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1.
Eur Rev Med Pharmacol Sci ; 25(24): 7654-7667, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34982427

RESUMO

Cervical cancer is characterized by the cellular transformation caused by Human Papillomavirus (HPV), favoring cell proliferation, migration, invasion, and metastasis. Cervical cancer is conventionally treated with radiation therapy, and chemotherapy focused on the destruction of tumor cells. However, chemoresistance and low selectivity between tumor and non-tumor cells have been reported, causing side effects in patients. Metabolites of natural origin have shown selectivity against tumor cells, suggesting their use for reducing the side effects caused by drugs used in conventional therapy. Among these compounds, several natural coumarins stand out, such as auraptene, scopoletin, osthole, and praeruptorin, of which antiproliferative, anti-migratory, and anti-invasive activity have been reported. Auraptene, scopoletin, osthole, and praeruptorin show a cytotoxic or antiproliferative effect on cervical tumor cells, arresting the cell cycle by inducing the overexpression of negative regulators of the cell cycle, or inducing cell death by increasing the expression of pro-apoptotic proteins and decreasing that of anti-apoptotic proteins. On the other hand, auraptene, scopoletin, and praeruptorin inhibit the capacity for migration, invasion, and metastasis of cervical tumor cells, mainly by inhibiting the expression and activity of matrix metalloproteinase-2 and -9. The PI3K/Akt signal pathway appears to be central to the anti-tumor activity of the coumarins analyzed in this review. In addition, auraptene, osthole, and praeruptorin are useful in sensitizing tumor cells to radiotherapy or chemotherapeutic molecules, such as FOLFOX, cisplatin, or DOX. Coumarins offer an excellent possibility for developing new drugs as complementary medicine with an integrative approach against cervical cancer.


Assuntos
Antineoplásicos/uso terapêutico , Cumarínicos/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Terapias Complementares , Cumarínicos/farmacologia , Feminino , Humanos
2.
Medwave ; 20(2): e7830, 31-03-2020.
Artigo em Inglês, Espanhol | LILACS | ID: biblio-1097789

RESUMO

Los feocromocitomas y paragangliomas son tumores neuroendocrinos raros, caracterizados por una alta tasa de morbilidad debida a un exceso de niveles de catecolaminas. Este exceso de catecolaminas es independiente de los estresores fisiológicos. Para el diagnóstico de un feocromocitoma-paraganglioma son fundamentales las pruebas bioquímicas. Las más utilizadas son las metanefrinas fraccionadas urinarias o metanefrinas libres plasmáticas. Seguido del diagnóstico bioquímico, debe realizarse un estudio imagenológico. La evaluación del paciente con diagnóstico de feocromocitoma-paraganglioma debe realizarse teniendo presente sus principales causas de morbimortalidad perioperatoria. Las dos grandes intervenciones que han disminuido la mortalidad perioperatoria son la introducción del α bloqueo y la restauración de la volemia. El otro gran avance ha sido la introducción de la cirugía laparoscópica como el estándar de oro para el abordaje quirúrgico. En relación con el manejo intraoperatorio, no se ha identificado que alguna técnica anestésica sea superior a otra. Sí se ha logrado establecer criterios de inestabilidad hemodinámica que se correlacionan con mayor morbilidad, por lo que los principales objetivos intraoperatorios son mantener estabilidad hemodinámica. El avance en el manejo preoperatorio e intraoperatorio con la consecuente disminución en la mortalidad relacionada a esta patología ha llevado el foco al manejo postoperatorio tanto agudo como a largo plazo. También se debe considerar el riesgo de recurrencia tumoral, por lo que estos pacientes deben tener un control anual de por vida.


Pheochromocytomas and paragangliomas are rare neuroendocrine tumors, characterized by a high morbidity rate due to catecholamine excess. These high levels are independent of physiologic stressors. For the diagnosis, a biochemical workup is paramount. The most widely used are plasma-free metanephrines and urinary fractionated metanephrines. Imaging studies should be initiated once the biochemical diagnosis is established. Evaluation of the patient with pheochromocytomas and paragangliomas must be done taking into account the leading causes of perioperative morbidity and mortality. The two primary interventions that have reduced perioperative mortality are alpha-adrenergic blockade and intravascular volume normalization. Another significant advance has been the establishment of laparoscopic surgery as the gold standard for the surgical approach. No anesthetic technique has been found to be superior to another. Intraoperative hemodynamic instability has been correlated with poorer outcomes; thus one of the main intraoperative goals is maintaining hemodynamic stability. Lower morbidity and almost zero mortality rates due to preoperative and intraoperative management improvements have led to a focus on the immediate and long-term postoperative care. Anual lifelong follow-up is recommended to detect recurrent disease.


Assuntos
Humanos , Paraganglioma/cirurgia , Feocromocitoma/cirurgia , Neoplasias das Glândulas Suprarrenais/cirurgia , Laparoscopia
3.
Rev. cir. (Impr.) ; 71(2): 173-177, abr. 2019. graf
Artigo em Espanhol | LILACS | ID: biblio-1058252

RESUMO

OBJETIVO: Se presentan 3 casos de obstrucción intestinal por hernia obturatriz atascada, su manejo y una breve revisión de la literatura. MATERIALES Y MÉTODOSles y Métodos: Discusión del cuadro clínico, imágenes y manejo. Todos los casos fueron operados dentro del mismo día del diagnóstico y se confirmó la presencia de hernia obturatriz. El manejo de la hernia y su contenido fue ajustado a la situación de cada paciente. RESULTADOS: Los tres casos de hernia obturatriz aquí discutidos tienen la presentación clásica del cuadro, cuando se los revisa en forma retrospectiva y con imagenología compatible. Los tres pacientes evolucionaron en forma satisfactoria con alta precoz y control posoperatorio sin incidentes. Discusión: Nuestros 3 casos se condicen tanto en hallazgos clínicos, imagenológicos y en manejo con lo descrito en la literatura internacional. CONCLUSIÓN: La hernia del agujero obturatriz siendo infrecuente, se presenta en un tipo particular de pacientes y con sintomatología clásica. La tomografía axial computada es de gran ayuda y suele hacer el diagnóstico preciso en el preoperatorio. Es importante recordar este diagnóstico diferencial al momento de estudiar pacientes con obstrucción intestinal.


OBJECTIVE: 3 cases of intestinal obstruction that resulted in diagnosis of obturator hernia, their management and a brief international literature review are presented. MATERIAL AND METHODS: Discussion of the presentation, images, and management. In all cases surgery was performed the same day from the diagnosis of intestinal obstruction and confirmation of obturator hernia. The management of the hernia and it's content was adjusted to each patient's situation. RESULTS: Our 3 patients, when reviewed retrospectively, had the classic presentations and images of obturator hernia. All of them had a favourable evolution with an early discharge and no complications on follow up. DISCUSSION: Our 3 cases had clinical presentations and imaging studies that correlated well with international literature. CONCLUSION: Obturator hernia is an infrequent pathology, but appears in a particular type of patient and with classic presentation. Axial computed tomography is an important tool and usually makes the diagnosis previously to surgical exploration. It is important to consider this diagnosis when being faced with patients with intestinal obstruction.


Assuntos
Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Hérnia do Obturador/cirurgia , Hérnia do Obturador/complicações , Obstrução Intestinal/cirurgia , Obstrução Intestinal/etiologia , Hérnia do Obturador/diagnóstico por imagem , Obstrução Intestinal/diagnóstico por imagem
4.
Rev. argent. dermatol ; Rev. argent. dermatol;99(1): 1-10, mar. 2018. ilus
Artigo em Espanhol | LILACS | ID: biblio-897398

RESUMO

El pioderma gangrenoso (PG), es una patología ulcerativa infrecuente de etiología desconocida, asociado ocasionalmente a enfermedades autoinmunes. Es una condición crónica, de curso clínico impredecible y puede ser invalidante. Al ser complejo su diagnóstico, el retraso del mismo puede ocasionar al paciente morbilidades añadidas, como: tratamientos incorrectos y períodos de hospitalizaciones prolongados. Se presenta el caso de un paciente de 52 años, sin antecedentes mórbidos, que ingresa a Urgencias en el Hospital el Pino, por dolor abdominal recurrente. Durante el estudio de imágenes se evidencia una masa retroperitoneal, asociada a hidro-uretero-nefrosis izquierda. Ingresa al Servicio de Cirugía para estudio, realizándose una laparotomía media exploratoria y toma de muestras para biopsia. Procedimiento realizado sin incidentes. El paciente pese a múltiples tratamientos otorgados en esa unidad, evoluciona con dehiscencia de suturas recurrentes por tres meses. Evaluado por Dermatología se inicia estudio y se diagnostica PG, teniendo una excelente respuesta al tratamiento indicado.


Gangrenous pioderma (PG) is an uncommon ulcerative pathology of unknown etiology associated with autoimmune diseases. It is a non-predictable chronic condition, that can be incapacitating and patients that suffer this disease can also present systemic compromise. As it is a diagnosed by exclusion it may lead to long periods of failed treatments. The present work deals with a case of a 52-year-old male patient with no prior record of disease, who was admitted to the ER of El Pino Hospital suffering from recurrent abdominal pain. During the imaging study a retroperitoneal mass was found, associated with a left hydro-uretero-nephrosis. He was admitted and a exploratory mid-laparotomy was performed and samples were taken for biopsy. The procedure was successful and the established protocol was followed. However, during the recovery period the patient developed repeated surgical wound dehiscences of the surgical wounds. An internal consultation with the Dermatology Service took place, and the diagnosis of PG was made; proper pharmaceutical treatment was provided attaining excellent results.

5.
Rev. argent. dermatol ; Rev. argent. dermatol;98(1): 21-26, mar. 2017. ilus
Artigo em Espanhol | LILACS | ID: biblio-843109

RESUMO

El pénfigo familiar benigno o enfermedad de Hailey Hailey, es una genodermatosis vesico-ampollar autosómica dominante, con penetrancia incompleta y expresividad variable de presentación infrecuente. Se presenta el caso de un paciente con un cuadro de cinco años de evolución, caracterizado por lesiones vesiculares intertriginosas, de olor desagradable, con mala respuesta al tratamiento tópico con antifúngicos y corticoides. Se realiza biopsia de piel compatible con pénfigo de Hailey Hailey, el que fue manejado con antibióticoterapia y corticoides sistémicos, evolucionando favorablemente.


The benign familial pemphigus or Hailey Hailey´s disease is a rare autosomal dominant disorder. We present the clinical case of a patient with a five years history, characterized by vesicular intertriginous malodorous lesions with poor response to topical antifungal therapy. Skin biopsy it was compatible with Hailey Hailey´s disease which was managed with antibiotic therapy and systemic corticosteroids. The patient evolved favorably.


Assuntos
Humanos , Masculino , Idoso , Pênfigo Familiar Benigno/patologia , Intertrigo/patologia , Pele/patologia , Biópsia , Doença Crônica , Pênfigo Familiar Benigno/diagnóstico , Diagnóstico Diferencial , Intertrigo/diagnóstico
6.
Metallomics ; 8(1): 108-17, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26560799

RESUMO

Mercury salts and tellurite are among the most toxic compounds for microorganisms on Earth. Bacterial mercury resistance is established mainly via mercury reduction by the mer operon system. However, specific mechanisms underlying tellurite resistance are unknown to date. To identify new mechanisms for tellurite detoxification we demonstrate that mercury resistance mechanisms can trigger cross-protection against tellurite to a group of Pseudomonads isolated from the Chilean Antarctic territory. Sequencing of 16S rRNA of four isolated strains resulted in the identification of three Pseudomonads (ATH-5, ATH-41 and ATH-43) and a Psychrobacter (ATH-62) bacteria species. Phylogenetic analysis showed that ATH strains were related to other species previously isolated from cold aquatic and soil environments. Furthermore, the identified merA genes were related to merA sequences belonging to transposons commonly found in isolated bacteria from mercury contaminated sites. Pseudomonas ATH isolates exhibited increased tellurite resistance only in the presence of mercury, especially ATH-43. Determination of the growth curves, minimal inhibitory concentrations and growth inhibition zones showed different tellurite cross-resistance of the ATH strains and suggested a correlation with the presence of a mer operon. On the other hand, reactive oxygen species levels decreased while the thiol content increased when the isolates were grown in the presence of both toxicants. Finally, qPCR determinations of merA, merC and rpoS transcripts from ATH-43 showed a synergic expression pattern upon combined tellurite and mercury treatments. Altogether, the results suggest that mercury could trigger a cell response that confers mercury and tellurite resistance, and that the underlying mechanism participates in protection against oxidative damage.


Assuntos
Mercúrio/toxicidade , Pseudomonas/efeitos dos fármacos , Pseudomonas/isolamento & purificação , Telúrio/toxicidade , Regiões Antárticas , Chile , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Geografia , Testes de Sensibilidade Microbiana , Fenótipo , Filogenia , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Compostos de Sulfidrila/metabolismo
8.
Arch Virol ; 160(8): 1909-21, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26026955

RESUMO

In Argentina, classical vaccines are used to control infectious bursal disease virus (IBDV); however, outbreaks of IBDV are frequently observed. This could be due to failures in the vaccination programs or to the emergence of new strains, which would be able to break through the protection given by vaccines. Hence, genetic characterization of the viruses responsible for the outbreaks that occurred in recent years is crucial for the evaluation of the control programs and the understanding of the epidemiology and evolution of IBDV. In this study, we characterized 51 field samples collected in Argentina (previously identified as IBDV positive) through the analysis of previously identified apomorphic sequences. Phylogenetic analysis of regVP2 showed that 42 samples formed a unique cluster (Argentinean lineage), seven samples were typical classical strains (one of them was a vaccine strain), and two belonged to the very virulent lineage (vvIBDV). Interestingly, when the analysis was performed on the regVP1 sequences, the field samples segregated similarly to regVP2; thus, we observed no evidence of a reassortment event in the Argentinean samples. Amino acid sequence analysis of regVP2 showed a particular pattern of residues in the Argentinean lineage, particularly the presence of T272, P289 and F296, which had not been reported before as signature sequences for any IBDV phenotype. Notably, the residue S254, characteristic of the antigenic variant, was not present in any of the Argentinean samples.


Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Argentina/epidemiologia , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Galinhas , Surtos de Doenças , Vírus da Doença Infecciosa da Bursa/química , Vírus da Doença Infecciosa da Bursa/classificação , Dados de Sequência Molecular , Filogenia , Doenças das Aves Domésticas/epidemiologia , Alinhamento de Sequência , Proteínas Estruturais Virais/química , Proteínas Estruturais Virais/genética , Virulência
9.
Gac. méd. boliv ; 37(2): 83-86, dic. 2014. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: lil-737929

RESUMO

Objetivos: determinar la prevalencia de metástasis óseas, evaluando la predominancia respecto al género, grupo etáreo, e identificar la frecuencia de los tipos de cáncer primario. Métodos: la presente investigación es de tipo, descriptiva, retrospectiva, transversal que considero una muestra de 1593 estudios de gammagrafías óseas realizados con MDP 99mTc en el Centro de Medicina Nuclear Cochabamba durante el periodo 2009 al 2013. Resultados: la prevalencia de metástasis ósea obtenida fue de 24,7%, siendo el género masculino (65%) el grupo más afectado respecto al femenino (35%). El grupo etáreo con mayor número de casos fue el de 61-70 años. Con relación al cáncer de origen primario se obtuvieron los siguientes datos: próstata (59,3%); mama (26,2%), pulmón (4,6%), cáncer cérvicouterino (1,7%), mieloma múltiple (1,7%); sarcoma (1,4%); riñón (1,1%), colon (0,9%) y otros (3,1%). Conclusiones: se obtuvo una prevalencia de metástasis óseas en la cuarta parte de la población, donde el género masculino fue más afectado. El grupo etáreo con mayor cantidad de neoplasias estuvo en la población adulta a partir de los 61 años. Finalmente en nuestro estudio el cáncer de origen primario con mayor frecuencia fue el de próstata, seguido de mama y pulmón respecto a otros.


Objectives: to determine the prevalence of bone metastases, assessing the predominance respect to gender, age group, and to identify the frequency of primary cancers. Methods: this research type is descriptive, retrospective; I consider a cross-sample of 1593 studies performed bone scans with 99mTc MDP in the Nuclear Medicine Center Cochabamba during the period 2009 to 2013. Results: the prevalence of bone metastases obtained was 24.7%, male gender (65%) being the most affected compared to women (35%) group. The age group with the highest number of cases was 61-70 years. Relative to the source primary cancer the following data were obtained: prostate (59.3%); breast (26.2%), lung (4.6%), cervical cancer (1.7%), myeloma multiple (1.7%); sarcoma (1.4%); kidney (1.1%), colon (0.9%) and others (3.1%). Conclusions: the prevalence of bone metastases in a quarter of the population, where the male was most affected was obtained. The age group with the highest number of tumors were in the adult population aged 61 years. Finally, in our study the primary origin of cancer was most frequent prostate, breast and lung followed over others.


Assuntos
Metástase Neoplásica
10.
Transplant Proc ; 46(9): 3064-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25420823

RESUMO

BACKGROUND: Hematopoietic progenitor cell transplantation is considered a standard-of-care treatment for defined hematological and non-hematological conditions affecting bone marrow-derived cells. METHODS: Patients and potential donors are HLA typed for their HLA-A, -B, -C, -DRB1, and -DQB1 alleles. The best allogeneic donor is one for which each allele matches the patient at HLA-A, -B, -C, and -DRB1 (8/8). For patients with no related donor, the transplant physician will start a search for unrelated donors. The search is performed through a local registry and often includes the search for donors worldwide. The Argentinean HPC Donors Registry was established in 2003. Our National HPC Donor Registry has already typed more than 31,000 donors for HLA-A, -B, and -DR. RESULTS: We present the analysis of HLA frequencies and haplotypes estimates for the subset of our donor database that is additionally typed for HLA-C. We analyzed HLA data from 2657 donors. Antigen and haplotype frequencies were estimated through the use of expectation maximization. CONCLUSIONS: Our analysis showed for the first time the antigenic HLA frequency distribution from HPC donors in Argentina. Knowing haplotype frequencies in our population will help us to select potential donors for high-resolution typing for the patients.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Doadores de Tecidos , Adulto , Argentina , Feminino , Frequência do Gene , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C , Haplótipos , Teste de Histocompatibilidade , Humanos , Masculino , Sistema de Registros
11.
Rev Med Chil ; 142(2): 153-60, 2014 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-24953102

RESUMO

BACKGROUND: There is increasing interest in the study and improvement of health system resource allocation. The Adjusted Clinical Groups (ACG) System measures the morbidity burden of patient populations based on disease patterns, age and gender. This system can be used in primary health care settings. AIM: To report the use of the ACG system as a risk based patient classification system and its potential as a resource allocation mechanism in primary health care. MATERIAL AND METHODS: Patient diagnoses from a sample of primary care establishments were processed using the Johns Hopkins ACG System. Linear regressions were used to measure the ACG System's ability to explain resource use and ambulatory visit rates. RESULTS: The ACG System had a statistically significant capacity to explain primary health care costs with an adjusted R² of 0.26. These results are significantly better, compared with risk assessment models based on patients' age and sex, whose adjusted R² is 0.05. CONCLUSIONS: The use of risk adjustment mechanisms will contribute to improve health care resource allocation as well to know the disease profile of the population.


Assuntos
Grupos Diagnósticos Relacionados , Atenção Primária à Saúde/economia , Alocação de Recursos , Chile , Feminino , Humanos , Modelos Lineares , Masculino , Projetos Piloto , Medição de Risco
12.
Rev. méd. Chile ; 142(2): 153-160, feb. 2014. tab
Artigo em Espanhol | LILACS | ID: lil-710982

RESUMO

Background: There is increasing interest in the study and improvement of health system resource allocation. The Adjusted Clinical Groups (ACG) System measures the morbidity burden of patient populations based on disease patterns, age and gender. This system can be used in primary health care settings. Aim: To report the use of the ACG system as a risk based patient classification system and its potential as a resource allocation mechanism in primary health care. Material and Methods: Patient diagnoses from a sample of primary care establishments were processed using the Johns Hopkins ACG System. Linear regressions were used to measure the ACG System's ability to explain resource use and ambulatory visit rates. Results: The ACG System had a statistically significant capacity to explain primary health care costs with an adjusted R² of 0.26. These results are significantly better, compared with risk assessment models based on patients' age and sex, whose adjusted R² is 0.05. Conclusions: The use of risk adjustment mechanisms will contribute to improve health care resource allocation as well to know the disease profile of the population.


Assuntos
Feminino , Humanos , Masculino , Grupos Diagnósticos Relacionados , Atenção Primária à Saúde/economia , Alocação de Recursos , Chile , Modelos Lineares , Projetos Piloto , Medição de Risco
13.
J Fish Biol ; 82(1): 286-305, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23331151

RESUMO

The diet and diel feeding behaviour of the banded guitarfish Zapteryx xyster were examined along the Pacific coast of Costa Rica. A sample of 235 stomachs was collected between March 2010 and December 2011 as part of an ongoing shrimp-trawl by-catch monitoring programme. Samples from multiple day and night periods allowed testing the hypothesis that Z. xyster is more active at night, thus increasing the amount of food intake during night-time. Overall, shrimps (52·3% prey-specific index of relative importance, P(SIRIi) ) and teleosts (27·2% P(SIRIi) ) were the most important prey categories. Juveniles fed primarily on smaller shrimps (Solenocera spp.), while adults shifted to larger prey. The amount of food consumed (as % of bodymass) by juvenile and adult Z. xyster increased significantly between 0400 and 1200 hours, while the proportion of empty stomachs decreased during the same time interval. These findings contradict the hypothesis that Z. xyster is more active and feeds at night. The study also revealed that Z. xyster, particularly juveniles, forage on several shrimp species and overlap spatially with the Costa Rican bottom-trawl fisheries. This has important management and conservation implications as Z. xyster may be experiencing high by-catch rates, and because of their life history is presumed to be vulnerable to intense levels of exploitation.


Assuntos
Dieta , Comportamento Alimentar/fisiologia , Rajidae/fisiologia , Animais , Costa Rica , Conteúdo Gastrointestinal
14.
J Fish Biol ; 81(5): 1578-95, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23020562

RESUMO

Stomachs from 511 Raja velezi and 340 Mustelus henlei captured as by-catch in the commercial trawling fishery (2010-2012) were analysed to examine diet composition, ontogenetic shifts and degree of dietary overlap between species life stages in the Pacific Ocean of Costa Rica. Shrimps were the most important prey categories in the diet of R. velezi, while teleosts and cephalopods dominated the diet of M. henlei. Diet comparisons between different stages of R. velezi and M. henlei revealed clear ontogenetic dietary shifts: crustaceans (mainly shrimps, crabs and stomatopods) dominated the diet of immature individuals, and adults had a higher proportion of teleosts. The results suggest that R. velezi is an epibenthic predator that specializes in shrimps during early life stages, and to a lesser extent, teleosts as it matures, while M. henlei is an opportunistic predator with a highly diverse diet consisting of teleosts, cephalopods, shrimps and stomatopods. This study also found little evidence of dietary overlap between species or life stages and suggests that intra- and interspecific competition between R. velezi and M. henlei may be reduced by: (1) diet specialization in immature stages of R. velezi, (2) ontogenetic dietary shifts between immature and mature individuals, (3) prey-size selectivity in larger individuals of R. velezi and (4) differences in depth utilization in overlapping geographical regions.


Assuntos
Dieta , Comportamento Alimentar/fisiologia , Tubarões/fisiologia , Rajidae/fisiologia , Animais , Costa Rica , Cadeia Alimentar , Conteúdo Gastrointestinal , Oceano Pacífico
15.
J Phys Condens Matter ; 24(13): 135502, 2012 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-22406934

RESUMO

We study the effect of Rashba spin-orbit coupling on the Hofstadter spectrum of a two-dimensional tight-binding electron system in a perpendicular magnetic field. We obtain the generalized coupled Harper spin-dependent equations which include the Rashba spin-orbit interaction and solve for the energy spectrum and spin polarization. We investigate the effect of spin-orbit coupling on the fractal energy spectrum and the spin polarization for some characteristic states as a function of the magnetic flux α and the spin-orbit coupling parameter. We characterize the complexity of the fractal geometry of the spin-dependent Hofstadter butterfly with the correlation dimension and show that it grows quadratically with the amplitude of the spin-orbit coupling. We study some ground state properties and the spin polarization shows a fractal-like behavior as a function of α, which is demonstrated with the exponent close to unity of the decaying power spectrum of the spin polarization. Some degree of spin localization or distribution around +1 or -1, for small spin-orbit coupling, is found with the determination of the entropy function as a function of the spin-orbit coupling. The excited states show a more extended (uniform) distribution of spin states.


Assuntos
Elétrons , Magnetismo , Algoritmos , Eletroquímica , Modelos Estatísticos , Marcadores de Spin
16.
Kasmera ; 39(1): 59-67, ene.-jun. 2011. tab, graf
Artigo em Espanhol | LILACS | ID: lil-654000

RESUMO

Los establecimientos de atención en salud son entornos donde se congregan pacientes que en menor o mayor grado presentan compromisos inmunológicos. En este contexto, el ambiente hospitalario resulta un espacio donde podrían adquirir infecciones nosocomiales con el consiguiente deterioro del cuadro clínico preexistente. En el presente estudio se realizaron evaluaciones en ambientes hospitalarios de centros de salud ubicados en la ciudad de Valencia, Venezuela, tomando en cuenta áreas críticas como quirófanos. Para la captación de las muestras se tomó en cuenta las metodologías establecidas en las Normas Técnicas Españolas. La captación del aire sobre los medios de cultivo Nutritivoy Sabouraud se incubaron a 37°C de 24-72 horas, para determinar UFC/m3 de aire. Conjuntamente se midió la temperatura y humedad relativa. La identificación microbiológica se realizó utilizando galerias bioquímicas automatizadas (API). De los 6 centros hospitalarios evaluados, 5 quirófanos presentaron más de 10 UFC/m3 de aerobios mesófilos y más de 20 UFC/m3 de población fúngica, cuyo rango debería ser menor a 10UFC/m3. Los microorganismos identificados con mayor frecuencia fueron: Staphylococcus spp, Pseudomonas aeruginosa, Bacillus spp., Acinetobacter lowfii, Aspergillus nidulans, A. terreus y Geotrichum candidum. Las medidas de temperatura fueron mayores a 20°C y la humedad relativa mayor a 45%, siendo el rango establecido por la NTP 409 para la temperatura entre 15-18°C, y 50-70% en cuanto a la humedad relativa. Se infiere que existe poco compromiso en aplicar las medidas correctas para cumplir a cabalidad con las normas de manipulación de pacientes en áreas críticas, lo que propicia un entorno favorable para el desarrollo microbiano, además de factores como temperatura, humedad relativa, sistemas de climatización, que no cumplen con lo indicado según las normas técnicas Internacionales


Health center facilities are areas where patients who have a greater or lesser degree of immunological compromise congregate. In this context, the hospital environment is a space where nosocomial diseases could be acquired causing deterioration of the preexistent clinical condition. This study carried out evaluations in hospital environments at health centers in the city of Valencia, Venezuela, taking into account critical areas such as operating theatres. For sample collection, methodologies established by the Spanish Technical Standards were taken into account. The air samples taken over Nutritivo and Sabouraud cultivation media were incubated at 37°C for 24-72 hours, to determine the UFC/m3 for the air. Following a 24-hour incubation at 37°C, the bacterial charges (UFC/m3) were determined. Additionally, temperature and relative humidity were measured. Taxonomical identification was achieved through a computerized biochemical test (API galleries). Five out of the six health centers evidenced more than 10UFC/m3 and 20 UFC/m3 for the bacterial and fungal charges, respectively. These values are higher than those allowed by official legislation. The most frequently detected microorganisms were Staphylococcus spp, Pseudomonas aeruginosa, Bacillus spp., Acinetobacter lowfii, Aspergillus nidulans, A. terreus and Geotrichum candidum. The temperature and relative humidity were always higher than 20°C and 45%, whereas ranges established by the NTP 409 norm are 15-18ºC and 50-70%, respectively. It seems there is little commitment to applying correct measures to comply fully with standards for patient handling in critical areas, favoring an environment conducive to microbial development, as well as factors such as temperature, relative humidity and air conditioning systems, which do not comply with what is indicated in international technical standards


Assuntos
Poluição do Ar , Aerossóis/efeitos da radiação , Aerossóis/toxicidade , Qualidade Ambiental/prevenção & controle , Meio Ambiente , Centros de Saúde
17.
Rev Clin Esp ; 211(7): e37-41, 2011.
Artigo em Espanhol | MEDLINE | ID: mdl-21524743

RESUMO

BACKGROUND: Calcific uremic arteriolopathy is defined as a syndrome consisting of ischemic skin ulceration due to calcification of the wall of the arterioles of the subcutaneous tissue as a result of hyperparathyroidism in uremic patients. CASE REPORT: A 55-year old female patient, hypertense, with heart failure and kidney failure treated with hemodialysis, who presented lower limb pain and hypercalcemia. On physical examination, skin lesions with symmetrical peripheral pulses present in the limbs. Laboratory tests revealed hypercalcemia, hyperphosphatemia, and very high parathyroid hormone levels. Parathyroidectomy was performed and biopsy of skin lesions, the patient having a torpid course causing exitus. Autopsy was performed, with histologic features characteristic of calcific uremic arteriolopathy. CONCLUSIONS: Calcific calcium uremic arteriolopathy or calciphylaxis is a complex and variable disease that is difficult to diagnose and whose treatment is complicated. Despite the efforts of the investigators, there are still many questions regarding its pathogenesis. This acts as an incentive for further research to establish the most appropriate actions to take to maintain an adequate quality of life for the patients and avoid complications that trigger death in some cases.


Assuntos
Calcinose/diagnóstico , Hiperparatireoidismo Secundário/complicações , Úlcera Cutânea/diagnóstico , Uremia/diagnóstico , Doenças Vasculares/diagnóstico , Arteríolas/patologia , Calcinose/etiologia , Evolução Fatal , Feminino , Humanos , Falência Renal Crônica/complicações , Pessoa de Meia-Idade , Úlcera Cutânea/etiologia , Doenças Vasculares/etiologia
18.
Chemosphere ; 81(7): 876-83, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20817219

RESUMO

Adsorption isotherms of BTX aromatic hydrocarbons (benzene, toluene, and p-xylene) on pristine (SiO2) and metal-doped (Ag-SiO2, Cu-SiO2 and Fe-SiO2) mesoporous and microporous substrates were measured and interpreted. These adsorbents were synthesized by the sol-gel procedure and their BTX sorption isotherms were obtained by the gas chromatographic technique (GC) at several temperatures in the range 423-593 K. The uptake amount of these hydrocarbon adsorptives on SiO2, Ag-SiO2, Cu-SiO2 and Fe-SiO2 mesoporous and microporous substrates was temperature-dependent. Additionally, the interaction of BTX molecules with the pore walls was evaluated by means of the corresponding isosteric heat of adsorption (qst), which was found to follow the next increasing sequence: qst (benzene)

Assuntos
Derivados de Benzeno/química , Benzeno/química , Recuperação e Remediação Ambiental/métodos , Dióxido de Silício/química , Adsorção , Cobre/química , Ferro/química , Porosidade , Prata/química , Tolueno/química , Xilenos/química
19.
Allergol Immunopathol (Madr) ; 38(4): 197-202, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20227159

RESUMO

BACKGROUND: Papular urticaria caused by flea bite presents clinical symptoms of a hypersensitivity reaction accompanied by skin lesions. However, the pattern of recognition by different antibody isotypes during the progression of the disease is unknown. This study evaluated variations in immunoglobulin E and immunoglobulin G subclass antibody responses to flea antigens during the progression of papular urticaria caused by flea bite METHODS: Twenty-five patients clinically diagnosed with papular urticaria due to flea bite were included. Ten healthy children were included as controls. Recognition of antigens from complete flea body extract by patients and healthy controls was determined using immunoblot assays. RESULTS: The results revealed that patients with 2-5 years of papular urticaria evidenced more IgE bands than those with shorter or longer durations of symptoms. In contrast, healthy children showed a predominance of immunoglobulin G1 and immunoglobulin G3. The majority of the recognised antigens were low molecular weight proteins (<90 kDa). Proteins with molecular weights between 16-20, 21-25, and 31-35 kDa showed different patterns of recognition between patients and healthy children. CONCLUSION: The predominant specific antibody isotypes vary according to the time elapsed since the onset of symptoms in papular urticaria caused by flea bite.


Assuntos
Mordeduras e Picadas/imunologia , Epitopos/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Adolescente , Animais , Mordeduras e Picadas/complicações , Mordeduras e Picadas/diagnóstico , Mordeduras e Picadas/fisiopatologia , Criança , Pré-Escolar , Progressão da Doença , Epitopos/metabolismo , Feminino , Humanos , Lactente , Masculino , Sifonápteros , Dermatopatias Vesiculobolhosas/diagnóstico , Dermatopatias Vesiculobolhosas/etiologia , Dermatopatias Vesiculobolhosas/imunologia , Dermatopatias Vesiculobolhosas/fisiopatologia , Urticária/diagnóstico , Urticária/etiologia , Urticária/imunologia , Urticária/fisiopatologia
20.
J Hazard Mater ; 162(1): 254-63, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18583031

RESUMO

Adsorption isotherms of chlorobenzene, chloroform and carbon tetrachloride vapors on undoped SiO(2), and metal-doped Ag/SiO(2), Cu/SiO(2) and Fe/SiO(2) substrates were measured in the temperature range of 398-593K. These substrates were prepared from a typical sol-gel technique in the presence of metal dopants that rendered an assortment of microporous-mesoporous solids. The relevant characteristic of these materials was the different porosities and micropore to mesopore volume ratios that were displayed; this was due to the effect that the cationic metal valence exerts on the size of the sol-gel globules that compose the porous solid. The texture of these SiO(2) materials was analyzed by X-ray diffraction (XRD), FTIR, and diverse adsorption methods. The pore-size distributions of the adsorbents confirmed the existence of mesopores and supermicropores, while ultramicropores were absent. The Freundlich adsorption model approximately fitted the chlorinated compounds adsorption data on the silica substrates by reason of a heterogeneous energy distribution of adsorption sites. The intensity of the interaction between these organic vapors and the surface of the SiO(2) samples was analyzed through evaluation of the isosteric heat of adsorption and standard adsorption energy; from these last results it was evident that the presence of metal species within the silica structure greatly affected the values of both the amounts adsorbed as well as of the isosteric heats of adsorption.


Assuntos
Tetracloreto de Carbono/química , Clorobenzenos/química , Clorofórmio/química , Metais/química , Adsorção , Algoritmos , Cromatografia Gasosa , Cobre/química , Géis , Ferro/química , Nitrogênio/química , Porosidade , Dióxido de Silício/química , Prata/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Difração de Raios X
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