstract: Life Cycle and Development Methodology The First Steps The Core Effect Going to the Operational Site From Ideas to Success List of Examples List of Case Studies Subject Index.