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1.
Braz J Med Biol Res ; 55: e12351, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36629524

RESUMO

In cycling, there is a body of evidence that supports that an all-out start strategy is superior to an even-pacing strategy, but it is unknown whether an all-out start strategy is superior to a self-paced strategy. In the present study, we investigated the effects of three different pacing strategies on 4-km cycling time trial performance. After preliminary trials (familiarization trials and a baseline 4-km cycling time trial), in a randomized and counterbalanced order, twelve male cyclists (32.3±7.2 years old, maximum rate of O2 uptake (V̇O2peak) 4.3±0.4 L/min) completed: 1) a self-paced 4-km cycling time trial; 2) an all-out start (∼10 s), followed by maintenance of the average baseline trial power for the first km and self-paced cycling for the remaining trial (all-out+mean); and 3) an all-out start (∼10 s), followed by a power 5% above the average baseline trial power for the first km and self-paced cycling for the remaining trial (all-out+5%mean). Although there was a significant interaction between power and distance (P=0.001) with different power distribution profiles throughout the trial, there was no significant difference (P=0.99) between the three strategies for overall exercise performance (self-paced 379.8±13.9 s, all-out+mean 380.0±16.0 s, and all-out+5%mean 380.2±11.5 s). Oxygen uptake, rating of perceived effort, and heart rate were also similar across the pacing strategies. Different all-out start strategies did not confer additional benefits to performance compared to a self-paced strategy.


Assuntos
Desempenho Atlético , Exercício Físico , Adulto , Humanos , Masculino , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Exercício Físico/fisiologia , Teste de Esforço , Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia
2.
Braz. j. med. biol. res ; 55: e12351, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1420742

RESUMO

In cycling, there is a body of evidence that supports that an all-out start strategy is superior to an even-pacing strategy, but it is unknown whether an all-out start strategy is superior to a self-paced strategy. In the present study, we investigated the effects of three different pacing strategies on 4-km cycling time trial performance. After preliminary trials (familiarization trials and a baseline 4-km cycling time trial), in a randomized and counterbalanced order, twelve male cyclists (32.3±7.2 years old, maximum rate of O2 uptake (V̇O2peak) 4.3±0.4 L/min) completed: 1) a self-paced 4-km cycling time trial; 2) an all-out start (∼10 s), followed by maintenance of the average baseline trial power for the first km and self-paced cycling for the remaining trial (all-out+mean); and 3) an all-out start (∼10 s), followed by a power 5% above the average baseline trial power for the first km and self-paced cycling for the remaining trial (all-out+5%mean). Although there was a significant interaction between power and distance (P=0.001) with different power distribution profiles throughout the trial, there was no significant difference (P=0.99) between the three strategies for overall exercise performance (self-paced 379.8±13.9 s, all-out+mean 380.0±16.0 s, and all-out+5%mean 380.2±11.5 s). Oxygen uptake, rating of perceived effort, and heart rate were also similar across the pacing strategies. Different all-out start strategies did not confer additional benefits to performance compared to a self-paced strategy.

3.
J Dairy Sci ; 103(7): 6087-6099, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32389470

RESUMO

Our objective was to determine the effects of replacing alfalfa silage (AS) neutral detergent fiber (NDF) with corn silage (CS) NDF at 2 levels of forage NDF (FNDF) on enteric methane (CH4), lactation performance, ruminal fluid characteristics, digestibility, and metabolism of N and energy in Holstein and Jersey cows. Twelve Holstein and 12 Jersey cows (all primiparous and mid-lactation) were used in a triplicated split-plot 4 × 4 Latin square experiment, where breed and diet formed the main and subplots, respectively. The 4 iso-nitrogenous and iso-starch dietary treatments were arranged as a 2 × 2 factorial with 2 levels of FNDF [19 (low FNDF, LF) and 24% (high FNDF, HF) of dry matter] and 2 sources of FNDF (70:30 and 30:70 ratio of AS NDF to CS NDF). Soyhull (non-forage NDF) and corn grain were respectively used to keep dietary NDF and starch content similar across diets. Total collection of feces and urine over 3 d was performed on 8 cows (1 Latin square from each breed). The difference in dry matter intake (DMI) between Holsteins and Jerseys was greater when fed AS than CS. Compared with Jerseys, Holstein cows had greater body weight (48%), DMI (34%), fat- and protein-corrected milk (FPCM; 31%) and CH4 production (22%; 471 vs. 385 g/d). However, breed did not affect CH4 intensity (g/kg of FPCM) or yield (g/kg of DMI), nutrient digestibility, and N partitioning. Compared with HF, LF-fed cows had greater DMI (10%), N intake (8%), and FPCM (5%), but they were 5% less efficient (both FPCM/DMI and milk N/intake N). Compared with HF, LF-fed cows excreted 11 and 17% less urinary N (g/d and % of N intake, respectively). In spite of lower (2.5%) acetate and higher (10%) propionate (mol/100 mol ruminal volatile fatty acids) LF-fed cows had greater (6%) CH4 production (g/d) than did HF-fed cows, most likely due to increased DMI, as affected mainly by the soyhulls. Compared with AS, CS-fed cows had greater DMI (7%) and FPCM (4%), but they were less efficient (5%), and CH4 yield (g/kg of DMI) was reduced by 8%. In addition, per unit of gross energy intake, CS-fed cows lost less urinary energy (15%) and CH energy (11%) than did AS-fed cows. We concluded that, in contrast to level and source of FNDF, breed did not affect digestive and metabolic efficiencies, and, furthermore, neither breed nor dietary treatments affected CH4 intensity. The tradeoff between CH4 and N losses may have implications in future studies assessing the environmental effects of milk production when approached from a whole-farm perspective.


Assuntos
Fibras na Dieta/administração & dosagem , Digestão/efeitos dos fármacos , Lactação/efeitos dos fármacos , Metano/biossíntese , Nitrogênio/metabolismo , Silagem/análise , Animais , Bovinos , Estudos Cross-Over , Dieta/veterinária , Fibras na Dieta/metabolismo , Metabolismo Energético , Ácidos Graxos Voláteis/metabolismo , Fezes/química , Feminino , Medicago sativa/metabolismo , Leite/química , Proteínas do Leite/análise , Rúmen/metabolismo , Amido/metabolismo , Zea mays/metabolismo
4.
J Dairy Sci ; 102(9): 8546-8558, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301834

RESUMO

In the semi-arid highlands of central Mexico, triticale (× Triticosecale L.) is emerging as an alternative, less water-demanding forage crop than alfalfa for dairy cattle. Studies reported here were aimed at evaluating triticale hay (TH) relative to alfalfa hay (AH) for lactating cow performance, apparent digestibility, N partition, and ruminal degradation kinetics of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF). Study 1 was conducted on a privately owned farm. Four barns were used to conduct 4 replicated 3 × 3 Latin squares (1 barn = 1 square), where each barn included 3 pens (experimental units) receiving 1 of 3 dietary treatments. Each pen had 62 Holstein dairy cows. All diets included a forage-to-concentrate ratio of 42:58 (DM basis), which is typical for intensive dairy farms of the region. Dietary treatments were formulated to replace AH with TH on a CP basis, and included (DM basis) 15.1% AH and 0% TH, 9.0% AH and 7.4% TH, and 0% AH and 16.4% TH. Diets were iso-energetic (1.64 Mcal of net energy for lactation/kg of DM) and iso-nitrogenous (17.9% CP). Pen-level DM intake and milk production were from all cows in the pen, but pen-level milk composition, apparent digestibility, and N partitioning were from 8 cows (observational units) randomly selected in each pen. Orthogonal contrasts were used to determine linear and quadratic effects of increasing TH from 0 to 7.4, and 16.4% of dietary DM. Although DM intake was not affected, there was a tendency for CP intake to decline linearly and for NDF intake to increased linearly as TH replaced AH in the diet. Milk production declined linearly by 0.077 kg/d for each additional percentage unit of TH in the diet, which amounted to a 3.5% decline when TH replaced AH entirely. However, no effect was observed on energy-corrected milk production because of a compensatory linear effect of increasing milk fat concentration with the incorporation of TH in the diet. Total-tract NDF digestibility tended to increase linearly by 18.5%, but no differences were detected for urinary urea-N excretion and for N utilization estimated as milk N/(fecal N + urinary N + milk N). Study 2 was an in situ trial conducted to determine the degradation kinetics of AH and TH used in study 1. In spite of differences in degradation kinetics parameters for DM, CP, and NDF, only NDF effective ruminal degradation tended to be greater for TH than AH. Replacing AH with TH at the level typically found in intensive dairy farms of the semi-arid regions of Mexico had minimal effects on milk production and N utilization.


Assuntos
Bovinos/fisiologia , Lactação/fisiologia , Medicago sativa , Nitrogênio/metabolismo , Triticale , Ração Animal , Animais , Clima , Indústria de Laticínios/métodos , Dieta/veterinária , Fibras na Dieta/administração & dosagem , Digestão , Feminino , Medicago sativa/metabolismo , México , Leite/química , Zea mays/metabolismo
5.
Food Chem Toxicol ; 109(Pt 2): 1086-1092, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28416272

RESUMO

In this study we evaluated the effect of a pressure gradient (1-2 atm) in the extraction and composition of the essential oil (EO) of Piper hispidinervum by steam distillation. We also evaluated the insect antifeedant effects (Spodoptera littoralis, Leptinotarsa decemlineata, Myzus persicae and Rhopalosiphum padi) and nematicidal activity (Meloidogyne javanica) of the oils, their major components and their synergistic interactions. Safrole was the major component (78-81%) followed by terpinolene (5-9%). The EOs tested were effective insect antifeedants. Safrole, explained most of the insect antifeedant action of P. hispidinervum EOs. When safrole and terpinolene were tested in binary combinations, low ratios of safrole improved the antifeedant effects of terpinolene. P. hispidinervum EOs caused higher mortality of M. javanica juveniles than their major components. In binary combinations, low ratios of terpinolene increased the nematicidal effects of safrole. The EO treatment strongly suppressed nematode egg hatching and juvenile infectivity. P. hispidinervum EOs affected the germination of S. lycopersicum and L. sativa mostly at 24 h of treatment, being L. sativa the most sensitive. Safrole moderately affected germination and root growth of L. sativa, S. lycopersicum and L. perenne. Terpinolene only affected S. lycopersicum root growth.


Assuntos
Antinematódeos/farmacologia , Inseticidas/farmacologia , Óleos Voláteis/farmacologia , Piper/química , Óleos de Plantas/farmacologia , Animais , Antinematódeos/química , Antinematódeos/isolamento & purificação , Besouros/efeitos dos fármacos , Besouros/fisiologia , Sinergismo Farmacológico , Comportamento Alimentar/efeitos dos fármacos , Inseticidas/química , Inseticidas/isolamento & purificação , Larva/efeitos dos fármacos , Larva/fisiologia , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos de Plantas/química , Óleos de Plantas/isolamento & purificação , Raízes de Plantas/química , Spodoptera/efeitos dos fármacos , Spodoptera/fisiologia , Tylenchoidea/efeitos dos fármacos , Tylenchoidea/fisiologia
6.
In. Rigol Ricardo, Orlando; Santiesteban Alba, Stalina. Obstetricia y ginecología. La Habana, ECIMED, 3ra.ed; 2014. , tab.
Monografia em Espanhol | CUMED | ID: cum-58184
7.
Inflamm Res ; 61(4): 367-73, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22270621

RESUMO

OBJECTIVE AND DESIGN: Sodium caseinate (CasNa) induces differentiation and M-CSF production in mouse band granulocytes in vitro; however, it is not yet known if this molecule can also induce the proliferation and activation of the granulocyte lineage in vivo. In this work we evaluated the induction in vivo of granulopoiesis and the activation of granulocytes in mice treated with CasNa. MATERIAL OR SUBJECTS: BALB/c male mice 8-12 weeks old were used. TREATMENT: The animals were inoculated intraperitoneally with 1 ml of CasNa (10% in PBS p/v) four times (every 48 h). METHODS: Granulocyte proliferation was evaluated by flow cytometry; activation was evaluated by phagocytic indices. The cytokine was measured using an ELISA assay. RESULTS: We show that CasNa increased bone marrow granulopoiesis percentage (38.35 ± 10.88 vs. 64.94 ± 34.14 BrdU+/Gr-1+ cells) and the granulocytes generated presented increased phagocytic indices (0.3 ± 0.1 vs. 0.6 ± 0.11, p < 0.05). We also show that G-CSF (974 ± 411 vs. 3189 ± 350 pg/ml, p < 0.05) and GM-CSF increased in serum, but only G-CSF in bone marrow plasma. CONCLUSIONS: CasNa induces granulopoiesis with functional granulocytes, suggesting that this molecule could be an innate immune system activator.


Assuntos
Caseínas/farmacologia , Granulócitos/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Mielopoese/efeitos dos fármacos , Animais , Candida albicans , Proliferação de Células/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos/sangue , Fator Estimulador de Colônias de Granulócitos e Macrófagos/sangue , Granulócitos/citologia , Granulócitos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fagocitose/efeitos dos fármacos
9.
Emergencias (St. Vicenç dels Horts) ; 18(5): 285-290, oct. 2006. tab
Artigo em Es | IBECS | ID: ibc-051562

RESUMO

Objetivo: conocer la satisfacción de los pacientes en el Servicio de Urgencias a través del informe de usuarios. Método: Se construyó un cuestionario basado en la obligaciones de cada puesto de trabajo evaluando la adherencia a las mismas utilizando como método de evaluación el informe de usuario. Se formularon 14 preguntas que abordaban aspectos técnicos y aspectos interpersonales de la atención con sólo dos opciones de respuestas, afirmativa o negativa. Los criterios de inclusión fueron cualquier paciente, mayor de 16 años de edad. Se seleccionó de cada día un mismo número de pacientes de entre todos los que hubieran sido atendidos en urgencias, 8 pacientes por día para Medicina mientras que para Cirugía, Traumatología y Ginecología/Obstetricia 4 pacientes por día. Resultados: Un porcentaje elevado de pacientes no llegó a conocer el nombre del médico (62,4%). No se midió la presión arterial en el 38,4% de los pacientes, resaltando las especialidades de Traumatología (82,1%) y Cirugía (69,2%). La mitad de los pacientes no recibieron referencia para su médico de familia de la asistencia recibida en el SU (51,2%). El 95,5% de los pacientes estimó haber resuelto su problema de salud en el SU, mientras que el 97% regresaría al SU de necesitarlo nuevamente. Conclusiones: Podemos concluir que intervenciones que mejoren el conocimiento por parte de los pacientes del nombre del médico que los atiende, que incrementen la medición de la presión arterial y la realización de la referencia para el médico de familia podrán mejorar la satisfación (AU)


Objectives: To know the satisfaction of patients at the emergency service through the patient’s report. Methods: A questionnaire was prepared based on the obligations of each place of work checking the adherence to them using as an evaluating method the patient’s reports. Fourteen questions were formulated about technique aspects and interpersonal aspects of the attention with only two options of answers, affirmative or negative. Inclusion criteria were any patient, older than 16 years old. A same number of subjects were selected each day among all who were given care at the emergencies, for internal medicine 8 subjects, for surgery, traumatology and gynecology / obstetrics 4 subjects a day. Results: An elevated percentage of subjects didn’t reach to know the name of the physician (62.4%). The blood pressure was not read on 38.4% of patients being evident for traumatology (82.1%) and for surgery (69.2%) specialties. The half of subjects didn’t receive any reference for their family doctor from the emergency service (51.2%). 95.5% of patients esteemed to have solved their health problem at the emergency service, in the at mean time 97% would be back to the emergency service if they need it again. Conclusions: We have to sum up that interventions which improve the knowledge of the subjects about the name of the physician who takes care of then, that increase the reading of the blood pressure and the realization of the reference for the family doctor could improve the satisfaction at the emergency service (AU)


Assuntos
Humanos , Serviços Médicos de Emergência/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Satisfação do Paciente/estatística & dados numéricos , Cuba , Pesquisas sobre Atenção à Saúde/estatística & dados numéricos , Inquéritos e Questionários , Qualidade da Assistência à Saúde
10.
Col. med. estado Táchira ; 14(4): 45-50, oct.-dic. 2005. ilus
Artigo em Espanhol | LILACS | ID: lil-531060

RESUMO

El craniofaringioma es una neplasia epitelial benigna usualmente de origen supraselar, considerado un tumor hipofisiario de crecimiento lento, puede causar varios grados de hipopituitarismo. En este artículo se describe un caso manejado en el Hospital Dr. Patrocinio Peñuela Ruíz (IVSS) y se realiza una revisión bibliográfica acerca de la presentación, patología y tratamiento. Escolar masculino de 8 años, inicia enfermedad de 1 mes de evolución caracterizada por cefalea frontal de moderada intensidad, disminución de la agudeza visual, movimientos reiterativos a predominio de hemicuerpo derecho. En una primera intervención se coloca válvula de derivación ventrículo peritoneal por hidrocefalia obstructiva: al mes y medio se realizó exéresis completa del tumor mediante abordaje transcalloso. La evolución postoperatoria fue de difícil manejo por presentar alteraciones metabólicas e hidroelectrolíticas. En RMN se evidencia ausencia total del tumor. El trastorno hidroelectrol¡tico se mantuvo a pesar del tratamiento médico: 24 días después del acto quirúrgico, fallece por hipernatremia incohercible. La lesión apareció en nuestro paciente a los 8 años, como una tumoración de 6 por 4 cm. La clínica se presenta 1 mes antes de su ingreso, caracterizada por cefalea, trastornos visuales, movimientos repetitivos a predominio de hemicuerpo derecho sin alteraciones endocrinas al momento del diagnóstico. Mediante abordaje quirúrgico transcalloso se pudo resecar totalmente una tumoración que histopatológicamente determinó un adamantinoma. Sin embargo, el manejo multidisciplinario es condición sine cua non para terminar de lograr el éxito quirúrgico en cirugías tan d¡fíciles como la del paciente.


Assuntos
Humanos , Masculino , Criança , Cefaleia/diagnóstico , Hipopituitarismo/etiologia , Traumatismos Oculares/etiologia , Neoplasias Hipofisárias/cirurgia , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/patologia , Acuidade Visual , Células Epiteliais/citologia , Craniofaringioma/patologia , Neoplasias Hipofisárias/mortalidade , Procedimentos Cirúrgicos Oftalmológicos/métodos
11.
Emergencias (St. Vicenç dels Horts) ; 16(6): 252-257, dic. 2004. tab
Artigo em Es | IBECS | ID: ibc-37945

RESUMO

Objetivos: Conocer la satisfacción de los pacientes que son asistidos en el servicio de urgencias y que posteriormente son hospitalizados. Método: Se aplicó un cuestionario a los pacientes mayores de 16 años que acudieron a urgencias y fueron hospitalizados entre el 23 de febrero y el 1 de marzo 2003 y estaban capacitados para responder el cuestionario. Se seleccionó de cada día un mismo número de pacientes entre todos los que fueron atendidos y hospitalizados, manteniendo una proporción fija en relación al área en el que cada paciente fue atendido. Resultados: Un total de 184 pacientes fueron entrevistados. El 2,7 por ciento, 6,6 por ciento y 14,5 por ciento de los pacientes consideró el tiempo de espera hasta la clasificación, hasta la atención y hasta las pruebas como excesivo, respectivamente, mientras que el 9,5 por ciento de los pacientes consideró el tiempo de espera para el ingreso como excesivo. En general, la puntuación media más baja la obtuvo la sala de espera (9.,4ñ1,2), mientras que Traumatología obtuvo las puntuaciones medias más bajas en todos los aspectos, trato de enfermería y médico, información del médico, sala de espera, cuarto de exploración, mobiliario y calidad global. El 97,8 por ciento de los pacientes refirió haber resuelto su problema de salud y el 99,4 por ciento volvería al SU de necesitarlo. Conclusión: Las mayores posibilidades de mejora están en los servicios de Ginecología Obstetricia y Traumatología si se interviene para disminuir el tiempo de espera para la clasificación y la atención médica, en el primer caso, y mejorando los aspectos interpersonales de la atención en el segundo, y en general, mejorando el tiempo de espera hasta las pruebas, que particularmente en esta subpoblación es muy elevado (AU)


Assuntos
Adolescente , Adulto , Feminino , Masculino , Humanos , Satisfação do Paciente/estatística & dados numéricos , Serviços Médicos de Emergência/estatística & dados numéricos , Qualidade da Assistência à Saúde , Cuba/epidemiologia , Encaminhamento e Consulta/estatística & dados numéricos , Inquéritos e Questionários , Entrevistas como Assunto , Listas de Espera
12.
In. Rigol Ricardo, Orlando. Obstetricia y ginecología. La Habana, Ecimed, 2004. , tab.
Monografia em Espanhol | CUMED | ID: cum-48563
13.
Eur J Epidemiol ; 18(3): 259-62, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12800952

RESUMO

THE AIMS OF OUR STUDY WERE: (i) to know the seroprevalence of Coxiella burnetii infection in the Canary Islands, (ii) to evaluate its epidemiologic features and (iii) to compare the rates of seroprevalence using two different cut-offs (1:20 and 1:80) for the diagnosis of past infection. METHODS: We analysed a representative sample of the canarian population. 662 sera were tested. For the detection of IgG and IgM antibodies against C. burnetii phase II antigens an immuofluorescence assay was used. The serologic screening for IgG detection begun with a 1:20 dilution. A titer of IgG > or = 1:80 along with a negative IgM were used as criteria for previous infection. RESULTS: At an IgG antibody titer against C. burnetii of 1:80 as diagnostic for past infection, the observed global seroprevalence was 21.5%. If the cut-off used was 1:20, the observed prevalence increased up to 35.8% (p = 0.001). Significantly different seroprevalence rates were obtained at these different cut-offs when results were analysed for groups of age and socioeconomic status, but not for either the island of origin or for farmers. CONCLUSION: Our results strongly suggest that Coxiella burnetii infection is endemic in all the Canary Islands. Although it is more frequent in males above 30 years old, it do affect people of all ages, and thus it should be borne in mind in the face of any acute febrile syndrome.


Assuntos
Coxiella burnetii , Estudos Soroepidemiológicos , Anticorpos Antibacterianos , Humanos , Febre Q , Espanha/epidemiologia
16.
J Infect ; 42(2): 163-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11531327

RESUMO

In this paper we describe a case in which acute renal colic was associated with elimination of multiple hyphal masses of Aspergillus flavus. Also, we reviewed the literature on similar cases and we found a similar pattern characterized by a marked male predominance, association with at least one underlying medical condition that predisposes to fungal infection, the presence of local symptoms resembling acute ureteral colic, and the absence of systemic manifestations. Moreover, our data suggest that Aspergillus balls must be suspected when a diabetic and intravenous drug user presents with acute renal colic and that non-obstructive renal aspergillosis may be initially treated with itraconazole.


Assuntos
Aspergilose/complicações , Aspergillus flavus , Cólica/complicações , Doenças Ureterais/complicações , Adulto , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/urina , Cólica/tratamento farmacológico , Cólica/urina , Complicações do Diabetes , Suscetibilidade a Doenças , Humanos , Itraconazol/uso terapêutico , Masculino , Abuso de Substâncias por Via Intravenosa/complicações , Doenças Ureterais/tratamento farmacológico , Doenças Ureterais/urina
17.
Am J Physiol Heart Circ Physiol ; 280(5): H2136-43, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11299215

RESUMO

In isovolumic blood-perfused dog hearts, left ventricular developed pressure (DP) was recorded while a sudden ventricular dilation was promoted at three heart rate (HR) levels: low (L: 52 +/- 1.7 beats/min), intermediate (M: 82 +/- 2.2 beats/min), and high (H: 117 +/- 3.5 beats/min). DP increased instantaneously with chamber expansion (Delta(1)DP), and another continuous increase occurred for several minutes (Delta(2)DP). HR elevation did not alter Delta(1)DP (32.8 +/- 1.6, 33.6 +/- 1.5, and 34.3 +/- 1.2 mmHg for L, M, and H, respectively), even though it intensified Delta(2)DP (17.3 +/- 0.9, 20.7 +/- 1.0, and 26.8 +/- 1.2 mmHg for L, M, and H, respectively), meaning that the treppe phenomenon enhances the length dependence of the contraction component related to changes in intracellular Ca(2+) concentration. Frequency increments reduced the half time of the slow response (82 +/- 3.6, 67 +/- 2.6, and 53 +/- 2.0 s for L, M, and H, respectively), while the number of beats included in half time increased (72 +/- 2.9, 95 +/- 2.9, and 111 +/- 3.2 beats for L, M, and H, respectively). HR modulation of the slow response suggests that L-type Ca(2+) channel currents and/or the Na(+)/Ca(2+) exchanger plays a relevant role in the stretch-triggered Ca(2+) gain when HR increases in the canine heart.


Assuntos
Frequência Cardíaca/fisiologia , Contração Miocárdica/fisiologia , Função Ventricular Esquerda/fisiologia , Animais , Cateterismo , Cães , Técnicas In Vitro , Masculino , Tempo de Reação/fisiologia
19.
Enferm Infecc Microbiol Clin ; 18(4): 170-3, 2000 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-10932394

RESUMO

BACKGROUND: The aim of this study was to assess the seroprevalence and the risk factors of hepatitis A virus (HAV) infection in the population from Gran Canaria (Spain) and to determine at which age pre-vaccination testing would be useful. METHODS: A transversal observational study of the presence of HAV antibodies (IgG) on serum samples obtained from a population ranging from 8 months to 63 years old was performed between January 1995 and December 1996. IgG anti-HAV were detected by a commercial immunoenzyme assay. The study included 547 persons resident in Gran Canaria. Epidemiological data (age, sex, number of family members, educational level, urban/rural residence and previous history of hepatitis) were gathered through a personal interview. Confusing variables were excluded by mean a multiple logistic regression analysis. RESULTS: Global prevalence of anti-HAV (IgG) was 36.0% (CI 95% 32.0-40.0). The prevalence of anti-HAV increased significantly with age from 2.3% in children under 4 years until 98.9% in older than 40 years (OR 3956.0; CI 95% 241.7-64,753.5). Only three independent data (age, sex and educational level) were significantly associated with HAV seroprevalence. A previous history of hepatitis A was present only in 4.8% of HAV-positive subjects. CONCLUSIONS: The low prevalence of anti-HAV (IgG) in persons under 25 years old suggest that in the adolescent population the implementation of universal vaccination programs is recommended even without previous serologic screening. Otherwise, the results suggest that HAV prevaccination screening in our geographical were must be limited to subjects older than 25 years.


Assuntos
Hepatite A/epidemiologia , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Feminino , Vacinas contra Hepatite A , Humanos , Masculino , Fatores de Risco , Estudos Soroepidemiológicos , Espanha/epidemiologia , Vacinas contra Hepatite Viral
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