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1.
Mar Policy ; 140: 105054, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35399704

RESUMEN

The human response to the COVID-19 pandemic set in motion an unprecedented shift in human activity with unknown long-term effects. The impacts in marine systems are expected to be highly dynamic at local and global scales. However, in comparison to terrestrial ecosystems, we are not well-prepared to document these changes in marine and coastal environments. The problems are two-fold: 1) manual and siloed data collection and processing, and 2) reliance on marine professionals for observation and analysis. These problems are relevant beyond the pandemic and are a barrier to understanding rapidly evolving blue economies, the impacts of climate change, and the many other changes our modern-day oceans are undergoing. The "Our Ocean in COVID-19″ project, which aims to track human-ocean interactions throughout the pandemic, uses the new eOceans platform (eOceans.app) to overcome these barriers. Working at local scales, a global network of ocean scientists and citizen scientists are collaborating to monitor the ocean in near real-time. The purpose of this paper is to bring this project to the attention of the marine conservation community, researchers, and the public wanting to track changes in their area. As our team continues to grow, this project will provide important baselines and temporal patterns for ocean conservation, policy, and innovation as society transitions towards a new normal. It may also provide a proof-of-concept for real-time, collaborative ocean monitoring that breaks down silos between academia, government, and at-sea stakeholders to create a stronger and more democratic blue economy with communities more resilient to ocean and global change.

2.
Clin Exp Immunol ; 193(3): 346-360, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29745420

RESUMEN

In inflammatory bowel disease (IBD), inflammation is sustained by an exaggerated response of lymphocytes. This results from enhanced expression of anti-apoptotic B cell lymphoma (BCL-2) and BCL-XL associated with a diminished turnover. Azathioprine (AZA) directly targets BCL-2 family-mediated apoptosis. We investigated whether the BCL-2 family expression pattern could be used to predict treatment response to AZA and determined whether BCL-2 inhibitor A-1211212 effectively diminishes lymphocytes and ameliorates inflammation in a model of colitis. BCL-2 family expression pattern was determined by next-generation sequencing (NGS). BCL-2 inhibitor was administered orally to Il10-/- mice. Haematological analyses were performed with an ADVIA 2120 and changes in immune cells were investigated using quantitative polymerase chain reaction (qPCR) and fluorescence activated cell sorter (FACS). We determined similar expression levels of BCL-2 family members in patients with remission and patients refractory to treatment, showing that BCL-2 family expression can not predict AZA treatment response. Expression was not correlated with the modified Truelove and Witts activity index (MTWAI). BCL-2 inhibitor initiated cell death in T cells from patients refractory to AZA and reduced lymphocyte count in Il10-/- mice. FACS revealed diminished CD8+ T cells upon BCL-2 inhibitor in Il10-/- mice without influencing platelets. Tnf, Il1ß, IfnƔ and Mcp-1 were decreased upon BCL-2 inhibitor. A-1211212 positively altered the colonic mucosa and ameliorated inflammation in mice. Pro-apoptotic BCL-2 inhibitor A-1211212 diminishes lymphocytes and ameliorates colitis in Il10-/- mice without inducing thrombocytopenia. BCL-2 inhibition could be a new therapy option for patients refractory to AZA.


Asunto(s)
Azatioprina/uso terapéutico , Colitis/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Linfocitos/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/genética , Animales , Apoptosis , Células Cultivadas , Colitis/diagnóstico , Colitis/genética , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Mediadores de Inflamación/metabolismo , Enfermedades Inflamatorias del Intestino/diagnóstico , Enfermedades Inflamatorias del Intestino/genética , Interleucina-10/genética , Linfocitos/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Pronóstico , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Resultado del Tratamiento
3.
Rev Clin Esp (Barc) ; 223(6): 331-339, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37169081

RESUMEN

INTRODUCTION: Post-dural puncture headache (PDPH) is the most common complication following lumbar puncture. However, its incidence varies according to the series consulted. Different factors associated with its onset have been identified. OBJECTIVES: The purpose of this study is to determine the incidence of PDPH and to identify predisposing factors for its appearance. METHOD: Prospective, descriptive study in 57 patients who underwent lumbar puncture procedures. To this end, variables associated with patient-related risk factors, clinical and procedural factors with the presence of PDPH were analysed. The incidence of PDPH was 38.6% and factors associated with onset included young age and previous history of headache. RESULTS: The incidence of PDPH was higher in women and presented greater intensity in this group, though studies with a larger sample size would need to be conducted. CONCLUSIONS: We must bear in mind the factors associated with the appearance of PDPH, which include: young age, history of headache, and the perception of procedural difficulty, to better inform patients and optimise the techniques used.


Asunto(s)
Cefalea Pospunción de la Duramadre , Humanos , Femenino , Cefalea Pospunción de la Duramadre/epidemiología , Cefalea Pospunción de la Duramadre/etiología , Estudios Prospectivos , Cefalea/complicaciones , Cefalea/epidemiología , Factores de Riesgo , Punción Espinal/efectos adversos
4.
Interv Neuroradiol ; 29(3): 301-306, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35285737

RESUMEN

BACKGROUND AND PURPOSE: The carotid stent placement as a therapeutic option for carotid stenosis has been increasing among years; therefore, studies are required to evaluate the security and efficacy of its materials. The purpose of this study was to evaluate the distal filter and the proximal balloon-guided catheter with flow inversion as protection devices during carotid angioplasty and stenting. METHODS: This is a retrospective, observational study of patients diagnosed with carotid stenosis treated with angioplasty between January 1, 2014, and June 30, 2020; we analyzed a radiology service database to compare the distal filter and the proximal balloon-guided catheter as protection devices during angioplasty. RESULTS: One hundred seventy-five angioplasties were performed, the distal filter was the most prevalent embolic protection device used (66%), patients baseline characteristics did not differ between groups with different embolic protection devices, except for history of dyslipidemia (p < 0.000). As well, we did not find any significant differences between the groups in the device related complications, intervention time (p = 0.140), unrelated complications (p = 0.693) and functional independence at 90 days (p = 0.096). CONCLUSIONS: In our study the proximal balloon-guided catheter and the distal filter protection device as protection devices during the carotid stenting didn't show significant differences regarding complications related to the system.


Asunto(s)
Angioplastia de Balón , Estenosis Carotídea , Humanos , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/cirugía , Colombia , Resultado del Tratamiento , Catéteres , Stents
5.
Biochim Biophys Acta ; 1804(7): 1467-75, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20215052

RESUMEN

Under aerobic or anaerobic conditions, tyrosinase undergoes a process of irreversible inactivation induced by its physiological substrate L-dopa. Under aerobic conditions, this inactivation occurs through a process of suicide inactivation involving the form oxy-tyrosinase. Under anaerobic conditions, both the met- and deoxy-tyrosinase forms undergo irreversible inactivation. Suicide inactivation in aerobic conditions is slower than the irreversible inactivation under anaerobic conditions. The enzyme has less affinity for the isomer D-dopa than for L-dopa but the velocity of inactivation is the same. We propose mechanisms to explain these processes.


Asunto(s)
Dihidroxifenilalanina/química , Monofenol Monooxigenasa/química , Agaricales/enzimología , Catálisis , Dominio Catalítico , Catecol Oxidasa/química , Cinética , Espectroscopía de Resonancia Magnética , Modelos Biológicos , Modelos Químicos , Oxígeno/química , Unión Proteica , Espectrofotometría/métodos , Factores de Tiempo
6.
Biochim Biophys Acta ; 1794(12): 1766-74, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19695351

RESUMEN

There is controversy in the literature concerning the action of tetrahydropterines on the enzyme tyrosinase and on melanogenesis in general. In this study, we demonstrate that tetrahydropterines can inhibit melanogenesis in several ways: i) by non-enzymatic inhibition involving purely chemical reactions reducing o-dopaquinone to L-dopa, ii) by acting as substrates which compete with L-tyr and L-dopa, since they are substrates of tyrosinase; and iii) by irreversibly inhibiting the enzymatic forms met-tyrosinase and deoxy-tyrosinase in anaerobic conditions. Three tetrahydropterines have been kinetically characterised as tyrosinase substrates: 6-R-L-erythro-5,6,7,8-tetrahydrobiopterin, 6-methyl-5,6,7,8-tetrahydropterine and 6,7-(R,S)-dimethyl-5,6,7,8-tetrahydropterine. A kinetic reaction mechanism is proposed to explain the oxidation of these compounds by tyrosinase.


Asunto(s)
Melaninas/biosíntesis , Monofenol Monooxigenasa/antagonistas & inhibidores , Pterinas/farmacología , Agaricales/enzimología , Unión Competitiva , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Cinética , Levodopa/metabolismo , Monofenol Monooxigenasa/metabolismo , Oxidación-Reducción , Pterinas/química , Especificidad por Sustrato , Tirosina/metabolismo
7.
Sci Rep ; 8(1): 15182, 2018 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-30315190

RESUMEN

Intestinal fibrosis is thought to be a consequence of excessive tissue repair, and constitutes a common problem in patients with Crohn's disease (CD). While fibrosis seems to require inflammation as a prerequisite it is unclear whether the severity or persistence of inflammation influences the degree of fibrosis. Our aim was to investigate the role of sustained inflammation in fibrogenesis. For the initiation of fibrosis in vivo the models of Il10-/- spontaneous colitis, dextran sodium sulfate (DSS)-induced chronic colitis and heterotopic transplantation were used. In Il10-/- mice, we determined a positive correlation between expression of pro-inflammatory factors (Il1ß, Tnf, Ifnγ, Mcp1 and Il6). We also found a positive correlation between the expression of pro-fibrotic factors (Col3a1 Col1a1, Tgfß and αSma). In contrast, no significant correlation was determined between the expression of pro-inflammatory Tnf and pro-fibrotic αSma, Col1a1, Col3a1, collagen layer thickness and the hydroxyproline (HYP) content. Results from the DSS-induced chronic colitis model confirmed this finding. In the transplantation model for intestinal fibrosis a pronounced increase in Mcp1, inos and Il6 in Il10-/- as compared to WT grafts was observed, indicating more severe inflammation in Il10-/- grafts. However, the increase of collagen over time was virtually identical in both Il10-/- and WT grafts. Severity of inflammation during onset of fibrogenesis did not correlate with collagen deposition. Although inflammation might be a pre-requisite for the initiation of fibrosis our data suggest that it has a minor impact on the progression of fibrosis. Our results suggest that development of fibrosis and inflammation may be disconnected. This may be important for explaining the inefficacy of anti-inflammatory treatments agents in most cases of fibrotic inflammatory bowel diseases (IBD).


Asunto(s)
Fibrosis/patología , Inflamación/patología , Intestinos/patología , Animales , Colitis/metabolismo , Colitis/patología , Colágeno/metabolismo , Colon/metabolismo , Colon/patología , Enfermedad de Crohn/metabolismo , Enfermedad de Crohn/patología , Modelos Animales de Enfermedad , Fibrosis/metabolismo , Hidroxiprolina/metabolismo , Inflamación/metabolismo , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Interleucina-10/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Masculino , Ratones , Ratones Endogámicos C57BL
8.
J Agric Food Chem ; 55(3): 920-8, 2007 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-17263494

RESUMEN

Chlorogenic acid is the major diphenol of many fruits, where it is oxidized enzymatically by polyphenol oxidase (PPO) or peroxidase (POD) to its o-quinone. In spectrophotometric studies of chlorogenic acid oxidation with a periodate ratio of [CGA]0/[IO4-]0 < 1 and [CGA]0/[IO4-]0 > 1, the o-quinone was characterized as follows: lambda(max) at 400 nm and epsilon = 2000 and 2200 M-1 cm-1 at pH 4.5 and 7.0, respectively. In studies of o-quinone generated by the oxidation of chlorogenic acid using a periodate at ratio of [CGA]0/[IO4-]0 > 1, a reaction with the remaining substrate was detected, showing rate constants of k = 2.73 +/- 0.17 M-1 s-1 and k' = 0.05 +/- 0.01 M-1 s-1 at the above pH values. A chronometric spectrophotometric method is proposed to kinetically characterize the action of the PPO or POD on the basis of measuring the time it takes for a given amount of ascorbic acid to be consumed in the reaction with the o-quinone. The kinetic constants of mushroom PPO and horseradish POD are determined.


Asunto(s)
Catecol Oxidasa/metabolismo , Ácido Clorogénico/metabolismo , Peroxidasa/metabolismo , Quinonas/metabolismo , Agaricales/enzimología , Armoracia/enzimología , Concentración de Iones de Hidrógeno , Cinética , Oxidación-Reducción , Ácido Peryódico/metabolismo
9.
Biochim Biophys Acta ; 1650(1-2): 128-35, 2003 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-12922176

RESUMEN

A solvent deuterium isotope effect on the catalytic affinity (K(m)) and rate constant (k(cat)) of tyrosinase in its action on 4-tert-butylcatechol (TBC) was observed. Both parameters decreased as the molar fraction of deuterated water in the medium increased, while the k(cat)/K(m) ratio remained constant. In a proton inventory study, the representation of k(cat)(f(n))/k(cat)(f(0)) and K(m)(f(n))/K(m)(f(0)) vs. n (atom fractions of deuterium) was linear, indicating that, of the four protons transferred from the two molecules of substrate and which are oxidized in one turnover, only one is responsible for the isotope effects. The fractionation factor of 0.64+/-0.02 contributed to identifying the possible proton acceptor. Possible mechanistic implications are discussed.


Asunto(s)
Catecoles/metabolismo , Deuterio/metabolismo , Monofenol Monooxigenasa/metabolismo , Agaricales/enzimología , Cinética , Oxidación-Reducción
10.
Biochim Biophys Acta ; 1548(1): 1-22, 2001 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-11451433

RESUMEN

Tyrosinase can act on monophenols because of the mixture of met- (E(m)) and oxy-tyrosinase (E(ox)) which exists in the native form of the enzyme. The latter form is active on monophenols, while the former is not. However, the kinetics are complicated because monophenols can bind to both enzyme forms. This situation becomes even more complex since the products of the enzymatic reaction, the o-quinones, are unstable and continue evolving to generate o-diphenols in the medium. In the case of substrates such as L-tyrosine, tyrosinase generates very unstable o-quinones, in which a process of cyclation and subsequent oxidation-reduction generates o-diphenol through non-enzymatic reactions. However, the release of o-diphenol through the action of the enzyme on the monophenol contributes to the concentration of o-diphenol in the first pseudo-steady-state [D(0)](ss). Hence, the system reaches an initial pseudo-steady state when t-->0 and undergoes a transition phase (lag period) until a final steady state is reached when the concentration of o-diphenol in the medium reaches the concentration of the final steady state [D(f)](ss). These results can be explained by taking into account the kinetic and structural mechanism of the enzyme. In this, tyrosinase hydroxylates the monophenols to o-diphenols, generating an intermediate, E(m)D, which may oxidise the o-diphenol or release it directly to the medium. We surmise that the intermediate generated during the action of E(ox) on monophenols, E(m)D, has axial and equatorial bonds between the o-diphenol and copper atoms of the active site. Since the orbitals are not coplanar, the concerted oxidation-reduction reaction cannot occur. Instead, a bond, probably that of C-4, is broken to achieve coplanarity, producing a more labile intermediate that will then release the o-diphenol to the medium or reunite it diaxially, involving oxidation to o-quinone. The non-enzymatic evolution of the o-quinone would generate the o-diphenol ([D(f)](ss)) necessary for the final steady state to be reached after the lag period.


Asunto(s)
Agaricales/enzimología , Monofenol Monooxigenasa/química , Fenoles/química , Quinonas/química , Catecol Oxidasa/química , Relación Dosis-Respuesta a Droga , Cinética , Levodopa/química , Modelos Químicos , Modelos Teóricos , Monofenol Monooxigenasa/farmacología , Espectrofotometría , Tirosina/química
11.
Biochim Biophys Acta ; 1548(2): 238-56, 2001 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-11513969

RESUMEN

Using gas chromatography-mass spectrometry, the direct enzymatic release of o-diphenol (4-tert-butylcatechol) during the action of tyrosinase on a monophenol (4-tert-butylphenol) has been demonstrated for the first time in the literature. The findings confirm the previously proposed mechanism to explain the action of tyrosinase on monophenols (J.N. Rodríguez-López, J. Tudela, R. Varón, F. García-Carmona, F. García-Cánovas, J. Biol. Chem. 267 (1992)). Oxytyrosinase, the oxidized form of the enzyme with a peroxide group, is the only form capable of catalysing the transformation of monophenols into diphenols, giving rise to an enzyme-substrate complex in the process. The o-diphenol formed is then released from the enzyme-substrate complex or oxidized to the corresponding o-quinone. In order to detect the enzymatic release of o-diphenol, the non-enzymatic evolution of the o-quinone to generate o-diphenol by weak nucleophilic attack reactions and subsequent oxidation-reduction was blocked by the nucleophilic attack of an excess of cysteine. Furthermore, the addition of catalytic quantities of an auxiliary o-diphenol (e.g. catechol) considerably increases the accumulation of 4-tert-butylcatechol. The enzyme acting on 4-tert-butylphenol generates the enzyme-4-tert-butylcatechol complex and 4-tert-butylcatechol is then released (with k(-2)) generating mettyrosinase. The auxiliary o-diphenol added (catechol) and the 4-tert-butylcatechol generated by the enzyme then enter into competition. When [catechol] >> [4-tert-butylcatechol], the enzyme preferentially binds with the catechol to close the catalytic cycle, while 4-tert-butylcatechol is accumulated in the medium. In conclusion, we demonstrate that the enzyme produces 4-tert-butylcatechol from 4-tert-butylphenol, the concentration of which increases considerably in the presence of an auxiliary o-diphenol such as catechol.


Asunto(s)
Catecoles/química , Monofenol Monooxigenasa/química , Fenoles/química , Agaricales , Benzoquinonas/química , Catecoles/farmacología , Cisteína/química , Cisteína/farmacología , Cromatografía de Gases y Espectrometría de Masas/métodos , Cinética , Melanosomas/metabolismo , Modelos Químicos , Modelos Teóricos , Monofenol Monooxigenasa/metabolismo , Oxidación-Reducción
12.
J Clin Pathol ; 58(6): 605-10, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15917411

RESUMEN

BACKGROUND: Ciliated cells in gastrectomies from patients dwelling in the Pacific and Atlantic basins have been reported previously. AIM: To compare all the results in an attempt to explain the findings. METHODS: Sections from 3406 gastrectomies were reviewed: 1966 and 1440 from the Atlantic and Pacific basins, respectively. Ciliated cells and intestinal metaplasia (IM) were recorded; IM was classified into focal or extensive IM. The total number of sections/gastrectomy was noted. RESULTS: In the Atlantic basin, 5% of specimens had ciliated metaplasia (CM); it was more frequent in intestinal carcinoma (IC; 9%) than diffuse carcinoma (DC; 3%) or miscellaneous gastric diseases (MGD; 3%). In the Pacific basin, the frequency of specimens with CM was 29%: it was more frequent in IC (43%) than in DC (16%) or MGD (10%). The difference between the frequency of CM in specimens with IC or with DC/MGD in the Atlantic and the Pacific basins was significant (p < or = 0.05). The presence of CM was influenced by age and the extent of IM in both basins, but not by sex or the number of sections investigated. CONCLUSIONS: CM-apparently an independent microscopic marker-was significantly higher in the Pacific than in the Atlantic basin. Environmental carcinogens involved in the evolution of IM and IC seem to be implicated in gastric ciliogenesis. Carcinogens that differ in nature and/or in strength in both basins might activate the latent natural genes encoding ciliated processes in gastric cells in patients subsequently developing gastric carcinoma, more notably of intestinal type.


Asunto(s)
Cilios/patología , Lesiones Precancerosas/etnología , Gastropatías/etnología , Estómago/patología , Adulto , Factores de Edad , Anciano , Américas/epidemiología , Europa (Continente)/epidemiología , Femenino , Gastrectomía , Mucosa Gástrica/patología , Humanos , Masculino , Metaplasia/etnología , Metaplasia/patología , Persona de Mediana Edad , Islas del Pacífico/epidemiología , Lesiones Precancerosas/patología , Antro Pilórico/patología , Factores Sexuales , Gastropatías/patología , Neoplasias Gástricas/etnología , Neoplasias Gástricas/patología
13.
Biochem J ; 380(Pt 3): 643-50, 2004 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-15025557

RESUMEN

A solvent deuterium isotope effect on the catalytic affinity (km) and catalytic constant (kcat) of tyrosinase in its action on different monophenols and o-diphenols was observed. The catalytic constant decreased in all substrates as the molar fraction of deuterated water in the medium increased, while the catalytic affinity only decreased for the o-diphenols with an R group in C-1 [-H, -CH3 and -CH(CH3)2]. In a proton inventory study of the oxidation of o-diphenols, the representation of kcat fn/kcat f0 against n (atom fractions of deuterium), where kcat fn is the catalytic constant for a molar fraction of deuterium (n) and kcat f0 is the corresponding kinetic parameter in a water solution, was linear for all substrates, indicating that only one of the four protons transferred from the hydroxy groups of the two molecules of substrate, which are oxidized in one turnover, is responsible for the isotope effects, the proton transferred from the hydroxy group of C-4 to the peroxide of the oxytyrosinase form (Eox). However, in the representation of Km fn/Km f0 against n, where Km fn represents the catalytic affinity for a molar fraction of deuterium (n) and Km f0 is the corresponding kinetic parameter in a water solution, a linear decrease was observed as n increased in the case of o-diphenols with the R group [-H, -CH3 and -CH(CH3)2], and a parabolic increase with other R groups, indicating that more than one proton is responsible for the isotope effects on substrate binding. In the case of monophenols with six protons transferred in the catalytic cycle, the isotope effect occurs in the same way as for o-diphenols. In the present paper, the fractionation factors of different monophenols and o-diphenols are described and possible mechanistic implications are discussed.


Asunto(s)
Deuterio/metabolismo , Monofenol Monooxigenasa/metabolismo , Fenoles/metabolismo , Agaricales/enzimología , Proteínas Fúngicas/metabolismo , Isótopos/metabolismo , Oxidación-Reducción
14.
J Clin Epidemiol ; 48(9): 1167-74, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7636519

RESUMEN

Inter-observer variation in cytohistological diagnosis was assessed for 1506 cervical smears and 883 histological slides from four case-control studies on cervical neoplasia. The kappa statistic among a panel of three cytopathologists was highest for diagnosis of invasive cancer (0.70 for cytology and 0.74 for histology), followed by normal/inflammatory in cytology (0.68) and CIN III in histology (0.58). There was also nearly perfect agreement between the final panel diagnoses and the original diagnoses made by local cytopathologists, except for those of CIN III. Inter-observer variation in diagnosis for CIN III was inversely associated with age, number of children (in histology) and sexual activity (in cytology). However, the odds ratios for CIN III calculated by each cytopathologist's diagnosis were not different from each other for any etiologic factor. These results indicate that the diagnoses of invasive cancer and of normal/inflammatory changes are highly reproducible and that the inter-observer variation does not have much impact on the etiologic risk estimates.


Asunto(s)
Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/patología , Adulto , Femenino , Humanos , Persona de Mediana Edad , Variaciones Dependientes del Observador , Paridad , Fumar , España/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Frotis Vaginal , Displasia del Cuello del Útero/epidemiología
15.
Int J Epidemiol ; 27(3): 370-6, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9698122

RESUMEN

BACKGROUND: This study presents the evaluation of the Mexico City Cervical Cancer Screening Programme (CCSP). Uterine cervical cancer (CC) is still a major public health problem in Mexico. Various actions aimed at reducing mortality from CC have been unsuccessful with an estimated 62000 deaths reported between 1980 and 1995. METHODS: The authors performed a study of cases and controls chosen on a population basis that included a sample of 233 cases of cancer in situ, and 397 cases of invasive cervical cancer obtained from eight hospitals, and a sample of 1005 controls representative of the general population. The results are presented stratified by case type, classified according to whether the cancer is invasive or not. RESULTS: The results show low impact of the cervical cancer screening programme in Mexico. Women who had a history of use of the Papanicolaou smear (PAP), who did not seek testing due to gynaecological symptoms and who had received their PAP results, had a 2.63 times lower risk of developing invasive cervical cancer (OR = 0.38; 95% CI: 0.28-0.52). CONCLUSIONS: The principal findings of this study in relation to the low impact of the screening programme in Mexico, are the low level of existing coverage and late use of health services by women at risk.


Asunto(s)
Países en Desarrollo , Tamizaje Masivo/estadística & datos numéricos , Neoplasias del Cuello Uterino/mortalidad , Adolescente , Adulto , Anciano , Carcinoma in Situ/diagnóstico , Carcinoma in Situ/mortalidad , Carcinoma in Situ/patología , Estudios de Casos y Controles , Causas de Muerte , Estudios Transversales , Femenino , Humanos , Incidencia , México/epidemiología , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Prueba de Papanicolaou , Factores de Riesgo , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Frotis Vaginal/estadística & datos numéricos
16.
Am J Clin Pathol ; 96(3): 330-3, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1877529

RESUMEN

Histologic sections of 205 gastrectomy specimens, which were obtained for benign and malignant diseases, were reviewed. All patients were Mexican nationals. The following histologic features were recorded: intestinal metaplasia, intramucosal cysts, ciliated gastric cells, and different types of pyloric cells ("ordinary"; with granular cytoplasm; with small cytoplasmic vacuoles; with large cytoplasmic vacuoles; or with homogeneous "glassy" cytoplasm). The percentage of specimens showing intestinal metaplasia was similar in those containing gastric ulcers (42.7%) or adenocarcinomas (50.0%). Intestinal metaplasia was decreased in men 59 years of age or older and in women 69 years of age or older. Diffuse-type adenocarcinoma accounted for 90% of the gastric tumors. Only 3 of the 205 specimens (1.9%) contained intramucosal cysts, and only 1 (0.4%) showed ciliated cells. Pyloric cells with granular cytoplasm were observed in 21.2% of the specimens, and pyloric cells with small cytoplasmic vacuoles were seen in 1.9%. Pyloric cells with large vacuoles or "glassy" cytoplasm were not found in any case. These results indicate differences in the proportions of several histopathologic findings in the gastric mucosa, between Mexicans and other ethnic groups that have been investigated in previous surveys. The authors' findings support the hypothesis that different environmental factors, acting in disparate geographic regions, may account for dissimilarities in the histologic appearance of "normal gastric mucosa."


Asunto(s)
Mucosa Gástrica/patología , Gastropatías/patología , Neoplasias Gástricas/patología , Adolescente , Adulto , Factores de Edad , Anciano , Niño , Quistes/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Píloro/patología , Caracteres Sexuales
17.
Biophys Chem ; 84(1): 65-76, 2000 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-10723545

RESUMEN

Tyrosinase hydroxylates 3-hydroxyanisole in the 4-position. The reaction product accumulates in the reaction medium with a lag time (tau) which diminishes with increasing concentrations of enzyme and lengthens with increasing concentrations of substrate, thus fulfilling all the predictions of the mechanism proposed by us for 4-hydroxyphenols. The kinetic constants obtained, kcatM = (46.87 +/- 2.06) s-1 and KmM = (5.40 +/- 0.60) mM, are different from those obtained with 4-hydroxyanisole, kcatM = (184.20 +/- 6.1) s-1 and KmM = (0.08 +/- 0.004) mM. The catalytic efficiency, kcatM/KmM is, therefore, 265.3 times greater with 4-hydroxyanisole. The possible rate-determining steps for the reaction mechanism of tyrosinase on 3- and 4-hydroxyanisole, based on the NMR spectra of both monophenols, are discussed. These possible rate-determining steps are the nucleophilic attack of hydroxyl's oxygen on the copper and the electrophilic attack of the peroxide on the aromatic ring. Both steps may be of similar magnitude, i.e. take place in the same time scale.


Asunto(s)
Anisoles/metabolismo , Monofenol Monooxigenasa/metabolismo , Agaricales/enzimología , Benzotiazoles , Catálisis , Hidrazonas , Hidroxilación , Isomerismo , Cinética , Resonancia Magnética Nuclear Biomolecular , Oxidación-Reducción , Tiazoles
18.
Diagn Cytopathol ; 10(1): 10-4, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8005035

RESUMEN

An external evaluation of the quality of diagnosis of gynecological cytology specimens (Papanicolaou or "Pap" tests) in the Cytopathological Laboratory at the Mexico General Hospital was performed, with evaluation of 6,011 Pap tests randomly selected from 31,378 Pap studies previously reported as negative during 1988-1989. These tests were part of the early detection program for cervical cancer run by the Ministry of Health of Mexico City. A quality index for specimens was constructed based on the presence of endocervical cells, mucus, and squamous metaplastic cells. The index of false negatives for the diagnosis of cervical neoplasm in this sample which correspond to diagnostic error by the examiner was 0.18% (11). The constructed quality index revealed that 64.1% of specimens were low quality. The correlation between diagnostic error and low quality was .87. Results indicate that laboratories participating in early detection programs for cervical cancer in developing countries need to implement (1) external evaluation programs for Pap diagnosis; (2) permanent training programs in registration; and (3) monitoring procedures for collection, fixation, and transportation of cytologic materials.


Asunto(s)
Prueba de Papanicolaou , Frotis Vaginal/normas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , México , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Control de Calidad , Reproducibilidad de los Resultados
19.
Intensive Crit Care Nurs ; 9(1): 28-39, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8485348

RESUMEN

Biopsychosocial being is now accepted in nursing as a term which can be used to describe any human being. This is an account of what it means, illustrated in the life of one person. Pilar Arcas Ruiz is a Spanish nurse who left medical education to train as a nurse, but later completed the requirements for medical qualification in order to use it when necessary to advance nursing in Spain.


Asunto(s)
Cuidados Críticos/psicología , Enfermeras y Enfermeros/psicología , Estado Asmático/psicología , Adulto , Femenino , Humanos , Estado Asmático/enfermería
20.
Rev Invest Clin ; 49(2): 111-6, 1997.
Artículo en Español | MEDLINE | ID: mdl-9380963

RESUMEN

OBJECTIVE: To evaluate the diagnostic agreement in Papanicolaou of pathologists and cytotechnologists using kappa values for concordancy. METHODS: The diagnostic variation was estimated in 20 gynecological cytology (Pap) specimens by 30 pathologists and 7 cytotechnologists attending the XXXVII Congress of the Mexican Association of Pathologists in 1994. RESULTS: The best concordancy versus an expert was in tumoral diathesis (pathologists' kappa = 0.36; cytotechnologists' kappa = 0.35) and kollocytos (pathologists' kappa = 0.55; cytotechnologists' kappa = 0.36). The least concordancy was observed in anisonucleosis (pathologists' kappa = 0.11; cytotechnologists' kappa = 0.02), nuclear hyperchromasia (pathologists' and cytotechnologists' kappa = 0.11) and dyskeratosis (pathologists' kappa = 0.11; cytotechnologists' kappa = 0.16). The kappa values for cervical neoplasia showed poor agreement, and in invasive cervical cancer it was 0.30. CONCLUSIONS: There was a low concordancy of Pap diagnosis in the study. It is convenient to try to improve the concordancy of cytologic diagnosis in Mexico. One strategy could be the use of a uniform diagnostic criteria and the adoption of a single nomenclature.


Asunto(s)
Prueba de Papanicolaou , Enfermedades del Cuello del Útero/diagnóstico , Frotis Vaginal , Carcinoma/diagnóstico , Carcinoma/patología , Núcleo Celular/ultraestructura , Cuello del Útero/citología , Femenino , Humanos , México , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Enfermedades del Cuello del Útero/clasificación , Enfermedades del Cuello del Útero/patología , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Frotis Vaginal/normas , Frotis Vaginal/estadística & datos numéricos
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