Showing papers by "University of Modena and Reggio Emilia published in 1999"

Dynamic load balancing on Web-server systems

Abstract: Popular Web sites cannot rely on a single powerful server nor on independent mirrored-servers to support the ever-increasing request load. Distributed Web server architectures that transparently schedule client requests offer a way to meet dynamic scalability and availability requirements. The authors review the state of the art in load balancing techniques on distributed Web-server systems, and analyze the efficiencies and limitations of the various approaches.

Hereditary Hemochromatosis in Adults without Pathogenic Mutations in the Hemochromatosis Gene

Abstract: Background and Methods Hereditary hemochromatosis in adults is usually characterized by mutations in the hemochromatosis (HFE) gene on the short arm of chromosome 6. Most patients have a substitution of tyrosine for cysteine at position 282 (C282Y). We studied a large family from Italy that includes persons who have a hereditary iron-overload condition indistinguishable from hemochromatosis but without apparent pathogenic mutations in the HFE gene. We performed biochemical, histologic, and genetic studies of 53 living members of the family, including microsatellite analysis of chromosome 6 and direct sequencing of the HFE gene. Results Of the 53 family members, 15 had abnormal serum ferritin levels, values for transferrin saturation that were higher than 50 percent, or both. Thirteen of the 15 had elevated body iron levels, diagnosed on the basis of the clinical evaluation and liver biopsy, and underwent iron-removal therapy. The other two, both children, did not undergo liver biopsy or iron-removal thera...

Oestrogen deficiency in men: where are we today?

Abstract: The precise role of oestrogen in mammals is poorly understood. Actually, the importance of oestrogen for the normal postnatal female physiology is well known, but uncertainty regarding the mechanisms and sites of action in health and disease within a variety of target tissues both in males and females does exist. Oestrogens exert a wide range of biological effects on a large variety of cell types, for example they regulate cell growth and apoptosis, being major regulators of many physiological functions in the adult, especially those associated with reproduction. Furthermore, oestrogens are involved in the organization and differentiation of the developing organism, notably of the endocrine system, nervous system and peripheral reproductive structures. Remarkably, oestrogen receptors (ERs) were found at very early stages of embryonic development and it seemed obvious that oestrogen insensitivity would be a lethal condition as a consequence of the defective implantation of the blastocyst (1). Indeed, until recently no condition of oestrogen insensitivity had been reported, unlike well-documented inactivating mutations of other members of the steroid/ thyroid/retinoid receptor gene superfamily, such as androgen (2), thyroid hormone (3, 4) and glucocorticoid hormone receptors (5). Thus, the general acceptance that oestrogens are essential for life worked until the beginning of this decade, when sporadic cases of congenital oestrogen deficiency in humans were reported (6–11) and a viable line of mutant mice lacking functional ERs was created (12, 13). Since then, the idea of a pivotal role of oestrogen for survival has begun to look thin in the light of these new findings, which undoubtedly raise many questions in turn. Here we will discuss recent breakthroughs in our understanding of the consequences of congenital oestrogen deficiency, which vary widely within the target tissues, from the skeletal to the reproductive tract. In particular, this review addresses many aspects of congenital oestrogen deficiency in the male, including recent developments in molecular studies and treatment options. Until now, two different conditions have been identified as possible underlying causes of congenital oestrogen deficiency in humans: (a) oestrogen resistance caused by disruptive mutations of the ER gene (11); and (b) aromatase deficiency due to mutations of the gene encoding aromatase cytochrome P450 (P450arom) (6–10, 14–17), the enzyme responsible for aromatization of the A ring of androgens to form the A ring characteristic of oestrogens. Whatever the mechanism, all the tissueand organ-specific physiological responses triggered by oestrogens are lacking.

Vehicle Detection under Day and Night Illumination.

Abstract: Effective detection of vehicles in urban traffic scenes can be achieved by exploiting image analysis techniques. Nevertheless, vehicle detection in daytime and at night can’t be approached with the same image analysis algorithms, due to the strongly different illumination conditions. This paper describes the two different sets of image analysis algorithms that have been used in the VTTS system (Vehicular Traffic Tracking System) for extracting vehicles from image sequences acquired in daytime and at night. In the system, a supervising level selects the set of algorithms to apply and performs vehicle tracking under control of a rule-based decision module. The paper describes the tracking module, and reports experimental results for both vehicle detection and tracking.

Role of oestrogen in male sexual behaviour: insights from the natural model of aromatase deficiency.

Abstract: OBJECTIVE In order to evaluate the role of oestrogens on human male sexual behaviour, the gender-identity, psychosexual orientation and sexual activity of a man with a congenital lack of oestradiol resulting from an inactivating mutation of the aromatase P450 gene was investigated. The psychosexual and sexual behavioural evaluations were performed before and during testosterone treatment and before oestradiol treatment, during three phases of different dosages of oestradiol treatment. DESIGN The study was performed before (phase A) and during (phase B) testosterone enanthate treatment (250 mg i.m. every 10 days, for 6 months), during testosterone withdrawal (phase C), and during each of the following transdermal oestradiol treatments: 50 μg twice a week for 6 months (phase D); 25 μg twice a week for 9 months (phase E), and 12.5 μg twice a week for 9 months (phase F). MEASUREMENTS Sexual behaviour was investigated by a sexological interview and by a 2-month self-reported daily diary performed during each phase of the protocol study. Furthermore, during each oestradiol treatment (phase C, D, E and F), a study of depression, anxiety trait and sexual behaviour was performed by the Beck Depression Inventory (BDI), the Spielberger Trait Anxiety Inventory (STAI) and the Golombok-Rust Inventory of Sexual Satisfaction (GRISS), respectively. Sexual orientation and gender-identity were evaluated by the BEM Sex Role Inventory (BSRI). Serum testosterone and oestradiol were measured during each phase of the study. RESULTS Before oestradiol treatment (phase C), serum oestradiol was undetectable, while it rose to 356.1, 88.1 and 55.1 pmol/l during phases D, E and F, respectively. Before any oestradiol treatment, during phase D, phase E and phase F serum testosterone was 18.13, 0.72, 14.3 and 18.51 nmol/l, respectively. The patient's gender-identity as assessed by BSRI and by the sexological interview was clearly male. The psychosexual orientation evaluated by BSRI, by the sexological interview and by the analysis of the self-filled diary was heterosexual. Relevant modification of the patient's sexual behaviour occurred only during oestrogen treatment. This was more evident during both phase E and phase F, and concerned the behavioural parameters with an increase of libido, frequency of sexual intercourse, masturbation and erotic fantasies. A reduction of BDI and STAI scores was detected during the oestrogen phases. CONCLUSIONS The study of the sexual behaviour in this man with aromatase deficiency suggests that oestrogens in humans do not affect gender-identity and sexual orientation but could have a role in male sexual activity.

Stimulating property of Turnera diffusa and Pfaffia paniculata extracts on the sexual-behavior of male rats.

Abstract: Sexually potent and sexually sluggish/impotent male rats were treated orally with different amounts of Turnera diffusa and Pfaffia paniculata fluid extracts (0.25, 0.50, 1.0 ml/kg). While having no effect on the copulatory behavior of sexually potent rats, both plant extracts--singly or in combination--improved the copulatory performance of sexually sluggish/impotent rats. The highest dose of either extract (1 ml/kg) (as well as the combination of 0.5 ml/kg of each extract) increased the percentage of rats achieving ejaculation and significantly reduced mount, intromission and ejaculation latencies, post-ejaculatory interval and intercopulatory interval. Neither extract affected locomotor activity. These results seem to support the folk reputation of Turnera diffusa and Pfaffia paniculata as sexual stimulants.

Suspected hereditary nonpolyposis colorectal cancer: International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer (ICG-HNPCC) criteria and results of genetic diagnosis.

Abstract: PURPOSE: The aim of this study was to determine the frequency of mutations in the mismatch repair genes in families suspected of having hereditary nonpolyposis colorectal cancer. METHODS: We devised two criteria for families suspected of having hereditary nonpolyposis colorectal cancer (Criteria I and II). Criteria I consist of at least two first-degree relatives affected with colorectal cancer with at least one of the following: development of multiple colorectal tumors including adenomatous polyp, at least one colorectal cancer case diagnosed before the age of 50, and occurrence of a hereditary nonpolyposis colorectal cancer extracolonic cancer (endometrium, urinary tract, small intestine, stomach, hepatobiliary system, or ovary) in family members. Criteria II consist of one colorectal cancer patient with at least one of the following: early age of onset (<40 years); endometrial, urinary tract, or small intestine cancer in the index patient or a sibling (one aged <50 years); and two siblings with other integral hereditary nonpolyposis colorectal cancer extracolonic cancers (one aged <50 years). A questionnaire was mailed to members of the International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer to determine the mutation detection rate in mismatch repair genes from the families fulfilling these criteria. For comparison the mutation detection rate for families fulfilling the Amsterdam hereditary nonpolyposis colorectal cancer criteria in each institution was also obtained. RESULTS: Data were obtained from eight different institutions (in 7 different countries). In a total of 123 patients from 123 families (67 families fulfilling Criteria I and 56 families fulfilling Criteria II), genetic testing for germline mismatch repair gene variants was performed. Germline mutations of the hMLH1 or hMSH2 genes were identified in 24 families (20 percent). Of these, the mutation detection rate for families fulfilling Criteria I was 28 percent (19/67). The mutation detection rate for families fulfilling Criteria II was 9 percent (5/56). In these eight institutions, the overall mutation detection rate for families fulfilling the Amsterdam hereditary nonpolyposis colorectal cancer criteria was 50 percent (77/154). CONCLUSION: The Criteria I for suspected hereditary nonpolyposis colorectal cancer have the advantages that they can be applied to nuclear families and they can include extracolonic cancers. The results of this study suggest that families fulfilling Criteria I should be offered genetic testing. The relatively low mutation detection rate in those families fulfilling Criteria II suggests that, using current techniques, genetic testing in these families is not practical.

Kinematic Clearance Sensitivity Analysis of Spatial Structures With Revolute Joints (

Abstract: The paper presents a new method to assess the influence of joint clearances in spatial structures that are composed of links connected by revolute joints. The method allows assessment of the amount by which joint clearances affect the rigid-body position of a generic link of the structure when an external load is exerted on the link. Unlike other procedures, the proposed method relies on the clearance-free idealization of the structure under investigation. An example shows application of the proposed method to the analysis of the structure derived from a multi-loop manipulator by freezing its actuators.

Variations in facial skin thickness and echogenicity with site and age.

Abstract: The characteristic pattern of reflectivity of facial skin, as evaluated by ultrasound, has not previously been described quantitatively. The aim of this study was to evaluate site- and age-dependent variations in skin thickness and echogenicity of facial skin. A total of 40 women, in different age groups, were studied at 12 different facial skin sites. Echographic images were recorded with a 20 MHz B-Scanner and processed by dedicated software. Skin thickness measurements showed significantly higher values on the lower part of the face, whereas skin echogenicity was higher on the upper part of the face. In elderly subjects, an increase in facial skin thickness and overall echogenicity was observed compared with the younger subjects at all assessed skin areas, except the infraorbital regions. Moreover, modifications of skin echogenicity according to age, consisting in the appearance of a subepidermal band and an enhancement of the lower dermis' reflectivity, were observable at most facial skin sites.

Oral health in children and adolescents with IDDM--a review.

Abstract: Children with insulin-dependent diabetes mellitus have a lower salivary flow rate, pH and buffer capacity, but a higher glucose content and peroxidase, IgA, magnesium and calcium concentration, in comparison with healthy children. Nevertheless the incidence of caries is lower than normal in diabetic children with good metabolic control. Periodontal disease usually starts at puberty as mild gingivitis with bleeding and gingival recession, and it may develop into severe periodontitis, especially in children with poor control of diabetes. Microangiopathy, impaired immune response, different bacterial microflora and collagen metabolism are involved in the pathogenesis of diabetic periodontal disease. The gingival flora is mostly composed of Gram-negative, anaerobic bacteria, while collagen has a lower solubility and is atrophic and inadequate to support the occlusion forces. For these reasons, prevention of periodontitis is important in diabetic children; they should receive oral hygiene instruction and visit a dentist at least twice a year.

Influence of S-adenosyl-L-methionine on chronic mild stress-induced anhedonia in castrated rats.

Abstract: S-adenosyl-L-methionine (SAMe) is the most important methyl donor in the brain and is essential for polyamine synthesis. Methyl group deficiency in the brain has been implicated in depression; on the other hand, polyamines enhance phosphorylation processes, and phosphorylation of functional proteins in neurons is involved in the therapeutic mechanisms of antidepressants. The effect of SAMe in an animal model of ‘depression’, the chronic mild stress-induced anhedonia, was studied using long-term castrated male and female Lister hooded rats. Chronic daily exposure to an unpredictable sequence of mild stressors produced, within 3 weeks, a significant reduction of the consumption of a sucrose solution. SAMe (100, 200 or 300 mg kg−1 daily i.m.) while having no influence on sucrose intake in non-stressed animals, dose-dependently reinstated sucrose consumption within the first week of treatment, both in male and in female stressed rats. Imipramine (10 mg kg−1 daily i.p.) produced a similar effect after a 3 week treatment. Similarly, a palatable food reward-induced place preference conditioning was developed in SAMe (200 or 300 mg kg−1 daily i.m.)- and in imipramine (10 mg kg−1 daily i.p.)-treated chronically stressed animals (males and females), whilst it could not be obtained in vehicle-treated rats. Moreover, the same doses of SAMe (but not of imipramine) restored the exploratory activity and curiosity for the environment (rearing), in the open-field test. While imipramine caused a blockade of the growth throughout the treatment, SAMe produced only a transient growth arrest during the first week of treatment. These results show that SAMe reverses an experimental condition of ‘depression-like’ behaviour in rats, the effect being more rapid and complete than that of imipramine, and without apparent side effects. British Journal of Pharmacology (1999) 127, 645–654; doi:10.1038/sj.bjp.0702589

Missense mutations in the PML/RARalpha ligand binding domain in ATRA-resistant As(2)O(3) sensitive relapsed acute promyelocytic leukemia

Abstract: BACKGROUND AND OBJECTIVE: Acute promyelocytic leukemia is characterized by the chromosomal translocation t(15;17) which yields the fusion product PML/RARa. All-trans retinoic acid probably induces differentiation of atypical promyelocytes and clinical remission in APL patients by binding to the ligand binding domain (LBD) of the RARa portion of the PML-RARa chimeric protein. Structural alterations of the LBD of the PML/RARa have been revealed in ATRA-resistant APL cell lines and in a few APL patients with acquired clinical resistance to ATRA therapy. Two APL relapsed patients with clinical resistance to ATRA therapy were evaluated for the presence of nucleotide mutations in the LBD of PML/RARa gene and then treated with arsenic trioxide (As2O3). DESIGN AND METHODS: DNA fragments from the LBD of the PML/RARa chimeric transcript were obtained by reverse-transcribed polymerase chain reaction. Direct sequencing was performed by an unambiguous bi-directional automatic analysis. Samples representative of APL onset and relapse were analyzed from both patients. RESULTS: In both patients, at the ATRA-resistant relapse, a missense point mutation in the LBD of the PML/RARa gene was found. The mutations, absent at APL onset, led to an Arg272Gln and to an Arg276Trp amino acid substitution, according to the sequence of the RARa protein. Both patients had complete clinical and hematologic remission after treatment with As2O3. INTERPRETATION AND CONCLUSIONS: LBD missense mutations appear to be a significant mechanism of acquired ATRA-resistance in vivo, closely related to clinical APL relapse. The two cases reported here provide the first in vivo evidence of APL relapsed patients, who have become ATRA-resistant for molecular reasons, being sensitive to arsenic trioxide.

Supporting cooperative WWW browsing: a proxy-based approach

Abstract: The paper presents a system for synchronous cooperative browsing that permits users within a workgroup to share information and cooperate toward a common goal. The system implementation is based on a Java proxy, to achieve portability without requiring modification neither to browsers nor to servers. In addition, the paper shows that the implemented system defines a general framework for interactive multi-user WWW applications.

Tuning of Magnetic Anisotropy in Hexairon(III) Rings by Host–Guest Interactions: An Investigation by High‐Field Torque Magnetometry

Abstract: Full chemical control of magnetic anisotropy in hexairon(III) rings can be achieved by varying the size of the guest alkali metal ion. Dramatically different anisotropies characterize the Li(I) and Na(I) complexes of [Fe(6)(OMe)(12)(L)(6)] (L=1,3-propanedione derivatives; a schematic representation of the Li(I) complex is shown), as revealed by high-field torque magnetometry-Iron: (g), oxygen: o, carbon: o, Li(+): plus sign in circle.

Magnetic anisotropy of Fe 6 and Fe 10 molecular rings by cantilever torque magnetometry in high magnetic fields

Abstract: We studied the magnetic anisotropy of two molecular magnets, ${\mathrm{Fe}}_{6}$ and ${\mathrm{Fe}}_{10},$ which comprise six- and ten-membered rings of antiferromagnetically coupled iron (III) ions ${(S}_{i}=\frac{5}{2}),$ respectively. Spin-flip transitions induced by the applied magnetic field (up to 23 T) were investigated by cantilever torque magnetometry on microgram single crystals at very low temperature (down to 0.45 K). From the sharp, steplike variations of magnetic anisotropy at the transition fields, we determined the singlet-triplet energy gap $({\ensuremath{\Delta}}_{1})$ and the axial zero-field splitting parameter ${(D}_{1})$ for the triplet state of ${\mathrm{Fe}}_{6}$ [${\ensuremath{\Delta}}_{1}=15.28(1){\mathrm{cm}}^{\mathrm{\ensuremath{-}}1},$ ${D}_{1}=4.32(3){\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$] and ${\mathrm{Fe}}_{10}$ [${\ensuremath{\Delta}}_{1}=4.479(4){\mathrm{cm}}^{\mathrm{\ensuremath{-}}1},$ ${D}_{1}=2.24(2){\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$]. By analyzing the additional steps observed in the ${\mathrm{Fe}}_{10}$ sample, we evaluated the ${\ensuremath{\Delta}}_{S}$ and ${D}_{S}$ parameters for the total-spin multiplets with S up to 5. On the basis of our findings, we discuss the origin of magnetic anisotropy in iron (III) rings and the application of torque magnetometry to the study of field induced level crossing in molecular magnets.

Resistance to apoptosis in CTLL-2 cells overexpressing B-Myb is associated with B-Myb-dependent bcl-2 induction.

Abstract: Transcriptional regulators of the Myb family play important roles in cell proliferation, differentiation, and survival. To investigate the role of Myb proteins in the regulation of apoptosis, we studied the apoptotic response of interleukin 2-dependent CTLL-2 cells stably transfected with B-Myb. B-Myb-overexpressing cells showed a diminished cytokine dependence and were resistant to apoptosis induced by doxorubicin, ceramide, and dexamethasone. Overexpression of B-Myb was associated with enhanced expression of bcl-2, which was dependent, at least in part, on increased transcription. In transient transfection assays in T-lymphoblastic cells, B-Myb was able to stimulate the promoter activity of the bcl-2 5' flanking region linked to the chloramphenicol acetyltransferase reporter gene. A segment of the bcl-2 promoter (nucleotides +34 to +58 relative to the transcription initiation site) contained a putative Myb-binding site and was shown to specifically interact with B-Myb and to confer B-Myb responsiveness to a bcl-2/chloramphenicol acetyltransferase reporter construct. These results indicate that B-Myb promotes T cells survival by enhancing the expression of bcl-2 and identify bcl-2 as a B-Myb target gene regulated in a DNA binding-dependent manner.

Evidence that melanocortin 4 receptor mediates hemorrhagic shock reversal caused by melanocortin peptides.

Abstract: Melanocortin peptides are known to be extremely potent in causing the sustained reversal of different shock conditions, both in experimental animals and humans; the mechanism of action includes an essential brain loop. Three melanocortin receptor subtypes are expressed in brain tissue: MC(3), MC(4,) and MC(5) receptors. In a volume-controlled model of hemorrhagic shock in anesthetized rats, invariably causing the death of control animals within 30 min after saline injection, the i.v. bolus administration of the adrenocorticotropin fragment 1-24 (agonist at MC(4) and MC(5) receptors) at a dose of 160 microg/kg i.v. (54 nmol/kg) produced an almost complete and sustained restoration of cardiovascular and respiratory functions. An equimolar dose of gamma(1)-melanocyte stimulating hormone (selective agonist at MC(3) receptors) was completely ineffective. The selective antagonist at MC(4) receptors, HS014, although having no influence on cardiovascular and respiratory functions per se, dose-dependently prevented the antishock activity of adrenocorticotropin fragment 1-24, with the effect being complete either at the i.v. dose of 200 microg/kg or at the i.c.v. dose of 5 microg/rat (17-20 microg/kg). We concluded that the effect of melanocortin peptides in hemorrhagic shock is mediated by the MC(4) receptors in the brain.

Selective horizontal dysmetropsia following prestriate lesion

Abstract: Summary We describe a patient (P.S.) who, following a right prestriate lesion, reported that objects in the left visual field appeared distorted and smaller than those on the right. Other aspects of visual processing were remarkably unaffected. We carried out a series of size comparison tests using simple or complex stimuli and requiring different types of behavioural responses. We found that P.S. significantly underestimated the size of stimuli presented in her left visual field. When comparison tasks