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1.
Clin Cancer Res ; 29(2): 379-388, 2023 01 17.
Article in English | MEDLINE | ID: mdl-36074154

ABSTRACT

PURPOSE: Chemotherapy plus anti-EGFR is standard first-line therapy in RAS wild-type (wt) metastatic colorectal cancer (mCRC), but biomarkers of early response are clinically needed. We aimed to define the utility of ctDNA to assess early response in patients with mCRC receiving first-line anti-EGFR therapy. EXPERIMENTAL DESIGN: Prospective multicentric study of tissue patients with RAS wt mCRC treated with first-line chemotherapy plus cetuximab undergoing sequential liquid biopsies. Baseline and early (C3) ctDNA were analyzed by NGS. Trunk mutations were assessed as surrogate marker of total tumor burden. RAS/BRAF/MEK/EGFR-ECD were considered mutations of resistance. ctDNA results were correlated with clinical outcome. RESULTS: One hundred patients were included. ctDNA was detected in 72% of patients at baseline and 34% at C3. Decrease in ctDNA trunk mutations correlated with progression-free survival (PFS; HR, 0.23; P = 0.001). RAS/BRAF were the only resistant mutations detected at C3. An increase in the relative fraction of RAS/BRAF at C3 was followed by an expansion of the RAS clone until PD, and was associated with shorter PFS (HR, 10.5; P < 0.001). The best predictor of response was the combined analysis of trunk and resistant mutations at C3. Accordingly, patients with "early molecular response" (decrease in trunk and decrease in resistant mutations) had better response (77.5% vs. 25%, P = 0.008) and longer PFS (HR, 0.18; P < 0.001) compared with patients with "early molecular progression" (increase in trunk and/or increase in resistant mutations). CONCLUSIONS: ctDNA detects early molecular response and predicts benefit to chemotherapy plus cetuximab. A comprehensive NGS-based approach is recommended to integrate information on total disease burden and resistant mutations. See related commentary by Eluri et al., p. 302.


Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Rectal Neoplasms , Humans , Cetuximab , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Proto-Oncogene Proteins B-raf/genetics , Prospective Studies , Treatment Outcome , Colonic Neoplasms/drug therapy , Rectal Neoplasms/drug therapy , Liquid Biopsy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Mutation , Proto-Oncogene Proteins p21(ras)/genetics
2.
BMC Med Genomics ; 15(1): 45, 2022 03 04.
Article in English | MEDLINE | ID: mdl-35246124

ABSTRACT

BACKGROUND: DNA methylation (DNAm) age metrics have been widely accepted as an epigenetic biomarker for biological aging and disease. The purpose of this study is to assess whether or not individuals carrying Lynch Syndrome-associated mutations are affected in their rate of biological aging, as measured by the epigenetic clock. METHODS: Genome-wide bisulfite DNA sequencing data were generated using DNA from CD4 + T-cells obtained from peripheral blood using 27 patient samples from Lynch syndrome families. Horvath's DNAm age model based on penalized linear regression was applied to estimate DNAm age from patient samples with distinct clinical and genetic characteristics to investigate cancer mutation-related aging effects. RESULTS: Both Lynch mutation carriers and controls exhibited high variability in their estimated DNAm age, but regression analysis showed steeper slope for the Lynch mutation carriers. Remarkably, six Lynch Syndrome-associated mutation carriers showed a strong correlation to the control group, and two sisters carrying Lynch Syndrome-associated mutations, with no significant difference in lifestyle and similar chronological age, were assigned very different DNAm age. CONCLUSIONS: Future studies will be required to explore, in larger patient populations, whether specific epigenetic age acceleration is predictive of time-to-cancer development, treatment response, and survival. Epigenetic clock DNAm metrics may be affected by the presence of cancer mutations in the germline, and thus show promise of potential clinical utility for stratified surveillance strategies based on the relative risk for imminent emergence of tumor lesions in otherwise healthy Lynch Syndrome-associated mutation carriers.


Subject(s)
Colorectal Neoplasms, Hereditary Nonpolyposis , DNA Methylation , Acceleration , Aging/genetics , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , Epigenesis, Genetic , Humans , Mutation
3.
Drugs Aging ; 38(3): 219-231, 2021 03.
Article in English | MEDLINE | ID: mdl-33615402

ABSTRACT

BACKGROUND: Biologicals, in combination with chemotherapy, are recommended as first-line treatment of metastatic colorectal cancer (mCRC); however, evidence guiding the appropriate management of older patients with mCRC is limited. OBJECTIVE: This study was undertaken to compare the efficacy and safety outcomes in older versus younger patients with mCRC who received first-line biological therapy. METHODS: This retrospective analysis used pooled data from five trials undertaken by the Spanish Cooperative Group for the Treatment of Digestive Tumours. All were studies of adults with advanced CRC who received first-line treatment with chemotherapy plus bevacizumab, cetuximab or panitumumab, stratified by age (≥ 65 vs. < 65 years). Endpoints included progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and safety. RESULTS: In total, 999 patients from five studies were included in the analysis: 480 (48%) were aged ≥ 65 years, and 519 (52%) were aged < 65 years. Median PFS did not differ significantly between patients aged ≥ 65 and < 65 years (9.9 vs. 9.4 months; hazard ratio [HR] 1.01; 95% confidence interval [CI] 0.88-1.17). Median OS was significantly shorter in older than in younger patients (21.3 vs. 25.0 months; HR 1.21; 95% CI 1.04-1.41). There was no significant difference between older and younger patients in ORR (59 vs. 62%). Patients aged ≥ 65 years experienced significantly more treatment-related grade 3 or higher adverse events (61.67%) than did patients aged < 65 years (45.86%). CONCLUSIONS: Biologicals plus chemotherapy is an effective first-line treatment option for selected patients aged ≥ 65 years with mCRC and has a manageable safety profile and efficacy comparable to that observed in younger patients.


Subject(s)
Biological Factors , Colorectal Neoplasms , Aged , Bevacizumab/adverse effects , Colorectal Neoplasms/drug therapy , Humans , Panitumumab , Retrospective Studies
4.
Target Oncol ; 15(5): 613-622, 2020 10.
Article in English | MEDLINE | ID: mdl-33025213

ABSTRACT

BACKGROUND: The cell cycle checkpoint G1/S, dependent on cyclin-dependent kinase (CDK) 4 amplification/overexpression and retinoblastoma phosphorylation, is altered in most anaplastic oligodendrogliomas (AOs). OBJECTIVE: We aimed to evaluate the efficacy of palbociclib, an oral inhibitor of CDK4/6 with proven efficacy in breast cancer, in patients with AO. The primary endpoint was progression-free survival at 6 months. PATIENTS AND METHODS: We conducted a multicenter, open-label, phase II trial evaluating the efficacy and safety of palbociclib in patients with AO who progressed on radiotherapy and chemotherapy with histologically and molecularly confirmed grade 3 oligodendroglioma and conserved retinoblastoma protein (pRb) expression by immunohistochemistry. Patients were treated with palbociclib (125 mg/day) for 3/1 weeks on/off. RESULTS: Overall, 34 patients were enrolled across 10 hospitals in the Spanish Group of Neuro-Oncology (GEINO) study. The study was stopped early owing to the lack of efficacy, with 74% of evaluable patients progressing within 6 months, which was insufficient to consider palbociclib as an active drug in this population. Within the median follow-up of 12 months, the median progression-free survival was 2.8 months [95% confidence interval (CI) 2.6-3.1] and the median overall survival was 32.1 months (95% CI 5.1-59.2). There were no partial or complete responses; only 13 patients (38%) achieved stable disease as the best response. Palbociclib was well tolerated, with neutropenia (grade 3 or higher: 58.8%) and thrombocytopenia (grade 3 or higher: 14.7%) as the most common adverse events (AEs). Both AEs had no significant impact. CONCLUSION: Despite the good tolerance, palbociclib monotherapy did not show favorable efficacy against recurrent AO. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov, identifier NCT0253032 (retrospectively registered on 21 August 2015).


Subject(s)
Oligodendroglioma/drug therapy , Piperazines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyridines/therapeutic use , Retinoblastoma/drug therapy , Adult , Aged , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local , Oligodendroglioma/pathology , Piperazines/pharmacology , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology , Retinoblastoma/pathology , Treatment Outcome
5.
Mikrochim Acta ; 187(8): 446, 2020 07 16.
Article in English | MEDLINE | ID: mdl-32676763

ABSTRACT

Accurate-controlled sized graphene quantum dots (GQDs) have been used as an analytical nanoprobe for detecting curcumin as a function of the photoluminescent quenching upon increasing concentrations of the analyte. Regarding the importance of curcumin nanoparticles in nutraceutical food, the analytical method described herein was also proven for the discrimination of curcumin remaining in free solution from that encapsulated into water-soluble nanomicelles of ca. 11 nm. This recognition is based on the displacement of GQD emission when interacting with both curcumin species. Maximum emission wavelength of GQDs suffers a gradual quenching as well as a red-shifting upon increasing concentrations of free curcumin (from 458 to 490 nm, exciting at 356 nm). On the other hand, in the presence of nanocurcumin, GQD photoluminescent response only displays a quenching effect (458/356 nm). The sensitivity of the described method in terms of detection limits was 0.3 and 0.1 µg mL-1 for curcumin and nanocurcumin, respectively. The applicability of the photoluminescent probe for the quantification and discrimination between both curcumin environments was demonstrated in nutraceutical formulations namely functional food capsules and fortified beverages such as ginger tea. Graphical abstract.


Subject(s)
Curcumin/analysis , Fluorescent Dyes/chemistry , Graphite/chemistry , Nanoparticles/chemistry , Quantum Dots/chemistry , Spectrometry, Fluorescence/methods , Curcumin/chemistry , Dietary Supplements/analysis , Zingiber officinale/chemistry , Limit of Detection , Teas, Herbal/analysis
6.
Oncologist ; 23(11): 1271-e128, 2018 11.
Article in English | MEDLINE | ID: mdl-30120161

ABSTRACT

LESSONS LEARNED: RAS- or BRAF-mutated metastatic colorectal cancers (mCRCs) progressing after first-line treatment have a poor prognosis.European and U.S. guidelines include the multikinase inhibitor regorafenib as a standard option for second-line therapy and beyond, based on the results of the randomized phase III CORRECT trial demonstrating improvement in survival.Although stopped prematurely for failing to accrue, the PREVIUM trial, the first prospective interventional study exploring regorafenib as second-line treatment for patients with mCRC bearing RAS or BRAF mutations, failed to demonstrate clinical activity in the population analyzed. BACKGROUND: Patients with RAS- or BRAF-mutated (mut) metastatic colorectal cancer (mCRC) progressing on first-line bevacizumab plus 5-FU/irinotecan/oxaliplatin (FOLFOXIRI) have a poor prognosis. We aimed to assess the efficacy and safety of regorafenib in this population. METHODS: Regorafenib was administered daily for 3 weeks of each 4-week cycle until disease progression or other reason. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: KRAS, NRAS, or BRAF was mutated in mCRC samples in 60%, 20%, and 13% of patients, respectively. Median time from initial diagnosis of metastases to the start of regorafenib and treatment duration was 13.8 months and 7 weeks, respectively. Reasons for discontinuation included disease progression (80%), investigator decision (13%), and adverse events (AEs; 7%). Seven patients (47%) required dose reduction, mostly for asthenia (43%). The most common regorafenib-related grade 3 AEs were asthenia (33%), dysphonia (13%), and hypertension (13%) (Table 1). There were no grade 4 toxicities. No patient was progression-free at 6 months. Median PFS, time to progression (TTP), and overall survival (OS) were 2.2, 2.0, and 3.3 months, respectively. CONCLUSION: Although stopped prematurely for failing to accrue, in the population analyzed, regorafenib failed to demonstrate clinical activity in KRAS- or BRAF-mutated mCRC with progression following first-line with FOLFOXIRI plus bevacizumab, although tolerability was acceptable. Our trial suggests that exploring regorafenib efficacy in an earlier line of therapy should not be undertaken without better population refinement.


Subject(s)
Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab/therapeutic use , Camptothecin/analogs & derivatives , Colorectal Neoplasms/drug therapy , Phenylurea Compounds/therapeutic use , Proto-Oncogene Proteins B-raf/genetics , Pyridines/therapeutic use , ras Proteins/genetics , Antineoplastic Agents, Immunological/pharmacology , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Bevacizumab/pharmacology , Camptothecin/pharmacology , Camptothecin/therapeutic use , Female , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Humans , Leucovorin/pharmacology , Leucovorin/therapeutic use , Male , Mutation , Neoplasm Metastasis , Organoplatinum Compounds/pharmacology , Organoplatinum Compounds/therapeutic use , Phenylurea Compounds/pharmacology , Pyridines/pharmacology
7.
BMC Cancer ; 18(1): 647, 2018 Jun 08.
Article in English | MEDLINE | ID: mdl-29884136

ABSTRACT

BACKGROUND: The BRCA1/2 mutation profile varies in Spain according to the geographical area studied. The mutational profile of BRCA1/2 in families at risk for hereditary breast and ovarian cancer has not so far been reported in Andalusia (southern Spain). METHODS: We analysed BRCA1/2 germline mutations in 562 high-risk cases with breast and/or ovarian cancer from Andalusian families from 2010 to 2015. RESULTS: Among the 562 cases, 120 (21.4%) carried a germline pathogenic mutation in BRCA1/2; 50 in BRCA1 (41.7%) and 70 in BRCA2 (58.3%). We detected 67 distinct mutations (29 in BRCA1 and 38 in BRCA2), of which 3 in BRCA1 (c.845C > A, c.1222_1223delAC, c.2527delA) and 5 in BRCA2 (c.293 T > G, c.5558_5559delGT, c.6034delT, c.6650_6654delAAGAT, c.6652delG) had not been previously described. The most frequent mutations in BRCA1 were c.5078_5080delCTG (10%) and c.5123C > A (10%), and in BRCA2 they were c.9018C > A (14%) and c.5720_5723delCTCT (8%). We identified 5 variants of unknown significance (VUS), all in BRCA2 (c.5836 T > C, c.6323G > T, c.9501 + 3A > T, c.8022_8030delGATAATGGA, c.10186A > C). We detected 76 polymorphisms (31 in BRCA1, 45 in BRCA2) not associated with breast cancer risk. CONCLUSIONS: This is the first study reporting the mutational profile of BRCA1/2 in Andalusia. We identified 21.4% of patients harbouring BRCA1/2 mutations, 58.3% of them in BRCA2. We also characterized the clinical data, mutational profile, VUS and haplotype profile.


Subject(s)
BRCA1 Protein/genetics , BRCA2 Protein/genetics , Hereditary Breast and Ovarian Cancer Syndrome/genetics , Adult , DNA Mutational Analysis , Female , Genetic Predisposition to Disease/genetics , Germ-Line Mutation , Humans , Middle Aged , Spain
8.
Mikrochim Acta ; 185(3): 204, 2018 03 03.
Article in English | MEDLINE | ID: mdl-29594680

ABSTRACT

A voltammetric analytical assay for the selective quantification of vanillin is described. It is based on the use of a gold nanoparticle-modified screen-printed carbon electrode (SPCE) modified with graphene quantum dots (GQD) in a Nafion matrix. The GQD were synthesized by an acidic thermal method and characterized by UV-Vis, photoluminescence, and FTIR spectroscopy. The modified SPCE displays a strongly enhanced response to vanillin. Linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) were applied to optimize the methods. The analytical assay has linear responses in the 13 to 660 µM and 0.66 to 33 µM vanillin concentration ranges. The detection limits are 3.9 µM and 0.32 µM when using LSV and DPV, respectively. The analytical assay is selective and stable. It was applied to the determination of vanillin in several food samples with satisfactory results. Recoveries from spiked samples ranged between 92.1 and 113.0%. Graphical abstract The selective and sensitive quantification of vanillin is carried out by the use of a gold nanoparticle-modified screen-printed carbon electrode modified with graphene quantum dots in a Nafion matrix.

9.
Spectrochim Acta A Mol Biomol Spectrosc ; 198: 177-181, 2018 Jun 05.
Article in English | MEDLINE | ID: mdl-29544115

ABSTRACT

Graphene quantum dots (GQD) were determined in water samples using terbium-sensitized luminescence (TSL). Terbium ions complex with GQD due to the carboxylic groups that are usually present in these nanomaterials, increasing the luminescence signal of terbium. In Tb(III)-GQD complexes, GQD absorb energy at their characteristic excitation wavelength and transfer it to terbium ion, which emits at its particular emission wavelength. The analytical signal, measured at λexc=257nm and λem=545nm, increases proportionally to GQD concentration between 50 and 500µgL-1. Under optimum conditions, the proposed method presents a detection limit of 15µgL-1 and is selective to GQD in the presence of other nanomaterials of similar size. As GQD are highly water-soluble, they are potential contaminants in environmental or drinking waters water samples, and hence the method was applied to the analysis of different drinking waters which were the target samples for the application of the developed method.

10.
Anal Bioanal Chem ; 410(2): 391-398, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29147748

ABSTRACT

We propose an alternative approach for the development of analytical methods based on terbium-sensitized luminescence (TSL). TSL is based on the complexation between Tb(III) ions and fluorescent organic compounds that have appropriate functional groups to complex with Tb(III). We report the use of graphene quantum dot (GQDs) nanoparticles to improve the sensitivity and selectivity of TSL detection. GQDs can react with terbium ions through the carboxylic groups present in their structure. These Tb(III)-GQD complexes, formed in situ in aqueous solution, can be used as time-resolved luminescent probes. Ascorbic acid was selected as a target analyte to demonstrate the suitability of the proposed method. The selectivity of the TSL method was highly improved for most of the interferences tested. Under the optimum conditions [Tb(III) concentration 5 × 10-4 mol L-1, GQD concentration 4 mg L-1], a minimum 100% increase in selectivity was observed for several vitamins and common cations that may be present in the samples to be analyzed. In addition, the analytical signal showed a 30% enhancement with the use of GQDs compared with the use of merely Tb(III) ions, with a detection limit of 0.12 µg mL-1. The repeatability and intermediate precision were lower than 3% and 5%, respectively. From the results obtained, the implementation of GQDs in TSL can lead to the development of novel time-resolved luminescent probes with high analytical potential. Graphical abstract Quenching of Tb(III)-graphene quantum dot (GQD) luminescence by ascorbic acid (AA). TBL terbium-sensitized luminescence.

11.
J Pharm Anal ; 7(5): 324-331, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29404056

ABSTRACT

A simple methodology was developed to quantify penicillamine (PA) in pharmaceutical samples, using the selective interaction of the drug with Cu-modified graphene quantum dots (Cu-GQDs). The proposed strategy combines the advantages of carbon dots (over other nanoparticles) with the high affinity of PA for the proposed Cu-GQDs, resulting in a significant and selective quenching effect. Under the optimum conditions for the interaction, a linear response (in the 0.10-7.50 µmol/L PA concentration range) was observed. The highly fluorescent GQDs used were synthesized using uric acid as single precursor and then characterized by high resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence, and absorption spectroscopy. The proposed methodology could also be extended to other compounds, further expanding the applicability of GQDs.

12.
J Electroanal Chem (Lausanne) ; 765: 8-15, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-27175108

ABSTRACT

This article details the study of electrochemical behavior of new carbon electrodes based on pyrolysis of different paper sources to be used in biosensor applications. The resistivity of the pyrolyzed papers was initially used as screening parameters to select the best three paper samples (imaging card paper, multipurpose printing paper, and 3MM chromatography paper) and assemble working electrodes that were further characterized by a combination of microscopy, electrochemistry, and spectroscopy. Although slight differences in performance were observed, all carbon substrates fabricated from pyrolysis of paper allowed the development of competitive biosensors for uric acid. The presented results demonstrate the potential of these electrodes for sensing applications and highlight the potential advantages of 3MM chromatography paper as a substrate to fabricate electrodes by pyrolysis.

13.
Mikrochim Acta ; 183(2): 611-616, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-27057067

ABSTRACT

A simple and inexpensive method to fabricate a colloidal CdSe/ZnS quantum dots-modified paper-based assay for glucose is herein reported. The circular paper sheets were uniformly loaded and displayed strong fluorescence under a conventional hand-held UV lamp (365 nm). The assay is based on the use of glucose oxidase enzyme (GOx), which impregnated the paper sheets, producing H2O2 upon the reaction with the glucose contained in the samples. After 20 min of exposure, the fluorescence intensity changed due to the quenching caused by H2O2. To obtain a reading, the paper sheets were photographed under 365 nm excitation using a digital camera. Several parameters, including the amount of QD, sample pH, and amount of GOx were optimized to maximize the response to glucose. The paper-based assay showed a sigmoidal-shaped response with respect to the glucose concentration in the 5-200 mg·dL-1 range (limit of detection of 5 µg·dL-1), demonstrating their potential use for biomedical applications.

14.
Sens Actuators B Chem ; 227: 626-633, 2016 May.
Article in English | MEDLINE | ID: mdl-26858513

ABSTRACT

A one-step approach for the synthesis and integration of copper nanoparticles (CuNPs) onto paper-based carbon electrodes is herein reported. The method is based on the pyrolysis (1000 °C under a mixture of 95% Ar / 5% H2 for 1 hour) of paper strips modified with a saturated solution of CuSO4 and yields to the formation of abundant CuNPs on the surface of carbonized cellulose fibers. The resulting substrates were characterized by a combination of scanning electron microscopy, EDX, Raman spectroscopy as well as electrical and electrochemical techniques. Their potential application, as working electrodes for nonenzymatic amperometric determination of glucose, was then demonstrated (linear response up to 3 mM and a sensitivity of 460 ± 8 µA·cm-2·mM-1). Besides being a simple and inexpensive process for the development of electrochemically-active substrates, this approach opens new possibilities for the in-situ synthesis of metallic nanoparticles without the traditional requirements of solutions and adjuvants.

15.
Talanta ; 131: 286-91, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25281104

ABSTRACT

An optical sensor for vanillin in food samples using CdSe/ZnS quantum dots (QDs) modified with ß-cyclodextrin (ß-CD) was developed. This vanillin-sensor is based on the selective host-guest interaction between vanillin and ß-cyclodextrin. The procedure for the synthesis of ß-cyclodextrin-CdSe/ZnS (ß-CD-CdSe/ZnS-QDs) complex was optimized, and its fluorescent characteristics are reported. It was found that the interaction between vanillin and ß-CD-CdSe/ZnS-QDs complex produced the quenching of the original fluorescence of ß-CD-CdSe/ZnS-QDs according to the Stern-Volmer equation. The mechanism of the interaction is discussed. The analytical potential of this sensoring system was demonstrated by the determination of vanillin in synthetic and food samples. The method was selective for vanillin, with a limit of detection of 0.99 µg mL(-1), and a reproducibility of 4.1% in terms of relative standard deviation (1.2% under repeatability conditions). Recovery values were in the 90-105% range for food samples.


Subject(s)
Benzaldehydes/analysis , Biosensing Techniques/methods , Cadmium Compounds/chemistry , Food Analysis/methods , Quantum Dots , Selenium Compounds/chemistry , Sulfides/chemistry , Zinc Compounds/chemistry , beta-Cyclodextrins/chemistry
16.
J Colloid Interface Sci ; 428: 235-41, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-24910058

ABSTRACT

A simple and fast procedure for water solubilization of CdSe/ZnS quantum dots (QDs) using microwave irradiation (MW) has been optimized. The CdSe/ZnS QDs were synthesized in organic media and water solubilization was achieved by replacing the initial hydrophobic ligands (TOPO and TOP) with hydrophilic heterobifunctional thiol ligands, such as L-cysteine (L-Cys), 3-mercaptopropionic acid (3-MPA) and cysteamine (CTAM). The use of MW irradiation allowed carrying out the modification of the surface thiol of QDs in a simple and fast way (only 40 s was required). Different optimization studies based on activation-time, irradiation-time, concentration of ligands, pH and lifetime fluorescent properties were carried out in order to obtain the best results for the solubilization of QDs. By the proposed method, the resulting water-soluble QDs exhibit a strong fluorescence emission at about 590 nm, with a high and reproducible photostability and acceptable yields. With the aim of contributing to exploiting the advantages of synthetized QDs from an analytical point of view, the different behavior with sulfonylurea herbicides (SUHs) were studied.

17.
Anal Chim Acta ; 801: 84-90, 2013 Nov 01.
Article in English | MEDLINE | ID: mdl-24139578

ABSTRACT

Based on the highly sensitive fluorescence change of water-soluble CdSe/ZnS core-shell quantum dots (QD) by paraquat herbicide, a simple, rapid and reproducible methodology was developed to selectively determine paraquat (PQ) in water samples. The methodology enabled the use of simple pretreatment procedure based on the simple water solubilization of CdSe/ZnS QDs with hydrophilic heterobifunctional thiol ligands, such as 3-mercaptopropionic acid (3-MPA), using microwave irradiation. The resulting water-soluble QDs exhibit a strong fluorescence emission at 596 nm with a high and reproducible photostability. The proposed analytical method thus satisfies the need for a simple, sensible and rapid methodology to determine residues of paraquat in water samples, as required by the increasingly strict regulations for health protection introduced in recent years. The sensitivity of the method, expressed as detection limits, was as low as 3.0 ng L(-1). The lineal range was between 10-5×10(3) ng L(-1). RSD values in the range of 71-102% were obtained. The analytical applicability of proposed method was demonstrated by analyzing water samples from different procedence.

18.
Lung Cancer ; 56(2): 255-62, 2007 May.
Article in English | MEDLINE | ID: mdl-17276537

ABSTRACT

OBJECTIVE: We conducted a phase II trial to evaluate the efficacy and toxicity of a combination consisting of second-line docetaxel and gemcitabine in patients with advanced non-small-cell lung cancer (NSCLC) previously treated with platinum-based chemotherapy. ELIGIBILITY CRITERIA: histologically confirmed advanced NSCLC with progressive disease to platinum-based chemotherapy, ECOG performance status (PS) 0 or 1, and adequate kidney, liver and bone marrow function. Treatment consisted of docetaxel 36 mg/m(2) i.v. over 60 min followed by gemcitabine 1000 mg/m(2) i.v. over 30 min on days 1 and 8 of each 3-week cycle for a planned six cycles or unacceptable toxicity. RESULTS: Of the 52 patients enrolled, 50 were evaluable for response and toxicity. The mean age was 59 years (range 42-79), 46 male and 4 female. Histology subtypes were: adenocarcinoma 26 patients, bronchioloalveolar 1 patient, large cell carcinoma 5 patients, and squamous cell carcinoma 18 patients. Thirty-eight patients had ECOG PS 1 and 12 patients had PS 0. The median number of cycles administered was four (range 2-6). The overall response rate was 28%. The median follow-up was 9 months (range 5-34 months). The median survival time (MST) was 8.2 months (95% CI, 4-12%), and the 1-year survival was 25%. The median progression-free survival was 4.4 months (95% CI, 2-6%). In the Cox regression model, survival was only significantly affected by the PS. The median survival in patients with PS 0 was 17.8 months (95% CI, 18.8-21.8%) compared with a median survival for patients with PS 1 of 6.1 months (95% CI, 4.1-8.2%) (P=0.0057). TOXICITY: three patients had grade 3 anemia, three patients had grade 3 thrombocytopenia, four patients had grade 3 neutropenia and only one patient developed grade 4 febrile neutropenia. Non-hematologic toxicity was also mild; the most frequent was asthenia, with grade 3 in eight patients (16%), and one patient with grade 4. CONCLUSION: This regimen of docetaxel in combination with gemcitabine in advanced second-line NSCLC is an active and safe regimen.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Adult , Aged , Carcinoma, Non-Small-Cell Lung/mortality , Deoxycytidine/administration & dosage , Deoxycytidine/adverse effects , Deoxycytidine/analogs & derivatives , Docetaxel , Female , Humans , Lung Neoplasms/mortality , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/mortality , Survival Analysis , Survival Rate , Taxoids/administration & dosage , Taxoids/adverse effects , Gemcitabine
19.
Med. segur. trab ; 51(201): 27-36, dic. 2005. ilus, tab
Article in Es | IBECS | ID: ibc-056181

ABSTRACT

profesional, está caracterizado por cansancio emocional, despersonalización y falta de realización personal. Es un estrés laboral frecuente entre trabajadores con profesiones asistenciales como asistencia sanitaria y enseñanza. Objetivo: Determinar la influencia de factores sociodemográficos y laborales en la prevalencia del burnout del personal sanitario hospitalario. Métodos: Participaron 126 profesionales sanitarios de cuidados paliativos, intensivos y urgencias del hospital Gregorio Marañón de Madrid. Todos cumplimentaron un cuestionario de características sociodemográficas y laborales, y el "Maslach Burnout Inventory", en versión española validada para sanitarios, que valora el nivel de burnout. El análisis estadístico: "t" de Student, test de Kolmogorov-Smirnov y ANOVA. Resultados: Por servicios: los niveles más altos de burnout se observaron en urgencias, seguidos de intensivos y paliativos (diferencias significativas). Profesionales de enfermería presentaban niveles más altos de burnout, mostrando diferencias significativas con los obtenidos en médicos. Turno de trabajo: niveles más altos de burnout en turno de tarde, que en otros obteniéndose diferencias significativas. Se observaron diferencias significativas en burnout y componentes (CE, DP y FR) según sexo, edad y estado civil entre trabajadores de los tres servicios, pero no según antigüedad profesional. Conclusiones: El nivel de burnout varía en los tres servicios analizados. Encontramos relación entre burnout y determinadas variables sociodemográficas y laborales


Background: The burnout syndrome is characterized by emotional exhaustion, depersonalization and decrease of the feeling of personal accomplishment. It is a type of occupational stress frequent in the helping professions and the most affected professions are healthcare professionals and teaching. Objective: To determine the influence of occupational and sociodemographic factors in the prevalence of burnout in hospital health workers. Methods: 126 healthcare professionals belonging to palliative, intensive and urgency services of Gregorio Marañón Hospital participate in the study. A general questionnaire and a Spanish version of the Maslach Burnout Inventory were used. The statistical analysis included: the Student "t" test, the Kolmogorov- Smirnov test and the ANOVA. Results: For services, the most high burnout levels were observed in urgency services in a row of intensive and palliative care units (differences were significant). For professions, the most high burnout levels were observed in nurses and significant differences were obtained with respect to physicians. For work shifts: higher burnout levels in evening shifts than in morning or night shifts. Significant differences were also observed with respect to sex, age and civil state, but not for professional antiquity. Conclusions: The level of burnout is different in the three services analyzed. We found a correlation between burnout and several sociodemographic and occupational conditions


Subject(s)
Male , Female , Adult , Middle Aged , Humans , Burnout, Professional/epidemiology , Personnel, Hospital/psychology , Personnel, Hospital/statistics & numerical data , Statistics, Nonparametric , Socioeconomic Factors , Analysis of Variance , Surveys and Questionnaires , Spain
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