Structural Lesions of Proteins Connected to Lipid Membrane Damages Caused by Radical Stress: Assessment by Biomimetic Systems and Raman Spectroscopy

Model systems constituted by proteins and unsaturated lipid vesicles were used to gain more insight into the effects of the propagation of an initial radical damage on protein to the lipid compartment. The latter is based on liposome technology and allows measuring the trans unsaturated fatty acid content as a result of free radical stress on proteins. Two kinds of sulfur-containing proteins were chosen to connect their chemical reactivity with membrane lipid transformation, serum albumins and metallothioneins. Biomimetic systems based on radiation chemistry were used to mimic the protein exposure to different kinds of free radical stress and Raman spectroscopy to shed light on protein structural changes caused by the free radical attack. Among the amino acid residues, Cys is one of the most sensitive residues towards the attack of free radicals, thus suggesting that metal-Cys clusters are good interceptors of reactive species in metallothioneins, together with disulfides moieties in serum albumins. Met is another important site of the attack, in particular under reductive conditions. Tyr and Phe are sensitive to radical stress too, leading to electron transfer reactions or radical-induced modifications of their structures. Finally, modifications in protein folding take place depending on reactive species attacking the protein.

Structural analysis of the neuropeptide substance P by using vibrational spectroscopy

Substance P (SP) is one of the most studied peptide hormones and knowing the relationship between its structure and function may have important therapeutic applications in the treatment of a variety of stress-related illnesses. In order to obtain a deeper insight into its folding, the effects of different factors, such as pH changes, the presence of Ca²⁺ ions, and the substitution of the Met-NH₂ moiety in the SP structure, was studied by Raman and infrared spectroscopies. SP has a pH-dependent structure. Under acidic-neutral conditions, SP possesses a prevalent β-sheet structure although also other secondary structure elements are present. By increasing pH, a higher orderliness in the SP secondary structure is induced, as well as the formation of strongly bound intermolecular β-strands with a parallel alignment, which favour the self-assembly of SP in β-aggregates. The substitution of the Met-NH₂ moiety with the acidic functional group in the SP sequence, giving rise to a not biologically active SP analogue, results in a more disordered folding, where the predominant contribution comes from a random coil. Conversely, the presence of Ca²⁺ ions affects slightly but sensitively the folding of the polypeptide chain, by favouring the α-helical content and a different alignment of β-strands; these are structural elements, which may favour the SP biological activity. In addition, the capability of SERS spectroscopy to detect SP in its biologically active form was also tested by using different metal nanoparticles. Thanks to the use of silver NPs prepared by reduction of silver nitrate with hydroxylamine hydrochloride, SP can be detected at very low peptide concentration (~ 90 nM). However, the SERS spectra cannot be obtained under alkaline conditions since both the formation of SP aggregates and the lack of ion pairs do not allow a strong enough interaction of SP with silver NPs. Graphical abstract.

Analysis of the soybean metallothionein system under free radical stress: protein modification connected to lipid membrane damage

Metallothioneins are small Cys-rich peptides capable of coordinating metal ions, and proposed to be involved in radical stress. The four Zn(ii)-GmMT complexes of soybean (Glycine max) were recombinantly synthesised and exposed to oxidative (HO˙) and reductive (H˙ atoms and eaq-) stress conditions. Gamma-irradiation was used to simulate the endogenous formation of the reactive species in both aqueous solutions and unsaturated lipid vesicle suspensions, a biomimetic model that showed that tandem protein/lipid damage occurs, in particular under reductive radical stress. This is due to the formation of diffusible sulphur-centred radicals, which migrate from the aqueous phase to the lipid bilayer and are thus able to transform the cis double bond of the oleate moiety into the trans isomer. Among the amino acid residues present in GmMTs, Cys is one of the most sensitive residues towards the attack of free radicals, thus suggesting metal-clusters to be good interceptors of free radicals. Also Met, Tyr and Phe residues are sensitive amino acid sites of attack under both oxidative and reductive conditions. The modification of the Zn(ii)-GmMT complexes, in particular isoform 2, was monitored by Raman spectroscopy and mass spectrometry. Free radical stress on the Zn(ii)-GmMT complexes is able to induce significant structural changes such as partial deconstruction and/or rearrangement of the metal clusters, but not the complete demetallation of the proteins nor breaking of the backbone, thus confirming their capability to act as protectors under free radical stress conditions.

Evaluation of Seaweed Extracts From Laminaria and Ascophyllum nodosum spp. as Biostimulants in Zea mays L. Using a Combination of Chemical, Biochemical and Morphological Approaches

Seaweed extracts can be employed as biostimulants during crop cultivation owing to their positive effects on plant performance. Therefore, in this study one extract from Laminaria (A) and five extracts from Ascophyllum nodosum (B-F) were assayed on maize (Zea mays L.) plants supplied for 2 days with 0.5 mL L^-1 of single products to evaluate their capacity to stimulate root growth and morphology, nutrition, and sugars accumulation. Firstly, extracts were chemically characterized via Fourier transform infrared (FT-IR) and FT-Raman spectroscopies, and their content in carbon, nitrogen, phenolic acids and hormones (indole-3-acetic acid, IAA, and Isopentenyladenosine, IPA) was quantified. The auxin like- and gibberellic acid -like activities of all extracts were also determined. FT-IR and FT-Raman spectra provided complementary information depicting distinct spectral pattern for each extract. Bands assigned to alginic and uronic acids were dominant in FT-IR spectra, while those corresponding to polyaromatic rings were evident in FT-Raman spectra. In general, extracts stimulated root growth, nutrition, esterase activity, and sugar content. However, they showed high variation in chemical features, which may explain their different capacity in triggering physiological responses in maize. Among A. nodosum extracts for instance, E was the most efficient in promoting root morphology traits, likely because of its elevate content in IAA (32.43 nM), while F extract was the highest in phenol content (1,933 mg L^-1) and the most successful in improving plant nutrition. On the other hand, C extract was very effective in stimulating root elongation, but did not influence plant nutrition. B and D extracts induced similar positive effects on plants, although they greatly varied in chemical composition. Laminaria extract (A) differed from A. nodosum extracts, because of its low content in total phenols and the presence of both IAA- and GA-like activity. We conclude that all seaweed extracts acted as biostimulants in maize, but their chemical properties appeared crucial in predicting the physiological response preferentially elicited by individual seaweed extracts.

Biological Activity of Vegetal Extracts Containing Phenols on Plant Metabolism

The influence of vegetal extracts derived from red grape, blueberry fruits and hawthorn leaves on Zea mays L. plant growth and the activity of phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid pathway, was investigated in laboratory experiments. The extracts were characterized using FT-IR and Raman spectroscopies in order to obtain a pattern of the main functional groups. In addition, phenols content was determined by HPLC, whereas the content of indoleacetic acid and isopentenyladenosine hormones was determined by ELISA test and the auxin and gibberellin-like activities by plant-bioassays. The treated maize revealed increased root and leaf biomass, chlorophyll and sugars content with respect to untreated plants. Hawthorn, red grape skin and blueberry at 1.0 mL/L induced high p-coumaric content values, whilst hawthorn also showed high amounts of gallic and p-hydroxybenzoic acids. PAL activity induced by hawthorn at 1.0 mL/L had the highest values (11.1-fold UNT) and was strongly and linearly related with the sum of leaf phenols. Our results suggest that these vegetal extracts contain more than one group of plant-promoting substances.

A Promising Raman Spectroscopy Technique for the Investigation of trans and cis Cholesteryl Ester Isomers in Biological Samples

Lipid geometry is an important issue in biology and medicine. The cis-trans geometry conversion of double bonds in lipids is an endogenous process that can be mediated by sulfur-centered free radicals. Trans isomers of polyunsaturated fatty acids can be used as biological markers of free radical stress, and their presence in biological samples can be determined by synthesis and characterization of appropriate reference compounds. Fractions of plasma lipids, such as cholesteryl linoleate and arachidonate esters, are interesting targets because of their connection with membrane phospholipid turnover and their roles in cardiovascular health. In this context, Raman spectroscopy can provide a useful contribution, since Raman analysis can be performed directly on the lipid extracts without any derivatization reaction, is nondestructive, and can rapidly supply biochemical information. This study focused on the build up of Raman spectral libraries of different cis and trans isomers of cholesteryl esters to be used as references for the examination of complex biological samples and to facilitate isomer recognition. Unsaturated cholesteryl esters obtained by chemical synthesis and with different alkyl chain lengths, double bond numbers, or both, were analyzed. The potential of Raman analysis for trans isomer detection in biological samples was successfully tested on some cholesteryl ester lipid fractions from human serum. The data suggest promising applications of Raman spectroscopy in metabolomics and lipidomics.

Characterization of polymorphic ampicillin forms

In this work polymorphs of α-aminobenzylpenicillin (ampicillin), a β-lactamic antibiotic, were prepared and investigated by several experimental and theoretical methods. Amorphous monohydrate and three crystalline forms, the trihydrate, the crystal form I and the crystal form II, were investigated by FT-IR and micro-Raman. Also data obtained by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD) and hot-stage Raman spectroscopy are reported. Finally, quantum mechanical calculations were performed by density functional theory (DFT) to assist the assignment of spectroscopic experimental bands. For the first time, the ampicillin molecule in its zwitterionic form was studied at the B3LYP/aug-cc-pVDZ level and the corresponding theoretical vibrational spectra were computed. In fact, ampicillin in the crystal is in zwitterionic form and concentrations of this same form are quite relevant in solutions at physiological pH. Experimental and theoretical results allowed identification of specific features for polymorph characterization. Bands typical of the different polymorphs are identified both in IR and Raman spectra: in particular in the NH stretching region (IR), in the amide I+δNH region (both techniques), in the 1520-1490cm(-1) region (IR), in the 1320-1300cm(-1) and 1280-1220cm(-1) (IR), in the 1200-1170cm(-1) (Raman), in the amide V region (IR), and, finally, in the 715-640cm(-1) and 220-200cm(-1) (Raman). Interconversion among different polymorphs was investigated by hot-stage Raman spectroscopy and thermal analysis, clarifying the complex pattern of transformations undergone as a function of temperature and heating rate. In particular, DSC scans show how the trihydrate crystals transform into anhydrous forms on heating. Finally, stability tests demonstrated, after a two years period, that no transformation or degradation of the polymorphs occurred.

Blood meal-based compound. Good choice as iron fertilizer for organic farming

Prevention of iron chlorosis with Fe synthetic chelates is a widespread agronomical practice but implies high costs and environmental risks. Blood meal is one of the main fertilizers allowed to be used in organic farming. Through this work a novel blood meal fertilizer was audited. Measurements such as FTIR, Raman, electron paramagnetic resonance, and Mössbauer spectroscopy, UV-visible properties, stability against pH, and batch experiments were performed to characterize and assess the reactivity on soil constituents and agronomic soils. The spectroscopy findings give clear indications that Fe is in the ferric oxidation state, is hexacoordinated, and has a low-spin form suggesting a similar structure to hemin and hematin. A spectrophotometric method at 400 nm was validated to quantify blood meal concentration at low electrolyte concentrations. Batch experiments demonstrated high reactivity of blood meal fertilizer with soil constituents, mainly in the presence of calcium, where aggregation processes are predominant, and its ability to take Fe from synthetic Fe (hydr)oxides. The beneficial profile of blood meal by a providing nitrogen source together with the capability to keep the Fe bound to porphyrin organic compounds makes it a good candidate to be used as Fe fertilizer in organic farming.

IR, Raman and SERS spectra of propantheline bromide

The two known propantheline bromide polymorphs (form I and form II) were studied and characterized by a multianalytical approach. In the present work, the identification of propantheline bromide polymorphic forms through vibrational IR spectroscopies are presented and for the first time Raman microscopy and hot stage Raman microscopy (HSRM) studies are reported. Finally, quantum mechanical calculations were performed. For assisting the assignment of the experimental picks, the two IR spectra of the most and least stable representatives of a set of 56 conformers are calculated and studied. DSC thermograms data, are also reported. The surface enhanced Raman scattering (SERS) spectrum was also recorded in a silver colloid; it could be inferred that propantheline bromide is adsorbed on silver colloid through the oxygen atom with the molecular plane perpendicular to the metal surface.

Plasmodium falciparum-infected erythrocytes and beta-hematin induce partial maturation of human dendritic cells and increase their migratory ability in response to lymphoid chemokines

Acute and chronic Plasmodium falciparum infections alter the immune competence of the host possibly through changes in dendritic cell (DC) functionality. DCs are the most potent activators of T cells, and migration is integral to their function. Mature DCs express lymphoid chemokine receptors (CCRs), expression of which enables them to migrate to the lymph nodes, where they encounter naïve T cells. The present study aimed to investigate the impact of the synthetic analog to malaria parasite pigment hemozoin, i.e., β-hematin, or infected erythrocytes (iRBCs) on the activation status of human monocyte-derived DCs and on their expression of CCRs. Human monocyte-derived DCs partially matured upon incubation with β-hematin as indicated by an increased expression of CD80 and CD83. Both β-hematin and iRBCs provoked the release of proinflammatory and anti-inflammatory cytokines, such as interleukin-6 (IL-6), IL-10, and tumor necrosis factor alpha, but not IL-12, and induced upregulation of the lymphoid chemokine receptor CXCR4, which was coupled to an increased migration to lymphoid ligands. Taken together, these results suggest that the partial and transient maturation of human myeloid DCs upon stimulation with malaria parasite-derived products and the increased IL-10 but lack of IL-12 secretion may lead to suboptimal activation of T cells. This may in turn lead to impaired adaptive immune responses and therefore insufficient clearance of the parasites.

Apatite formation on bioactive calcium-silicate cements for dentistry affects surface topography and human marrow stromal cells proliferation

The effect of ageing in phosphate-containing solution of bioactive calcium-silicate cements on the chemistry, morphology and topography of the surface, as well as on in vitro human marrow stromal cells viability and proliferation was investigated. A calcium-silicate cement (wTC) mainly based on dicalcium-silicate and tricalcium-silicate was prepared. Alpha-TCP was added to wTC to obtain wTC-TCP. Bismuth oxide was inserted in wTC to prepare a radiopaque cement (wTC-Bi). A commercial calcium-silicate cement (ProRoot MTA) was tested as control. Cement disks were aged in DPBS for 5 h ('fresh samples'), 14 and 28 days, and analyzed by ESEM/EDX, SEM/EDX, ATR-FTIR, micro-Raman techniques and scanning white-light interferometry. Proliferation, LDH release, ALP activity and collagen production of human marrow stromal cells (MSC) seeded for 1-28 days on the cements were evaluated. Fresh samples exposed a surface mainly composed of calcium-silicate hydrates CSH (from the hydration of belite and alite), calcium hydroxide, calcium carbonate, and ettringite. Apatite nano-spherulites rapidly precipitated on cement surfaces within 5 h. On wTC-TCP the Ca-P deposits appeared thicker than on the other cements. Aged cements showed an irregular porous calcium-phosphate (Ca-P) coating, formed by aggregated apatite spherulites with interspersed calcite crystals. All the experimental cements exerted no acute toxicity in the cell assay system and allowed cell growth. Using biochemical results, the scores were: fresh cements>aged cements for cell proliferation and ALP activity (except for wTC-Bi), whereas fresh cements<aged cements for collagen synthesis. Summarizing (1) non-aged cements showed higher cell proliferation than aged cements, probably favoured by the presence of Si-OH gel and the early formation of apatite nano-spherulites; (2) the alpha-TCP doped cement aged for 28 days displayed the highest bioactivity and cell proliferation; (3) the deleterious effect of bismuth on cell proliferation was reduced by the progressive increase of the biocoating thickness on aged cement. In conclusion, the experimental cements have adequate biological properties to be used as root-end/root repair filling materials or pulp capping materials. The alfa-TCP doped cement represents a new potential bioactive material for expanded applications in dentistry.

Structural study of the zinc and cadmium complexes of a type 2 plant (Quercus suber) metallothionein: Insights by vibrational spectroscopy

Zn- and Cd-complexes of Quercus suber metallothionein (QsMT) were obtained by in vivo-synthesis, in order to obtain physiologically representative aggregates, and characterized by spectrometric and spectroscopic methods. The secondary structure elements and the coordination environments of the metal binding sites of the two aggregates were determined, as well as the main metal-containing species formed. The results obtained from the analysis of the Raman and IR spectra reveal that these metal-MT complexes predominantly contain beta-sheet elements (about 60%), whereas they lack alpha-helices. These structural features slightly depend on the divalent metal bound. In particular, Cd(II) binding to QsMT induces a slight increase of the beta-sheet percentage, as well as a decrease in beta-turn elements with respect to Zn(II) binding. Conversely, the in vivo capability of QsMT to inglobe metal and sulfide ions is metal-depending. Spectroscopic vibrational data also confirm the presence of sulfide ligands in the metal clusters of both Zn- and Cd-QsMT, while the participation of the spacer His residue in metal coordination was only found in Cd-QsMT, in agreement with the CD results. Overall data suggest different coordination environments for Zn(II) and Cd(II) ions in QsMT.

Comparison of Human Mandibular Osteoblasts Grown on Two Commercially Available Titanium Implant Surfaces

BACKGROUND

Surface characteristics play a major role in determining tissue response to implants and therefore their clinical outcome. The aim of the present study was to compare two commercially available titanium surfaces: plasma sprayed (TPS) and sand-blasted, acid-etched surface (SLA).

METHODS

The surfaces were characterized by roughness testing, scanning electronic microscopy (SEM), Raman spectroscopy, and protein adsorption to determine their microtopographic and chemical properties. The effect of the surfaces on human mandibular osteoblasts was then studied in terms of cell morphology, adhesion, proliferation, and differentiation. Human osteoblasts from the mandible were cultured on these two surfaces and evaluated at 3, 6, 24, and 48 hours to determine cell attachment and morphology. Growth and differentiation kinetics were subsequently investigated by evaluating cell growth, alkaline phosphatase activity, osteocalcin and osteoprotegerin production at 7, 14, and 21 days.

RESULTS

Although roughness was quite similar, the two surfaces presented strong differences in their topography, and cell morphology varied as a consequence. Osteoblasts on SLA appeared more elongated and spindle shaped than those on TPS, and their adhesion at 3 and 6 hours was weaker, but reached that of cells on TPS at hour 24. Cell proliferation was greater on SLA surfaces but differentiation parameters; i.e., alkaline phosphatase and osteocalcin, provided better results on TPS surfaces. Osteoprotegerin production was enhanced on TPS surfaces at days 14 and 21.

CONCLUSION

Although cells grown on both surfaces exhibited good adhesion capabilities, a well-differentiated osteoblastic phenotype, and maintained a clear proliferation potential, our study suggests that plasma-sprayed treatment offers a better performance than SLA by creating, at least in the early phases, better conditions for tissue healing.

Comparison between the in vitro surface transformations of AP40 and RKKP bioactive glasses

Two bioactive silica-phosphate glasses, AP40 and RKKP, were compared in their behaviour in simulated biological environment. Their chemical composition is practically identical, except that RKKP contains small amounts of amphoteric network-former oxides Ta2O5 and La2O3 (composition in wt% for AP40: beta-Ca3(PO4)2 24.50, SiO2 44.30, CaO 18.60, Na2O 4.60, K2O 0.19, MgO 2.82, CaF2 4.99; RKKP: beta-Ca3(PO4)2 24.23, SiO2 43.82, CaO 18.40, Na2O 4.55, K2O 0.19, MgO 2.79, CaF2 4.94, Ta2O5 0.99, La2O3 0.09). Previous investigations showed a better performance in osteopenic bone for RKKP. To gain more insight into these differences in biological behaviour, the in vitro bioactivity of the glasses was studied by treatment with a continuously replenished Hanks' Balanced Salt Solution (HBSS). The glasses were examined before and after HBSS treatment for 20 and 40 days by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Energy Dispersion (EDX), Raman and IR vibrational spectroscopies. Some slight but notable differences between the two glasses were observed after HBSS treatment. IR and EDX analyses showed that deposits formed on both glasses were composed of a calcium deficient carbonate-apatite; however, the layer formed on RKKP glass was found to be slightly more calcium deficient and thinner. EDX analysis evidenced the presence of a small percentage of F- ions only in the layers formed on the RKKP samples. The differences disclosed, although slight, can contribute to the understanding of the different biological behaviour previously observed.

Spectroscopic behavior of copper complexes of nonsteroidal anti-inflammatory drugs

The proposed curative properties of Cu-based nonsteroidal anti-inflammatory drugs (NSAIDs) have led to the development of numerous Cu(II) complexes of NSAIDs with enhanced anti-inflammatory activity. Crystalline complexes, Cu(II)-NSAID (ibuprofen, naproxen, tolmetin, and diclofenac), with a carboxylic function have been studied by means of infrared and Raman spectroscopy. All NSAIDs bind the metal through the carboxylate group. On the basis of the comparison between the wavenumber of the COO(-) group vibrations and Delta nu (nu(asimm)COO(-) - nu(simm)COO(-)) between Na salts and Cu(II) complexes, conclusions on the probable structure of the complexes have been drawn. The spectroscopic data support the formation of dimeric [Cu(2)L(4)(H(2)O)(2)] complexes in which the COO(-) group behaves as a bridging bidentate ligand. The low wavenumber region of the Raman spectrum provided information on Cu-O and Cu-Cu bonds in the complexes. Thermogravimetric results gave further support to the vibrational data.

Different Titanium Surface Treatment Influences Human Mandibular Osteoblast Response

BACKGROUND

Six titanium disks with six different surface treatments were examined: SS: smooth (polished) surface; TPS: plasma spray; C100: sand blasting by aluminum oxide (Al2O3) diameter 100 microm and acid etching; C150: sand blasting by Al2O3 diameter 150 microm and acid etching; B60: sand blasting by zirconium oxide (ZrO2) diameter 60 microm and acid etching; and B120: sand blasting by ZrO2 diameter 120 microm and acid etching.

METHODS

The surface characteristics were determined by scanning electron microscopy (SEM) observation and a roughness tester. Raman spectroscopy was used to determine the presence of residual substances on the samples. Cells were seeded onto the disk and after 24 hours, 6 days, and 12 days were observed under SEM and growth curves generated with a cell counter. Some samples were used to determine alkaline phosphatase activity (ALP), using a colorimetric assay.

RESULTS

SEM observation revealed drastic differences in surface microtopography, with a higher cell density on sand-blasted and acid-etched (SLA) samples than SS and TPS, and more regularly aligned cells on B60 and B120 surfaces than on the others. The growth curves showed a greater adhesion of cells on the etched/blasted surfaces compared to the SS and TPS surfaces. The number of cells increased on all the SLA samples, especially B60, throughout the experiment. At the same time, there was considerable ALP activity on the B60 sample, while it remained at extremely low levels on SS and TPS surfaces. Raman analyses revealed Al2O3 debris on C100 and C150, partly explaining the poorer performances of these two surface treatments, since this substance was shown to be toxic for cultured osteoblasts.

CONCLUSIONS

Surface treatments influence the growth and the metabolic activity of cultured osteoblasts, and B60 seems to be the most favorable surface inducing a more pronounced proliferation of cells together with a high differentiation degree.

Spectroscopic study on the enzymatic degradation of a biodegradable composite periodontal membrane

The enzymatic in vitro degradation of a commercial biodegradable hydroxyapatite (HA)-polymer (poly(epsilon-caprolactone)-poly(oxyethylene)(POE)-poly(epsilon-caprolactone) block copolymer) composite membrane was investigated by Raman and IR spectroscopies in two enzymatic solutions at 37 degrees C: esterase and alpha-chymotrypsin in saline phosphate buffer (SPB, pH 7.4). The degradation was found to be faster in the enzymatic medium than in SPB and alkaline solutions. The fastest degradation rate was observed in esterase solution. The trend of properly chosen Raman and IR intensity ratios was evaluated to go deeper inside the degradation mechanism: both polymeric and apatitic components were found to be involved in degradation. The former underwent preferential degradation of POE blocks, while HA is removed by the degradation medium faster than the polymer. Vibrational spectroscopy proved a valid tool for investigating the degradation of the membrane.

[Reliability of extemporaneous histological sentinel lymph node examination during breast surgery for neoplasia]

Lymphatic mapping and sentinel lymph node (SLN) biopsy for breast cancer is rapidly becoming the standard of care. This is mainly due to the accuracy of the procedure, with a significant decrease in morbidity compared with the standard level III node dissection. We present our experience with SLN biopsy and a small series in which we performed an immediate histologic evaluation of the SLN: in case of positive SLN, a complete lymph node dissection was carried out in the same operative time, thus reducing the need of a second operation. In our experience, we had a 100% accordance between immediate and definitive results: we had neither false positive, which could lead to overtreat the patients with an unnecessary lymph node dissection, nor false negative.

[172 consecutive total gastrectomies for gastric cancer with Roux-en-Y loop reconstruction and without fistulization of the esophago-jejunal anastomosis]

In the treatment of gastric cancer total gastrectomy (TG) is one of the most important operation and the esophagojejunal anastomotic leakage is the most important early complication. In our series of 172 consecutive TGs (all controlled with Gastrografin-Rx in fifth postoperative day) we did not have any anastomotic fistula, independently from age, stage, type of limphadenectomy and visceral demolition. We believe that the correct technical performance is the most important factor in the esophagojejunal anastomosis.

1H-NMR and 13C-NMR lipid profiles of human renal tissues

Lipids from human renal tissues are studied by means of (1)H- and (13)C-NMR spectroscopy. The total lipid fractions obtained from healthy kidneys, malignant renal cell carcinomas, and benign oncocytomas are characterized and analyzed to elucidate the main differences between the functional and neoplastic tissues. In all cases the lipid components are well identified. The healthy kidney is characterized by high amounts of triglycerides and the presence of cholesterol in its free form. On the contrary, renal cell carcinomas contain high amounts of cholesterol that are almost completely esterified as oleate, suggesting an intracellular localization of the cholesteryl esters synthesis. Cholesteryl esters are considered markers of renal cell carcinomas, thus supporting recent theories that these compounds play a leading role in cell proliferation. Oncocytomas are particularly rich in phosphatidylcholine and, analogous to the healthy kidney, are completely lacking in cholesteryl esters. Healthy kidneys and oncocytomas appear to have other similarities if compared with renal cell carcinomas: a very high fatty acyl/cholesterol ratio, the presence of dolichols, and a higher grade of unsaturation. The (13)C data suggest a new method for the direct evaluation of the saturated/unsaturated fatty acyl ratio.

Detachment of titanium and fluorohydroxyapatite particles in unloaded endosseous implants

The shape, surface composition and morphology of orthopaedic and endosseous dental titanium implants are key factors to achieve post-surgical and long-term mechanical stability and enhance implant osteointegration. In this study a comparison was made between 12 titanium screws, plasma-spray-coated with titanium powders (TPS), and 12 screws with an additional coating of fluorohydroxyapatite (FHA-Ti). Screws were implanted in the femoral and tibial diaphyses of two mongrel sheep and removed with peri-implant tissues 12 weeks after surgery. The vibrational spectroscopic, ultrastructural and morphological analyses showed good osteointegration for both types of implants in host cortical bone. The portion of the FHA-Ti implants in contact with the medullary canal showed a wider area of newly formed peri-implant bone than that of the TPS implants. Morphological and EDAX analyses demonstrated the presence of small titanium debris in the bone medullary spaces near the TPS surface, presumably due to the friction between the host bone and the implant during insertion. Few traces of titanium were detected around FHA-Ti implants, even if smaller FHA debris were present. The present findings suggest that the FHA coating may act as a barrier against the detachment of titanium debris stored in the medullary spaces near the implant surface.

Characterization of lipids from human brain tissues by multinuclear magnetic resonance spectroscopy

Multinuclear ((1)H, (13)C, and (31)P) magnetic resonance spectroscopy are applied to the biochemical characterization of the total lipid fraction of healthy and neoplastic human brain tissues. Lipid extracts from normal brains, glioblastomas, anaplastic oligodendrogliomas, oligodendrogliomas, and meningiomas are examined. Moreover, the unknown liquid content of a cyst adjacent to a meningioma is analyzed. Two biopsies from glioblastomas are directly studied by (1)H-NMR without any treatment (ex vivo NMR). The (1)H- and (13)C-NMR analysis allows full characterization of the lipid component of the cerebral tissues. In particular, the presence of cholesteryl esters and triglycerides in the extracts of high grade tumors is correlated to the vascular proliferation degree, which is different from normal brain tissue and low grade neoplasms. The (31)P spectra show that phosphatidylcholine is the prominent phospholipid and its relative amount, which is higher in gliomas, is correlated to the low grade of differentiation of tumor cells and an altered membrane turnover. The ex vivo (1)H-NMR data on the glioblastoma samples show the presence of mobile lipids that are correlated to cell necrotic phenomena. Our data allow a direct correlation between biochemical results obtained by NMR and the histopathological factors (vascular and cell proliferations, differentiation, and necrosis) that are prominent in determining brain tumor grading.

Effects of the sterilisation method on the wear of UHMWPE acetabular cups tested in a hip joint simulator

Ultra-high molecular-weight-polyethylene is the most commonly used bearing material in total joint replacement. Wear of polyethylene is a Serious Clinical problem that limits the longevity of orthopaedic implants. Information on degradative changes in the material properties and on the methods used for the sterilisation of polyethylene may help in the selection process of orthopaedic implants with the best wear resistance. This study was performed to investigate the effects of the sterilisation method (gamma irradiation and ethylene oxide treatment) on the wear and on the changes in physical properties of polyethylene acetabular cups. At this purpose, gamma-sterilised and ethylene oxide (EtO)-sterilised acetabular cups were tested against CoCr femoral heads in a hip joint simulator run for 5 million cycles in bovine calf serum. The crystallinity of the cups was evaluated by micro-Raman spectroscopy as a function of the inner surface position. The partial least square calibration was used to correlate the Raman spectra with the crystallinity of the polymer measured by differential scanning calorimetry. The analysis performed on soak control acetabular cups demonstrated that the gamma-sterilised cups are significantly more crystalline than the EtO-sterilised ones. The mean crystallinity values obtained for the gamma-sterilised and EtO-sterilised soak control cups were 65.0% and 63.4%, respectively. Weight loss measurements revealed that the gamma-sterilised acetabular cups exhibited a lower wear rate than that by EtO-sterilised. Thc Raman results obtained on gamma-sterilised and EtO-sterilised acetabular cups showed that the changes in surface crystallinity were mainly caused by irradiation rather than by the mechanical friction during the in vitro tests.

Molecular characterization of human healthy and neoplastic cerebral and renal tissues by in vitro (1)H NMR spectroscopy (review)

The clinical impact of (1)H NMR spectroscopy in the study of human organs, brain and kidney in particular, is well demonstrated. The in vitro (1)H NMR technique is a powerful tool for monitoring changes in intracellular metabolites of human normal and neoplastic cerebral and renal tissues. Healthy and tumoral tissues of different histologic types have been fully characterized from a biochemical standpoint. Molecular characterization is performed on both the aqueous and lipid extracts of surgically removed tissue biopsies yielding a full picture of tissue biochemistry. These analyses have disclosed markers of healthy brain and kidney and of their respective neoplastic lesions. Moreover, some biochemical features can differentiate neoplasms within the same histological type. In particular, lipidic components, like cholesteryl esters (namely oleate), detected in highest grade tumors, warrant further investigation. A better understanding of the biochemistry of diseased human tissues could open the way to new diagnostic and treatment strategies.

Study of the vibrational spectrum of cuprorivaite

In this research, after tracing a history of the pigment, the preparation and analysis of samples of Egyptian blue have been reported. The main reactions taking place during its preparation are indicated. X-ray diffractions show that, starting from mixtures of precursors with stoichiometric composition, the product is practically only cuprorivaite. The kind of flux and cristallinity of silica does not seem determining factors for the pigment formation. Infrared and Raman spectra and an assignment of the bands are reported. Impurities ascertained are discussed on the basis on the data available.

Congenital defect in the abdominal wall in an adult: a case report

We describe a rare case of a woman aged 38 who presented with an untreated omphalocele in association with a duplication of the vena cava and malposition of the right kidney. An aesthetic and functional reconstruction of the abdomen was achieved with local flaps and the creation of a neoumbilicus.

Vibrational spectroscopic characterization of new calcium phosphate bioactive coatings

In this work calcium phosphate (CaP) compounds with different PO(3-)(4)/HPO(2-)(4) R molar ratios in the 0.65-149 range were synthesized. In fact, all these CaPs contain different amounts of HPO(2-)(4) and PO(3-)(4) ions as well as the amorphous precursors (tricalcium phosphate and octacalcium phosphate) of hydroxyapatite deposition, which was shown by in vitro and in vivo measurements. Spectroscopical IR and Raman results showed the presence of bands whose intensity ratio can be related to the molar ratio R; in particular, the Raman I(962)/I(987) and the IR I(1035)/I(1125) intensity ratios were characterized as markers of the molar ratio. For these CaP compounds a nucleation model, which was based on the ability of HPO(2-)(4) ions to form strong H bonds with PO(3-)(4) ions, was proposed.

Development of arthritis and hypothyroidism during alpha-interferon therapy for chronic hepatitis C

Alpha-interferon (alpha-IFN) therapy may induce, reveal or exacerbate various autoimmune-related disorders. The most common is the development of autoantibodies, while clinically overt autoimmune diseases are rare. We describe a 49-year-old woman who developed seronegative rheumatoid-like arthritis and autoimmune hypothyroidism after 7 months of human lymphoblastoid alpha-IFN therapy given for hepatitis C virus-related chronic active hepatitis (CAH-HCV). There was no family or personal history of autoimmune, thyroid or articular diseases. Our patient required continuous therapy for arthritis and hypothyroidism despite discontinuation of alpha-IFN. This suggests that alpha-IFN therapy may induce the contemporary appearance of two different persistent autoimmune-related diseases in the same patient. However, chronic HCV infection may play an important adjuvant role in the development of these diseases.

[Use of Doppler color ultrasonography in the microsurgical treatment of idiopathic varicocele]

The aim of this paper is to evaluate the role of Doppler and echo color-Doppler in the microsurgical treatment of varicocele. Since December 1993, 87 consecutive patients underwent microsurgical treatment of varicocele. The study demonstrates that Doppler and Color-flow-Duplex scanning provide an accurate, non-invasive method to identify the position of accessory spermatic veins, evaluating at the same time the flow characteristics of the microsurgical anastomosis.

[Pre- and postoperative color Doppler ultrasonography of myocutaneous flaps in reconstructive surgery of the breast]

The authors present their experience in the study of blood supply of flaps. The machine used to study both pre and postoperatively the myocutaneous flap is the echo-color Doppler, a brand new device which has recently been used in investigating the morphology and the blood supply. The use of such method has provided us with the following information: detailed ultrasound structure of the skin, subcutaneous and muscular tissues of the examined flap; localization of vessels within the flap; size of the vessel in its whole length; quality and speed of both the arterial and venous flow. Such information is very important for the surgeon to plan in detail the reconstruction by knowing the blood supply of myocutaneous flap.