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1.
J Therm Biol ; 123: 103917, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38991264

RESUMO

Global warming poses a threat to lizard populations by raising ambient temperatures above historical norms and reducing thermoregulation opportunities. Whereas the reptile fauna of desert systems is relatively well studied, the lizard fauna of saline environments has not received much attention and-to our knowledge-thermal ecology and the effects of global warming on lizards from saline environments have not been yet addressed. This pioneer study investigates the thermal ecology, locomotor performance and potential effects of climate warming on Liolaemus ditadai, a lizard endemic to one of the largest salt flats on Earth. We sampled L. ditadai using traps and active searches along its known distribution, as well as in other areas within Salinas Grandes and Salinas de Ambargasta, where the species had not been previously recorded. Using ensemble models (GAM, MARS, RandomForest), we modeled climatically suitable habitats for L. ditadai in the present and under a pessimistic future scenario (SSP585, 2070). L. ditadai emerges as an efficient thermoregulator, tolerating temperatures near its upper thermal limits. Our ecophysiological model suggests that available activity hours predict its distribution, and the projected temperature increase due to global climate change should minimally impact its persistence or may even have a positive effect on suitable thermal habitat. However, this theoretical increase in habitat could be linked to the distribution of halophilous scrub in the future. Our surveys reveal widespread distribution along the borders of Salinas Grandes and Salinas de Ambargasta, suggesting a potential presence along the entire border of both salt plains wherever halophytic vegetation exists. Optimistic model results, extended distribution, and no evidence of flood-related adverse effects offer insights into assessing the conservation status of L. ditadai, making it and the Salinas Grandes system suitable models for studying lizard ecophysiology in largely unknown saline environments.


Assuntos
Lagartos , Animais , Lagartos/fisiologia , Argentina , Regulação da Temperatura Corporal , Extremófilos/fisiologia , Ecossistema , Aquecimento Global , Mudança Climática , Modelos Biológicos , Temperatura Alta
2.
Cir Cir ; 92(4): 469-474, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39079252

RESUMO

OBJECTIVE: To evaluate the health outcomes (postoperative morbidity and mortality) and the functional status at discharge of elderly patients older than 80 years who underwent emergency surgery. METHOD: Patients > 80 years of age who underwent emergency surgery during one year at the Marqués de Valdecilla University Hospital, Santander, Spain. Preoperative data (age, sex, type of surgery, comorbidity) and postoperative data (complications) were evaluated, as well as in-hospital mortality, at 30 days and 6 months after surgery. RESULTS: Five-hundred-sixty-eight patients underwent emergency surgery between 2018 and 2019. After the review, 407 patients were included in the study. Average age: 86.9 years. Women 61.7%. Mean hospital stay: 10.4 days. Traumatic interventions 41.3%, vascular surgery 19.7%, general-digestive surgery 25.3%. Medium ASA risk: 2.88. Functional status at discharge: 3.15. Postoperative complications: Clavien-Dindo I 40.8%, II 40.3%, IIIA 3.4%, IIIB 2.5%, IVA 3.9%, IVB 2.0% and V 7.1%. Hospital mortality 7.1%, 30-day mortality 10.3%, mortality at 6 months 24.6%. CONCLUSIONS: Patients > 80 years of age undergoing urgent surgery have high preoperative comorbidity, postoperative complications, and high mortality at 30 days and 6 months after surgery. This mortality is more significant in those ASA IV, nonagenarians and those undergoing high-risk surgery.


OBJETIVO: Evaluar los resultados en salud (morbilidad y mortalidad posoperatorias) y el estado funcional al alta de los pacientes mayores de 80 años sometidos a cirugía de urgencia. MÉTODO: Pacientes de edad > 80 años sometidos a cirugía de urgencia durante 1 año en el Hospital Universitario Marqués de Valdecilla, Santander, España. Se evaluaron datos preoperatorios (edad, sexo, tipo de cirugía, comorbilidad) y posoperatorios (complicaciones), así como mortalidad hospitalaria, a los 30 días y a los 6 meses de la cirugía. RESULTADOS: En 2018-2019 fueron operados de urgencia 568 pacientes, de los cuales 407 fueron incluidos en el estudio. Edad media: 86.9 años. El 61.7% fueron mujeres. Estancia media hospitalaria: 10.4 días. El 41.3% fueron intervenciones traumatológicas, el 19.7% cirugía vascular, el 25.3% cirugía general-digestiva. Riesgo ASA medio: 2.88. Estado funcional al alta: 3.15. Complicaciones posoperatorias: Clavien-Dindo I 40.8%, II 40.3%, IIIA 3.4%, IIIB 2.5%, IVA 3.9%, IVB 2.0% y V 7.1%. Mortalidad: hospitalaria 7.1%, a los 30 días 10.3% y a los 6 meses 24.6%. CONCLUSIONES: Los pacientes > 80 años sometidos a cirugía urgente presentan elevada comorbilidad preoperatoria, complicaciones posoperatorias y elevada mortalidad a 30 días y 6 meses de la cirugía. Esta mortalidad es más significativa en los ASA IV, nonagenarios y sometidos a cirugía de alto riesgo.


Assuntos
Emergências , Mortalidade Hospitalar , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Operatórios , Humanos , Idoso de 80 Anos ou mais , Feminino , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Espanha/epidemiologia , Procedimentos Cirúrgicos Operatórios/mortalidade , Tempo de Internação/estatística & dados numéricos , Estado Funcional , Estudos Retrospectivos , Comorbidade , Alta do Paciente/estatística & dados numéricos
3.
J Pediatr ; 241: 188-195.e3, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34571019

RESUMO

OBJECTIVE: To assess the relation between leisure screen time and emotional and behavioral problems in Spanish children aged 4-14 years. STUDY DESIGN: This cross-sectional study used a representative sample of children aged 4-14 years included in the 2017 Spanish National Health Survey (n = 4073). Emotional and behavioral problems of children were assessed through the parent-report Strengths and Difficulties Questionnaire. Daily leisure screen time in minutes was categorized as 0-59, 60-119, 120-179, and ≥180. We calculated adjusted prevalence ratios (aPR) and their 95% CIs of being at risk of developing emotional and behavioral problems. Associations were adjusted for potential confounding variables. RESULTS: Children spending 180 minutes or more of daily leisure screen time compared with children spending less than 1 hour were more likely to be at risk of developing emotional and behavioral problems: aPR≥180: 2.19 (95% CI 1.53-3.14), emotional symptomology: aPR≥180: 2.09 (95% CI 1.37-3.18), conduct problems aPR≥180: 1.85 (95% CI 1.34-2.54), peer problems aPR≥180: 1.78 (95% CI 1.15-2.75), and to behave less prosocially: aPR≥180: 2.20 (95% CI 1.43-3.37). CONCLUSIONS: We have found significant associations between daily leisure screen time and emotional and behavioral problems in Spanish children between 6 and 14 years of age. However, these findings should be confirmed in cohort studies, so institutions might consider including screen time as a new risk factor for children.


Assuntos
Sintomas Afetivos/etiologia , Transtornos do Comportamento Infantil/etiologia , Atividades de Lazer/psicologia , Comportamento Problema/psicologia , Tempo de Tela , Adolescente , Sintomas Afetivos/epidemiologia , Criança , Transtornos do Comportamento Infantil/epidemiologia , Pré-Escolar , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Fatores de Risco , Espanha
4.
Crit Pathw Cardiol ; 20(3): 140-142, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33731601

RESUMO

In the outpatient setting, ambulatory electrocardiography is the most frequently used diagnostic modality for the evaluation of patients in whom cardiac arrhythmias or conduction abnormalities are suspected. Proper selection of the device type and monitoring duration is critical for optimizing diagnostic yield and cost-effective resource utilization. However, despite guidance from major professional societies, the lack of systematic guidance for proper test selection in many institutions results in the need for repeat testing, which leads to not only increased resource utilization and cost of care, but also suboptimal patient care. To address this unmet need at our own institution, we formed a multidisciplinary panel to develop a concise, yet comprehensive algorithm, incorporating the most common indications for ambulatory electrocardiography, to efficiently guide clinicians to the most appropriate test option for a given clinical scenario, with the goal of maximizing diagnostic yield and optimizing resource utilization. The algorithm was designed as a single-page, color-coded flowchart to be utilized both as a rapid reference guide in printed form, and a decision support tool embedded within the electronic medical records system at the point of order entry. We believe that systematic adoption of this algorithm will optimize diagnostic efficiency, resource utilization, and importantly, patient care and satisfaction.


Assuntos
Eletrocardiografia Ambulatorial , Sistemas Automatizados de Assistência Junto ao Leito , Algoritmos , Análise Custo-Benefício , Eletrocardiografia , Humanos , Pacientes Ambulatoriais
5.
Arch Cardiol Mex ; 91(1): 73-83, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-33661880

RESUMO

Antecedentes: El conducto arterioso permeable (CAP) es un defecto cardiaco congénito y se considera un problema de salud pública. Se presenta en un alto porcentaje de recién nacidos y en algunos mayores de 1 mes. El cierre farmacológico es el tratamiento inicial preferido, ya que ha tenido excelentes resultados; sin embargo, en aquellos casos en los que no es posible, está indicado el cierre quirúrgico. Objetivo: Evaluar la eficacia y la seguridad del cierre quirúrgico del CAP por cirujanos pediatras sin especialidad en cirugía cardiovascular. Método: Ensayo clínico realizado en pacientes del Hospital General de Occidente, centro hospitalario público de segundo nivel, con diagnóstico de CAP, que requirieron corrección quirúrgica. Se revisaron en forma retrospectiva los expedientes de enero de 2001 a diciembre de 2018. Resultados: Se incluyeron 224 pacientes divididos en dos grupos: grupo I, con 184 (82%) recién nacidos, y grupo II, con 40 (18%) niños grandes de 2 meses a 8 años de edad. A todos se les realizó cierre quirúrgico: 3 por toracoscopía y 221 por toracotomía posterolateral izquierda. Presentaron complicaciones 36 pacientes, lo que representa el 16% del total; solo el 5.3% fueron complicaciones mayores. Fallecieron 24 pacientes en el posoperatorio, lo que representa una mortalidad del 10.7%; ninguno falleció por complicaciones transquirúrgicas. El CAP es un defecto cardíaco congénito que se presenta en alto porcentaje en pacientes prematuros. El cierre farmacológico es el principal tratamiento por tener excelentes resultados en recién nacidos; sin embargo, en aquellos casos en los que no sea posible está indicado el cierre quirúrgico. Todos los pacientes fueron operados por cirujanos pediatras generales, con una sobrevida global del 92%. Conclusiones: En los hospitales donde no hay cirujano cardiovascular pediátrico ni cardiólogo intervencionista, la corrección quirúrgica del CAP puede ser llevada a cabo por un cirujano pediatra. La técnica es reproducible, fácil de realizar y con mínimas complicaciones. Background: The Patent Ductus Arteriosus (PDA) is congenital heart defect and is considered a public health problem. It occurs in a high percentage of newborns and in some older than 1 month. Pharmacological closure is the preferred initial treatment, as it has had excellent results; however, in those cases where it is not possible, surgical closure is indicated. Objective: The objective is to evaluate the efficacy and safety of the surgical closure of the patent PDA when it is carried out by pediatric surgeons without specialization in cardiovascular surgery. Methods: This study was conducted at the West General Hospital, a 2nd level public hospital, with the diagnosis of patent ductus arteriosus that required surgical correction. For the collection of the information, the files from January 2001 to December 2018 were retrospectively reviewed. Results: 224 patients were included; divided into two groups: Group I: 184 (82%) "newborns" and Group II: 40 (18%) "big children" with ages from 2 months to 8 years. All had a surgical closure; 3 by thoracoscopy and 221 by left posterolateral thoracotomy. 36 patients presented complications representing 16% of the total of patients, only 5.3% were major complications. 24 patients died in the postoperative period, representing a mortality of 10.7%, none died due to trans-surgical complications. PDA is a congenital heart defect that occurs in a high percentage of premature patients. The pharmacological closure is the principal treatment because it has had excellent results in newborns; however, in those cases where it is not possible, surgical closure it´s indicated. All patients were operated by general pediatric surgeons, with a global survival of 92%. Conclusions: We conclude that in hospitals where there is no pediatric cardiovascular surgeon or interventional cardiologist, the surgical correction of the PDA can be carried out by a general pediatric surgeon. The technique is reproducible, easy to perform and with minimal complications.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Permeabilidade do Canal Arterial/cirurgia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Criança , Pré-Escolar , Feminino , Cirurgia Geral , Humanos , Lactente , Recém-Nascido , Masculino , Pediatria , Estudos Retrospectivos , Resultado do Tratamento
6.
Arch. cardiol. Méx ; Arch. cardiol. Méx;91(1): 73-83, ene.-mar. 2021. graf
Artigo em Espanhol | LILACS | ID: biblio-1152863

RESUMO

Resumen Antecedentes: El conducto arterioso permeable (CAP) es un defecto cardiaco congénito y se considera un problema de salud pública. Se presenta en un alto porcentaje de recién nacidos y en algunos mayores de 1 mes. El cierre farmacológico es el tratamiento inicial preferido, ya que ha tenido excelentes resultados; sin embargo, en aquellos casos en los que no es posible, está indicado el cierre quirúrgico. Objetivo: Evaluar la eficacia y la seguridad del cierre quirúrgico del CAP por cirujanos pediatras sin especialidad en cirugía cardiovascular. Método: Ensayo clínico realizado en pacientes del Hospital General de Occidente, centro hospitalario público de segundo nivel, con diagnóstico de CAP, que requirieron corrección quirúrgica. Se revisaron en forma retrospectiva los expedientes de enero de 2001 a diciembre de 2018. Resultados: Se incluyeron 224 pacientes divididos en dos grupos: grupo I, con 184 (82%) recién nacidos, y grupo II, con 40 (18%) niños grandes de 2 meses a 8 años de edad. A todos se les realizó cierre quirúrgico: 3 por toracoscopía y 221 por toracotomía posterolateral izquierda. Presentaron complicaciones 36 pacientes, lo que representa el 16% del total; solo el 5.3% fueron complicaciones mayores. Fallecieron 24 pacientes en el posoperatorio, lo que representa una mortalidad del 10.7%; ninguno falleció por complicaciones transquirúrgicas. El CAP es un defecto cardíaco congénito que se presenta en alto porcentaje en pacientes prematuros. El cierre farmacológico es el principal tratamiento por tener excelentes resultados en recién nacidos; sin embargo, en aquellos casos en los que no sea posible está indicado el cierre quirúrgico. Todos los pacientes fueron operados por cirujanos pediatras generales, con una sobrevida global del 92%. Conclusiones: En los hospitales donde no hay cirujano cardiovascular pediátrico ni cardiólogo intervencionista, la corrección quirúrgica del CAP puede ser llevada a cabo por un cirujano pediatra. La técnica es reproducible, fácil de realizar y con mínimas complicaciones.


Abstract Background: The Patent Ductus Arteriosus (PDA) is congenital heart defect and is considered a public health problem. It occurs in a high percentage of newborns and in some older than 1 month. Pharmacological closure is the preferred initial treatment, as it has had excellent results; however, in those cases where it is not possible, surgical closure is indicated. Objective: The objective is to evaluate the efficacy and safety of the surgical closure of the patent PDA when it is carried out by pediatric surgeons without specialization in cardiovascular surgery. Methods: This study was conducted at the West General Hospital, a 2nd level public hospital, with the diagnosis of patent ductus arteriosus that required surgical correction. For the collection of the information, the files from January 2001 to December 2018 were retrospectively reviewed. Results: 224 patients were included; divided into two groups: Group I: 184 (82%) "newborns" and Group II: 40 (18%) "big children" with ages from 2 months to 8 years. All had a surgical closure; 3 by thoracoscopy and 221 by left posterolateral thoracotomy. 36 patients presented complications representing 16% of the total of patients, only 5.3% were major complications. 24 patients died in the postoperative period, representing a mortality of 10.7%, none died due to trans-surgical complications. PDA is a congenital heart defect that occurs in a high percentage of premature patients. The pharmacological closure is the principal treatment because it has had excellent results in newborns; however, in those cases where it is not possible, surgical closure it´s indicated. All patients were operated by general pediatric surgeons, with a global survival of 92%. Conclusions: We conclude that in hospitals where there is no pediatric cardiovascular surgeon or interventional cardiologist, the surgical correction of the PDA can be carried out by a general pediatric surgeon. The technique is reproducible, easy to perform and with minimal complications.


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Permeabilidade do Canal Arterial/cirurgia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Pediatria , Cirurgia Geral , Estudos Retrospectivos , Resultado do Tratamento
7.
Anim Reprod ; 16(3): 376-385, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-32435281

RESUMO

Establishment of pregnancy in mammals requires reciprocal molecular communication between the conceptus and endometrium that modifies the endometrial transcriptome and uterine luminal milieu to support pregnancy. Due to the small size of the early embryo and elongating conceptus relative to the volume of the uterine lumen, collection of endometrium adjacent to the developing conceptus is difficult following conventional uterine flushing methods in cattle. Use of endometrial explants in culture can overcome this challenge and reveal information about the dialogue between the developing embryo and the uterus. The aim of this short review is to summarize some of our recent findings in relation to embryo maternal interaction during bovine pregnancy establishment and to put them in the wider context of fertility in cattle.

8.
J Med Chem ; 60(3): 899-912, 2017 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-28075589

RESUMO

Three water-soluble Ru(II) chiral heteroleptic coordination compounds [Ru(en)(pdto)]Cl2 (1), [Ru(gly)(pdto)]Cl (2), and [Ru(acac)(pdto)]Cl (3), where pdto = 2,2'-[1,2-ethanediylbis-(sulfanediyl-2,1-ethanediyl)]dipyridine, en = ethylendiamine, gly = glycinate, and acac = acetylacetonate, have been synthezised and fully characterized. The crystal structures of compounds 1-3 are described. The IC50 values for compounds 1-3 are within nanomolar range (14, 12, and 6 nM, respectively). The cytotoxicity for human peripheral blood lymphocytes is extremely low (>100 µM). Selectivity indexes for Ru(II) compounds are in the range 700-1300. Trophozoites exposed to Ru(II) compounds die through an apoptotic pathway triggered by ROS production. The orally administration to infected mice induces a total elimination of the parasite charge in mice faeces 1-2-fold faster than metronidazole. Besides, all compounds inhibit the trophozoite proliferation in amoebic liver abscess induced in hamster. All our results lead us to propose these compounds as promising candidates as antiparasitic agents.


Assuntos
Antiprotozoários/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Compostos de Rutênio/farmacologia , Animais , Antiprotozoários/química , Antiprotozoários/uso terapêutico , Apoptose/efeitos dos fármacos , Células Cultivadas , Cricetinae , Cristalografia por Raios X , Humanos , Concentração Inibidora 50 , Abscesso Hepático Amebiano/tratamento farmacológico , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Compostos de Rutênio/química , Compostos de Rutênio/uso terapêutico , Estereoisomerismo
9.
Rev. luna azul ; (41): 365-384, jul.-dic. 2015.
Artigo em Espanhol | LILACS | ID: lil-783587

RESUMO

El objetivo central de este artículo es analizar las bases, la plataforma y los principios de la pedagogía que Fritjof Capra ha denominado Alfabetización Ecológica, para referirse a una particular forma de abordar la educación ambiental, ya no desde el salón de clases sino a partir del lugar mismo donde se busca intervenir, teniendo como soporte filosófico-científico a la Ecología Profunda; y con una vasta experiencia de trabajo colectivo que ha rebasado fronteras geográficas, y no exige más doctrina que la voluntad y humildad para seguir los pasos que permitan descubrir los problemas y actuar en consecuencia, en el aquí y ahora de nuestras complejas relaciones comunitarias con los sistemas vivientes.


The central objective of this article is to analyze the bases, the platform and the principles of the pedagogy Fritjof Capra has called Ecological Literacy to refer to a particular way of addressing environmental education, no longer from the classroom but from the very place where it seeks to be intervened having Deep Ecology as the philosophical-scientific support and with a vast experience of collective work that has gone beyond geographical borders, and does not require more doctrine that willingness and humbelness to follow the steps to discover the problems and act accordingly in the here and now of the complex community relations with living systems.


Assuntos
Humanos , Alfabetização , Ensino , Educação em Saúde Ambiental , Ecologia
10.
Bol Asoc Med P R ; 103(1): 5-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21696096

RESUMO

Esophageal variceal bleeding is a frequent complication in patients with chronic liver disease. There is no published study that evaluates the management of this complication in Puerto Rico. Our study describes the management of patients with esophageal varices admitted to the emergency room of the Puerto Rico Medical Center from January 2002 to December 2004. Seventy-four patients were included, 50% of which presented stigmata of recent bleeding from esophageal varices. In patients who presented stigmata of recent esophageal variceal bleeding, larger varices were identified (65% vs. 27% p = 0.002). Significant bleeding and banding of esophageal varices was most common in patients with stigmata of recent bleed. Octreotide infusion and prophylactic antibiotics were received by the vast majority. The management of esophageal variceal bleeding in our institution is compliant with the American Association for the Study of Liver Diseases guidelines.


Assuntos
Varizes Esofágicas e Gástricas/complicações , Varizes Esofágicas e Gástricas/terapia , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/terapia , Cirrose Hepática/complicações , Feminino , Instalações de Saúde , Humanos , Masculino , Porto Rico , Estudos Retrospectivos
11.
Am J Bot ; 98(4): 698-703, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21613168

RESUMO

PREMISE OF THE STUDY: Seed dispersal distance-a key process in plant population dynamics-remains poorly understood because of the difficulty of finding a source plant so well isolated from conspecifics that seeds or seedlings can be unambiguously attributed to it. Inverse modeling (IM) of seed dispersal, a simple statistical technique for parameterizing dispersal kernels, has been widely used since 1992; surprisingly, however, this approach has never been verified in the field. METHODS: We released from 20 nearby trees the winged seeds of a liana species, Entada polystachya, near the coast in a tropical, dry forest in Jalisco, Mexico. KEY RESULTS: With a two-parameter log-normal function, we found that IM predicted both the shape and scale parameters well as long as we used the entire data set. When, however, we subsampled (thus simulating the use of transects for seedlings or an array of seed traps), the estimates of the scale and shape parameters were often more than double the real values. The problem was due to the marked anisotropy (directional bias; in this case, in the direction of the diurnal sea breeze) of the individual dispersal curves. When we randomized the direction of dispersal of individual seeds from the trees (keeping dispersal distances unchanged), predictions of parameter values were excellent. CONCLUSIONS: Inverse modeling must include directional parameters when dealing with areas where strong anisotropy is to be expected, e.g., for wind dispersal of seeds near coasts or pollination by any vector where a plant species is limited to a strongly linear habitat such as river banks.


Assuntos
Fabaceae , Dispersão de Sementes , Sementes , Ecossistema , México , Modelos Biológicos , Reprodutibilidade dos Testes
12.
Behav Processes ; 84(1): 526-35, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20117190

RESUMO

This paper investigates the possible role of neuroanatomical features in Pavlovian conditioning, via computer simulations with layered, feedforward artificial neural networks. The networks' structure and functioning are described by a strongly bottom-up model that takes into account the roles of hippocampal and dopaminergic systems in conditioning. Neuroanatomical features were simulated as generic structural or architectural features of neural networks. We focused on the number of units per hidden layer and connectivity. The effect of the number of units per hidden layer was investigated through simulations of resistance to extinction in fully connected networks. Large networks were more resistant to extinction than small networks, a stochastic effect of the asynchronous random procedure used in the simulator to update activations and weights. These networks did not simulate second-order conditioning because weight competition prevented conditioning to a stimulus after conditioning to another. Partially connected networks simulated second-order conditioning and devaluation of the second-order stimulus after extinction of a similar first-order stimulus. Similar stimuli were simulated as nonorthogonal input-vectors.


Assuntos
Condicionamento Clássico , Redes Neurais de Computação , Algoritmos , Simulação por Computador , Condicionamento Clássico/fisiologia , Dopamina/metabolismo , Extinção Psicológica/fisiologia , Hipocampo/anatomia & histologia , Hipocampo/fisiologia , Humanos , Modelos Neurológicos , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Neurônios/fisiologia , Processos Estocásticos , Sinapses/fisiologia
13.
P R Health Sci J ; 24(1): 11-7, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15895872

RESUMO

PURPOSE: The incidence and prevalence of Crohn's disease (CD) varies geographically and with racial/ ethnic background. The highest frequency of occurrence is in North America and Northern Europe. Incidence is highest among Caucasians, lower in blacks and Hispanics, and lowest in Asians. However in the mid-1980s and 1990s, the incidence and prevalence increased in continental Europe, the Middle East, the Pacific Rim, Africa, and Latin America. An increase in the incidence of CD has been noted in Puerto Rico, although our population differs genetically from other described CD populations. A study in our population showed lower prevalence of ASCA and no NOD2 in our CD patients. Infliximab, a TNFa antibody, is effective in refractory inflammatory CD and in fistulizing disease. Since limited data exists regarding CD in Hispanics, the fastest growing minority group in the United States, we designed this retrospective study with patients treated with infliximab at our institution. We wanted to determine if the response to infliximab in genetically admixed Hispanics differed from that previously reported. METHODS: Baseline characteristics, infusion related information and clinical response was abstracted from medical records. Clinical response was classified as complete response, partial response, and nonresponse. RESULTS: The study included 15 patients treated for refractory inflammatory disease, 9 for fistulizing disease, and 11 for both. The positive response rate was 83%(29/35) and the non response rate was 17%(6/35). Overall the patients with complete, partial, and no response were 13/35(37%), 16/35(46%), and 6/ 35(17%), respectively. No statistically significant association was found between response and disease location. Significant association was found between response and fistula type (p = 0.02). Steroid withdrawal was possible in 21/31 patients (68%). In terms of safety, 9/35 patients (26 %) suffered an adverse reaction, 4 patients required therapy discontinuation. CONCLUSION: This study suggests that infliximab has similar global response, allowance of steroid withdrawal and safety in Hispanics as in other populations. Ethnicity does not seem to influence response rate to infliximab.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antirreumáticos/uso terapêutico , Doença de Crohn/tratamento farmacológico , Doença de Crohn/etnologia , Adolescente , Adulto , Idoso , Criança , Doença de Crohn/diagnóstico , Feminino , Glucocorticoides/uso terapêutico , Hispânico ou Latino , Humanos , Infliximab , Masculino , Pessoa de Meia-Idade , Porto Rico/etnologia , Estudos Retrospectivos , Resultado do Tratamento
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