Enhanced adsorption-catalysis combination for the removal of sulphur from fuels using polyoxometalates supported on amphipathic hybrid mesoporous silica nanoparticles.

Polyoxometalate (POM) mesoporous silica-based materials with a low POM loading have been designed with hydrophilic and hydrophobic properties. These materials act as powerful heterogeneous catalysts in oxidative desulfurization (ODS), owing to their ability to adsorb both H2O2 and sulphur-containing compounds from the model oil simultaneously. The formation of charge transfer salts through ion pair interaction with a choline functionality, available on the hybrid silica support, affords robust and recyclable heterogeneous catalysts for the ODS process under mild conditions (45 min and 40 °C). Besides, the nature of the polyoxometalate anions is highly dependent on the characteristics of the silica surface. The masking of silanol groups present on the silica surface using silylating agents, with diverse reactivity and steric hindrance, influences the silica surface-heteropolyanion interactions, as well as heteropolyanion-heteropolyanion interactions. In addition, it modifies the hydrophobic properties of the surface, which is a determining factor in the adsorption properties of non-polar dibenzothiophene (DBT) by the catalysts. Adsorption, an anterior step to the oxidation reaction, has been demonstrated to be key to the superior activity of POM-SiMe3-Chol-MSN, where the silanol groups have been capped by trimethylsilyl groups. For the first time, and to better understand POM-surface and POM-POM anion interactions, an extensive characterization of the materials has been performed using 13C, 31P, and 95Mo MAS NMR spectroscopy and solid-state electrochemical techniques, among others.

Frequency of microsatellite instability (MSI) in upper tract urothelial carcinoma: comparison of the Bethesda panel and the Idylla MSI assay in a consecutively collected, multi-institutional cohort.

AIMS: Upper tract urothelial carcinoma (UTUC) is a rare malignancy with a poor prognosis which occurs sporadically or in few cases results from a genetic disorder called Lynch syndrome. Recently, examination of microsatellite instability (MSI) has gained importance as a biomarker: MSI tumours are associated with a better response to immunomodulative therapies. Limited data are known about the prevalence of MSI in UTUC. New detection methods using the fully automated Idylla MSI Assay facilitate analysis of increased patient numbers. METHODS: We investigated the frequency of MSI in a multi-institutional cohort of 243 consecutively collected UTUC samples using standard methodology (Bethesda panel), along with immunohistochemistry of mismatch repair (MMR) proteins. The same tumour cohort was retested using the Idylla MSI Assay by Biocartis. RESULTS: Using standard methodology, 230/243 tumours were detected as microsatellite stable (MSS), 4/243 tumours as MSI and 9/243 samples as invalid. In comparison, the Idylla MSI Assay identified four additional tumours as MSS, equalling 234/243 tumours; 4/243 were classified as MSI and only 5/243 cases as invalid. At the immunohistochemical level, MSI results were supported in all available cases with a loss in MMR proteins. The overall concordance between the standard and the Idylla MSI Assay was 98.35%. Time to result differed between 3 hours for Idylla MSI Assay and 2 days with the standard methodology. CONCLUSION: Our data indicate a low incidence rate of MSI tumours in patients with UTUC. Furthermore, our findings highlight that Idylla MSI Assay can be applied as an alternative method of MSI analysis for UTUC.

Her2-Positive and Microsatellite Instability Status in Gastric Cancer-Clinicopathological Implications.

Gastric cancer (GC) is one of the leading causes of cancer-related death. The combination of new molecular classifications with clinicopathological data could contribute to the individualization of patients and to the development of new therapeutic strategies. We examined the various associations in two molecular types of GC: HER2-positive (human epidermal growth factor receptor 2) and microsatellite instability (MSI), assessing their influence on treatment and prognosis. A retrospective study of 142 GC patients was performed with molecular characterization through HER2 overexpression and DNA repair protein expression for MSI. The percentage of HER2-positive tumors was 13.4%, predominantly in men. Correlations were found with intestinal type, metastases, advanced stages and chemotherapy. Almost 75% of HER2-positive patients died. MSI occurred in 16.2%, associated with advanced age, female sex, distal location and intestinal type. These patients had few metastases and low stages. The percentage of deaths was higher among MSI patients who received perioperative chemotherapy. The determination of HER2 and MSI status in GC is important for their association with specific clinicopathological features and for their prognostic and predictive value.

Copper-functionalized nanostructured silica-based systems: Study of the antimicrobial applications and ROS generation against gram positive and gram negative bacteria.

A series of copper-functionalized SBA-15 (Santa Barbara Amorphous) materials containing the ligands triethoxysilylpropylmaleamic acid (maleamic) or triethoxy-3-(2-imidazolin-1-yl)propylsilane (imidazoline) have been prepared. The nanostructured silica-based systems SBA-maleamic, SBA-imidazoline, SBA-maleamic-Cu and SBA-imidazoline-Cu were characterized by several methods observing that the functionalization took place mainly inside the pores of the mesoporous system. The antimicrobial behaviour of the synthesized materials against Staphylococcus aureus and Escherichia coli was tested observing a very potent activity of the copper-functionalized systems (minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for SBA-maleamic-Cu of ca. 31.25 µg/mL, which correspond with ca. 1.13 µg/mL of Cu). A study of the oxidative stress promoted by the synthesized materials showed that the SBA-maleamic-Cu and the SBA-imidazoline-Cu were able to increase the reactive oxygen species (ROS) production in S. aureus by 427% and 373%, respectively, while this increase was slightly lower in E. coli (387 and 324%, respectively). Furthermore, an electrochemical study was carried out in order to determine if these materials interact with lysine or alanine to validate a potential antimicrobial mechanism based on the inhibition of the synthesis of the peptidoglycan of the bacterial wall. Finally, these studies were also performed to determine the potential interaction of the copper-containing materials with glutathione in order to assess if they are able to perturb the metabolism of this tripeptide.

A new generation of anticancer drugs: mesoporous materials modified with titanocene complexes.

Dehydroxylated MCM-41 and SBA-15 surfaces were modified by the grafting of two different titanocene complexes ([Ti(eta(5)-C(5)H(4)Me)(2)Cl(2)] and [Ti{Me(2)Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(4))}Cl(2)]) to give new materials, which have been characterized by powder X-ray diffraction, X-ray fluorescence, nitrogen gas sorption, MAS-NMR spectroscopy, thermogravimetry, SEM, and TEM. The toxicity of the resulting materials toward human adenocarcinoma HeLa, human myelogenous leukemia K562, human malignant melanoma Fem-x, and normal immunocompetent cells, such as peripheral blood mononuclear cells PBMC has been studied. Estimation of the number of particles per gram of material led to the calculation of Q(50) values for these samples, which is the number of particles required to inhibit normal cell growth by 50%. In addition, M(50) values (quantity of material needed to inhibit normal cell growth by 50%) of the studied surfaces is also reported. Nonfunctionalized MCM-41 and SBA-15 did not show notable antiproliferative activity, whereas functionalization of these materials with different titanocene based anticancer drugs led to very promising antitumoral activity. The best Q(50) values correspond to titanocene functionalized MCM-41 surfaces (MCM-41/[Ti(eta(5)-C(5)H(4)Me)(2)Cl(2)] (1) and MCM-41/[Ti{Me(2)Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(4))}Cl(2)] (2)) with Q(50) values between 3.8+/-0.6x10(8) and 24.5+/-3.0x10(8) particles. Titanocene functionalized SBA-15 surfaces (SBA-15/[Ti(eta(5)-C(5)H(4)Me)(2)Cl(2)] (3) and SBA-15/[Ti{Me(2)Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(4))}Cl(2)] (4)) gave higher Q(50) values, showing lower activity from 73.2+/-9.9x10(8) to 362+/-7x10(8) particles. The best response of the studied materials in terms of M(50) values was observed against Fem-x (309+/-42 microg for 4) and K562 (338+/-18 microg for 2), whereas moderate activities were observed in HeLa cells (from 508+/-63 microg of 2 to 912+/-10 microg of 1). In addition, the analyzed surfaces presented only marginal activity against unstimulated and stimulated PBMC, showing a slight selectivity on human cancer cells. Comparison of the in vitro cytotoxicity in solution of the titanocene complexes [Ti(eta(5)-C(5)H(4)Me)(2)Cl(2)] and [Ti{Me(2)Si(eta(5)-C(5)Me(4))(eta(5)-C(5)H(4))}Cl(2)] and the corresponding titanocene functionalized materials is also described.

Solid-state (49/47)Ti NMR of titanium-based MCM-41 hybrid materials.

Titanium solid-state NMR spectroscopy data for a series of organic-inorganic titanium MCM-41 based materials have been collected. These materials have been synthesized by first modifying the mesoporous silica MCM-41 in one step with a mixture of silanes: a triazine propyl triethoxysilane acting as functional linker and methyltrimethoxysilane or hexamethyldisilizane as capped agents to mask the remaining silanol groups. Second, the appropiate titanium precursor Ti(OPr(i))(4), [{Ti(OPr(i))(3)(OMent)}(2)] (OMent = 1R,2S,5R-(-)-menthoxo), Ti(OPr(i))(4), or [Ti(eta(5)-C(5)HMe(4))Cl(3)], has been immobilized by reaction with the modified MCM-41. Finally, after Ti(OPr(i))(4) immobilization onto the organomodified support the reaction with the chiral (+)-diethyl-l-tartrate was accomplished. The materials without functional linker have been also prepared by reaction in one step of the capped agent and the titanium precursor with the mesoporous silica. Relevant correlations of titanium NMR resonance chemical shifts and line widths can be inferred depending on different factors. The immobilization procedure used to prepare titanium-based MCM-41 hybrid materials and the choice of the silylating reagents employed to mask the silanol groups present on the silica surfaces produce significant differences in the Ti NMR spectra. Furthermore, depending on the electronic and sterical influence of the substituents directly attached to the titanium center, chemical shifts and line widths are modified providing novel information about titanium structure.

HPLC with polysaccharide chiral stationary phase in polar-organic phase mode: application to the asymmetric epoxidation of allylic alcohols.

A simple and rapid HPLC method using a polysaccharide-based chiral stationary phase (Chiralpak AD-H) in polar-organic phase mode has been developed for direct resolution of glycidyl nitrobenzoate (GNB) and 2-methyl glycidyl nitrobenzoate (MGNB) enantiomers. ACN and methanol were used as mobile phase and the effects of the addition of ethanol and 2-propanol as organic modifier in the mobile phase, flow rate and the column temperature were tested. The optimized conditions were: methanol/ethanol (80:20) at a flow rate of 0.9 mL/min and 40 degrees C. Analysis time was < or = 13 min and the chiral resolution was > or = 2. The method was validated and resulted to be selective, precise and accurate. The method was found to be linear in 2-300 microg/mL range (R(2) >0.999) with an LOD nearly 0.5 microg/mL for four enantiomers. GNB and MGNB enantiomers were obtained by asymmetric epoxidation of allyl alcohol and 2-methyl allyl alcohol, respectively, using chiral titanium-tartrate complexes as catalyst and dichloromethane as solvent after in situ derivatization of the intermediate glycidols derivatives. The quite simple and rapid validated method was applied successfully for direct determination of the enantiomeric excess (> or = 90%) and yield obtained in real samples of asymmetric epoxidation of allylic alcohols without further purification, workup or solvent removal. The method provides a useful and value-added tool for controlling the enantiomeric purity of the synthesized epoxides.

Synthesis and characterization of novel mesoporous silicas of the MSU-X family for environmental applications.

Submicron particles of mesoporous MSU-2 silica have been obtained by using Tergitol NP-9 as nonionic surfactant and TEOS as silica precursor. The material has been chemically modified with 5-mercapto-1-methyltetrazole and characterized by powder X-ray diffraction, TEM, SEM, N2 adsorption, FT-IR spectroscopy, 29Si-NMR spectroscopy, thermogravimetric analysis and elemental analysis. The enviromental application of such material (denoted MTTZ-MSU-2b) in the treatment of heavy metal-contaminated waters has been demonstrated. The maximum adsorption capacity of this material was found to be 0.73 +/- 0.01 mmol/g for Pb(II) and 0.94 +/- 0.01 mmol/g for Zn(II), and is higher than the capacity of most of the other functionalized mesoporous materials previously reported. The very high access of these metal ions to the binding sites in the adsorbent has also been demonstrated (adsorption efficiency equal to 0.88 and 1.13 for Pb(II) and Zn(II), respectively).

Enantiomeric separation of glycidyl tosylate by CE: application to the study of catalytic asymmetric epoxidation of allyl alcohol.

A CE method using CDs as chiral selectors was developed and validated to achieve the separation of glycidyl tosylate enantiomers originated by in situ derivatization of glycidol enantiomers obtained in asymmetric epoxidation of allyl alcohol with chiral titanium-tartrate complexes as catalysts. The effects of the nature, pH and concentration of the buffer, the nature and concentration of chiral selector, the addition of SDS, methanol, ethanol or 2-propanol, the capillary temperature, the effective capillary length and the applied voltage on the chiral resolution of glycidyl tosylate enantiomers were investigated. The best separation conditions were achieved using a Tris-borate buffer mixture (50 and 25 mM, respectively) at pH=9.3 with a dual CD system consisting of 2.5% succinyl-beta-CD and 1.0% beta-CD w/v at 15 degrees C. A baseline separation (resolution approximately 2.0) of the glycidyl tosylate enantiomers was obtained in a relatively short time (less than 12 min). Satisfactory results were obtained in terms of linearity (r>0.99) and intermediate precision (RSD below 8.5%). The LOD and LOQ were 3.0 and 10.0 mg/L, respectively, and the recoveries ranged from 99.8 to 108.8%. Finally, the method was applied to the determination of the enantiomeric excess and the yield obtained in the asymmetric epoxidation of allyl alcohol employing chiral titanium-tartrate complexes as catalysts after an in situ derivatization of glycidol enantiomers to glycidyl tosylate.

Mesoporous SBA-15 modified with titanocene complexes and ionic liquids: interactions with DNA and other molecules of biological interest studied by solid state electrochemical techniques.

The immobilization of two titanocene complexes on SBA-15 has been accomplished following post-synthetic procedures. The ionic liquid, 1-methyl-3-[(triethoxysilyl)propyl]imidazolium chloride, has also been incorporated into the titanium containing materials to determine its influence on the interaction with molecules of biological interest. Cyclic voltammetry has been used to study the influence of the ionic liquid on the mechanism of reduction of titanocene derivatives. The interaction of titanocene and titanocene/ionic liquid-containing mesoporous silica SBA-15 materials, with molecules of biological interest associated with important processes of metallodrug action against cancer cells, has been studied. Thus, we have carried out hydrolysis experiments on the materials functionalized with titanocene derivatives in physiological media to determine their stability and the interaction with serum/transport proteins such as transferrin and BSA and with target molecules such as guanosine, single-stranded DNA and double-stranded DNA by means of solid state voltammetry techniques. A qualitative analysis of the data based on peak current and reduction potential value changes of the couple Ti(iv)/Ti(iii) in the presence of biomolecules at physiological pH, has revealed that grafted titanocene complexes show higher affinity for serum/transport proteins than for nucleic acids, indicating that the transport steps to the cells may be easier than the subsequent attack on DNA.

Modulation of the mechanism of apoptosis in cancer cell lines by treatment with silica-based nanostructured materials functionalized with different metallodrugs.

The mesoporous silica-based material SBA-15 (Santa Barbara Amorphous-15) has been modified with the aminodiol ligand 3-[bis(2-hydroxyethyl)amino]propyltriethoxysilane (PADOH) to give the corresponding material SBA-PADOH. Subsequent functionalization with a diorganotin(iv) compound, SnPh2Cl2 (1), and with two titanocene derivatives, TiCp2Cl2 ([Ti(η5-C5H5)2Cl2] (2)) and TiCpCpPhNfCl2 ([Ti(η5-C5H5)(η5-C5H4CHPhNf)Cl2] (3) (Ph = C6H5; Nf = C10H7)), gave the materials SBA-PADO-SnPh2 (M1), SBA-PADO-TiCp2 (M2) and SBA-PADO-TiCpCp* (M3), respectively. SBA-PADOH and M1-M3 have been characterized by various techniques such as FT-IR, XRD, XRF, solid-state NMR, nitrogen adsorption-desorption isotherms, electrochemical methods, SEM and TEM, observing that the functionalization has mainly taken place inside the pores of the corresponding porous system. In addition, mechanistic aspects of the apoptosis triggered by the synthesized materials have been studied in vitro in tumour cell lines derived from three distinct types of cancer in order to elucidate their growth inhibition and interference with the expression of tumour necrosis factor alfa (TNF-α) and the first apoptosis signal receptor (Fas or tumour necrosis factor receptor 6). It was observed that the antiproliferative and proapoptotic capacity of the materials depends on their functionalization with the different cytotoxic prodrugs (organotin or titanocene derivatives). The study shows that M1-M3 influence the metabolic activity of the tumour cells and modulate the apoptotic pathways by different mechanisms, according to the active compound inside the material.

Preparation, characterization, and Zn(2+) adsorption behavior of chemically modified MCM-41 with 5-mercapto-1-methyltetrazole.

A mesoporous silica (MCM-41) has been chemically modified with 5-mercapto-1-methyltetrazole using the homogeneous route. This synthetic route involved the reaction of 5-mercapto-1-methyltetrazole with 3-chloropropyltriethoxysilane prior to immobilization on the support. The resulting material (MTTZ-MCM-41) has been characterized by powder X-ray diffraction, nitrogen gas sorption, FT-IR and MAS NMR spectroscopy, thermogravimetry, and elemental analysis. The solid was employed as a Zn(II) adsorbent from aqueous solutions at room temperature. The effect of several variables (stirring time, pH, metal concentration, addition of ethanol, presence of other metals in the medium) has been studied using batch and column techniques. Flame atomic absorption spectrometry was used to determine the Zn(II) concentration in the filtrate or in the eluted solution after the adsorption process. Results obtained indicate that under the optimum conditions (pH 8 and 2 h stirring time), the maximum adsorption value for Zn(II) was 1.59+/-0.01 mmol/g, whereas the adsorption capacity of the unmodified mesoporous silica was about 0.010+/-0.001 mmol/g. On the other hand, the Zn(II) adsorption on the MTTZ-MCM-41 was independent of the presence of ethanol and other metals (Cu(II), Mn(II), Ca(II), and Mg(II)) in the medium. Finally, experiments carried out in order to study the regeneration capacity of the MTTZ-MCM-41 revealed that the adsorption capacity of this material was maintained after 3 cycles of the adsorption/desorption process.

2-Mercaptothiazoline modified mesoporous silica for mercury removal from aqueous media.

Mesoporous silicas (SBA-15 and MCM-41) have been functionalized by two different methods. Using the heterogeneous route the silylating agent, 3-chloropropyltriethoxysilane, was initially immobilized onto the mesoporous silica surface to give the chlorinated mesoporous silica Cl-SBA-15 or Cl-MCM-41. In a second step a multifunctionalized N, S donor compound (2-mercaptothiazoline, MTZ) was incorporated to obtain the functionalized silicas denoted as MTZ-SBA-15-Het or MTZ-MCM-41-Het. Using the homogeneous route, the functionalization was achieved via the one step reaction of the mesoporous silica with an organic ligand containing the chelating functions, to give the modified mesoporous silicas denoted as MTZ-SBA-15-Hom or MTZ-MCM-41-Hom. The functionalized mesoporous silicas were employed as adsorbents for the regeneration of aqueous solutions contaminated with Hg (II) at room temperature. SBA-15 and MCM-41 functionalized with MTZ by the homogeneous method present good mercury adsorption values (1.10 and 0.7mmolHg (II)/g of silica, respectively). This fact suggests a better applicability of such mesoporous silica supports to extract Hg (II) from aqueous solutions. In addition, it was observed the existence of a correlation between mercury adsorption with pore size and volume since, SBA-15 with lower areas and higher pore sizes functionalized with sterically demanding ligands, show better adsorption capacities than functionalized MCM-41.

The catalytic performance of metal complexes immobilized on SBA-15 in the ring opening polymerization of ε-caprolactone with different metals (Ti, Al, Zn and Mg) and immobilization procedures.

A family of heterogeneous catalysts has been prepared by employing different strategies: firstly by direct reaction or grafting of titanium, zinc, aluminium and magnesium precursors with dehydrated SBA-15 and secondly by reaction of the metallic derivatives with a hybrid SBA-15 mesoporous material, which possesses a new covalently bonded linker based on an amino alcohol chelate ligand. These materials have been characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption-desorption, FT-IR and multi-nuclear NMR spectroscopy. The catalytic performance of the prepared materials has been studied in the ring opening polymerization of ε-caprolactone and compared with that of their homogeneous counterparts. Conversion values obtained by using homogeneous and heterogeneous catalysts depend on the metal precursor and the synthetic procedure. The most active heterogeneous Ti-SBA-15, Zn-SBA-15 and Zn-PADO-HMDS-SBA-15 catalysts produced poly(ε-caprolactone) with a narrow molecular weight distribution, close to one. In all cases polymerization was confirmed to proceed via a coordination insertion mechanism after end group analysis by (1)H NMR.

Simultaneous determination of phenylglycidol enantiomers and cinnamyl alcohol in asymmetric epoxidation processes by chiral liquid chromatography.

A high-performance liquid chromatographic method has been developed for the simultaneous determination of phenylglycidol enantiomers and cinnamyl alcohol (CA). Separations were achieved on an amylose tris(3, 5-dymethylphenylcarbamate) chiral stationary phase (Chiralpak AD). The effect of concentration of organic modifier (2-propanol and ethanol) in the mobile phase and flow-rate was studied. The mobile phase selected consisted of a mixture of n-hexane-ethanol (85:15, v/v) with a flow-rate of 1.2 ml/min. The UV-vis detector was set at 254 nm. Resolution for the phenylglycidol enantiomers in the suitable chromatographic conditions was 2.4 with an analysis time of 12 min. The method developed was validated and was found to be linear in the range from 5 x 10(-4) to 3 x 10(-2) M, for phenylglycidol enantiomers and in the range from 5 x 10(-5) to 1 x 10(-3) M, for CA (r > 0.999 for the three compounds). Repeatability and intermediate precision for the three analytes at three different concentrations were below 3.6 and 2.8% R.S.D., respectively. This method has been applied to study the asymmetric epoxidation of CA with titanium(IV) alkoxide compounds as catalysts in order to evaluate their catalytic activity and stereoselectivity of the epoxidation processes.

[Relationship between pesticide exposure and low-grade superficial bladder urothelial carcinoma]. / Relación entre la exposición a pesticidas y el desarrollo de carcinoma urotelial vesical superficial de bajo grado.

BACKGROUND AND OBJECTIVE: Few studies have been published analyzing the association between pesticides use and the increased risk of developing urothelial cancer of the bladder (UCB). The aim of this work was to investigate, in a geographical area with a high prevalence of UCB (Axarquia, Malaga province, southern Spain) if a) subjects with occupational exposure to pesticides have greater risk of developing UCB and b) there are histopathological differences with regard to UCB in patients without any exposure. PATIENTS AND METHOD: Case control study. During two years (1994-1996) 96 cases of UCB were included. The histologic grade and the depth of the invasion as well as the associated inflammatory infiltrate were analyzed. A questionnaire was answered by the patients. RESULTS: 58.3% of the case group were working with or had history of exposure to pesticides, compared to 40.6% in the control group (OR = 2.04; 95% CI, 1.1-3.6). The risk increased with a greater time of exposure. In exposed subjects, low grade tumors (OR = 2.6; 95% CI, 1.3-5.2) as well as superficial tumors (OR = 2.3; 95% CI, 1.2-4.4) were more frequent. They were more frequently accompanied by a chronic inflammatory infiltrate (OR = 4.5; 95% CI, 1.8-11.1). CONCLUSIONS: The subjects with occupational exposure to pesticide have greater risk of developing UCB, which is directly proportional to the exposure time. In comparison with the population in the zone without exposure, patients who use pesticides present low grade UCB and less invasive tumors more frequently. These facts were not modified when they were adjusted for tobacco consumption. Exposed patients have UCB with chronic (moderate) inflammatory reaction more frequently than the tumors in non-exposed subjects.

Granular cell tumor of the bladder: a case report.

BACKGROUND: Granular cell tumor is usually a benign tumor, generally believed to be of neural origin, most commonly affecting the tongue and skin. Although it can present in any part of the body, the bladder is a rare location, with only 16 cases found in the English-language literature. CASE: We report the case of a 54-year-old woman with hematuria who had a solid tumor in the posterior wall of the bladder. Histological study of the samples obtained by transurethral resection revealed a granular cell tumor, confirmed by immunohistochemical techniques. CONCLUSION: Granular cell tumors of the bladder are rare and generally benign but frequently present macroscopic features resembling those of urothelial carcinoma. The similarity can lead to an erroneous clinical diagnosis and unnecessary, aggressive treatment. A careful histopathological assessment is essential for an accurate diagnosis.

Study of the cytotoxicity and particle action in human cancer cells of titanocene-functionalized materials with potential application against tumors.

Titanocene dichloride [Ti(η(5)-C(5)H(5))(2)Cl(2)] (1), has been grafted onto dehydrated hydroxyapatite (HAP), Al(2)O(3) and two mesoporous silicas MSU-2 (Michigan State University Silica type 2) and HMS (Hexagonal Mesoporous Silica), to give the novel materials HAP/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S1) (1.01 wt.% Ti), Al(2)O(3)/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S2) (2.36 wt.% Ti), HMS/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S3) (0.75 wt.% Ti) and MSU-2/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S4) (0.74 wt.% Ti), which have been characterized by powder X-ray diffraction, X-ray fluorescence, nitrogen gas sorption, multinuclear magic angle spinning NMR spectroscopy, IR spectroscopy, thermogravimetry analysis, UV spectroscopy, scanning electronic microscopy and transmission electronic microscopy. The cytotoxicity of the titanocene-functionalized materials toward human cancer cell lines from five different histogenic origins: 8505C (anaplastic thyroid cancer), A253 (head and neck cancer), A549 (lung carcinoma), A2780 (ovarian cancer) and DLD-1 (colon cancer) has been determined. M(50) values (quantity of material needed to inhibit normal cell growth by 50%) and Ti-M(50) values (quantity of anchored titanium needed to inhibit normal cell growth by 50%) indicate that the activity of S1-S4 against studied human cancer cells depended on the surface type as well as on the cell line. In addition, studies on the titanocene release and the interaction of the materials S1-S4 with DNA show that the cytotoxic activity may be due to particle action, because no release of titanium complexes has been observed in physiological conditions, while electrostatic interactions of titanocene-functionalized particles with DNA have been observed.

Stromal expression of vascular endothelial growth factor C is relevant to predict sentinel lymph node status in melanomas.

The dissemination of tumour cells to the lymph nodes is a complex process involving the formation of new lymph vessels, or lymphangiogenesis, produced by the tumour itself. The main growth factor involved in lymphangiogenesis is vascular endothelial growth factor C (VEGF-C), which is secreted by several different malignant tumours, including melanoma. Not only has VEGF-C expression been found in tumour cells, it has also been detected in tumour stromal cells like macrophages and fibroblasts. This study aimed to determine whether the expression of VEGF-C in tumour and stromal cells in cutaneous melanoma determines lymphangiogenesis and neoplastic dissemination to lymph nodes. We examined cases from 50 patients with melanoma who underwent selective biopsy of the sentinel lymph node. Immunohistochemical study was done with D2-40 to label lymph vessels, and the expression of VEGF-C was evaluated in tumour and stromal cells. Lymph vessel density was greater in sentinel lymph node-positive than in sentinel lymph node-negative cases, though the difference was not significant (P = 0.075). A significant correlation was seen between lymph vessel density and tumour thickness and the presence of ulceration. The main finding was that the expression of VEGF-C in fibroblasts was highly associated with the presence of metastasis in the sentinel node and with the Clark level. However, VEGF-C expression showed no relation in either tumour cells or macrophages with node status or other prognostic factors, such as the Breslow index or Clark level. Our results highlight the relevance of the stroma in tumour progression in cutaneous melanoma and its role in the spread to lymph nodes.

Mantle cell lymphoma stage IV affecting lacrimal glands, retro-orbital tissue, optic nerve and ocular motor muscles.

Mantle cell lymphoma (MCL) is an entity which exceptionally affects the ocular region and periorbital tissues, but which should be included in the differential diagnosis of lesions which affect the orbital region in a diffused manner. We report the case of a 60-year-old patient diagnosed with stage IV MCL, whose fi rst clinical manifestation was a result of the damage of lacrimal glands, retro-orbital tissue and ocular motor muscles. The patient was treated with rituximab and chemotherapy, achieving a complete response of those lesions.