Physicochemical investigation of acrylamide solubilization in sodium bis(2-ethylhexyl)sulfosuccinate and lecithin reversed micelles.

The state of acrylamide confined within dry sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles dispersed in CCl4 has been investigated by FTIR and H-1 NMR spectroscopy. Measurements have been performed at 25 degreesC as a function of the acrylamide-to-surfactant molar ratio (R) at a fixed surfactant concentration (0.1 mol kg(-1)). The analysis of experimental data, corroborated by the results of SAXS measurements, is consistent with the hypothesis that acrylamide is quite uniformly distributed among reversed micelles mainly located in proximity to the surfactant head-group region and that its presence induces significant unidimensional growth of micellar aggregates.…

Multiplicity and history have a detrimental effect on survival in patients with T1G3 bladder tumors selected for conservative treatment.

Purpose: In the absence of Tis tumor we assessed whether history and multiplicity have a detrimental effect on conservative treatment in carefully selected patients with T1G3 bladder carcinoma. Materials and Methods: Between January 1976 and December 1999, 165 select patients with T1G3 bladder tumors were conservatively treated with transurethral resection plus adjuvant intravesical therapy. Patients with concomitant or previous Tis, previous T1G3, tumor size greater than 3 cm and more than 3 lesions were excluded from analysis. Repeat transurethral resection was not routinely performed. However, cytology had to be negative for atypia before the start of adjuvant intravesical therapy. Resul…

Physicochemical investigation of cobalt?iron cyanide nanoparticles synthesized by a novel solid?solid reaction in confined space

Cobalt–iron cyanide (Cox[Fe(CN)6]) nanoparticles have been synthesized by a novel solid–solid reaction in the confined space of dry sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reversed micelles dispersed in n-heptane. The reaction has been carried out by mixing two dry AOT/n-heptane solutions containing CoCl2 and K4Fe(CN)6 or K3Fe(CN)6 nanoparticles in the micellar core, respectively. By UV-Vis spectroscopy it was ascertained that, after the mixing process, the formation of stable nanoparticles is fast and complete. Microcalorimetric measurements of the thermal effect due to the Cox[Fe(CN)6] nanoparticle formation allowed the determination of the stoichiometric ratio (x) and of the molar e…

STUDIO DI FASE II: DOCETAXEL SETTIMANALE COME SECONDA LINEA CHEMIOTERAPICA NEL CARCINOMA PROSTATICO AVANZATO

Variations PSA Value in Patients Candidate to Biopsy of the Prostate

Subclinical infections of the prostate can increase the prostate-specific antigen (PSA) values in patients with normal digital rectal examination. This study aimed to evaluate the role of short-term antimicrobial therapy in reducing the PSA value in patients as candidates for transrectal biopsy. Fifty-eight patients with negative digital rectal examination and PSA values between 4 and 20 ng/mL were included in the study. Antibiotics were administered to all patients for 3 weeks, and the PSA was reassessed 10 days after the end of the treatment. Patients were subsequently submitted to prostate biopsy. A reduction in PSA was detected in 34 patients (59%). Mean percentage reduction was 32%. I…

FT-IR investigation of the acetamide state in AOT reversed micelles

The state of acetamide nanoparticles encapsulated in the hydrophilic core of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reversed micelles and dispersed in CCl4 has been investigated by Fourier transform infrared spectroscopy. The analysis of the vibrational spectra reveals even at the higher acetamide to AOT molar ratio some changes of the typical H-bonded structure of solid acetamide ascribable to their small size, confinement effects, and acetamide-AOT head group interactions. The stretching modes of acetamide CO and AOT sulfonate groups indicate unambiguously specific acetamide-AOT head group interactions.

Interactions of α-tocopherol with biomembrane models: Binding to dry lecithin reversed micelles

Abstract The state of α-tocopherol (Vitamin E) in solutions of dry lecithin reversed micelles dispersed in an apolar medium has been investigated as a function of the Vitamin E to surfactant molar ratio (RVE) at fixed surfactant concentration by FT-IR, 1H NMR and SAXS with the aim to emphasize the role played by anisotropic intermolecular interactions and confinement effects as driving forces of its partitioning between apolar bulk solvent and polar nanodomains and of mutual Vitamin E/reversed micelle effects. It has been found that its binding strength to reversed micelles, triggered by steric and orientational constrains, is mainly regulated by specific interactions between the hydrophili…

CHEMIOPROFILASSI PRECOCE CON EPIRUBICINA AD ALTA DOSE NEL CARCINOMA VESCICALE SUPERFICIALE. STUDIO RANDOMIZZATO DEL GSTU

Physico-chemical investigation of the state of cyanamide confined in AOT and lecithin reversed micelles

Sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles containing cyanamide have been investigated by small-angle X-ray scattering, FT-IR, and 1H NMR spectroscopy at various cyanamide-to-surfactant molar ratio (X) and at fixed surfactant concentration (0.1 mol kg-1). Experimental data are consistent with a model of cyanamide molecules confined in reversed micelles, quite uniformly distributed among them and mainly located among surfactant headgroups. SAXS data analysis leads also to hypothesize a unidimensional growth of the reversed micelles with increasing the X value. Moreover, the cyanamide state and the cyanamide/cyanamide interactions in reversed micelles have bee…

Structure of Urea Clusters Confined in AOT Reversed Micelles

The structure of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and that of urea containing AOT reversed micelles has been investigated by small-angle neutron scattering (SANS) and Fourier transform infrared (FT-IR) spectroscopy at different AOT concentrations and urea/AOT molar ratios. For the AOT/n-heptane system, SANS data analysis indicates that AOT molecules form prolate ellipsoidal aggregates, which grow asymmetrically along the major axis upon increasing the surfactant concentration. For the urea/AOT/n-heptane system, the SANS results are consistent with the hypothesis that urea is encapsulated as small-sized ellipsoidal hydrogen-bonded clusters within the hydrophilic micellar core of …

Study of AOT-stabilized microemulsions of urea dispersed in carbon tetrachloride

Measurements of some physico-chemical properties (density, viscosity, permittivity) of the urea/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/CCl4 system as a function of the volume fraction of the dispersed phase (0<Φ<0.7) at various urea to AOT molar ratio (Rurea) have been carried out at 25 °C. The experimental data analysis are consistent with the hypothesis that urea is entrapped as small-size molecular clusters within the hydrophilic core of the AOT reversed micelles and that this structure is preserved well above a threshold Φ value where a percolative transition occurs. Besides, X-ray diffraction spectra of samples at Φ=1, obtained by complete evaporation under vacuum of the apolar …

Microwave-Induced Hyperthermia and Cytostatic Agent for Superficial Bladder Cancer

The efficacy and local toxicity of the intravesical combination of microwave-induced hyperthermia with a cytostatic agent in patients affected by superficial bladder cancer is presented. Between 1994 and 2002, two studies were performed on ablative and adjuvant intravesical thermo-chemotherapy. The ablative study demonstrated complete tumor eradication in 88% of patients who should have undergone cystectomy due to diffuse multiple papillary tumors non-responsive TUR and intravescical adjuvant therapy. In a randomized study, comparing adjuvant thermo-chemotherapy vs. standard chemotherapy with mitomycin C, recurrence-free survival analysis at 24 months revealed a significant difference in f…

Study of Confined 5-Aza[5]helicene in Ytterbium(III) Bis(2-ethylhexyl) Sulfosuccinate Reversed Micelles

Some relevant physicochemical properties of 5-aza[5]helicene (H5) in solutions of ytterbium bis(2-ethylhexyl) sulfosuccinate (Yb(DEHSS)3) reversed micelles have been investigated by UV-vis-NIR, photoluminescence, and FT-IR techniques with the aim of emphasizing the role played by specific Yb(III)/H5 interactions and confinement effects as driving forces of its binding to reversed micelles, preferential solubilization site, and local photophysical properties. It has been found that the binding strength of 5-aza[5]helicene to reversed micelles, triggered by steric and orientational constrains as well as the water content, is mainly regulated by its interaction with the Yb(III) counterion. Mor…

Results of a Phase I-II Pilot Study with Intravescical Gemcitabine in Superficial Bladder Cancer (Ta-T1)

To study the ablative activity of intravescical gemcitabine against superficial transitional cell carcinoma of the bladder at different doses and concentrations. Methods Twenty-seven patients were treated with intravescical gemcitabine after transurethral resection, during which one to three papillary marker lesions were left unresected. Starting 14 days after transurethral resection, six gemcitabine instillations were given at weekly intervals. Gemcitabine, diluted in 50 mL of saline solution and maintained for 2 hr, was given at a dose of 500, 1000 and 2000 mg in groups of nine patients each. A complete response (CR) was defined as negative cutologycystoscopy and biopsy findings. Results…

Antibiotic Prophylaxis in Prostate Biopsy

Introduction Prostate biopsy is nowadays one of the most frequent diagnostic procedures in urology. The incidence of bacteraemia, bacteriuria and infective complications is higher after the transrectal procedure than after the transperineal one. A survey demonstrated that 98% of the urologists in USA use antibiotics to prevent infective complications. The transrectal prostate biopsy is the only diagnostic intervention procedure in urology for which an antibiotic prophylaxis is recommended, also for low-risk patients, by the guidelines of the European Association of Urology. If the perineal route is adopted, the antibiotic prophylaxis is recommended only in high-risk patients. Materials and …

Physicochemical Investigation of Nanostructures in Liquid Phases: Ytterbium Nitrate Ionic Clusters Confined in Ytterbium Bis(2-ethylhexyl) Sulfosuccinate Reversed Micelles and Liquid Crystals

The confinement of finite amounts of ytterbium nitrate in the nanoscopic space of ytterbium bis(2-ethylhexyl)sulfosuccinate (Yb(DEHSS) 3 ) reversed micelles dispersed in n-heptane has been investigated by UV-vis-NIR, FT-IR, and SAXS. The analysis of the experimental data is consistent with the hypothesis that Yb(NO 3 ) 3 is distributed among reversed micelles as small size ionic clusters surrounded by the Yb 3+ surfactant counterions and anionic heads while the surfactant alkyl chains point toward the solvent medium. As a consequence of confinement and interfacial effects, the ionic clusters display photophysical properties different from those in the bulk state or isolated species. Moreove…

1H-NMR and FT-IR study of the state of melatonin confined in membrane models: location and interactions of melatonin in water free lecithin and AOT reversed micelles

The state of melatonin confined either in dry lecithin or bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reversed micelles has been investigated by H-1-NMR and FT-IR spectroscopies as a function of the melatonin to surfactant molar ratio (R). The analysis of experimental results leads to hypothesize that, independently of R and the surfactant nature and as a consequence of anisotropic melatonin/surfactant interactions, melatonin is totally solubilized in reversed micelles and mainly located by opportune orientation in the nanodomain constituted by the surfactant head groups. The absence of significant spectral changes related to the protons linked to the first carbon atoms of surfactant…

Tossicità e mantenimento nella chemioprofilassi endovescicale precoce (entro 6 ore) dopo TUR di carcinoma vescicale superficiale.

Surfactant self-assembling in gas phase: electrospray ionization- and matrix-assisted laser desorption/ionization-mass spectrometry of singly charged AOT clusters.

The self-assembling of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in gas phase has been investigated by electrospray ionization- and matrix-assisted laser desorption/ionization mass spectrometry. Large surfactant clusters with an aggregation number close to that found in apolar media have been observed either as positive or negative ions. Moreover, the marked predominance of singly charged species as well as preliminary theoretical calculations strongly suggest an aggregate structure characterized by an internal hydrophilic core hosting the extra charge surrounded by an apolar shell constituted by the surfactant alkyl chains. This structure is similar to that of the more familiar revers…

FT-IR investigation of the urea state in lecithin and sodium bis(2-ethylhexyl)phosphate reversed micelles

Abstract FT-IR spectra of urea/lecithin/CCl4 and urea/sodium bis(2-ethylhexyl) phosphate (NaDEHP)/CCl4 systems as a function of the urea-to-surfactant molar ratio (Rurea) at a fixed surfactant concentration (0.1 mol kg−1) have been recorded at 25 °C. Analysis of the absorption spectra leads the to hypothesis that urea is confined within the hydrophilic micellar core of lecithin and NaDEHP reversed micelles. The encapsulation of urea involves some changes of the urea NH stretching band with respect to that of the pure solid urea, attributable to confinement effects. The stretching modes of the surfactant head group are affected by the presence of urea, indicating specific urea-surfactant hea…

Cigarette Smoking and Drinking Water Source: Correlation with Clinical Features and Pathology of Superficial Bladder Carcinoma

&lt;i&gt;Objective:&lt;/i&gt; Water source and cigarette smoking are related to clinical characteristics and pathology of superficial transitional cell carcinoma of the bladder. &lt;i&gt;Methods:&lt;/i&gt; Tumor number, dimension, G-grade, T-stage, recurrences, cigarette smoking and water supply were recorded in patients harboring Ta–T1 G1–3 transitional cell carcinoma of the bladder. &lt;i&gt;Results:&lt;/i&gt; Of 577 patients, 61% had multiple and 36% recurrent tumors. Two hundred and forty-one patients (42%) were current smokers and 188 (33%) were former smokers. Bottled water was the only drinkable source for 249 (45%) patients, municipal water supply for 177 (32%), artesian wells for 3…

Structural investigation of the confinement of finite amounts of trehalose in water-containing sodium bis(2-ethylhexyl)sulfosuccinate reversed micelles

The structural effect of trehalose confined in water-containing sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reversed micelles at water to AOT molar ratio W = 5 and 10 as a function of the trehalose to AOT molar ratio T (0 < T < 0.1) has been investigated by small-angle neutron scattering (SANS). SANS data analysis is consistent with the hypothesis that trehalose is encapsulated within the quite spherical hydrophilic micellar cores of water-containing reversed micelles, causing an increase of the aggregate size and a decrease of the polydispersion. Moreover, SANS results suggest that the trehalose confinement in water-containing reversed micelles involves marked changes on the molecular pac…