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1.
Ocul Immunol Inflamm ; : 1-11, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38814046

RESUMO

PURPOSE: To analyze the referral patterns and the clinical and therapeutic features of patients diagnosed with uveitis in an Italian tertiary referral center to provide a comparison with previously published series from the same center. METHODS: Retrospective retrieval of data on all new referrals to the Ocular Immunology Unit in Reggio Emilia (Italy) between November 2015 and April 2022 and comparison with previously published series from the same center. RESULTS: Among the 1557 patients, the male-to-female ratio was 1:1.27. Anterior uveitis was the most common diagnosis (53.7%), followed by posterior (21.6%), pan- (18.5%), and intermediate (6.2%) uveitis. The most identifiable specific diagnoses were anterior herpetic uveitis (18.4%), Fuchs uveitis (12.8%), and tuberculosis (6.1%). Infectious etiologies were the most frequent (34.1%) and were more diffuse among non-Caucasian patients (p < 0.001), followed by systemic disease-associated uveitis (26.5%), and ocular-specific conditions (20%). Idiopathic uveitis accounted for 19.4% of cases. Fuchs uveitis presented the longest median diagnostic delay (21 months). Immunosuppressants were administered to 25.2% of patients. Antimetabolites, calcineurin inhibitors, and biologicals were prescribed to 18.4%, 3%, and 11.4% of cases, respectively. Compared to our previous reports, we observed a significant increase in foreign-born patients and in infectious uveitis, a decrease in idiopathic conditions, and an increasing use of non-biological and biological steroid-sparing drugs. CONCLUSIONS: The patterns of uveitis in Italy have been changing over the last 20 years, very likely due to migration flows. Diagnostic improvements and a more widespread interdisciplinary approach could reduce the incidence of idiopathic uveitis as well as diagnostic delay.

2.
Graefes Arch Clin Exp Ophthalmol ; 257(1): 181-186, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30392022

RESUMO

PURPOSE: The diagnosis of cytomegalovirus (CMV) anterior uveitis in immunocompetent patients requires confirmation by polymerase chain reaction (PCR) analysis and/or intraocular antibody index (AI) assay. In this study, we analyzed the different contributions of PCR and AI to CMV diagnosis by performing one single aqueous tap. METHODS: A retrospective chart review was conducted of HIV-negative patients attending the Ocular Immunology Unit of Azienda Unità Sanitaria Locale - IRCCS, Reggio Emilia, Italy, from March 2015 to April 2018 with a diagnosis of hypertensive anterior granulomatous uveitis compatible with suspected CMV etiology. Diagnosis was confirmed by real-time PCR (RT-PCR) and intraocular antibody production against CMV on aqueous humor samples. Clinical features were compared to antibody titer and diagnostic delay. RESULTS: Twenty-three patients with suspected CMV uveitis (13 males, 10 females, mean age 48 ± 16 years) were included in the analysis. AI was positive in 20/23 (87%) samples, and PCR tested positive in 9/23 (39%). By combining both tests, the sensitivity was 100%. Median diagnostic delay was 29 months (IQR 9-107). Diagnostic delay and antibody titer were significantly associated with glaucoma (r = 0.714, p < 0.0001; r = 0.476, p = 0.02, respectively). CONCLUSIONS: Our data suggest that to improve the diagnostic accuracy of CMV anterior uveitis, PCR and AI are both useful and complimentary. In our series, AI was the most sensitive diagnostic tool. One single aqueous tap is sufficient to achieve 100% sensitivity in CMV diagnosis. Early diagnosis is necessary to prevent the development of glaucoma.


Assuntos
Humor Aquoso/virologia , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/genética , DNA Viral/análise , Diagnóstico Tardio , Infecções Oculares Virais/diagnóstico , Uveíte Anterior/diagnóstico , Infecções por Citomegalovirus/virologia , Ensaio de Imunoadsorção Enzimática , Infecções Oculares Virais/virologia , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Uveíte Anterior/virologia
3.
Clin Microbiol Infect ; 25(7): 906.e1-906.e7, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30472417

RESUMO

OBJECTIVE: We aimed to investigate HBx genetic elements correlated with hepatitis B virus (HBV) -related hepatocellular carcinoma (HCC) and their impact on (a) HBV replicative efficiency, (b) HBx binding to circular covalently closed DNA (cccDNA), (c) apoptosis and cell-cycle progression, and (d) HBx structural stability. METHODS: This study included 123 individuals chronically infected with HBV: 27 with HCC (77.9% (21/27) genotype D; 22.1% (6/27) genotype A) and 96 without HCC (75% (72/96) genotype D; 25.0% (24/96) genotype A). HepG2 cells were transfected by wild-type or mutated linear HBV genome to assess pre-genomic RNA (pgRNA) and core-associated HBV-DNA levels, HBx-binding onto cccDNA by chromatin immunoprecipitation-based quantitative assay, and rate of apoptosis and cell-cycle progression by cytofluorimetry. RESULTS: F30V was the only HBx mutation correlated with HCC (18.5% (5/27) in HCC patients versus 1.0% (1/96) in non-HCC patients, p 0.002); a result confirmed by multivariate analysis. In vitro, F30V determined a 40% and 60% reduction in pgRNA and core-associated HBV-DNA compared with wild-type (p <0.05), in parallel with a significant decrease of HBx binding to cccDNA and decreased HBx stability. F30V also decreased the percentage of apoptotic cells compared with wild-type (14.8 ± 6.8% versus 19.1 ± 10.1%, p <0.01, without affecting cell-cycle progression) and increased the probability of HBx-Ser-31 being phosphorylated by PI3K-Akt kinase (known to promote anti-apoptotic activity). CONCLUSIONS: F30V was closely correlated with HBV-induced HCC in vivo, reduced HBV replicative efficiency by affecting HBx-binding to cccDNA and increased anti-apoptotic HBx activity in vitro. This suggests that F30V (although hampering HBV's replicative capacity) may promote hepatocyte survival, so potentially allowing persistent production of viral progeny and initiating HBV-driven hepatocarcinogenesis. Investigation of viral genetic markers associated with HCC is crucial to identify those patients at higher risk of HCC, who hence deserve intensive liver monitoring and/or early anti-HBV therapy.


Assuntos
Apoptose , Carcinoma Hepatocelular/virologia , Vírus da Hepatite B/genética , Neoplasias Hepáticas/virologia , Transativadores/genética , Replicação Viral , Adulto , Idoso , DNA Viral/genética , Feminino , Genótipo , Células Hep G2 , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/virologia , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Homologia Estrutural de Proteína , Transativadores/química , Proteínas Virais Reguladoras e Acessórias
4.
Oncogene ; 28(49): 4344-52, 2009 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-19784068

RESUMO

ApoJ/Clusterin (CLU) is a heterodimeric protein localized in the nucleus, cytoplasm or secretory organelles and involved in cell survival and neoplastic transformation. Its function in human cancer is still highly controversial. In this study, we examined the prostate of mice in which CLU has been genetically inactivated. Surprisingly, we observed transformation of the prostate epithelium in the majority of CLU knockout mice. Either PIN (prostate intraepithelial neoplasia) or differentiated carcinoma was observed in 100 and 87% of mice with homozygous or heterozygous deletion of CLU, respectively. Crossing CLU knockout with TRAMP (prostate cancer prone) mice results in a strong enhancement of metastatic spread. Finally, CLU depletion causes tumourigenesis in female TRAMP mice, which are normally cancer free. Mechanistically, deletion of CLU induces activation of nuclear factor-kB, a potentially oncogenic transcription factor important for the proliferation and survival of prostate cells.


Assuntos
Carcinoma/patologia , Transformação Celular Neoplásica/efeitos dos fármacos , Clusterina/antagonistas & inibidores , Clusterina/genética , Neoplasias da Próstata/patologia , RNA Interferente Pequeno/farmacologia , Animais , Carcinoma/genética , Transformação Celular Neoplásica/genética , Células Cultivadas , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Metástase Neoplásica , Neoplasia Prostática Intraepitelial/genética , Neoplasia Prostática Intraepitelial/patologia , Neoplasias da Próstata/genética , Interferência de RNA/fisiologia
5.
J Phys Chem B ; 113(5): 1447-59, 2009 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-19143560

RESUMO

In this work, we use Langmuir monolayers of dipalmitoyl phosphatidylcholine (DPPC) as model systems to enhance the understanding of specific anion effects in physicochemical and biological systems. The 298 K isotherms (equation of state, EOS) of DPPC over solutions of a range of sodium salts depend strongly on the type and concentration of the salt in the subphase. We focus in particular on the liquid expanded phase region of the DPPC EOS and assume that the deviation of the isotherms over electrolyte solutions from that over pure water is due entirely to the charging of the lipid monolayer by the ions. We then examine the ability of a range of phenomenological continuum models to explain the pressure increase in the presence of electrolytes. The important finding is that insoluble lipid monolayers allow the discrimination between possible modes of ion-lipid interaction. Chemical binding models, simple or modified, cannot fit the range of data presented in this work. Both dispersion interaction and partitioning models fit most of the experimental isotherms and provide unique values for dispersion coefficients or ionic partitioning constants, respectively, even though the nature of these models is completely different (the former concentrates on the potential of mean force that acts on an ion in the double layer, while the latter concentrates on the treatment of interactions at the interface). Surprisingly, the respective fitting parameters are very highly correlated, reflecting, we believe, the effect of ion size on ionic properties and interactions. With sodium fluoride (NaF) as the subphase electrolyte, it is demonstrated that sodium exhibits a weak complexation-type interaction with the zwitterionic lipids. The simple dispersion and partitioning models cannot account for the NaF results, highlighting the need for more complex salt-lipid interaction models that account both for sodium binding and anion partitioning. This realization sets the stage for the companion paper.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Modelos Biológicos , Difusão , Íons/química , Membranas Artificiais , Pressão , Fluoreto de Sódio/química
6.
Artigo em Inglês | MEDLINE | ID: mdl-23439246

RESUMO

INTRODUCTION: We investigated fluid responsiveness in a population of patients undergoing coronary artery revascularization, with respect to their right ventricular ejection fraction. MATERIALS AND METHODS: This was a multicenter trial involving 11 cardiac surgical Institutions and 65 patients undergoing elective coronary artery revascularization. Hemodynamic parameters were measured before and after volume expansion using a modified pulmonary artery catheter and transesophageal echocardiographic monitoring. Patients demonstrating an increase of stroke volume >20% after volume expansion were considered as responders. Volume expansion with 7 ml/kg of plasma expander was performed when required on a clinical basis. RESULTS: In the overall population, only the change in aortic blood velocity (cut-off 13%) was a predictor of fluid responsiveness. In patients with a reduced (<0.3) right ventricular ejection fraction only the value of mean pulmonary arterial pressure was predictive of fluid responsiveness (cut-off 18 mmHg). Patients with right ventricular ejection fraction ≥0.3 demonstrated three predictors: changes in aortic blood velocity (cut-off 15%), right ventricular end diastolic volume index (cut-off 80 ml/m(2)), and left ventricular end diastolic area index (cut-off 9 cm(2)/m(2)). CONCLUSIONS: When right ventricular systolic function is depressed, the right ventricle inability to fill the left chambers results in a lack of the left-sided responsiveness predictors. When the right ventricular systolic function is preserved, all the classical fluid responsiveness predictors are confirmed. Right ventricular function is therefore to be always considered when addressing the problem of fluid responsiveness.

7.
J Gen Virol ; 89(Pt 8): 1819-1828, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18632952

RESUMO

One of the major problems in gaining further insight into hepatitis B virus (HBV)/host-cell interactions is to improve the existing cellular models for the study of HBV replication. The first objective of this study was to improve the system based on transduction of HepG2 cells with a recombinant baculovirus to study HBV replication. A new HBV recombinant baculovirus, Bac-HBV-1.1, in which the synthesis of pre-genomic RNA is driven by a strong mammalian promoter, was generated. Transduction with this new recombinant baculovirus led to higher levels of HBV replication in HepG2 cells compared with levels obtained with previously described baculovirus vectors. The initiation of a complete HBV DNA replication cycle in Bac-HBV-1.1-transduced HepG2 cells was shown by the presence of HBV replicative intermediates, including covalently closed circular DNA (cccDNA). Only low levels of cccDNA were detected in the nucleus of infected cells. Data showed that cccDNA resulted from the recycling of newly synthesized nucleocapsids and was bound to acetylated histones in a chromatin-like structure. HBV particles released into the supernatant of transduced HepG2 cells were infectious in differentiated HepaRG cells. Several Bac-HBV-1.1 baculoviruses containing HBV strains carrying mutations conferring resistance to lamivudine and/or adefovir were constructed. Phenotypic analysis of these mutants confirmed the results obtained with the transfection procedures. In conclusion, an improved cell-culture system was established for the transduction of replication-competent HBV genomes. This will be useful for future studies of the fitness of HBV mutants.


Assuntos
Baculoviridae/genética , Vetores Genéticos , Genoma Viral , Vírus da Hepatite B/fisiologia , Hepatócitos/virologia , Replicação Viral , Linhagem Celular Tumoral , Replicação do DNA , Vírus da Hepatite B/genética , Vírus da Hepatite B/patogenicidade , Humanos , Recombinação Genética , Transdução Genética , Vírion/metabolismo , Vírion/patogenicidade , Virologia/métodos
8.
Biophys J ; 93(5): 1591-607, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17496050

RESUMO

The effects of Hofmeister anions on the perpendicular and lateral equation-of-state (EOS) of the dipalmitoylphosphatidylcholine lamellar phase discussed in the companion article are here examined using appropriate free energy models for the intra- and interbilayer interactions. Minimizing the free energy with respect to the two basic geometrical parameters of the lamellar phase, which are the interbilayer water thickness, d(w), and the lipid headgroup area, a(L), provides the perpendicular (osmotic pressure balance) and lateral EOS. Standard models were used for the hydration, undulation, and Van der Waals attractive force between the bilayers in the presence of electrolytes whereas two alternative treatments of electrostatic interactions were used to obtain "binding" or "partitioning" constants of anions to the lipid bilayers both in the absence and in the presence of sodium binding. The computed binding constants depend on anion type and follow the Hofmeister series, but were found to increase with electrolyte concentration, implying that the local binding approximation cannot fit bilayer repulsion data. The partitioning model was also found inadequate at high electrolyte concentrations. The fitting attempts revealed two additional features worthy of future investigation. First, at maximum swelling in the presence of electrolytes the osmotic pressure of the bilayer system cannot be set equal to zero. Second, at high salt concentrations an additional repulsion appears to come into effect in the presence of strongly adsorbing anions such as I(-) or SCN(-). Both these phenomena may reflect an inconsistent treatment of the ion-surface interactions, which have an impact on the osmotic pressure. Alternatively, they may arise from bulk solution nonidealities that cannot be handled by the classical Poisson-Boltzmann formalism. The inability of current models to explain the "lateral" EOS by fitting the area per lipid headgroup as a function of salt type and concentration shows that current understanding of phospholipid-ion interactions is still very incomplete.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Ânions , Biofísica/métodos , Bicamadas Lipídicas/química , Eletrólitos , Íons , Lipídeos/química , Modelos Químicos , Conformação Molecular , Osmose , Sais/química , Sódio/química , Eletricidade Estática , Termodinâmica , Água/química
9.
Pol J Vet Sci ; 10(1): 57-60, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17388027

RESUMO

Prostate cancer (CaP) is a fast-growing health and social problem already representing the second leading cause of cancer-related death among men in Western countries. Lifestyle-related factors and diet are major contributors for CaP promotion. Because of unfavourable prognosis of extra-prostatic CaP, prevention is considered the best approach to fight it at present time. Green Tea Catechins (GTCs) were proven effective at inhibiting cancer growth in several laboratory studies. We recently performed a pilot clinical trial in HG-PIN subjects showing that only 1/30 tumour was diagnosed in subjects treated for 1 year with 600 mg/die GTCs, while 9/30 cancers were found in placebo-treated men. CaP is an elusive disease, whose biological behaviour is difficult to predict. We have recently described and validated a RT-qPCR method based on a 8-genes signature that significantly discriminated benign tissue from CaP in both humans and TRAMP mice spontaneously developing CaP. In the animal model, also GTCs-resistant CaP was significantly discriminated from GTCs-sensitive CaP, i.e. responding to GTCs administration. Preliminary experiments in our laboratory have shown that this method can be successfully applied to a single tissue needle biopsy specimen in humans. The combination of these results may be of particular significance on the field. In fact, GTCs treatment for men at high risk of CaP as first line prevention therapy in combination with the 8-genes signature profiling in tissue needle biopsies for real time monitoring of patient's response might importantly change, in the near future, the clinical managing of this highly diffuse malignancy.


Assuntos
Catequina/farmacologia , Catequina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Chá/química , Animais , Catequina/análogos & derivados , Progressão da Doença , Humanos , Masculino
10.
Oncogene ; 25(25): 3606-12, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16652159

RESUMO

The P73 gene is transcribed from two promoters, P1 and P2, that direct the expression of multiple transactivation competent (TA) and dominant negative (DN) isoforms. TAp73 transcription factors mediate cell cycle arrest and/or apoptosis in response to DNA damage and are involved in developmental processes. P73 mRNA levels increase and the P1p73 promoter is upregulated during myogenic differentiation of C2C12 skeletal muscle satellite cells. The DNp73 proteins act as trans-repressors of p53- and p73-dependent transcription, and possess both antiapoptotic and pro-proliferative potential. Here, we show that DNp73alpha is expressed in proliferating C2C12 myoblasts, rapidly accumulates in differentiating myocytes and remains elevated in C2C12 myotubes. By combining transactivation assays and chromatin immunoprecipitation analysis, we could show that the upregulation of the P2p73 promoter during myogenic differentiation is mediated by the coordinated recruitment and activity of MyoD and p53/p73. Abrogation of DNp73 expression by specific siRNA led to a strong potentiation of the spontaneous apoptosis of C2C12 myoblasts induced to differentiate. Finally, unlike TAp73 that contributes to DNA damage-induced apoptosis of myotubes, endogenous DNp73 mediates the relative resistance of differentiated myotubes to DNA damage. Altogether, our findings identify DNp73alpha as an important target in designing strategies aimed at the potentiation of the regenerative potential of skeletal satellite cells.


Assuntos
Apoptose/fisiologia , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica , Células Musculares/citologia , Proteínas Nucleares/metabolismo , Animais , Immunoblotting , Camundongos , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno , Ativação Transcricional , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima
11.
Langmuir ; 22(8): 3798-806, 2006 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-16584258

RESUMO

Porous composite powders, prepared by spray drying of silica and polybromostyrene nanoparticles, were calcined at various temperatures up to 750 degrees C. The structure in these powders are quantitatively investigated by ultra small-angle X-ray scattering, thermogravimetric analysis, and nuclear magnetic resonance measurements. It has been found that the polybromostyrene latex is efficient in templating mesopores. However, polybromostyrene remains almost completely in the interstitial micropores in the grain after the spray-drying process. A post thermal treatment of the powders has been applied from 250 up to 750 degrees C. We found that the hydrocarbon part of the polybromostyrene is decomposed and leaves the micropores at around 350 degrees C. However, it is demonstrated that a significant amount of bromine remains in the interstitial micropores between the silica particles. At around 600 degrees C, the silica nanoparticles start to fuse with each other and a coalescence of the micropores takes place. At still higher temperature, around 750 degrees C, the micropore network totally disappears, and the growth in pore size occurs due to the coalescence of the mesopores with a significant decrease of the total porosity. During this process, the silica network densification is accompanied by a lowering of the specific surface area.

12.
Monaldi Arch Chest Dis ; 58(2): 174-82, 2002 Sep.
Artigo em Italiano | MEDLINE | ID: mdl-12418435

RESUMO

In the last few years the population referred to cardiac rehabilitation centers has changed profoundly: the number of survivors of acute cardiac events has increased and heart surgery is being proposed to ever greater numbers of elderly patients with frequent and greater comorbidities, which make the management of physical training programs more complex. Consequently, just as rehabilitation cardiologists have had to expand their field of analyses and professional skills and nurses have had to integrate their care protocols, physiotherapists too have had to adapt the management of motor rehabilitation programs to the various needs and problems of each patient in the different phases of recovery. The aim of this paper is to present and discuss the procedures followed in our center concerning both the mode and contents of a standard course of motor rehabilitation for patients without complications and those for patients with complications. The paper analyzes the various assessments, the training program, the instruments of control and verification of the results, and discusses the instruments of intervention in patients affected by complications such as respiratory disturbances, musculoskeletal impairment, complications arising from injury, neurological deficit and severe deconditioning. Finally, the role of the physiotherapist in the active, propositive management of a recovery program is discussed.


Assuntos
Terapia por Exercício , Cardiopatias/reabilitação , Humanos
13.
Eur Phys J E Soft Matter ; 9(4): 313-26, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15010901

RESUMO

The concentration profiles of monomers and counterions in star-branched polyelectrolyte micelles are calculated through Monte Carlo simulations, using the freely jointed chain model. We have investigated the onset of different regimes corresponding to the spherical and Manning condensation of counterions as a function of the strength of the Coulomb coupling. The Monte Carlo results are in fair agreement with the predictions of Self-Consistent-Field analytical models. We have simulated a real system of diblock copolymer micelles of (sodium-polystyrene-sulfonate)(NaPSS)-(polyethylene-propylene)(PEP) with f = 54 hydrophilic branches of N = 251 monomers at room temperature in salt-free solution. The calculated form factor compares nicely with our neutron scattering data.

14.
Eur Phys J E Soft Matter ; 9(1): 15-25, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15010925

RESUMO

We present the experimental and theoretical background of a method to characterize the protein-protein attractive potential induced by one of the mostly used crystallizing agents in the protein-field, the poly(ethylene glycol) (PEG). This attractive interaction is commonly called, in colloid physics, the depletion interaction. Small-Angle X-ray Scattering experiments and numerical treatments based on liquid-state theories were performed on urate oxidase-PEG mixtures with two different PEGs (3350 Da and 8000 Da). A "two-component" approach was used in which the polymer-polymer, the protein-polymer and the protein-protein pair potentials were determined. The resulting effective protein-protein potential was characterized. This potential is the sum of the free-polymer protein-protein potential and of the PEG-induced depletion potential. The depletion potential was found to be hardly dependent upon the protein concentration but strongly function of the polymer size and concentration. Our results were also compared with two models, which give an analytic expression for the depletion potential.

15.
Artigo em Inglês | MEDLINE | ID: mdl-11088729

RESUMO

We solve the nonlinear Poisson-Boltzmann equation around a charged colloidal sphere in an electrolyte that is confined in a cell. The colloid has an eccentric position inside the confining sphere. This models the situation in a highly concentrated charge-stabilized colloidal suspension, where a single colloid simultaneously interacts with the whole cage of neighboring colloids. We calculate the ion density profiles, the free energy, and the osmotic pressure as a function of the shifting position. We express the total force acting on the particle as a sum of pair contributions and compare the resulting pair interaction potential law with the standard Derjaguin-Landau-Verwey-Overbeck expression.

16.
J Colloid Interface Sci ; 187(1): 184-200, 1997 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9245328

RESUMO

The stability of a colloidal dispersion of nanometric zirconia particles has been studied during a compression process. Using the osmotic stress method, cycles of compression and reswelling were applied to the dispersion to test the reversibility of the process. Original dispersions are stable in a very limited pH range (0.5-2). At pH 3, the bare particles aggregate irreversibly under compression as checked by osmotic pressure and light and X-ray scattering measurements. To improve the stability, small organic complexing molecules (acetylacetone) were added to the original dispersion. The adsorbed monolayer on the particle surfaces acts as a steric barrier and prevents the two colloids from contacting. As a consequence, the dispersion becomes more compressible and the compression cycle is totally reversible. The experimental data are quantitatively reproduced with a classical theory of statistical mechanics of liquids based on a DLVO-like colloid-colloid potential.

17.
Minerva Med ; 86(11): 499-502, 1995 Nov.
Artigo em Italiano | MEDLINE | ID: mdl-8684674

RESUMO

Meningitis caused by Listeria monocytogenes is a rare affection: it develops from close contagion as professional illness (veterinarians, butchers) or in newborns by infected mothers; in indirect way for ingestion of contaminated food in subjects at high risk: elderly, immunosuppressed patients, alcoholics, diabetics. Clinically it is not diversified from the other bacterial meningitises. In this paper we present a case of Listeria monocytogenes meningitis in an adult female, without a sure occasion of infection and in absence of the factors of typical risk.


Assuntos
Listeria monocytogenes/isolamento & purificação , Meningite por Listeria/microbiologia , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Meningite por Listeria/diagnóstico , Meningite por Listeria/etiologia , Fatores de Risco
18.
Phys Rev Lett ; 74(13): 2515-2518, 1995 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-10057947
19.
Minerva Chir ; 47(15-16): 1229-40, 1992 Aug.
Artigo em Italiano | MEDLINE | ID: mdl-1407621

RESUMO

The Authors have analyzed all different methods for the treatment of gallbladder stones which are performed today: the non invasive treatment of the gallstones (oral dissolution therapy and the extracorporeal shockwave lithotripsy), the minimally invasive procedures (contact dissolution therapy and the cholecystolithotomy) and at the end the new surgical techniques (the "minicholecystectomy" and the laparoscopic cholecystectomy). From this study and their experience, based upon 1346 standard cholecystectomy, the Authors have reached the following conclusions: 1) the cholecystectomy remains the only definitive therapy for the gallbladder stones and it is the gold standard to which must be compared the other alternative therapies; 2) the laparoscopic cholecystectomy, even though introduced recently, would become the only method used for cholecystectomy.


Assuntos
Colelitíase/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ácido Quenodesoxicólico/uso terapêutico , Colecistectomia , Colelitíase/tratamento farmacológico , Colelitíase/cirurgia , Feminino , Humanos , Laparoscopia , Litotripsia , Masculino , Pessoa de Meia-Idade , Ácido Ursodesoxicólico/uso terapêutico
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