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Biomedical subjects

S Bruni

Publications and source records attributed to S Bruni.

At least 19 recordsLinked to original sources
PubMed2007

Biocompatibility evaluation of surface-treated AISI 316L austenitic stainless steel in human cell cultures.

The effects of AISI 316L austenitic stainless steel, tested in untreated state or subjected to glow-discharge nitriding (at 10 or 20 hPa) and nitriding + post-oxidizing treatments, on human umbilical vein endothelial cells (HUVEC) and on peripheral blood mononuclear cells (PBMC) were evaluated. All the treated samples showed a better corrosion resistance in PBS and higher surface hardness in comparison with the untreated alloy. In HUVEC put in contact for 72 h with the sample types, proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided + post-oxidized samples, while only slight differences in cytokine (TNF-alpha, IL-6, and TGF-beta1) release were registered. Intercellular adhesion molecule-1 (ICAM-1) increased in HUVEC incubated with all the treated samples, while vascular cell adhesion molecule-1 (VCAM-1) and E-selectin increased in the presence of all the sample types. PBMC incubated for 48 h with the samples showed a decrease in proliferation and an increase in apoptosis in the presence of the untreated samples and the nitrided + post-oxidized ones. All the sample types induced a remarkable increase in TNF-alpha and IL-6 release in PBMC culture medium, while only the untreated sample and the nitrided at 10 hPa induced an increase in ICAM-1 expression. In HUVEC cocultured with PBMC, previously put in contact with the treated AISI 316L samples, increased levels of ICAM-1 were detected. In HUVEC coincubated with the culture medium of PBMC, previously put in contact with the samples under study, a noteworthy increase in ICAM-1, VCAM-1, and E-selectin levels was always registered, with the exception of VCAM-1, which was not affected by the untreated sample. In conclusion, even if the treated samples do not show a marked increase in biocompatibility in comparison with the untreated alloy, their higher corrosion resistance may suggest a better performance as the contact with physiological environment becomes longer.

Biocompatible Materials↗
PubMed2003

Sludge dewatering using macrophytes in a small wastewater treatment system: a case study of a pilot scale plant in northern Italy.

A study was conducted on a system consisting of two beds of 12 m2 each, planted with reeds and filled with sludge from an activated sludge plant dimensioned for 3000 p.e. During 2001, 10 kg of TS/m2 were loaded in each bed using sludge with a dry matter content of 3% during winter and of 0.5% in summer. The aim of the study was to evaluate parameters such as: COD, TSS, P-PO4(3-), N-NO2-, N-NO3-, N-NH4+ in percolation water, the dewatering capability of the two beds and to estimate N mass balance. The observations on dewatering process showed that dried sludge reached a content of 23% TS in winter and of 30% TS in summer. During summertime the plant did not release any percolation flow; in the rest of the year the concentrations of COD, TSS, P-PO4(3-), N-NO2-, N-NH4- remained within bounds of the European directive (91/271/CEE). The N mass balance proved that 90% of N was removed by the denitrification process.

Biodegradation, Environmental↗
PubMed2002

Prebiotics in infant formulas: biochemical characterisation by thin layer chromatography and high performance anion exchange chromatography.

BACKGROUND: Breast-fed infants, unlike bottle-fed babies, have a microbic intestinal flora characterised by a marked predominance of bifidobacteria and lactic acid bacteria. This is essentially due to the prebiotic effect of oligosaccharides in human milk. Recently, oligosaccharides with a prebiotic effect have been added to formulas. Aim. To characterise the mixture of oligosaccharides contained in these new formulas. MATERIALS AND METHODS: The characterisation of oligosaccharides was performed using thin layer chromatography as well as high performance anion exchange chromatography. RESULTS: The mixture of oligosaccharides used in the formulas analysed was made up of oligosaccharides with low molecular weight (transgalactosylated oligosaccharides) and polysaccharides with high molecular weight (inulin). CONCLUSION: With the methods employed, it was possible to characterise the mixture of oligosaccharides used as prebiotics in the formulas now available on the market.

Chromatography, High Pressure Liquid↗
PubMed2001

Extended polymorphism in copper(II) imidazolate polymers: a spectroscopic and XRPD structural study.

Copper(II) bisimidazolate affords five different polymorphs; of these, one was structurally characterized 40 years ago by standard single-crystal X-ray diffraction (Jarvis, J. A. J.; Wells, A. F. Acta Crystallogr. 1960, 13, 1027), while the remaining four, selectively prepared as pure polycrystalline phases, have been now studied by X-ray powder diffraction (XRPD) methods. Of the four new (blue, green, olive-green, and pink) phases, three were solved by the ab initio XRPD technique and refined by the Rietveld method, and the fourth phase (pink) could not be structurally characterized. Crystal data for [Cu(imidazolate)(2)](n): blue phase, a = 27.559(3) A, c = 5.3870(9) A, trigonal, R3 macro, Z = 54; green phase, a = 21.139(1) A, b = 19.080(1) A, c = 9.2842(8) A, orthorhombic, Ccca, Z = 20; olive-green phase, a = 11.7556(8) A, b = 23.422(2) A, c = 9.0727(9) A, beta = 104.993(5) degrees, monoclinic, C2/c, Z = 12. All polymorphs contain four-coordinate CuN(4) chromophores and (N,N')-exobidentate imidazolate ligands, but show different spectroscopic and structural properties, the latter ranging from 2D to different 3D networks of the PtS, sodalite, and moganite archetypes. The intermediacy of the [Cu(imidazole)(2)CO(3)]-H(2)O species in the synthesis of the blue polymorph has been confirmed by spectroscopic and thermal analyses. FTIR, Raman, and electronic spectra were correlated with the structural features revealed in the present work, and used to gain insight into the coordination geometry of copper(II) ions of the pink polymorph. In addition, the correct Raman spectrum for copper(II) bisimidazolate, common for all polymorphs, has been definitely determined.

Journal Article↗
PubMed2001

Characterization of oligosaccharides in milk and feces of breast-fed infants by high-performance anion-exchange chromatography.

Human milk contains a large amount of oligosaccharides, which represent its third largest solute. Nevertheless, both the metabolism and the role of these substances are still largely unknown. A previous study we conducted documented that the amount of oligosaccharides excreted in the feces varies from 6% to 13% of the 24-hour ingested oligosaccharides. The aim of this study was to characterize the pattern of oligosaccharides in the feces compared with the pattern of the ingested milk. Six term newborn infants were studied at the end of the first month of life. A 7:00 AM milk sample was obtained with an electric breast pump. Feces were collected during the day of milk sampling. Analyses of oligosaccharides were performed using high-pH anion-exchange chromatography with pulsed amperometer detection. Pure milk oligosaccharides were used as reference standards. The chromatographic profile of the oligosaccharides present in the feces and in the milk samples showed more than 40 peaks, 20 of which have been identified. The oligosaccharide profile observed in the feces was similar to the pattern of oligosaccharides present in the milk ingested. A significant difference was represented by the almost complete absence of lactose in the feces of all infants and of sialyllacto-N-tetraose a and disialyllacto-N-neotetraose in 3 samples. A substantial reduction of lacto-N-tetraose was observed in 5 samples. Our results demonstrate that the oligosaccharide profile in the feces is similar to that of the ingested milk. Approximately 40% to 50% of the total ingested oligosaccharides can be found in feces of breast-fed infants.

Anions↗
PubMed2001

Determination of the quadratic hyperpolarizability of trans-4-[4-(dimethylamino)styryl]pyridine and 5-dimethylamino-1,10-phenanthroline from solvatochromism of absorption and fluorescence spectra: a comparison with the electric-field-induced second-harmonic generation technique.

For fluorescent compounds, the combined use of absorption and emission solvatochromic data allows to estimate indirectly the cavity radius of the molecule in solution, a very critical parameter in the application of the solvatochromic method for the determination of the quadratic hyperpolarizability beta of dipolar molecules. For two test compounds, trans-4-[4-(dimethylamino)styryl]pyridine (DASP) and 5-dimethylamino-1,10-phenanthroline (DAPHEN), the beta values so obtained are compared with those obtained by the EFISH (Electric Field Induced Second-Harmonic generation) technique. For DAPHEN, the versatility of the method described in this work in the presence of more than one electronic transition contributing to the non-linear optical response is demonstrated.

Absorption↗
PubMed2000

A spectroscopic and magnetic study of complexes of bis(2-benzothiazolyl)methanate and bis(2-benzoxazolyl)methanate with Co(II), Ni(II), Cu(II) and Zn(II).

The co-ordination geometry of the complexes M(bbtm)2 and M(bbom)2 (M: Co, Ni, Cu, Zn; bbtm, bis(2-benzothiazolyl)methanate; bbom, bis(2-benzoxazolyl)methanate) are discussed on the basis of their IR, Raman, resonance Raman, electronic and ESR spectra. Compounds of Ni, Co, Zn with both ligands and Cu(bbom)2 resulted to have a distorted tetrahedral geometry. The distortion towards a square planar geometry is more marked for the M(bbtm)2 series than for the M(bbom)2 one. It has been impossible to suggest a co-ordination geometry for Cu(bbtm)2, that probably has a polymeric structure.

Benzoxazoles↗
PubMed2000

Speciation and structure of copper(II) complexes with histidine-containing peptides in aqueous medium: a combined potentiometric and spectroscopic study.

The complex formation between copper(II) and some histidine-containing peptides has been investigated by means of potentiometric and spectroscopic measurements. Due to the interesting co-ordination mode towards copper(II), peptides with histidyl residue located in second position from the N-terminal amino group have been chosen. The stability constants evaluation has been performed by both pH-metric and ESR (room temperature) measurements; in this context a suitable computer program for the calculation of both stability constant values and the ESR spectrum for each complex has been written. Visible spectrophotometric and circular dichroism spectra, together with the isotropic ESR parameters, were used in order to propose a structure for each complex having a significant percentage of formation in solution.

Circular Dichroism↗
PubMed1999

Kinetic studies of hepatocyte UDP-glucuronosyltransferase: evidence of an allosteric enzyme.

The kinetic analysis of the enzyme UDP-glucuronosyltransferase (UDPGT) responsible for the conjugation of bilirubin, suggest that it is a multisubunit enzyme in which there is cooperative binding of substrate to the subunits. The binding of bilirubin to UDP-glucuronosyltransferase shows positive cooperativity with an apparent dissociation constant of 7.824 x 10(-4) +/- 6.405 x 10(-4) mM. The apparent Hill coefficient for bilirubin to UDPGT is 2.9. The binding of UDP-glucuronic acid exhibits kinetics with mixed cooperativity. Analysis with the Hill equation give an apparent dissociation constant of 6.873 +/- 3.816 mM and a Hill coefficient of 4.028 +/- 1.045. These values of the Hill coefficient are consistent with an enzyme being an oligomer with 6 subunits, since the actual number of subunits must be greater than the apparent Hill coefficient.

Allosteric Regulation↗
PubMed1999

Comparison of bilirubin conjugation in encapsulated hepatocytes, hepatocyte homogenate and intact hepatocytes.

Homogenized rat hepatocytes, whole hepatocytes and encapsulated hepatocytes were incubated with bilirubin and UDP-glucuronic acid to test their ability to form bilirubin conjugates. Bilirubin monoconjugated and diconjugated were detected in all the three preparations by HPLC analysis. The UDP-glucuronosyltransferase (UDPGT) activity of homogenized hepatocytes was 0.002 +/- 0.00006 mM/min per million cells; that of intact hepatocytes was 0.001 +/- 0.00006 mM/min per million cells and that of encapsulated hepatocytes was 0.0005 +/- 0.00002 mM/min per million cells.

Alginates↗
PubMed1998

Can non-linear muscle dynamics explain the smoothness of handwriting movements?

The paper addresses the issue of the role of non-linear muscle dynamics in determining the smoothness and invariance of handwriting trajectories. In particular, a specific neuromuscular control model is described that has recently been shown to explain the detailed time course of hand stiffness during arm reaching movements. In the paper the model is applied to more complex handwriting trajectories, with the purpose of verifying to which extent the load compensation capabilities of the periphery can subserve motor equivalence. Simulations show the power of the mechanism for movements of "normal" speed. For quicker movements periphery alone is not enough and a central load compensation action is clearly required.

Handwriting↗
PubMed1998

Loss of heterozygosity on the long arm of chromosome 11 in orbital embryonal rhabdomyosarcoma (OERMS): a microsatellite study of seven cases.

OBJECTIVES. To investigate, by means of microsatellite analysis, regions of chromosome 11 involved in the genesis of embryonal rhabdomyosarcoma (ERMS) localized to the orbit. METHODS. Microsatellite analysis was carried out on seven cases of orbital ERMS by comparing the electrophoretic migration patterns of PCR-amplified microsatellites of chromosome 11 from both constitutional (blood) and tumor genotypes. Five of the tumors analyzed were samples frozen at the time of surgery, and two were paraffin embedded. RESULTS. Overall, microsatellites D11S1396 (11q13.1-q22.3) and D11S976 (11q) showed loss of heterozygosity (LOH) in all tumor samples, thus indicating the presence, on the long arm of chromosome 11, of one or more tumor suppressor genes with a possible role in the genesis of the disease. CONCLUSION. While the role of genes on the short arm of chromosome 11 in the genesis of ERMS is well established, much less is known of the possible involvement of tumor suppressor genes on the long arm of the same chromosome. This is the first report showing the possible involvement of tumor suppressor genes in this portion of the chromosome in ERMS localized to the orbit.

Journal Article↗
PubMed1995

Kinetic analysis of UDP-glucuronosyltransferase in bilirubin conjugation by encapsulated hepatocytes for transplantation into Gunn rats.

Kinetic analysis of the enzyme UDP-glucuronosyltransferase (UDPGT), responsible for the conjugation of bilirubin, suggests that it is a multisubunit enzyme in which there is cooperative binding of the substrate to the subunits. The binding of bilirubin to UDPGT shows positive cooperativity with an apparent Hill coefficient of 2.9. The binding of UDP-glucuronic acid (UDPGA) exhibits kinetics with mixed cooperativity with an apparent Hill coefficient of 4.028. Homogenized rat hepatocytes, intact hepatocytes, and hepatocytes encapsulated in alginate-polylysine-alginate artificial cells, when incubated with bilirubin (1.6 mM) and UDPGA (20 mM), can form monoconjugated and diconjugated bilirubin. However, the presence of the artificial membrane offers some mass transfer resistance. The intraperitoneal transplantation into the Gunn rat of free and microencapsulated Wistar rat hepatocytes shows that both are equally effective in lowering the serum bilirubin. Thus, the membrane did not contribute to a lowering of efficacy after transplantation.

Alginates↗
PubMed1995

Effect of inhaled nedocromil sodium therapy on blood gas changes in children challenged with ultrasonically nebulized distilled water. A comparison of 8 mg versus 16 mg daily dose.

Changes in time course of blood partial pressures of oxygen (PtcO2) and carbon dioxide (PtcCO2) before, during and after challenge with ultrasonically nebulized distilled water (UNDW) were evaluated in 22 children with mild asthma in basal conditions, and after 8 weeks of therapy with inhaled nedocromil sodium at a daily dosage of 8 or 16 mg. PtcO2 and PtcCO2 were followed using transcutaneous O2 and CO2 monitoring system. All asthmatic subjects presented a significant decrease in PtcO2 and/or PtcCO2 (> 20% basal value) during or after challenge. After therapy, the decrease in PtcO2 and PtcCO2 was normalized in the group treated with 16 mg/day, whereas only a partial yet significant reduction in the decrease of O2 and CO2 was observed in the group assuming 8 mg/-day. These data indicate that inhaled nedocromil is effective in treating bronchial hyperresponsiveness in childhood and that the dose required to achieve this effect is of 16 mg/day.

Administration, Inhalation↗
PubMed1995

Effect of donor strains and age of the recipient in the use of microencapsulated hepatocytes to control hyperbilirubinemia in the Gunn rat.

Hepatocytes of certain rat strains are spontaneously accepted when they are implanted in the peritoneal cavity. Therefore to evaluate if microcapsules are able to immunoisolate the hepatocytes, it is necessary to find the strain of rat whose free hepatocytes are rejected. Hepatocytes were collected from Buffalo rats and were implanted intraperitoneally in one year old Gunn rats. During the first two weeks both groups of Gunn rats which received free and encapsulated hepatocytes showed a reduction in the bilirubin level relative to the control. After 15 days, the bilirubin levels increased in the group which received free hepatocytes. This suggests that an acute rejection had taken place. Bilirubin continued to stay high until the end of the experiment and there was no difference between this group and the control. As the animal ages, there is a significant accumulation of bilirubin in the tissues which affects the net reduction of serum bilirubin since once bilirubin is conjugated by the transplanted hepatocytes and eliminated, some of the bilirubin deposited in the tissues diffuses into the blood preventing a major drop in serum bilirubin levels. The findings that UDP-glucuronosyltransferase (UDPGT) activity of Buffalo rat hepatocytes is the same as the UDPGT activity of Wistar rat hepatocytes, imply that the age of the animal is a very critical factor in determining how great the depression of serum bilirubin will be after implantation of hepatocytes.

Animals↗
PubMed1993

Hypercalcemia in breast cancer.

Hypercalcemia is relatively frequent in malignancy with or without osteolytic bone metastases. It is thought that neoplastic cells may secrete substances which not only stimulate osteoclastic activity but are also capable of modifying the absorption, excretion, and resorption of calcium and phosphate ions. Since 1987, we have studied 24 breast cancer patients with hypercalcemia (22 with bone metastases and two without). The group of 22 patients with bone metastases were divided into two subgroups. The first consisted of 10 patients with high serum levels of humoral factors, such as parathyroid hormone-related protein (PTHrP), and/or prostaglandin E2 (PGE2) and/or interleukin 1 (IL-1), and high levels of bone markers, such as alkaline phosphatase, bone Gla protein and urinary hydroxyproline. The second subgroup consisted of 12 patients with high levels of bone markers alone. Bone histologic analysis showed an osteoclastic activation surrounding metastatic tumor tissue in six out of 10 patients of the first subgroup, while an evident osteolysis caused by the tumor cells was noted in seven out of 12 patients of the second subgroup. The two patients without bone metastases showed normal biochemistry and bone histologic examination. The authors, having tried to explain the pathogenesis of hypercalcemia, emphasize the importance of humoral factors secreted by tumor cells as a direct or indirect cause of hypercalcemia. The origin of hypercalcemia remains unclear in two patients without bone metastases.

Bone Neoplasms↗
PubMed1991

Encapsulated hepatocytes for controlling hyperbilirubinemia in Gunn rats.

Hepatocytes encapsulated in an alginate-polylysine-membrane were used to lower bilirubin levels in hyperbilirubinemia. The animal model was the Gunn rat. The microencapsulated hepatocytes were implanted intraperitoneally. 15 x 16(6) microencapsulated hepatocytes from Wistar rats lowered the bilirubin from 14 mg/100 ml to 6 mg/100 ml after 20 days. 15 x 10(6) microencapsulated hepatocytes from Sprague-Dawley rats lowered the bilirubin levels from 8 mg/100 ml to 5 mg/100 ml. They were as effective as free Sprague-Dawley hepatocytes. 12 x 10(6) Guinea pig hepatocytes, whether encapsulated or free, lowered the bilirubin from 9.36 mg/100 ml to 4.37 mg/100 ml.

Alginates↗