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Biomedical subjects

M Innocenti

Publications and source records attributed to M Innocenti.

At least 19 recordsLinked to original sources
PubMed2007

Effects of varying doses of supplemental conjugated linoleic acid on production and energetic variables during the transition period.

Supplementing a high dose of dietary conjugated linoleic acid (CLA) inhibits milk fat synthesis in dairy cows immediately postpartum. During negative net energy balance (EBAL), it appears that moderate CLA-induced milk fat depression causes a positive response in milk yield; however, as milk fat depression becomes more severe, the milk yield response diminishes. Multiparous Holstein cows (n = 31) were randomly assigned to 1 of 3 treatments beginning 9 +/- 6 d before expected calving and ceased at 40 d in milk (DIM): 1) 578 g/d of a rumen-inert (RI) palm fatty acid distillate (control), 2) 600 g/d of RI-CLA for the entire trial period (CLA-1), and 3) 600 g/d of RI-CLA until 10 DIM followed by 200 g/d for the remainder of the trial (CLA-2). Each dose provided equal amounts of fatty acids by replacing and balancing each treatment with a RI palm fatty acid distillate. Doses provided a total of 522 g of fatty acids/ d and 0, 174, or 58 (depending upon DIM) g of CLA (mixed isomers)/d. To improve palatability, doses were mixed with 600 g/d of dried molasses; one-half of the supplement was fed at 0800 h, and the remainder at 1900 h. Individual milk yield, dry matter intake, and body weight were recorded daily and milk composition determined every other day. There was no overall CLA effect on either the content or yield of milk protein or lactose. Both CLA treatments decreased overall milk fat content (26.0 and 18.3%) and yield (22.5 and 17.3%) with CLA-induced milk fat depression becoming significant by d 8. The CLA-induced milk fat depression increased in magnitude with progressing DIM until reaching a plateau on d 18 for CLA-1 (43%) and on d 14 for CLA-2 (33%), although neither milk fat trans-10, cis-12 CLA content (1.8 mg/g) nor its transfer efficiency (6.3%) changed over time. Treatments had no effect on overall dry matter intake or milk yield, but there was a treatment x time interaction for milk production, as cows fed either CLA treatment had increased milk yield after the second week of lactation. Cows fed either CLA treatment had a significant improvement in overall EBAL (-5.1 vs. -1.8 Mcal/d), a decrease in nonesterified fatty acid levels (12%), and an increase in glucose levels (11%). A dietary supplement containing trans-10, cis-12 CLA markedly improves EBAL and bioenergetic variables and increases milk yield in the total mixed ration-fed transitioning dairy cow.

Animals↗
PubMed2005

Chemical composition and physical features of summer aerosol at Terra Nova Bay and Dome C, Antarctica.

During the 2002-2003 austral summer field season, aerosol samples were collected at a coastal (Terra Nova Bay--Northern Victoria Land) and an inland site (Dome C--East Antarctic Plateau). The sampling was carried out by stacked filter units made up of two filters at different porosity (5.0 and 0.4 microm at Terra Nova Bay and 3.0 and 0.4 microm at Dome C), able to roughly separate a coarse from a fine fraction. At Dome C, a further investigation on aerosol size distribution was performed by an inertial impactor able to collect aerosol particles on 8 size classes (from 10 to 0.4 microm). Atomic Force Microscopy was applied to the filter collecting the finer fraction in both sites in order to assess the real cut-off value of the filter sandwich apparatus and to reconstruct the volume size distribution. At the employed flow conditions, the real cut-off value was revealed to be about one third with respect to the filter nominal porosity in both stations. The size distribution plots showed a bimodal distribution with a mode centered around 0.22 microm in both the sites and a second broader mode which is centered between 0.3 microm and 1.2 microm diameter at Terra Nova Bay and shifted toward higher values (centred around 1.0 microm diameter) at Dome C. Each filter was analysed for the main and trace ionic components allowing evaluation of the contributions of primary and secondary aerosol sources at the two sites as a function of the particle size class. The coastal site is mainly affected by primary and secondary marine inputs: the sea spray contribution (Na+, Mg2+, Cl- and ssSO4(2-)) is dominant (77% w/w) in the coarse fraction whereas the biogenic source (methanesulfonate and nssSO4(2-)) prevails (67.5% w/w) in the fine fraction. In this fraction a significant contribution (15.5% w/w) is provided by ammonium likely to be related to surrounding penguin colonies. Dome C atmosphere is characterised by fine particles arising from secondary sources and long-range transport processes. The main component in the fine and coarse fractions at Dome C is sulfate whose nssSO4(2-) represents the 99.5% and the 92.3%(w/w) in fine and coarse fraction, respectively. The observed agreement between nssSO4(2-) and methanesulfonate temporal profiles in the fine fraction demonstrates that biogenic emissions dominate the inland background aerosol. Results from the sampling by the 8-stage impactor at Dome C are presented here: chloride and nitrate are mainly deposited on the 10-2.1 microm stages while the highest sulfate concentration was found in the submicrometric fraction which turned out to be the most acidic. Such a distribution is able to prevent nitrate and chloride re-emission as gaseous HCl and HNO3 in the 10-2.1 microm stages, arising from the exchange reaction between chloride and nitrate salts and sulfuric acid. Moreover, the concentration peak observed for nitrate in coarser fractions is probably related also to the formation of hygroscopic NH4NO3 particles and nitrate adsorption on sea salt particles.

Aerosols↗
PubMed2005

Formaldehyde determination in seawater. Preliminary application to coastal samples at Terra Nova Bay (Antarctica).

A sensitive spectrofluorimetric-FIA (flow injection analysis) method for formaldehyde (HCHO) determination was improved with the aim of analysing seawater samples. The fluorescence emission versus HCHO concentration shows a linear pattern from sub microg L(-1) to about 1000 microg L(-1). The reproducibility at 15 ppb level is about 2%. Interferences from other aldehydes were checked; only glyoxal shows a significative interference, but only when its concentration is about 6000 times higher than that of formaldehyde. Superficial (microlayer, just sub-pack or sea-ice free sea surface) and deep (along the water column, sub-pack or in sea-ice free areas) seawater samples were collected near the coast at Terra Nova Bay (Ross Sea, Antarctica) during the 1998/1999 and 2001/2002 Italian Antarctic Expedition. We report here the preliminary results of the spectrofluorimetric-FIA determination of the HCHO content. The mean seawater superficial formaldehyde concentration was 15 microg L(-1); the concentration along the water column ranged between 4.5 to over 40 microg L(-1)(20 microg L(-1) mean concentration), usually with a maximum value for the 30 m depth, corresponding to a fluorescence maximum. The sampling was repeated 7 times in the austral summer in order to evaluate seasonal changes in the formaldehyde concentration/seawater depth profiles. The results show changes in the formaldehyde concentration at different depths.

Antarctic Regions↗
PubMed2005

Ternary CdSxSe 1-x deposited on Ag(111) by ECALE: synthesis and characterization.

Morphology and electronic properties of CdS, CdSe, and the ternary compounds of formula CdSxSe(1-x) deposited on Ag(111) by ECALE have been characterized as a function of the composition. The number of the attainable x values is limited by the necessity of using well-defined CdS/CdSe deposition sequences. However, the quantitative analysis carried out by XPS and electrochemical stripping experiments indicates that the ECALE method has a good control on composition. The AFM images together with the electrochemical characterization indicate both two-dimensional and three-dimensional growth contributions. The photospectra recorded at CdS film electrodes in liquid junction with an alkaline (poly)sulfide electrolyte show good efficiency of photoconversion and band gap typical of the single crystal. Lower photoconversion efficiency and the presence of subband gap response are observed for CdSe; a possible reason is some crystalline disorder due to lower control of the layer-by-layer deposition in the case of Se. The dependence of band gap on composition of ternary CdSxSe(1-x) ECALE films is monotonic and in agreement with literature data reported for bulk materials.

Journal Article↗
PubMed2002

Helicobacter pylori-induced activation of human endothelial cells.

Helicobacter pylori infection causes active chronic inflammation with a continuous recruitment of neutrophils to the inflamed gastric mucosa. To evaluate the role of endothelial cells in this process, we have examined adhesion molecule expression and chemokine and cytokine production from human umbilical vein endothelial cells stimulated with well-characterized H. pylori strains as well as purified proteins. Our results indicate that endothelial cells actively contribute to neutrophil recruitment, since stimulation with H. pylori bacteria induced upregulation of the adhesion molecules VCAM-1, ICAM-1, and E-selectin as well as the chemokines interleukin 8 (IL-8) and growth-related oncogene alpha (GRO-alpha) and the cytokine IL-6. However, there were large variations in the ability of the different H. pylori strains to stimulate endothelial cells. These interstrain variations were seen irrespective of whether the strains had been isolated from patients with duodenal ulcer disease or asymptomatic carriers and were not solely related to the expression of known virulence factors, such as the cytotoxin-associated gene pathogenicity island, vacuolating toxin A, and Lewis blood group antigens. In addition, one or several unidentified proteins which act via NF-kappaB activation seem to induce endothelial cell activation. In conclusion, human endothelial cells produce neutrophil-recruiting factors and show increased adhesion molecule expression after stimulation with certain H. pylori strains. These effects probably contribute to the continuous recruitment of neutrophils to H. pylori-infected gastric mucosa and may also contribute to tissue damage and ulcer formation.

Adult↗
PubMed2001

An effector region in Eps8 is responsible for the activation of the Rac-specific GEF activity of Sos-1 and for the proper localization of the Rac-based actin-polymerizing machine.

Genetic and biochemical evidence demonstrated that Eps8 is involved in the routing of signals from Ras to Rac. This is achieved through the formation of a tricomplex consisting of Eps8-E3b1-Sos-1, which is endowed with Rac guanine nucleotide exchange activity. The catalytic subunit of this complex is represented by Sos-1, a bifunctional molecule capable of catalyzing guanine nucleotide exchange on Ras and Rac. The mechanism by which Sos-1 activity is specifically directed toward Rac remains to be established. Here, by performing a structure-function analysis we show that the Eps8 output function resides in an effector region located within its COOH terminus. This effector region, when separated from the holoprotein, activates Rac and acts as a potent inducer of actin polymerization. In addition, it binds to Sos-1 and is able to induce Rac-specific, Sos-1-dependent guanine nucleotide exchange activity. Finally, the Eps8 effector region mediates a direct interaction of Eps8 with F-actin, dictating Eps8 cellular localization. We propose a model whereby the engagement of Eps8 in a tricomplex with E3b1 and Sos-1 facilitates the interaction of Eps8 with Sos-1 and the consequent activation of an Sos-1 Rac-specific catalytic ability. In this complex, determinants of Eps8 are responsible for the proper localization of the Rac-activating machine to sites of actin remodeling.

Actins↗
PubMed2001

Cloning and characterization of mouse UBPy, a deubiquitinating enzyme that interacts with the ras guanine nucleotide exchange factor CDC25(Mm)/Ras-GRF1.

We used yeast "two-hybrid" screening to isolate cDNA-encoding proteins interacting with the N-terminal domain of the Ras nucleotide exchange factor CDC25(Mm). Three independent overlapping clones were isolated from a mouse embryo cDNA library. The full-length cDNA was cloned by RACE-polymerase chain reaction. It encodes a large protein (1080 amino acids) highly homologous to the human deubiquitinating enzyme hUBPy and contains a well conserved domain typical of ubiquitin isopeptidases. Therefore we called this new protein mouse UBPy (mUBPy). Northern blot analysis revealed a 4-kilobase mRNA present in several mouse tissues and highly expressed in testis; a good level of expression was also found in brain, where CDC25(Mm) is exclusively expressed. Using a glutathione S-transferase fusion protein, we demonstrated an "in vitro" interaction between mUBPy and the N-terminal half (amino acids 1-625) of CDC25(Mm). In addition "in vivo" interaction was demonstrated after cotransfection in mammalian cells. We also showed that CDC25(Mm), expressed in HEK293 cells, is ubiquitinated and that the coexpression of mUBPy decreases its ubiquitination. In addition the half-life of CDC25Mm protein was considerably increased in the presence of mUBPy. The specific function of the human homolog hUBPy is not defined, although its expression was correlated with cell proliferation. Our results suggest that mUBPy may play a role in controlling degradation of CDC25(Mm), thus regulating the level of this Ras-guanine nucleotide exchange factor.

3T3 Cells↗
PubMed2001

Orally administered bovine lactoferrin systemically inhibits VEGF(165)-mediated angiogenesis in the rat.

Lactoferrin (Lf) systemically suppresses tumor growth and metastasis by unknown mechanisms. We have studied the effect of orally administered iron-unsaturated bovine Lf on angiogenesis induced by VEGF(165) and IL-1-alpha in adult rats using the mesenteric-window angiogenesis assay. VEGF(165) is a major angiogenic factor in most, if not all, tumors and other angiogenesis diseases of clinical relevance. A number of objective angiogenesis variables were analyzed using microscopic morphometry and image analysis. Lf treatment significantly inhibited the VEGF(165)-mediated response in terms of microvessel spatial extension, overall vascularity and incidence of crossover. The response to IL-1-alpha decreased significantly only in terms of microvessel crossover. In vitro, Lf exerted an antiproliferative effect on endothelial cells. To our knowledge, Lf is the first endogenous protein that has been shown to be antiangiogenic following oral administration. The oral administration of Lf thus appears to be of potential interest as an antiangiogenesis treatment modality in the clinical setting. Since tumor growth is angiogenesis dependent, the extensive therapeutic potential warrants further study to elucidate the mechanisms responsible for the angiostatic effect of Lf.

Administration, Oral↗
PubMed2001

Skeletal reconstruction with a free vascularized fibula graft associated to bone allograft after resection of malignant bone tumor of limbs.

Over the last twenty years, progress in diagnosis and in adjuvant therapy in the field of malignant bone tumor treatment has allowed for development of limb-saving surgical techniques after oncological excision. In this context, the use of vascularized fibula for transplantation represents an important instrument in the reconstruction of bone, either with or without allografts.Moreover, in pediatric cases, the vascularized transplant of the proximal fibula with its open physis allows for an adequate reconstruction of the bone loss and the possibility of conserving the growth potential of the segment. The purpose of this article is to illustrate the various reconstructive possibilities that the use of the combined graft technique (VFT plus allograft) offers in the treatment of large-scale bone loss. In our department from 1988 to 2000, 142 vascularized fibula transplants were performed in oncological cases. Surgical reconstruction was carried out on the tibia in 70 cases, on the femur in 40, on the humerus in 26 and on the radius in 6. Combined graft intercalary reconstructions were 92. In 22 pediatric cases the fibula was transplanted, including the proximal growing epiphysis in the graft; in two of these cases massive allograft was associated to the VFG. Because of its biological properties, the grafted vascularized fibula allowed for fast bone fusion at the level of the osteotomy. It has also demonstrated a tendency of progressive hypertrophy and osteointegration with the allograft, when used. In 22 pediatric cases, the fibula graft with the proximal epiphysis maintained its ability to grow. Unsuccessful outcomes caused by vascular, mechanical, or septic failure were equal to 8.2 %. The fibula graft in the reconstruction of bone loss secondary to oncological excision is a trustworthy and versatile technique.

Adolescent↗
PubMed2001

Helicobacter pylori lipopolysaccharides preferentially induce CXC chemokine production in human monocytes.

Helicobacter pylori infection can cause duodenal ulcers and may also induce gastric adenocarcinoma. The bacteria colonize the gastric mucosa and areas of gastric metaplasia in the duodenum for decades, resulting in active chronic inflammation in the infected areas. A characteristic feature of the infection is the ongoing recruitment of neutrophils to the infected sites. To evaluate the role of H. pylori lipopolysaccharides (LPS) in the recruitment of leukocytes to the gastric mucosa, we have examined the cytokine and chemokine production from human monocytes stimulated with LPS isolated from different H. pylori strains, as well as from several other gram-negative bacteria. Our results show that H. pylori LPS induce a large production of neutrophil-recruiting CXC chemokines (interleukin-8 and growth-related oncogene alpha) from purified human monocytes, to almost the same extent as Escherichia coli LPS. However, and in agreement with previous studies, H. pylori LPS was much less potent in inducing production of proinflammatory cytokines by purified human monocytes and was also a weak inducer of the CC chemokine RANTES. There was no difference between LPS preparations from different H. pylori strains in their ability to induce cytokines and chemokines. The preferential production of CXC chemokines after stimulation with H. pylori LPS indicates an important contribution of this molecule in maintaining neutrophil recruitment during the infection, irrespective of the infecting strain.

Chemokines, CXC↗
PubMed2000

Signaling from Ras to Rac and beyond: not just a matter of GEFs.

Members of a family of intracellular molecular switches, the small GTPases, sense modifications of the extracellular environment and transduce them into a variety of homeostatic signals. Among small GTPases, Ras and the Rho family of proteins hierarchically and/or coordinately regulate signaling pathways leading to phenotypes as important as proliferation, differentiation and apoptosis. Ras and Rho-GTPases are organized in a complex network of functional interactions, whose molecular mechanisms are being elucidated. Starting from the simple concept of linear cascades of events (GTPase-->activator--> GTPase), the work of several laboratories is uncovering an increasingly complex scenario in which upstream regulators of GTPases also function as downstream effectors and influence the precise biological outcome. Furthermore, small GTPases assemble into macromolecular machineries that include upstream activators, downstream effectors, regulators and perhaps even final biochemical targets. We are starting to understand how these macromolecular complexes work and how they are regulated and targeted to their proper subcellular localization. Ultimately, the acquisition of a cogent picture of the various levels of integration and regulation in small GTPase-mediated signaling should define the physiology of early signal transduction events and the pathological implication of its subversion.

Animals↗
PubMed1999

CDC25(Mm)/Ras-GRF1 regulates both Ras and Rac signaling pathways.

The Ras-GRF1 exchange factor molecule contains in addition to the catalytic domain two pleckstrin homology (PH1 and PH2), one IQ and one Dbl homology (DH) domains. In this study we investigated the role of such additional domains. We found that a Ras-GRF1 mutant lacking PH1 and IQ domains is sufficient to activate c-fos promoter in response to lysophosphatidic acid (LPA). The same mutant did not increase external stimuli-regulated kinase (ERK) activity, suggesting an additional mechanism for the induction of gene transcription. Isolated DH-PH2 module activates c-Jun NH(2)-terminal kinase and the c-fos promoter in response to LPA, providing the basis for an ERK-independent mechanism. These results provide evidence that Ras-GRF1 acts as a bifunctional molecule on both ERK-dependent and independent pathways.

3T3 Cells↗
PubMed1999

Confocal and scanning electron microscopic study of teeth restored with fiber posts, metal posts, and composite resins.

Forty-two single-rooted lower premolars, extracted for periodontal reasons, were endodontically treated and divided into 7 groups of 6 teeth each. In five of the groups, three different types of carbon fiber posts, quartz fiber posts, and titanium posts were used in combination with All Bond 2 dental adhesive. In two groups, two types of carbon fiber posts were also cemented with Panavia 21 dental adhesive. After 3 wk storage in saline, the teeth were longitudinally sectioned; one half was observed using confocal microscopy and the other by scanning electron microscopy. The specimens were evaluated for the presence of a resin dentin interdiffusion zone for the presence of voids at post-resin-dentin interfaces and for the determination of the fiber posts' structure. Upon examination with the confocal microscope, the interfaces of teeth restored with All Bond 2 showed a higher percentage (p < 0.05) of resin dentin interdiffusion zone than those treated with panavia. The fiber size and the post structure were similar in all the fiber posts observed. Some voids were present inside the fiber post structure.

Bicuspid↗
PubMed1999

Low risk of Lyme borreliosis in a protected area on the Tyrrhenian coast, in central Italy.

A comprehensive Lyme borreliosis risk assessment process was applied in S. Rossore Estate, on the Tyrrhenian coast, near Pisa, Italy. Host-seeking Ixodes ricinus nymphs peaked in May in oak-dominated deciduous wood (median, Q1-Q3, number of nymphs/50 m dragging = 4.5, 2.5-8), whereas host-seeking larvae peaked in August in the same habitat type (6.0, 4-17/50 m dragging). Prevalence of I. ricinus infestation was 88.9% in wild rodents (n = 11), 64.3% in fallow deer (n = 28) and 0.0% in wild boars (n = 5). Borrelia burgdorferi sensu lato was not isolated from rodents' organs, and from 80 I. ricinus nymphs and 50 adults. Moreover, PCR for B. burgdorferi sl carried out on 110 nymphs and 12 adult ticks also gave negative results. Forest workers were at higher risk of tick bite than other Estate employees (relative risk (RR): 1.7, p = 0.02). In spite of high levels of tick exposure, B. burgdorferi sl specific antibodies were not detected in sera from Estate personnel (n = 30) and sentinel animals (dogs, n = 23, fallow deer, n = 61).

Animals↗
PubMed1999

Dye leakage and SEM study of roots obturated with Thermafill and dentin bonding agent.

The apical seal of roots obturated with a dentin bonding agent and Thermafill with and without the use of sodium hypochlorite as an irrigating solution was compared by a dye leakage test. Roots obturated with Thermafill and a zinc oxide eugenol sealer were used as controls. Thirty-eight roots were prepared chemomechanically and divided into three experimental groups. The teeth of group 1 were filled with Thermafill and the dentin bonding agent using sodium hypochlorite as the irrigant. The teeth of group 2 were filled in the same way, but saline solution was used as the irrigant. Before the root canal was filled the smear layer was removed from the root canal walls of both groups by rinsing the root canal with a 17% EDTA solution. The teeth of group 3 were filled with Thermafill and a zinc oxide eugenol sealer. The teeth were immersed in 2% methylene blue solution. The root fillings of groups 1 and 2 leaked significantly more than those of group 3. The resin-dentin-guttapercha interface of group 1 was observed by scanning electron microscopy and showed a typical hybrid layer. An intimate contact between resin and dentin was present in group 2, but a resin-dentin interdiffusion zone was only occasionally observed. The use of dental adhesives and the hybrid layer formation did not improve the seal of Thermafill root canal fillings.

Coloring Agents↗
PubMed1999

Intraepiphyseal resection of the proximal tibia and its impact on lower limb growth.

From 1989 through 1996, 10 children affected by high grade bone tumors of the proximal tibia underwent an intraepiphyseal intercalary resection. The residual epiphyseal bone segment measured less than 2 cm in thickness in all cases and reconstruction always was performed using the combination of a vascularized fibular autograft and a massive bone allograft. The proximal epiphyseal osteosynthesis was fixed by small fragment screws. The aim of this study was to report the growth pattern of the residual proximal tibial epiphysis and to evaluate any possible lower limb discrepancy and/or deformity after the end of skeletal maturity. At current followup six patients were available for the final evaluation. Radiographic documentation included computed tomography scan of both knees before surgery, a panoramic radiographic view and a computed tomography scan of both lower limbs after the end of skeletal growth. The length of both femurs and tibias, the size of the tibial plateau and of the opposite distal femur, and any possible deformity of femur or tibia were measured and compared with the preoperative data. No patient had a limb length discrepancy greater than 3.5 cm. In all cases the ipsilateral femur had a valgus deformity of the hip develop. In two patients this deformity was associated with an elongation of the femur, partially compensating for the shortening of the tibia. The tibial plateau close to reconstruction grew less than the contralateral one (range 2%-8%) but maintained its normal relationship with the distal femur. None of these patients reported any restriction in recreational activities. They could walk, run, and jump. Their functional result according the International Society of Limb Salvage functional grading system was satisfactory in all cases.

Bone Neoplasms↗