Clinical evaluation of the oral health status in vascular-type dementia patients. A case-control study.

AIM: The aim of this study was to evaluate the oral health status in patients with vascular dementia (VaD). Moreover, the association of the disease severity and the patients' cognitive and functional impairment with the oral findings have been recorded. METHODS: The study was directed on the study group (86 VaD patients) and the control group (82 healthy volunteers of the same age) from the IRCSS Neurolesi Bonino-Pulejo in Messina, Italy. Cognitive status was evaluated with the MMSE scoring system. Oral parameters, such as decaying, missing, filled teeth (DMFT) index, plaque index (PI), periodontal probing depth (PPD) and bleeding on probing (BOP) were evaluated in all patients. Denture condition and denture-induced stomatitis were also analysed. The frequency of untreated caries, periodontal diseases and missing teeth of the Study Group was significantly higher than in Control Group. RESULTS: Particularly, VaD patients presented higher number of decayed teeth and deeper periodontal pockets. Decreased cognitive functions in VaD patients have been demonstrated to result in a decline of denture care and increased denture-related mucosal lesions. CONCLUSION: These results underlined that clinicians should direct high attention to oral hygiene of patients with VaD in order to prevent the evolution of those pathologic dental and periodontal conditions, especially in patients with decreased cognitive functions.

FEM Analysis of Mandibular Prosthetic Overdenture Supported by Dental Implants: Evaluation of Different Retention Methods.

Prosthetic rehabilitation of total edentulous jaws patients is today a common technique that clinicians approach in their daily practice. The use of dental implants for replacing missing teeth is going to be a safe technique and the implant-prosthetic materials give the possibility of having long-term clinical success. Aim of this work is to evaluate the mechanical features of three different prosthetic retention systems. By applying engineering systems of investigations like FEM and von Mises analyses, how the dental implant material holds out against the masticatory strength during the chewing cycles has been investigated. Three common dental implant overdenture retention systems have been investigated. The ball attachment system, the locator system, and the common dental abutment have been processed by Ansys Workbench 15.0 and underwent FEM and von Mises investigations. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed different response for both types of device, although locator system showed better results for all conditions of loading. The data of this virtual model show all the features of different prosthetic retention systems under the masticatory load. Clinicians should find the better prosthetic solution related to the patients clinical condition in order to obtain long-term results.

Clinical and radiological 12-year follow-up of full arch maxilla prosthetic restoration supported by dental implants positioned through guide flapless surgery.

The computer-guided flapless surgery for implant placement using stereolithographic templates is going to be considered a daily practice technique. The advantages of this kind of surgery are related with its no flap opening, with the precision of the implant positioning and with the possibility of having a quick rehabilitation and low post-surgical discomfort. The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses. This case presented a 12-year follow-up of a maxillary prosthesis supported by dental implant immediately loading and positioned with the first kind of guided flapless surgery technique. Aim of this paper was to report how the guide surgery implant position technique can be considered a predictable and safe technique giving the surgeon excellent long-term results.

FEM and Von Mises analyses of different dental implant shapes for masticatory loading distribution.

The rehabilitation of edentulous patients is today a challenge for the clinicians. The healthy of the hard and soft issue may be considered a fundamental element for having long-term results. The dental implant progresses about the predictable and safe results made this technique chosen from a large group of practitioners. However some problems related intra-operative and postoperative conditions may create discomfort on the patients and consequently to the clinician. The unfavourable results are often related to the bone tissue quality but sometime the dental implant shape and the prosthesis framework may undergo to technical difficulties. The purpose of this work is, through the use of appropriate FEM models, to analyse the effect of all these parameters in the construction of a prosthesis type "Toronto", evaluating all the surgical and prosthetic components in order to direct the choices made by the surgeon and to optimize the distribution of loads reducing the patient's discomfort and having a long term clinical success.

Oral health-related quality of life in partially edentulous patients before and after implant therapy: a 2-year longitudinal study.

OBJECTIVES: The aim of this study was to measure the Oral Health-Related Quality of Life (OHRQoL) before and after a prosthodontic implant therapy so to determine the physical and psychological impact of implant-supported fixed partial dentures (IFPD) rehabilitation among edentulous patients. METHODS: 50 partially edentulous patients aged 40-70 years, treated with IFPD, completed the OHRQoL questionnaire before the implant surgery (Time 0) and 2 years after their whole implant-prosthetic rehabilitation (Time 1). The questionnaire was proposed in a short version of Oral Health Impact Profile (OHIP-14, range 0-56) and analyzed through the 'additive method'. We evaluated statistical mean, standard deviation, median, variance and mode of all OHIP-14 domains and the statistical significance about oral changes at Time 0 and Time 1 using the Chi-square test (p-values < 0.05). RESULTS: Patients reported significant changes in mean OHIP scores (Time 0: 2.15; Time 1: 0.65; p < 0.01). The most prevalently affected domain was "functional limitation", followed by "psychological discomfort" and "physical pain". There were no significant differences dependent on age, gender and antagonistic teeth (p > 0.05). Patients with I and IV Kennedy's class edentulism showed better improvement (p < 0.05). CONCLUSIONS: Preoperative and post-treatment assessments of OHRQoL exhibited significant differences. The IFPD treatment had a positive effect on the OHRQoL, which improved better in patients with I and IV Kennedy's edentulous class.

Multi-technique study of a ceramic archaeological artifact and its content.

In this paper we report the results of a study performed with different physical and chemical methods on a ceramic vase originally attributed to the I century CE. The joint use of infrared spectroscopic analysis and laser techniques, as well as pyrolysis-gas chromatography coupled with mass spectrometry and thermoluminescence, allowed us to characterize the vase material and its content. The chemical data were combined with morphological and stylistic examinations of the object and helped in defining its actual geographical and chronological pertinence.

Clinical assessment of submerged vs non-submerged implants placed in pristine bone.

The medium-long term success of osseointegrated dental implants is evaluated on the basis of the degree of osseointegration over time, assessed by radiographic or instrumental analysis (ISQ). Over the years, the question has always been which surgical technique can provide a better performance in the medium-long term and, thanks to literature studies, it has been evidenced that there are no differences between "one stage" and "two stage" interventions. The purpose of this study is to evaluate clinical and radiographic parameters, referring to interventions for the insertion of dental implants characterized by a new kind of implant surface (Synthegra® GEASS, Udine). The prospective study, not randomized and controlled, referred to the insertion of 18 implants on 9 patients with mono or bilateral edentulism, with measurements at 1, 3, 6 and 12 months and an overall follow-up at 3 years, in order to evaluate the different degree of crestal bone resorption using the submerged and transmucosal surgical technique. The results of our study show that there are no differences in the resorption of the two surgical techniques, with an average bone resorption of 2,05±0,16 mm, comparable with values reported in literature.

The determination of S-nitrosothiols in biological samples--procedures, problems and precautions.

Despite the considerable number of published studies in the field of S-nitrosothiols (RSNO), the determination of these compounds in biological samples still represents an analytical challenge, due to several technical obstacles and often long sample preparation procedures. Other problems derive from the intrinsic lability of RSNO and the absence of certified reference material, analytically validated methods or suitable internal standards. Also, thiols and nitrites are usually present at high concentrations in biological matrices, and all precautions must be adopted in order to prevent artifactual formation of RSNO. Preanalytical steps (sampling, preservation and pre-treatment of samples) are particularly critical for the obtainment of reliable measurements. Three main mechanisms have been identified capable of compromising the assays: metal-catalyzed RSNO decomposition, reduction of the S-NO bond by thiols (transnitrosylation reactions) and enzymatic degradation of S-nitroso-glutathione (GSNO) by endogenous γ-glutamyltransferase (GGT) activity possibly present in the sample. If not adequately controlled, these factors likely contribute to the wide dispersion of values reported in the literature for RSNO and GSNO concentration in biological fluids, blood in the first place. The use of metal chelators, thiol reagents and GGT inhibitors appears therefore mandatory.

Cemento-ossyfying fibroma juvenile of the oral cavity.

OBJECTIVES: Fibro-osseous neoplasm remains somewhat controversial, and differing concept have been advanced regarding their nature and the proper terminology for them. Cemento-ossyfying fibroma juvenile (JOF) is a rare type of fibro-osseous tumor as also been included under the "umbrella" of cemento-ossyfying fibroma. The JOF is most often seen in patients who are between 5 and 15 years of age. With this work we emphasize the importance of a correct diagnostic approach. MATERIAL AND METHODS.: The case describes a form of cemento-ossyfying fibroma hight active and aggressive like JOF. The patient thirteen older showed from 2004 to 2008 three times the palatal lesion, it was performed with a incisional biopsy and excisional biopsy. The tumor were fixed in 10% buffered formalin embedded in paraffin cut into thick sections and stained with ematoxylineosin. RESULTS: The incisional biopsy was inadequate to formulate a correct diagnosis. The histological exams have showed for three times different aspects. CONCLUSION: Some authors in the past have suggested different classification. The COFs show different clinical, histological and radiographical patterns.

The evaluation of disphagic syndrome, in patients with previously acquired brain damages.

Recently clinical studies have proved without doubts that in patients affect by neurological diseases, like stroke, parkinsonism syndromes and others neurodegenerative pathologies, there is a very elevated incidence of swallowing disorders even severe. The disease can show up in a full blown way, with clinical evident signs like suffocation or frequent and sudden cough, at the moment in which the patient tries to feed or to drink; or it can appear in a less clear way, through an unable protection of the low airway and with possible pathologies ab ingestis. The first signals are represented by frequent resulting of cough reflex at nutrition or hydratation. Important is to assess the validity of this reflection, monitoring the amount of food reflux in the mouth after swallowing, which then could be perceived like foreign body and be aspired. The main diagnostic tests are the pHmetry in 24h, ultrasound, esophagography, videofluoroscopy, endoscopic examination and scintigraphy. Through the FEES (Fiberoptic Endoscopic Evaluation of Swallowing) we can then identify the time of swallowing deficit. Early diagnosis of Dysphagia Syndrome is important to improve living condition and survival of patients.

Separation and determination of denatured caseins by hydrophobic interaction chromatography Part II. Method validation and applications.

A method recently described for the separation of denatured alpha-, beta- and kappa-caseins by hydrophobic interaction chromatography was validated by the analysis of reference skim milk powder (BCR-063R) certificated for total nitrogen content. The method is based on fast and easy solubilization of commercial and real samples by 4.0 M guanidine thiocyanate and elution on a TSK-Gel Phenyl-5PW column (TosoHaas) in the presence of 8.0 M urea in the mobile phase. No preliminary precipitation or separation of the casein fraction is required. A linear relationship between the concentration of casein and peak area (UV absorbance detector at 280 nm) was obtained over the concentration range 0.5-60 microM. The detection limits for alpha-, beta- and kappa-caseins ranged between 0.30 and 0.65 microM. The precision of the method was evaluated; the relative standard deviation for alpha-, beta- and kappa-casein determination ranged between 2.2 and 2.7% for standard solutions and between 3.5 and 6.2% for real sample solutions. The mean casein content found in 10 aliquots of BCR-063R calculated with respect to the total protein content (estimated on the basis of certified total nitrogen content) was 79.1+/-2.7%. Results of linear fitting of standard additions data for alpha-, beta- and kappa-caseins to BCR-063R were compared with linear fitting of alpha-, beta- and kappa-casein calibration data. The method was applied to commercial caseins and to 31 real, raw samples [processed cow's milk (pasteurised, UHT-treated), follow-up milk powders, cream, cheeses, casein-free infant formulae, cookies for babies containing milk proteins] with the aim of showing the wide applicability of the method in order to determine alpha-, beta- and kappa-caseins.

New method for separation and determination of denatured caseins by hydrophobic interaction chromatography.

A new method for the separation of denatured alpha-, beta- and kappa- caseins by hydrophobic interaction chromatography (HIC) is proposed. The method is based on an easy solubilization of commercial and real samples by 4.0 M guanidine thiocyanate (GdmSCN) and elution on a TSK-Gel(R) Phenyl-5PW column (TosoHaas) in the presence of 8.0 M urea in the mobile phase. The procedure, applied to commercial caseins and to real, raw samples (whole milk powder and fat-free yoghurt) is not expensive, it requires common high performance liquid chromatography (HPLC) instrumentation and allows the separation of caseins also in the presence of whey proteins. Quantitative results on the analysis of alpha-, beta- and kappa-caseins in real samples are also reported.

Multidimensional analysis of poly(ethylene glycols) by size exclusion chromatography and dynamic surface tension detection

Substantial improvements in a multidimensional dynamic surface tension detector (DSTD) are presented. Rapid, online calibration and measurement of the dynamic surface tension for high-performance liquid chromatography separations is achieved. Dynamic surface tension is determined by measuring the differential pressure across the liquid-air interface of repeatedly growing and detaching drops. Continuous surface tension measurement throughout the entire drop growth (50 ms to 2 s) is achieved, for each eluting drop, providing insight into the kinetic behavior of molecular orientation processes at the liquid-air interface. Three-dimensional data are obtained, with surface tension first converted to surface pressure, which is plotted as a function of elution time axis versus drop time axis. Two key innovations will be reported. First, a novel calibration procedure is described and implemented. Differential pressure signals from three drops (mobile phase, standard in mobile phase, and analyte in mobile phase) are utilized to make the dynamic surface tension measurement, thereby eliminating the need for optical imaging, and viscosity and hydrostatic pressure corrections, as required by other methods. Only pressure signals from one mobile-phase drop and one standard drop pressure signal are required, while the analyte drop pressure signal is measured along the chromatographic time axis. Second, corrections for drop elongation are not required, because the drops are precisely detached by an air burst actuation method in a regime were the surface tension forces significantly dominate gravitational forces. Drops that would fall with a volume of approximately 10 microL due to gravity are precisely and repeatedly detached earlier at a volume of 2 microL. The sensitivity and unique selectivity of the DSTD opens up new possibilities in the analysis of small molecular weight polymers of varying degrees of surface activity, as illustrated for the size-exclusion chromatography analyses of complex poly(ethylene glycol) (PEG) samples. Using partial least squares for data analysis, polydispersity of complex PEG samples is determined at a relative precision of approximately 1%.

Structural dependence of the cellular isoform of prion protein on solvent: spectroscopic characterization of an intermediate conformation.

Using circular dichroism, fluorescence, and infrared spectroscopies, we studied the secondary structure of purified hamster PrP(C) in the presence of the mild, nonionic detergent octylglucoside. Under these native conditions, PrP(C) displayed an unexpectedly high beta-sheet component, intermediate between the values previously reported for PrP(Sc) and an isoform of PrP(C) isolated in a zwitterionic detergent. The structure of PrP(C) appeared to depend strongly on the detergent and/or phase. Switching from octylglucoside to zwitterion 3-14 drastically modified PrP secondary structure by increasing the alpha-helix while abolishing the beta-sheet component. In contrast, the conformation of PrP(C) in zwitterion was highly stable, since reverting to octylglucoside did not restore the original native structure. These and other results show that native PrP(C) in octylglucoside has some of the conformational characteristics that make the protein susceptible to conversion into PrP(Sc). Most importantly, this is the first study to demonstrate the intrinsic plasticity of the full-length native PrP(C) isolated from animal brains.

Application of mercury cold vapor atomic fluorescence spectrometry to the characterization of mercury-accessible -SH groups in native proteins.

A new analytical approach has been applied to the determination and characterization of mercury-accessible -SH groups in pure native protein samples (ovalbumin, hemoglobin, glyceraldehyde-3-phosphate dehydrogenase, aldolase, pyruvate kinase, hexokinase, lactate dehydrogenase, alcohol dehydrogenase, creatine phosphokinase, lysozyme, and cytochrome c). The method is based on the selective reduction of Hg(II) in the presence of Hg(II)-thiol complexes with alkaline sodium tetrahydroborate, to give Hg(0) in a continuous flow reaction system coupled with atomic fluorescence spectrometric (AFS) detection. The method is fast and specific and allows one to work with nanomole amounts of a single protein without any preliminary incubation and without any separation of Hg(II) from thiol-complexed mercury. The meaning of the results obtained in the determination of the accessible -SH groups in native proteins by using chemical probes is discussed.

Clay-nucleic acid complexes: characteristics and implications for the preservation of genetic material in primeval habitats.

The equilibrium adsorption of three nucleic acids: chromosomal DNA, supercoiled plasmid DNA, and 25S rRNA, on the clay minerals, montmorillonite (M) and kaolinite (K), were studied. Adsorption of the nucleic acid on the clays was rapid and maximal after 90 min of contact time. Chromosomal DNA was adsorbed to a greater extent than plasmid DNA and RNA, and the adsorption was also greater on M than on K. Adsorption isotherms were of the L type, and a plateau was reached with all the complexes, with the exception of chromosomal DNA adsorbed on M. To deterine where nucleic acids are adsorbed on clay minerals and the nature of the interaction, complexes were studied by X-ray diffraction (X-RD), electron microscopy, and Fourier transform infrared (FT-IR) spectroscopy. X-RD showed that nucleic acids did not penetrate the clay, indicating that the adsorption occurred primarily on the external surfaces of clay particles, as also suggested by electron microscopy observations. FT-IR spectra of clay-tightly bound nucleic acid complexes showed adsorption bands that indicate a variation of the nucleic acids status as a consequence of their adsorption on clay. Data obtained suggested that the formation of clay-nucleic acid complex could have an important role in the preservation of genetic material in primeval habitats.

Use of CD and FT-IR to determine the secondary structure of purified proteins in the low-microgram range.

The spectroscopic characterization of protein secondary structure is often partially unreliable when samples are not extremely pure and abundant. This problem may be overcome by the combination of circular dichroism (CD) and Fourier transform infrared spectroscopy (FT-IR). We used these methods to characterize the secondary structure of two proteins of neurobiological interest, calexcitin (CE) and the cellular isoform of prion protein (PrPC). Both proteins were purified with multiple chromatographic steps and were obtained in buffer with high purity (> 95%) and in low amount (approximately 2 micrograms). The samples were analyzed by circular dichroism (down to 184 or 182 nm), recovered, and deposited on films for infrared analysis. The spectral deconvolution from the two methods yielded secondary structures in good agreement with each other as well as with theoretical predictions based on amino acid sequence. The conformation of CE was found to be dependent on its concentration and on calcium binding. The secondary structure of cellular native PrP varied dramatically with the detergent used. In conclusion, the combination of CD and FT-IR analysis is suitable for the characterization of the conformational changes induced by ligand binding and/or by different solvent conditions when the protein of interest is only scarcely available. The methods used here provide valuable insights into the putative correlation between protein structure and activity.

An approach to the study of primitive thrombocythemia (PT) megakaryocytes by means of Fourier transform infrared microspectroscopy (FT-IR-M).

Chronic myeloid leukemia (CML), polycythemia vera (PV), idiopathic myelofibrosis (IM) and primary thrombocythemia (PT) are myeloproliferative diseases of clonal origin. Megakaryocyte series are commonly involved in these disorders. In a previous paper of us, megakaryocytes (MKs) from PV and PT patients were shown to be more pathological with respect to the MKs from CML. This paper describes a Fourier transform infrared microspectroscopy (FT-IR-M) study analyzing the cytoplasm and nucleus areas of MKs from thrombocythemic patients which exhibited numerous giant cells (from 100 to 190 microm in diameter). The size of these cells makes it possible to analyze the cell parts using FT-IR-M technique. The infrared determinations on 10 single MKs for each case examined in these two different cell regions revealed spectral differences with a high degree of reproducibility. Finally, the spectra of whole MKs from normal donors and from thrombocythemic patients were also compared.

Secondary structure and Ca2+-induced conformational change of calexcitin, a learning-associated protein.

Calexcitin/cp20 is a low molecular weight GTP- and Ca2+-binding protein, which is phosphorylated by protein kinase C during associative learning, and reproduces many of the cellular effects of learning, such as the reduction of potassium currents in neurons. Here, the secondary structure of cloned squid calexcitin was determined by circular dichroism in aqueous solution and by Fourier transform infrared spectroscopy both in solution and on dried films. The results obtained with the two techniques are in agreement with each other and coincide with the secondary structure computed from the amino acid sequence. In solution, calexcitin is one-third in alpha-helix and one-fifth in beta-sheet. The conformation of the protein in solid state depends on the concentration of the starting solution, suggesting the occurrence of surface aggregation. The secondary structure also depends on the binding of calcium, which causes an increase in alpha-helix and a decrease in beta-sheet, as estimated by circular dichroism. The conformation of calexcitin is independent of ionic strength, and the calcium-induced structural transition is slightly inhibited by Mg2+ and low pH, while favored by high pH. The switch of calexcitin's secondary structure upon calcium binding, which was confirmed by intrinsic fluorescence spectroscopy and nondenaturing gel electrophoresis, is reversible and occurs in a physiologically meaningful range of Ca2+ concentration. The calcium-bound form is more globular than the apoprotein. Unlike other EF-hand proteins, calexcitin's overall lipophilicity is not affected by calcium binding, as assessed by hydrophobic liquid chromatography. Preliminary results from patch-clamp experiments indicated that calcium is necessary for calexcitin to inhibit potassium channels and thus to increase membrane excitability. Therefore the calcium-dependent conformational equilibrium of calexcitin could serve as a molecular switch for the short term modulation of neuronal activity following associative conditioning.

Qualitative and quantitative analysis of the secondary structure of cytochrome C Langmuir-Blodgett films.

A qualitative and quantitative analysis of the conformation of Langmuir-Blodgett (LB) dried films of cytochrome C on silicon wafers was performed by Fourier transform ir (FTIR) spectroscopy. A deconvolution procedure was applied to the amide I band analysis, in order to determine the percentage of the different secondary structures. Qualitative analysis was performed by examining difference spectra. Films obtained by spreading protein solutions at pH 7.4 and 1, dried at 25 and 100 degrees C, on silicon wafers were also examined in order to detect spectral components associated with denatured protein domains, and to compare them with cytochrome C LB films. FTIR spectroscopy showed that the following important changes characterise LB film spectra: (a) the alpha-helix component is higher (its percentage is 57 and 54%) than the one estimated in dried film obtained by spreading the solutions at pH 7.4 on a silicon substrate (43%), (b) there is an increase in the intensity of bands attributed to protonated carboxy group bands, involved and not involved in the formation of hydrogen bonds, and a decrease in those attributed to deprotonated carboxy groups, (c) the intensity of several bands attributed to aromatic amino acids and aliphatic chains increases, and (d) bands due to O-H stretching vibrations of crystallization water are present. These conformational changes could be induced by protein-protein interaction caused by the close packing of molecules that occurs during LB film formation; it cannot be excluded that they may be accompanied by partial changes in the tertiary structure of the protein. A preferential orientation of protein molecules in LB films is also a possibility.