123 research outputs found
Estudio de la frecuencia, distribución y rendimiento diagnóstico en las lesiones neoplásicas sincrónicas del carcinoma colo-rectal
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
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
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
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
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 . 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
© 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
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
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
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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