123 research outputs found

    Estudio de la frecuencia, distribución y rendimiento diagnóstico en las lesiones neoplásicas sincrónicas del carcinoma colo-rectal

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    ABSTRACT To analyse the frequency, characteristics and diagnosis of synchronic neoplastic lesions in colorectal cancer. A review was carried out of 384 colorectal cancers, diagnosed through complete colonoscopy and resected. The synchronic cancers and the characteristics of the adenomas were determined: number, size, histological type, dysplasia, as well as their localisation in the colon and with respect to the carcinoma. Twenty-eight synchronic cancers were found (7.3% of the total); 8 developed tumours and 20 malignant polyps. In 54.4% of the cases there was a synchronic adenoma. In patients with synchronic lesions, 43% showed an advanced adenoma. Twenty percent of the synchronic polyps found were proximal to the splenic flexure; 41% were distal and 38% had both localisations. Fifty-nine point one percent of the patients had some adenoma proximal to the cancer, with criteria of advanced adenoma in 13.9%. The distribution of the adenomas was more uniformly spread in the cancers with a proximal localisation (p = 0.038). Seventeen percent of the distal cancers presented synchronic lesions with a proximal colon localisation exclusively. Partial endoscopies would diagnose the distal cancers, but would omit a synchronic adenoma in 42.3% of the sigmoidoscopies and 40% of the short colonoscopies. High rates of carcinoma and synchronic adenomas were registered. We underline the high index of advanced adenomas and the frequency of synchronic lesions proximal to the cancer, which is why incomplete colonoscopies, although allowing the diagnosis of the distal cancer, omit a high percentage of synchronic adenomas, including advanced lesions. All of this confirms the need to perform a complete pre- , intra- and post operational colonoscopy in resectable colorectal cancer

    Estudio de las lesiones neoplásicas metacrónicas en el carcinoma colorrectal

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    Fundamento. Analizar la frecuencia y las características de las lesiones neoplásicas metacrónicas, carcinomas y adenomas, tras la resección de un cáncer colo-rectal (CCR). Pacientes y métodos. Revisamos 382 CCR operados y seguidos mediante colonoscopias completas en dos hospitales de nuestra comunidad. Analizamos las lesiones metacrónicas registradas valorando su localización, momento del diagnóstico, histología, número y tamaño. Estudiamos la frecuencia de adenomas de aparición precoz (12 meses), comparando su tamaño con respecto al resto de lesiones. Resultados. La mediana de seguimiento fue de 48 meses (12-112), con 2,74±1,47 colonoscopias/caso. Diagnosticamos 7 cánceres metacrónicos (1,8%), 4 de ellos en estadio I. La mediana de tiempo hasta su diagnóstico fue de 24 meses (13-54). Registramos adenomas metacrónicos en 162 casos (42,4%), sin diferencias entre los dos hospitales: 42,1% vs. 43,8% (p=0,88). Un 6,3% de los pacientes presentaron adenomas avanzados. En 164 casos en que el primer control se efectuó a los 12 meses, la incidencia de adenomas fue del 24%. Los adenomas fueron mayoritariamente únicos (60,8%) y menores de 5 mm (68,5%). En un 55,5% de los casos con pólipos, alguno tenía una localización proximal. El diagnóstico se realizó en la 1ª exploración (56,2%), 2ª (27,8%) ó 3ª (9%). La mediana de tiempo hasta el diagnóstico fue de 21 meses (12-112) para el adenoma simple y de 35 (12-112) para el avanzado. Conclusiones. Nuestro seguimiento permitió aplicar un tratamiento teóricamente curativo en la mayoría de los carcinomas metacrónicos diagnosticados. La alta incidencia de adenomas y su frecuente localización proximal hacen necesario un seguimiento con colonoscopias completas, que debería iniciarse al año de la operación y podría pasar a ser menos estricto tras tres exploraciones consecutivas sin pólipos

    Synchronous neoplastic lesions in colorectal cancer. An analysis of possible risk factors favouring presentation

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    Aim: few data have been published regarding the causes of synchronous lesions in patients with colorectal cancer. The aim of our study was to identify potential factors that might be implicated in the development of multicentric lesions, since this knowledge could be useful for tailored follow-up once initial synchronous lesions have been removed. Methods: we retrospectively reviewed 382 colorectal cancer cases diagnosed by total colonoscopy and histological study of surgical specimens. We divided our population into 2 groups, based on whether they had synchronous lesions or otherwise. Several data related to personal and family history, habits, symptoms, and tumor characteristics were assessed. Univariate and multivariate statistical analyses were performed. Results: 208 (54.5%) patients had synchronous adenomas and 28 (7.3%) had synchronous cancer. A multivariate analysis showed that the following parameters were consistently related to the presence of multicentric lesions –male gender: OR = 1.97; CI = 1.13-3.45; p = 0.017; age ≥ 59 years: OR = 2.57; CI = 1.54-4.29; p < 0.001; personal history of colonic adenomas: OR = 3.04; CI = 1.04-8.85; p = 0.042; and obstructive tumors: OR = 0.48; CI = 0.27-0.85; p = 0.012. Conclusion: our results show that several parameters that are easy to measure could be considered risk factors for the development of multicentric lesions. These factors need to be confirmed with follow-up studies analyzing their role in patients with and without metachronic lesions once all synchronous lesions have been removed

    Análisis de la posible influencia de las lesiones sincrónicas en el pronóstico del cáncer colorrectal resecado

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    Aim: To analyze the relationship between synchronous lesions in patients with colorectal cancer and their prognostic value. Patients and methods: We have retrospectively reviewed 369 patients with resected colorectal cancer. We compared the rate of apparently curative surgery, progression and tumoral relapse, development of extracolonic cancer and mortality between patients with and without synchronous cancer. Afterwards, we analyzed the same parameters in colorectal cancer with and without synchronous adenomas. Finally, we repeated the analysis after stratification of cancers in 2 groups according to pTNM staging: 0-I-II stage vs III-IV. Results: We found synchronous adenomas in 54.7% of our patients and synchronous cancers in 7.6%. Follow-up period of groups with and without synchronous lesions were: 70.8 ± 22.9 and 67.2 ± 24.5 months (p = 0.55) respectivelly. Synchronous cancers showed higher mortality: 35.7 vs. 14.4%: p = 0.006; OR = 3.31 (1.33-8.13), higher tumoral progression : 39.3 vs. 19.1%: p = 0.011; OR = 2.75 (1.14-6.56) and higher relapse rate: 10.7 vs. 3.5%: p = 0.096. Stratifying according to stage, patients with stage 0-I-II and synchronous cancer showed worse prognosis: mortality = 27.7 vs. 8.1%, p = 0.019; OR = 4.45 (1.2-15.1), tumoral progression = 27.8 vs. 8.5%, p = 0.02; OR = 4.12 (1.14-14.19), and extracolonic cancer = 16.7 vs. 6.4% p = 0.095. There were no statistical differences between cases with and without synchronous adenomas. Conclusions: Synchronous cancers showed worse prognosis after resection, with higher rate of tumoral progression and mortality. This difference is focused on the cases diagnosed in stage 0-I-II, not being found in III-IV. The presence of synchronous adenomas doesn’t influence prognosis

    Theory of magnetoresistance in films of dilute magnetic alloys

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    Earlier a magnetic anisotropy for magnetic impurities nearby the surface of non-magnetic host was proposed in order to explain the size dependence of the Kondo effect in dilute magnetic alloys. Recently Giordano has measured the magnetoresistance of dilute Au(Fe) films for different thicknesses well above the Kondo temperature TKT_K. In this way he verified the existence of that anisotropy even for such a case where the Kondo effect is not dominating. For detailed comparison of that suggestion with experiments, the magnetic field dependence of the magnetoresistance is calculated in the lowest approximation, thus in the second order of the exchange coupling. The strength of the anisotropy is very close to earlier estimates deduced from the size dependence of the Kondo resistivity amplitude.Comment: (11 pages, 8 figures, essential changes compared to the old version

    Treatments used for obsessive-compulsive disorder-An international perspective

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    © 2019 John Wiley & Sons, Ltd.OBJECTIVE: The objective of this study was to characterise international trends in the use of psychotropic medication, psychological therapies, and novel therapies used to treat obsessive-compulsive disorder (OCD). METHODS: Researchers in the field of OCD were invited to contribute summary statistics on the characteristics of their samples. Consistency of summary statistics across countries was evaluated. RESULTS: The study surveyed 19 expert centres from 15 countries (Argentina, Australia, Brazil, China, Germany, Greece, India, Italy, Japan, Mexico, Portugal, South Africa, Spain, the United Kingdom, and the United States) providing a total sample of 7,340 participants. Fluoxetine (n = 972; 13.2%) and fluvoxamine (n = 913; 12.4%) were the most commonly used selective serotonin reuptake inhibitor medications. Risperidone (n = 428; 7.3%) and aripiprazole (n = 415; 7.1%) were the most commonly used antipsychotic agents. Neurostimulation techniques such as transcranial magnetic stimulation, deep brain stimulation, gamma knife surgery, and psychosurgery were used in less than 1% of the sample. There was significant variation in the use and accessibility of exposure and response prevention for OCD. CONCLUSIONS: The variation between countries in treatments used for OCD needs further evaluation. Exposure and response prevention is not used as frequently as guidelines suggest and appears difficult to access in most countries. Updated treatment guidelines are recommended.Peer reviewe

    Pyrite-induced hydroxyl radical formation and its effect on nucleic acids

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    BACKGROUND: Pyrite, the most abundant metal sulphide on Earth, is known to spontaneously form hydrogen peroxide when exposed to water. In this study the hypothesis that pyrite-induced hydrogen peroxide is transformed to hydroxyl radicals is tested. RESULTS: Using a combination of electron spin resonance (ESR) spin-trapping techniques and scavenging reactions involving nucleic acids, the formation of hydroxyl radicals in pyrite/aqueous suspensions is demonstrated. The addition of EDTA to pyrite slurries inhibits the hydrogen peroxide-to-hydroxyl radical conversion, but does not inhibit the formation of hydrogen peroxide. Given the stability of EDTA chelation with both ferrous and ferric iron, this suggests that the addition of the EDTA prevents the transformation by chelation of dissolved iron species. CONCLUSION: While the exact mechanism or mechanisms of the hydrogen peroxide-to-hydroxyl radical conversion cannot be resolved on the basis of the experiments reported in this study, it is clear that the pyrite surface promotes the reaction. The formation of hydroxyl radicals is significant because they react nearly instantaneously with most organic molecules. This suggests that the presence of pyrite in natural, engineered, or physiological aqueous systems may induce the transformation of a wide range of organic molecules. This finding has implications for the role pyrite may play in aquatic environments and raises the question whether inhalation of pyrite dust contributes to the development of lung diseases

    Pyrite oxidation inhibition by a cross-linked lipid coating

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    The effect of a diacetylene-containing phospholipid on the oxidation of pyrite, FeS(2), was investigated. Earlier work reported by our research group showed that the adsorption of l,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine on pyrite suppressed the extent of its oxidation by about 75% over a specific time period. Results presented here show that the pre-exposure to UV radiation of this lipid after sorption onto pyrite results in a 90% suppression. Attenuated total reflection (ATR) Fourier transform infra-red spectroscopy (FTIR) suggests that the UV irradiation of the lipid does not result in degradation of the adsorbed layer. It is believed that the UV exposure results in the cross-linking and polymerization of the adsorbed phospholipid into a relatively impermeable barrier that separates the pyrite from the aqueous phase. The results of this study might have implications for the protection of pyrite from oxidation in the environment

    Spintronics: Fundamentals and applications

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    Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio
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