Showing papers by "University of Siena published in 2000"

Focused Crawling Using Context Graphs

Abstract: Maintaining currency of search engine indices by exhaustive crawling is rapidly becoming impossible due to the increasing size and dynamic content of the web. Focused crawlers aim to search only the subset of the web related to a specific category, and offer a potential solution to the currency problem. The major problem in focused crawling is performing appropriate credit assignment to different documents along a crawl path, such that short-term gains are not pursued at the expense of less-obvious crawl paths that ultimately yield larger sets of valuable pages. To address this problem we present a focused crawling algorithm that builds a model for the context within which topically relevant pages occur on the web. This context model can capture typical link hierarchies within which valuable pages occur, as well as model content on documents that frequently cooccur with relevant pages. Our algorithm further leverages the existing capability of large search engines to provide partial reverse crawling capabilities. Our algorithm shows significant performance improvements in crawling efficiency over standard focused crawling.

Hormonal responses to whole-body vibration in men.

Abstract: The aim of this study was to evaluate the acute responses of blood hormone concentrations and neuromuscular performance following whole-body vibration (WBV) treatment. Fourteen male subjects [mean (SD) age 25 (4.6) years] were exposed to vertical sinusoidal WBV, 10 times for 60 s, with 60 s rest between the vibration sets (a rest period lasting 6 min was allowed after 5 vibration sets). Neuromuscular performance tests consisting of counter-movement jumps and maximal dynamic leg presses on a slide machine, performed with an extra load of 160% of the subjects body mass, and with both legs were administered before and immediately after the WBV treatment. The average velocity, acceleration, average force, and power were calculated and the root mean square electromyogram (EMGrms) were recorded from the vastus lateralis and rectus femoris muscles simultaneously during the leg-press measurement. Blood samples were also collected, and plasma concentrations of testosterone (T), growth hormone (GH) and cortisol (C) were measured. The results showed a significant increase in the plasma concentration of T and GH, whereas C levels decreased. An increase in the mechanical power output of the leg extensor muscles was observed together with a reduction in EMGrms activity. Neuromuscular efficiency improved, as indicated by the decrease in the ratio between EMGrms and power. Jumping performance, which was measured using the counter-movement jump test, was also enhanced. Thus, it can be argued that the biological mechanism produced by vibration is similar to the effect produced by explosive power training (jumping and bouncing). The enhancement of explosive power could have been induced by an increase in the synchronisation activity of the motor units, and/or improved co-ordination of the synergistic muscles and increased inhibition of the antagonists. These results suggest that WBV treatment leads to acute responses of hormonal profile and neuromuscular performance. It is therefore likely that the effect of WBV treatment elicited a biological adaptation that is connected to a neural potentiation effect, similar to those reported to occur following resistance and explosive power training. In conclusion, it is suggested that WBV influences proprioceptive feedback mechanisms and specific neural components, leading to an improvement of neuromuscular performance. Moreover, since the hormonal responses, characterised by an increase in T and GH concentration and a decrease in C concentration, and the increase in neuromuscular effectiveness were simultaneous but independent, it is speculated that the two phenomena might have common underlying mechanisms.

Biotechnology and the European public

Abstract: The latest European sample survey of public perceptions of biotechnology reveals widespread opposition to genetically modified (GM) food in much of Europe, but public attitudes to medical and environmental applications remain positive.

Nitric oxide and angiogenesis

Abstract: The steps required for new vessel growth are biologically complex and require coordinate regulation of contributing components, including modifications of cell–cell interactions, proliferation and migration of endothelial cells and matrix degradation. The observation that in vivo angiogenesis is accompanied by vasodilation, that many angiogenesis effectors possess vasodilating properties and that tumor vasculature is in a persistent state of vasodilation, support the existence of a molecular/biochemical link between vasodilation and angiogenesis. Several pieces of evidence converge in the indication of a role for nitric oxide (NO), the factor responsible for vasodilation, in physiological and pathological angiogenesis. Data originated in different labs indicate that NO can act both as an 'actor' of angiogenesis and as a 'director of angiogenesis', both functions being equally expressed during physiological and pathological processes. NO significantly contributes to the prosurvival/proangiogenic program of capillary endothelium by triggering and transducing cell growth and differentiation via endothelial-constitutive NO synthase (ec-NOS) activation, cyclic GMP (cGMP) elevation, mitogen activated kinase (MAPK) activation and fibroblast growth factor-2 (FGF-2) expression. Re-establishment of a balanced NO production in the central nervous system results in a reduction of cell damage during inflammatory and vascular diseases. Elevation of NOS activity in correlation with angiogenesis and tumor progression has been extensively reported in experimental and human tumors. In the brain, tumor expansion and edema formation are sensitive to NOS inhibition. On this basis, the nitric oxide pathway appears to be a promising target for consideration in pro- and anti-angiogenic therapeutic strategies. The use of NOS inhibitors seems appropriate to reduce edema, block angiogenesis and facilitate antitumor drug delivery.

Clinical evaluation of fiber-reinforced epoxy resin posts and cast post and cores.

Abstract: PURPOSE This retrospective study evaluated treatment outcome of cast post and core and Composipost systems after 4 yrs of clinical service. MATERIALS AND METHODS 200 patients were included in the study. They were divided in two groups of 100 endodontically treated teeth restored with a post. Group 1: Composipost systems were luted into root canal following the manufacturer's instructions. Group 2: Cast post and cores were cemented into root canal preparations with a traditional technique. The patients were recalled after 6 months, 1, 2 and 4 yrs and clinical and radiographic examinations were completed. Endodontic and prosthodontic results were recorded. RESULTS Group 1: 95% of the teeth restored with Composiposts showed clinical success; 3% of these samples were excluded for noncompliance and 2% showed endodontic failure. Group 2: Clinical success was found with 84% of teeth restored with cast post and core. 2% of these samples were excluded for noncompliance, 9% showed root fracture, 2% dislodgment of crown and 3% endodontic failure. Statistical evaluation showed significant differences between Groups 1 and 2 (P < 0.001). The results of this retrospective study indicated that the Composipost system was superior to the conventional cast post and core system after 4 yrs of clinical service.

Bonding to root canal: structural characteristics of the substrate.

Abstract: Purpose To evaluate in vitro the dentin morphology in root canals in terms of tubule orientation, density and increase in surface area after etching. Materials and methods Thirty anterior teeth were divided in 3 groups at random: the samples of Group 1 were used to study tubular morphology in SEM. Groups 2 and 3 samples were etched with 32% phosphoric acid. The teeth in Group 2 were examined by SEM without further treatment. The samples in Group 3 were treated with a bonding system and fiber posts were luted into the canal. These teeth were then processed for evaluation of hybrid layer formation and resin tags in dentin tubules. The observations were made according to location in the root dentin, tubule density was estimated, and the increase in area available for bonding after etching was calculated. Results The observations revealed variability in tubule density and orientation within different areas of any one sample. Statistically significant differences in the density of tubules were found depending on location. The dentin surface area available for bonding increased by 202% after etching in the cervical third, 156% in the middle third, and 113% in the apical third of the root dentin. Group 3 samples showed that the thickness of the hybrid layer depended on the density of tubules. In the sectors with a low density of tubules, the hybrid layer was significantly thinner than in areas with a higher density of tubules. The increase in dentin surface area might be responsible for the enhanced bond strength after acid etching, but not all areas exhibited equal responses to etching.

Retrospective study of the clinical performance of fiber posts.

Abstract: Purpose To evaluate the clinical performance of C-Posts, AEstheti Posts and AEstheti Plus Posts after a period of clinical service ranging from 1-6 yrs Materials and methods 1,304 posts were included in the study: 840 Composiposts, 215 AEstheti posts and 249 AEstheti Plus posts were placed into endodontically treated teeth Four combinations of bonding/luting materials were used The patients were recalled every 6 months and clinical and radiographic examinations were completed Endodontic and prosthodontic results were recorded Actuarial Life Table statistical analysis and Mantel-Haenszel comparison of survival curve have been performed at 95% level of confidence Results The 32% failure rate was due to two reasons: 25 posts debonded during removal of temporary restorations, and 16 teeth showed periapical lesions at the radiographic examination No statistical significant differences were found among the four groups The results of this retrospective study indicate that fiber posts in combination with bonding/luting materials can be routinely used

Characterization of the Metallo-β-Lactamase Determinant of Acinetobacter baumannii AC-54/97 Reveals the Existence of bla IMP Allelic Variants Carried by Gene Cassettes of Different Phylogeny

Abstract: The metallo-beta-lactamase determinant of Acinetobacter baumannii AC-54/97, a clinical isolate from Italy that was previously shown to produce an enzyme related to IMP-1, was isolated by means of a PCR methodology which targets amplification of gene cassette arrays inserted into class 1 integrons. Sequencing revealed that this determinant was an allelic variant (named bla(IMP-2)) of bla(IMP) found in Japanese isolates and that it was divergent from the latter by 12% of its nucleotide sequence, which evidently had been acquired independently. Similar to bla(IMP), bla(IMP-2) was also carried by an integron-borne gene cassette. However, the 59-base element of the bla(IMP-2) cassette was unrelated to those of the bla(IMP) cassettes found in Japanese isolates, indicating a different phylogeny for the gene cassettes carrying the two allelic variants. Expression of the integron-borne bla(IMP-2) gene in Escherichia coli resulted in a significant decrease in susceptibility to a broad array of beta-lactams (ampicillin, carbenicillin, cephalothin, cefoxitin, ceftazidime, cefepime, and carbapenems). The IMP-2 enzyme was purified from an Escherichia coli strain carrying the cloned determinant, and kinetic parameters were determined with several beta-lactam substrates. Compared to IMP-1, the kinetic parameters of IMP-2 were similar overall with some beta-lactam substrates (cefoxitin, ceftazidime, cefepime, and imipenem) but remarkably different with others (ampicillin, carbenicillin, cephaloridine, and meropenem), revealing a functional significance of at least some of the mutations that differentiate the two IMP variants. Present findings suggest that the environmental reservoir of bla(IMP) alleles could be widespread and raise a question about the global risk of their transfer to clinically relevant species.

Influence of ceramic and cement thickness on the masking of various types of opaque posts.

Abstract: Statement of problem: Dark-colored posts may negatively affect the esthetics of all-ceramic single unit crowns as the thin layers of luting cement may not be sufficiently opaque. Purpose: This in vitro study evaluated the influence of the color of 2 commercially available nonmetallic opaque posts (carbon fiber and zirconia) and an experimental esthetic post, and the shade and thickness of luting cements on the esthetics of all-ceramic restorations. Material and methods: Sample disks at several thickness values were made in glass-ceramic (IPS-Empress), an experimental ceramic, a zirconia, a carbon fiber post material, a resin composite material (Z100) as reference, and a luting cement (Variolink II). A laboratory procedure, with 3 possible combinations of stapling the disks, was used. This was performed for 4 substrates, 3 cement colors at 2 thickness values, and 3 heights of ceramic disks. For each combination, the shift in color was measured with a spectrophotometer. Readings were performed for 3 conditions: (1) ability of ceramic to mask the aspect of the abutment in relation to its thickness (1.0, 1.5, or 2.0 mm); (2) effect of a change in cement color (W, Y, or B) on the final color of the ceramic; and (3) influence of cement film thickness (0.1 or 0.2 mm) on the final color of the ceramic. Results: When ceramic thickness was 1 mm, all other variables were visually appreciable. For ceramic thickness of 1.5 mm, color differences decreased and most differences were appreciable only with laboratory instruments. For ceramic thickness of 2.0 mm, there were no detectable, clinically relevant differences. Conclusion: The final esthetic result of the all-ceramic IPS-Empress glass-ceramic restoration was not affected by the presence of different substrates with different colors when the thickness was more than 2.0 mm. When ceramic thickness decreases to 1.5 mm, it is advised to take the substrate aspects into consideration. If the ceramic thickness is less than 1.0 mm, the use of a full ceramic crown is contraindicated because color matching of the abutment is required to ensure an acceptable esthetic result. Differences in cement thickness (0.1 or 0.2 mm) may slightly affect the final result. As this parameter can be controlled by the operator only to a certain extent, it cannot be considered as a procedure to correct color. Availability of different cement shades allows only minor esthetic corrections, which might be instrumentally detectable but are clinically not relevant. (J Prosthet Dent 2000;83:412-7.)

Swelling Behavior of Carboxymethylcellulose Hydrogels in Relation to Cross-Linking, pH, and Charge Density

Abstract: Hydrogels of carboxymethylcellulose (CMC) with 2.5%, 25%, 50%, and 100% cross-linking were prepared. Cross-linking and stoichiometry was controlled by appropriate addition of CMPJ and determined by potentiometric titration. The cross-linked polymer was then sulfated using a sulfur trioxide−pyridine complex (SO3−Py) in a heterogeneous mixture. Water uptake of the gels was studied in relation to cross-linking, pH, and sulfation. FT-IR spectra of the gels were recorded at different pHs to evidence the hydrogen bonds. Hydrogen bonds formation between the chains may explain the correlation found between water uptake properties and the chemical composition of the gels.

Phalangeal Osteosonogrammetry Study: Age‐Related Changes, Diagnostic Sensitivity, and Discrimination Power

Abstract: Phalangeal osteosonogrammetry was introduced as a method for bone tissue investigation in 1992. It is based on the measure of the velocity of ultrasound (amplitude-dependent speed of sound [AD-SoS]) and on the interpretation of the characteristics of the ultrasound signal. In this study we have collected a database of 10,115 subjects to evaluate the performance of AD-SoS and to develop a parameter that is able to quantify the signal characteristics: ultrasound bone profile index (UBPI). The database only includes females of which 4.5% had documented vertebral osteoporotic fractures, 16% lumbar spine dual X-ray absorptiometry (DXA), and 6% hip DXA. The analysis of the ultrasound signal has shown that with aging the UBPI, first wave amplitude (FWA), and signal dynamics (SDy) follow a trend that is different from the one observed for AD-SoS; that is, there is no increase during childhood. In the whole population, the risk of fracture per SD decrease for AD-SOS was odds ratio (OR) 1.71 (CI, 1.58-1.84). The AD-SoS in fractured subjects was significantly lower than in a group of age-matched nonfractured subjects (p < 0.0001). In a small cohort of hip-fractured patients UBPI proved to be lower than in a control age-matched group (p < 0.0001). When the World Health Organization (WHO) working group criteria were applied to this population to identify the T score value for osteoporosis, for AD-SoS we found a T score of -3.2 and for UBPI we found a T score of -3.14. Sixty-six percent of vertebral fractures were below the AD-SoS -3.2 T score and 62% were below UBPI -3.14. We observed the highest incidence of fractures (63.6%) among subjects with AD-SoS who had both DXA T score values below the threshold. We conclude from this study that ultrasound investigation at the hand phalanges is a valid methodology for osteoporosis assessment. It has been possible to quantify signal changes by means of UBPI, a parameter that will improve the possibility of investigating bone structure.

Consumption of fresh fruit rich in vitamin C and wheezing symptoms in children

Abstract: BACKGROUND A beneficial effect of fresh fruit consumption on lung function has been observed in several studies. The epidemiological evidence of the effect on respiratory symptoms and asthma is limited. The consumption of fruit rich in vitamin C was examined in relation to wheezing and other respiratory symptoms in cross sectional and follow up studies of Italian children. METHODS Standardised respiratory questionnaires were filled in by parents of 18 737 children aged 6–7 years living in eight areas of Northern and Central Italy. The winter intake of citrus fruit and kiwi fruit by the children was categorised as less than once per week, 1–2 per week, 3–4 per week, and 5–7 per week. A subset of 4104 children from two areas was reinvestigated after one year using a second parental questionnaire to record the occurrence of wheezing symptoms over the intervening period. RESULTS In the cross sectional analysis, after controlling for several confounders (sex, study area, paternal education, household density, maternal smoking, paternal smoking, dampness or mould in the child9s bedroom, parental asthma), intake of citrus fruit or kiwi fruit was a highly significant protective factor for wheeze in the last 12 months (odds ratio (OR) = 0.66, 95% confidence intervals (CI) 0.55 to 0.78, for those eating fruit 5–7 times per week compared with less than once per week), shortness of breath with wheeze (OR = 0.68, 95% CI 0.56 to 0.84), severe wheeze (OR = 0.59, 95% CI 0.40 to 0.85), nocturnal cough (OR = 0.73, 95% CI 0.65 to 0.83), chronic cough (OR = 0.75, 95% CI 0.65 to 0.88), and non-coryzal rhinitis (OR = 0.72, 95% CI 0.63 to 0.83). In the follow up study fruit intake recorded at baseline was a strong and independent predictor of all symptoms investigated except non-coryzal rhinitis. In most cases the protective effect was evident even among children whose intake of fruit was only 1–2 times per week and no clear dose-response relationship was found. The effect was stronger (although not significantly so (p = 0.13)) in subjects with a history of asthma; those eating fresh fruit at least once a week experienced a lower one year occurrence of wheeze (29.3%) than those eating fruit less than once per week (47.1%) (OR = 0.46, 95% CI 0.27 to 0.81). CONCLUSIONS Although the effect of other dietary components cannot be excluded, it is concluded that the consumption of fruit rich in vitamin C, even at a low level of intake, may reduce wheezing symptoms in childhood, especially among already susceptible individuals.

A mutation in the rett syndrome gene, MECP2, causes X-linked mental retardation and progressive spasticity in males.

Abstract: Heterozygous mutations in the X-linked MECP2 gene cause Rett syndrome, a severe neurodevelopmental disorder of young females. Only one male presenting an MECP2 mutation has been reported; he survived only to age 1 year, suggesting that mutations in MECP2 are male lethal. Here we report a three-generation family in which two affected males showed severe mental retardation and progressive spasticity, previously mapped in Xq27.2-qter. Two obligate carrier females showed either normal or borderline intelligence, simulating an X-linked recessive trait. The two males and the two obligate carrier females presented a mutation in the MECP2 gene, demonstrating that, in males, MECP2 can be responsible for severe mental retardation associated with neurological disorders.

Germline mutations of the APC gene in patients with familial adenomatous polyposis-associated thyroid carcinoma: results from a European cooperative study.

Abstract: Papillary thyroid carcinoma (PTC) is one extracolonic manifestation affecting about 1-2% of patients with familial adenomatous polyposis (FAP). Ninety-seven patients with FAP-associated PTC have previously been reported, including 6 pairs of siblings. During a European collaborative study, 15 patients with FAP-associated PTC were collected. All 15 patients were females. The mean age at thyroidectomy was 24.9 yr (range, 19-39 yr). In 13 subjects, APC germline mutations had been detected; they were at codons 140, 593, 778, 976, 993, 1061 (n = 5), 1105 (n = 1), and 1309 (n = 2), respectively. A review of the literature added 11 other patients with FAP-associated PTC and detection of germline APC mutations; they were at codons 313 (n = 2), 698 (n = 3), 848 (n = 2), 1209 (n = 2), 1061 (n = 1), and 1105 (n = 1), respectively. The latter led to formation of the same stop codon (TAA) at 1125-1126 as the mutation at codon 1061. Therefore, 21 of 24 mutations were in exon 15 in the genomic area usually associated with congenital hypertrophy of the retinal pigment epithelium (CHRPE), i.e. codons 463-1387. Typical CHRPE was found in 17 of 18 affected patients who had specific screening. Interestingly, 22 of the 24 patients had their mutation out of the mutation cluster region (codons 1286-1513), which is currently considered the hot spot mutation area, in particular for extracolonic manifestations of FAP. The difference in the incidence of germline mutations before and after codon 1220 between PTC and non-PTC FAP patients was statistically significant (P<0.05) for both patients and kindreds (P = 0.005 and P = 0.049, respectively). Even if most mutations were scattered throughout the entire 5'-portion of exon 15, 8 of 23 patients (6 with mutation at 1061 and 2 with mutation at 1105; i.e. more than one third) had the same truncated protein product. The awareness that patients with PTC usually have APC mutations that cluster in a well defined genomic area, in addition to giving a deeper insight into gene function, could facilitate both earlier diagnosis and better treatment. In particular, intensive screening for thyroid nodules after age 15 yr is recommended when a single patient or an entire kindred have CHRPE and/or mutations in the 5'-portion of exon 15.

Coronally advanced flap procedure for root coverage. Flap with tension versus flap without tension: a randomized controlled clinical study.

Abstract: Background: This clinical controlled study was designed to measure the tension of coronally advanced flaps (CAF) performed to treat shallow gingival recessions and to compare the recession reduction (Rec Red) achieved in a test group (flaps with tension) and in a control group (flaps without tension) 3 months after surgery. Methods: Eleven patients, aged 22 to 41 years, with high levels of oral hygiene (full mouth plaque score <20%) were selected for the study. Each patient showed 2 bilateral Miller Class I maxillary or mandibular gingival recessions located on homologous teeth. A total of 22 recessions were treated. The recession depth at the right site was similar to that at the left site (difference ≤1 mm). For each patient, the 2 recessions underwent CAF procedure in the same surgical session. Before suturing, the residual tension (FTens) of both right and left flaps was measured with a dynamometer. Then, one site was randomly assigned to the test group and the contralateral site to the control group....

Functional and Ultrastructural Features of DNA‐Fragmented Human Sperm

Abstract: The functional significance of deoxyribonucleic acid(DNA) fragmentation in ejaculated human sperm is unclear. In thisstudy the extent of DNA strand breakage in swim-up selectedsper-matozoa was evaluated by terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end labeling (TUNEL)-coupledflow cytometry and correlated with several functional and morpho-logical sperm parameters. The extent of DNA fragmentation(mean 11.07% 8.00%, range 0.79%–42.64%, n 140) was pos-itively related to abnormal morphology and associated with defectsof the sperm tail. A negative correlation was found between DNAbreakage and progressive motility. When a stepwise multiple linearregression model was used to analyze the relationship betweenDNA fragmentation and the aforementioned parameters, only mo-tility results were included in the model. The presence of sper-matozoa showing submicroscopic characteristics resemblingthoseof somatic apoptosis has been reported in human ejaculate. Toverify whether sperm DNA fragmentation was associated with thepresence of such apoptotic-like cells, we performed electron mi-croscopy and TUNEL-coupled flow cytometry in a limited numberof sperm samples (n 24). Although we did not observe any sig-nificant relationship between DNA breakage and the characteris-tics that are suggestive of apoptosis, an association was foundwithseveral ultrastructural features, indicating an impaired motility.Hence, we conclude that in ejaculated sperm, DNA fragmentationdoes not correspond to the apoptosis-like phenomenon and that itis associated with defects of motility.Key words: Apoptosis, DNA fragmentation.J Androl 2000;21:903–912

Ultrafast Radiationless Deactivation of Organic Dyes: Evidence for a Two-State Two-Mode Pathway in Polymethine Cyanines

Abstract: CASSCF quantum chemical calculations (including dynamics) have been used to investigate the ultrafast photoisomerization of three symmetric cyanine dye models of different chain lengths. For the “model” trimethine cyanine, the photochemical isomerization path can be divided into two phases: initial barrierless skeletal stretching coupled with torsional motion and the decay process that takes place in the region of the twisted intramolecular charge-transfer (TICT) minimum state with an adjacent conical intersection. The path is consistent with both biexponential decay of fluorescence without rise time at short wavelengths and the rise time followed by monoexponential decay at long wavelengths observed in time-resolved experiments. For penta- and heptamethine cyanines, the photoisomerization about different C−C bonds is shown to be an activated process, where the torsional reaction path terminates, again, at a TICT state and the decay takes place at a twisted S1/S0 conical intersection. In agreement with t...

Prey selection and predation by wolves in białowieża primeval forest, poland

Abstract: Relationships of wolves (Canis lupus) and ungulates were studied in the Polish part of Biaowieza Primeval Forest with high densities of prey. The number of wolves ranged from 7 to 19, and the number of packs ranged from 2 to 4. Average densities were 2.3 wolves/ 100 km 2 . Red deer (Cervus elaphus) was the main prey of wolves. Roe deer (Capreolus capreolus), wild boar (Sus scrofa), moose (Alces alces), and European bison (Bison bon- asus) were hunted less than expected based on their abundance. Mean mass of ungulates killed by wolves was 55 kg. Prey were consumed quickly, with 57% of kills completely eaten on the 1st day after killing. Average killing rate by wolves was 0.78 ungulate per wolf pack per day (0.14 prey item per wolf per day). Results of this study combined with the data obtained in the Belarussian part of Biaowieza Primeval Forest in 1946-1985 allowed for analysis of dietary response of wolves to changes in densities of ungulates. Wolves showed a response to abundance of red deer. The amount of other ungulates in their diet depended on the densities of red deer. From 1991 to 1996, wolves annually removed 57-105 red deer, 19-38 wild boar, 19-25 roe deer, and 0-2 moose per 100 km 2 . Those amounts were equivalent to 9-13% of spring-summer densities of red deer, 4-8% of wild boar, 3-4% of roe deer, and 0-29% of moose. Additionally, hunters annually harvested 131-140 red deer, 44-114 roe deer, 1-7 moose, and 45-142 wild boar per 100 km 2 . Effects of predation and harvest by hunters on ungulate mortality were likely additive and caused declines in ungulate populations during our study.

Total hydroperoxide and advanced oxidation protein products in preterm hypoxic babies.

Abstract: Previous studies have shown that plasma lipoproteins are a common target of free radical-induced oxidative stress in hypoxic newborn infants. In contrast to lipids, the reaction of proteins with various oxidants during hypoxia has not been extensively studied. We tested the hypothesis that tissue hypoxia results in increased production of protein oxidation in cord blood of preterm newborns. Heparinized blood samples of 39 hypoxic and 16 control preterm newborns were obtained from the umbilical vein, after cord clamping immediately after delivery. Plasma levels of total hydroperoxide (TH), advanced oxidation protein products (AOPP), hypoxanthine (Hx), xanthine (Xa), and uric acid (UA) were measured. Higher Hx, Xa, UA, TH, and AOPP levels were found in hypoxic newborn infants than in controls. Statistically significant correlations were observed between: TH and Hx (r = 0.54, p = 0.003, n = 28), AOPP and Hx (r = 0.64, p = 0.0001, n = 27), and TH and AOPP plasma levels (r = 0.50, p = 0.02, n = 21). In summary, TH, AOPP, Hx, Xa, and UA production is increased in fetal blood during hypoxia. The more severe the hypoxia, the higher the lipid and protein damage by free radicals.

Hospital Outbreak of Carbapenem-Resistant Pseudomonas aeruginosa Producing VIM-1, a Novel Transferable Metallo-β-Lactamase

Abstract: A total of 8 Pseudomonas aeruginosa isolates was collected from 7 different patients in different wards of the University Hospital of Verona, Italy, from February 1997 to February 1998. The high level of resistance to carbapenems (imipenem minimum inhibitory concentration was always >128 microg/mL) and other broad-spectrum beta-lactams and the rate of imipenem hydrolysis and its inhibition by ethylenediamine-tetra-acetic acid were all suggestive of production of a carbapenem-hydrolyzing metallo-beta-lactamase. A specific DNA probe derived from the recently cloned bla(VIM-1) gene hybridized to all the isolates. A genomic DNA fingerprinting profile revealed clonal relatedness for 7 of 8 isolates. A description of this hospital outbreak is reported, the occurrence of which confirms that proliferation of metallo-beta-lactamase-producing strains multiply resistant to beta-lactams is already a reality outside Japan. These findings emphasize the need for early recognition of similar isolates.

The 121 amino acid isoform of vascular endothelial growth factor is more strongly tumorigenic than other splice variants in vivo

Abstract: Vascular endothelial growth factor (VEGF) is known to occur as at least six differentially spliced variants, giving rise to mature isoforms containing 121, 145, 165, 183, 189 and 206 amino acids. However, little is yet known concerning the in vivo activities of this differential splicing. Stably transfected MCF-7 breast carcinoma cells were constructed that secreted comparable amounts of the 121, 165 or 189 isoforms. Rabbit corneal angiogenesis assays showed the VEGF121 transfectant to have much greater angiogenic activity than the 165 or 189 expressing MCF-7 cells. While the VEGF121-expressing MCF-7 cells were reproducibly more tumorigenic than the control transfectants, this was not the case with the VEGF165- or VEGF189-expressing cells. More surprising was the observation that VEGF189 located to the nucleus, consistent with the presence of a highly conserved nuclear localization sequence in exon 6a that is expressed in VEGF189 but not 121 or 165. It was concluded that the VEGF121 isoform is both more angiogenic and tumorigenic than are the 165 and 189 isoforms. This is probably due to the ability of the 121 isoform, unlike the 165 and 189 isoforms, to freely diffuse from the cells producing it. © 2000 Cancer Research Campaign

The complex of Bacillus pasteurii urease with acetohydroxamate anion from X-ray data at 1.55 A resolution.

Abstract: The structure of Bacillus pasteurii urease inhibited with acetohydroxamic acid was solved and refined anisotropically using synchrotron X-ray cryogenic diffraction data (1.55 A resolution, 99.5% completeness, data redundancy = 26, R-factor = 15.1%, PDB code 4UBP). The two Ni ions in the active site are separated by a distance of 3.53 A. The structure clearly shows the binding mode of the inhibitor anion, symmetrically bridging the two Ni ions in the active site through the hydroxamate oxygen and chelating one Ni ion through the carbonyl oxygen. The flexible flap flanking the active site cavity is in the open conformation. The possible implications of the results on structure-based molecular design of new urease inhibitors are discussed.

Effects of Repetitive Transcranial Magnetic Stimulation on Movement-related Cortical Activity in Humans

Abstract: Several lines of evidence suggest that low-rate repetitive transcranial magnetic stimulation (rTMS) of the motor cortex at 1 Hz reduces the excitability of the motor cortex and produces metabolic changes under and at a distance from the stimulated side. Therefore, it has been suggested that rTMS may have beneficial effects on motor performance in patients with movement disorders. However, it is still unknown in what way these effects can be produced. The aim of the present study is to investigate whether rTMS of the motor cortex (15 min at 1 Hz) is able to modify the voluntary movement related cortical activity, as reflected in the Beretischaftspotential (BP), and if these changes are functionally relevant for the final motor performance. The cortical movement-related activity in a typical BP paradigm of five healthy volunteers has been recorded using 61 scalp electrodes, while subjects performed self-paced right thumb oppositions every 8-20 s. After a basal recording, the BP was recorded in three different conditions, counterbalanced across subjects: after rTMS stimulation of the left primary motor area (M1) (15 min, 1 Hz, 10% above motor threshold), after 15 min of sham rTMS stimulation and following 15 min of voluntary movements performed with spatio-temporal characteristics similar to those induced by TMS. The tapping test was used to assess motor performance before and after each condition. Only movement-related trials with similar electromyographic (onset from muscular 'silence') and accelerometric patterns (same initial direction and similar amplitudes) were selected for computing BP waveforms. TMS- evoked and self-paced thumb movements had the same directional accelerometric pattern but different amplitudes. In all subjects, the real rTMS, but neither sham stimulation nor prolonged voluntary movements, produced a significant amplitude decrement of the negative slope of the BP; there was also a shortening of the BP onset time in four subjects. The effect was topographically restricted to cortical areas which were active in the basal condition, irrespective of the basal degree of activation at every single electrode. No changes in the tapping test occurred. These findings suggest that rTMS of the motor cortex at 1 Hz may interfere with the movement related brain activity, probably through influence on cortical inhibitory networks.