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1.
Parasitology ; 143(8): 998-1011, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27046418

RESUMO

A multi-marker nuclear genotyping approach was performed on larval and adult specimens of Anisakis spp. (N = 689) collected from fish and cetaceans in allopatric and sympatric areas of the two species Anisakis pegreffii and Anisakis simplex (s. s.), in order to: (1) identify specimens belonging to the parental taxa by using nuclear markers (allozymes loci) and sequence analysis of a new diagnostic nuclear DNA locus (i.e. partial sequence of the EF1 α-1 nDNA region) and (2) recognize hybrid categories. According to the Bayesian clustering algorithms, based on those markers, most of the individuals (N = 678) were identified as the parental species [i.e. A. pegreffii or A. simplex (s. s.)], whereas a smaller portion (N = 11) were recognized as F1 hybrids. Discordant results were obtained when using the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) of the internal transcribed spacer (ITS) ribosomal DNA (rDNA) on the same specimens, which indicated the occurrence of a large number of 'hybrids' both in sympatry and allopatry. These findings raise the question of possible misidentification of specimens belonging to the two parental Anisakis and their hybrid categories derived from the application of that single marker (i.e. PCR-RFLPs analysis of the ITS of rDNA). Finally, Bayesian clustering, using allozymes and EF1 α-1 nDNA markers, has demonstrated that hybridization between A. pegreffii and A. simplex (s. s.) is a contemporary phenomenon in sympatric areas, while no introgressive hybridization takes place between the two species.


Assuntos
Anisaquíase/veterinária , Anisakis/genética , Doenças dos Peixes/parasitologia , Hibridização Genética , Animais , Anisaquíase/parasitologia , Anisakis/isolamento & purificação , Núcleo Celular/genética , DNA de Helmintos/genética , DNA Espaçador Ribossômico/genética , Feminino , Peixes , Marcadores Genéticos/genética , Genótipo , Geografia , Larva , Masculino , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Especificidade da Espécie
2.
Parasite ; 15(3): 408-19, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18814715

RESUMO

The genetic relationships among 11 taxa, belonging to the genus Contracaecum (C. osculatum A, C. osculatum B, C. osculatum (s.s.), C. osculatum D, C. osculatum E, C. osculatum baicalensis, C. mirounga, C. radiatum, C. ogmorhini (s.s.), C. margolisi) and Phocascoris (Phocoscris cystophorae), parasites as adults of seals, were inferred from sequence analysis 1519 bp) of the mitochondrial cytochrome c oxidase subunit II (mtDNA cox2) gene. Phylogenetic analyses obtained from Parsimony (MP) and Neighbour-Joining (NJ) K2P distance values generated similar topologies, each well supported at major nodes. All analyses delineated two main clades: the first encompassing the parasites of the phocid seals, i.e. the C. osculatum species complex, C. osculatum boicolensis, C. mirounga and C. radiatum, with the latter two species forming a separate subclade; the second including the parasites of otarids, i.e. C. ogmorhini (s.s.) and C. margolisi. An overall high congruence between mtDNA inferred tree topologies and those produced from nuclear data sets (20 allozyme loci) was observed. Comparison of the phylogenetic hypothesis here produced for Controcaecum spp. plus Phocascaris with those currently available for their definitive hosts (pinnipeds) suggests parallelism between hosts and parasite phylogenetic tree topologies.


Assuntos
Anisaquíase/parasitologia , Anisakis/classificação , Anisakis/genética , DNA Mitocondrial/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Animais , Anisakis/enzimologia , Sequência de Bases , DNA Mitocondrial/genética , Interações Hospedeiro-Parasita , Dados de Sequência Molecular , Phoca/parasitologia , Filogenia , Alinhamento de Sequência/veterinária , Especificidade da Espécie
3.
Syst Parasitol ; 54(1): 13-23, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12567006

RESUMO

Genetic variation of Contracaecum ogmorhini (sensu lato) populations from different otariid seals of the northern and southern hemisphere was studied on the basis of 18 enzyme loci as well as preliminary sequence analysis of the mitochondrial cyt b gene (260 bp). Samples were collected from Zalophus californianus in the boreal region and from Arctocephalus pusillus pusillus, A. pusillus doriferus and A. australis from the austral region. Marked genetic heterogeneity was found between C. ogmorhini (sensu lato) samples from the boreal and austral region, respectively. Two loci (Mdh-2 and NADHdh) showed fixed differences and a further three loci (Iddh, Mdh-1 and 6Pgdh) were highly differentiated between boreal and austral samples. Their average genetic distance was D(Nei) = 0.36 at isozyme level. At mitochondrial DNA level, an average proportion of nucleotide substitution of 3.7% was observed. These findings support the existence of two distinct sibling species, for which the names C. ogmorhini (sensu stricto) and C. margolisi n. sp., respectively, for the austral and boreal taxon, are proposed. A description for C. margolisi n. sp. is provided. No diagnostic morphological characters have so far been detected; on the other hand, two enzyme loci, Mdh-2 and NADHdh, fully diagnostic between the two species, can be used for the routine identification of males, females and larval stages. Mirounga leonina was found to host C. ogmorhini (s.s.) in mixed infections with C. osculatum (s.l.) (of which C. ogmorhini (s.l.) was in the past considered to be a synonym) and C. miroungae; no hybrid genotypes were found, confirming the reproductive isolation of these three anisakid species. The hosts and geographical range so far recorded for C. margolisi n. sp. and C. ogmorhini (s.s.) are given.


Assuntos
DNA Mitocondrial/genética , Nematoides/enzimologia , Nematoides/genética , Focas Verdadeiras/parasitologia , Animais , Oceano Atlântico , Sequência de Bases , Grupo dos Citocromos b/química , Grupo dos Citocromos b/genética , DNA Mitocondrial/química , Eletroforese em Gel de Amido/veterinária , Feminino , Variação Genética , Isoenzimas/química , Isoenzimas/genética , Masculino , Dados de Sequência Molecular , Nematoides/anatomia & histologia , Oceano Pacífico , Alinhamento de Sequência
4.
J Public Health Manag Pract ; 7(4): 67-73, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11434043

RESUMO

The Florida Department of Health (FDOH) was the first state to pilot test both the Centers for Disease Control and Prevention (CDC) state agency and local Public Health System Performance Standards. The standards were found to be complementary and supportive of the FDOH quality performance improvement system, which had been in place for a decade, and the new Quality Management initiative. The pilot test found uneven performance across the state's county health departments and identified several areas, especially workforce development, that required additional efforts. The FDOH, in collaboration with the Center for Leadership in Public Health Practice at the College of Public Health in the University of South Florida, have collaborated and will continue to collaborate to design and deliver training in critical workforce development areas.


Assuntos
Eficiência Organizacional , Liderança , Administração em Saúde Pública/normas , Saúde Pública/educação , Gestão da Qualidade Total , Florida , Humanos , Auditoria Administrativa , Projetos Piloto , Avaliação de Programas e Projetos de Saúde , Prática de Saúde Pública/normas , Recursos Humanos
5.
Science ; 292(5517): 713-6, 2001 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-11326095

RESUMO

Shear-wave splitting analysis of local events recorded on land and on the ocean floor in the Tonga arc and Lau backarc indicate a complex pattern of azimuthal anisotropy that cannot be explained by mantle flow coupled to the downgoing plate. These observations suggest that the direction of mantle flow rotates from convergence-parallel in the Fiji plateau to north-south beneath the Lau basin and arc-parallel beneath the Tonga arc. These results correlate with helium isotopes that map mantle flow of the Samoan plume into the Lau basin through an opening tear in the Pacific plate.

6.
Int J Parasitol ; 31(1): 9-14, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11165265

RESUMO

In order to assess the taxonomic status of Anisakis brevispiculata Dollfus, 1966 population samples of this taxon from central and south-eastern Atlantic ocean were compared at 22 enzymatic loci with samples belonging to Anisakis physeteris Baylis, 1923 from the Mediterranean sea and central-eastern Atlantic ocean. Very low interpopulational genetic divergence was observed both within A. brevispiculata (average D(Nei) = 0.008) and within A. physeteris (D(Nei) = 0.009) despite the geographic distance among the samples, indicating high levels of gene flow in both taxa. On the other hand, the average genetic distance between A. brevispiculata and A. physeteris was found to be D(Nei) = 0.80, a value generally observed between well differentiated congeneric species. The reproductive isolation between A. brevispiculata and A. physeteris is indicated by the following observations: (1) no F(1) hybrids or recombinant genotypes were until now observed; and (2) the two Anisakis species do not seem to share their definitive hosts. The main definitive host of A. brevispiculata is the pygmy sperm whale (Kogia breviceps), while for A. physeteris it is the sperm whale (Physeter catodon). Only adult males differ slightly in spicule length, while females and larval stages are not differentiated morphologically. Both A. brevispiculata and A.physeteris show a type II larva. The correct recognition of A. brevispiculata from A. physeteris and from other Anisakis species studied, in either sexes and at any life stage, is made easy by allozyme markers (e.g. Icdh, Gapdh, Sod-1, Np, Aat-2, Adk-2, fEst-2, PepB, PepC-2, Mpi). Diagnostic keys, which can be used for routine identification in the field of these Anisakis worms, based on genetic markers, are given.


Assuntos
Anisakis/genética , Variação Genética , Animais , Anisakis/classificação , Anisakis/fisiologia , Oceano Atlântico , Eletroforese/veterinária , Feminino , Masculino , Reprodução , Baleias/parasitologia
7.
Am J Respir Crit Care Med ; 162(4 Pt 1): 1277-84, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11029331

RESUMO

Bronchiectasis is a pathologic description of lung damage characterized by inflamed and dilated thick-walled bronchi. These findings may result from a number of possible causes and these may influence treatment and prognosis. The aim of this study was to determine causative factors in 150 adults with bronchiectasis (56 male, 94 female) identified using high-resolution computerized tomography. Relevant factors were identified in the clinical history; cystic fibrosis gene mutation analysis was performed; humoral immune defects were determined by measuring immunoglobulins, IgG subclasses and functional response to Pneumovax II vaccine; assessment was made of neutrophil function (respiratory burst, adhesion molecule expression, and chemotaxis); ciliary function was observed and those likely to have allergic bronchopulmonary aspergillosis (ABPA) were identified. Causes identified were: immune defects (12 cases), cystic fibrosis (4), Young's syndrome (5), ciliary dysfunction (3), aspiration (6), panbronchiolitis (1), congenital defect (1), ABPA (11), rheumatoid arthritis (4), and early childhood pneumonia, pertussis, or measles (44). Intensive investigation of this population of patients with bronchiectasis led to identification of one or more causative factor in 47% of cases. In 22 patients (15%), the cause identified had implications for prognosis and treatment.


Assuntos
Bronquiectasia/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bronquiectasia/diagnóstico por imagem , Bronquiectasia/epidemiologia , Causalidade , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Tomografia Computadorizada por Raios X
8.
Int J Parasitol ; 30(2): 223-6, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10704605

RESUMO

Polymerase-chain-reaction-based restriction fragment length polymorphism analysis was performed to establish genetic markers in rDNA, for the identification of the three sibling species of the Anisakis simplex complex and morphologically differentiated Anisakis species, i.e. Anisakis physeteris, Anisakis schupakovi, Anisakis typica and Anisakis ziphidarum. Different restriction patterns were found between A. simplex sensu stricto and Anisakis pegreffii with two of the restriction endonucleases used (HinfI and TaqI), between A. simplex sensu stricto and A. simplex C with one endonuclease (HhaI), and between A. simplex C and Aniskis pegreffii with three endonucleases (HhaI, HinfI and TaqI), while no variation in patterns was detected among individuals within each species. The species A. physeteris, A. schupakovi, A. typica and A. ziphidarum were found to be different from each other and different from the three sibling species of the A. simplex complex by distinct fragments using 10-12 of the endonucleases tested. The polymorphisms obtained by restriction fragment length polymorphisms have provided a new set of genetic markers for the accurate identification of sibling species and morphospecies.


Assuntos
Ascaridoidea/química , Ascaridoidea/genética , DNA Ribossômico/química , Animais , Ascaridoidea/classificação , Marcadores Genéticos , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição
9.
Isotopes Environ Health Stud ; 33(1-2): 43-51, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22087480

RESUMO

Abstract Locust nymphs were raised from hatching to adult locusts on either seedling wheat (C(3)) or maize (C(4)), to determine whether relative enrichments/depletions of (15)N and (13)C within body tissues are influenced by diet. The maize contained less hexose sugars and protein per gram than wheat. The isotopic spacing between the food and the whole insect was found to differ between the two diets. The lower quality maize diet showed an overall +5.1‰ enrichment in δ(15)N compared to + 2.8‰ for wheat, possibly due to increased fractionation due to protein recycling. The maize diet resulted in increased depletion in lipid and trehalose and depletion in chitin relative to diet. The results for both δ(15)N and δ(13)C suggest that substrate recycling was occurring on the low quality maize diet. Therefore diet quality determines the enrichment/depletion in δ(15)N and δ(13)C within organisms.

11.
J Acoust Soc Am ; 98(2 Pt 1): 712-21, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7642810

RESUMO

Calling blue and fin whales have been tracked using relative travel times and amplitudes from both direct and multipath arrivals to a seafloor array of seismometers. Calls of three fin whales swimming in the same general direction, but several kilometers apart, are believed to represent communication between the whales because of signature differences in call character, an alternating call pattern, and coordination of call and respiration times. Whale call tracks, call patterns, call character, and swimming speeds were examined during periods with and without the presence of noise. Noise sources included airguns, when the whales were subject to sound levels of up to 143 dB P-P (peak-to-peak) re: 1 microPa over the 10 to 60-Hz band, and transits of merchant ships, when the whales received continuous levels up to 106 dB rms re: 1 microPa over the 10 to 60-Hz band (115 dB P-P). Whale responses associated with these noises remain arguable.


Assuntos
Baleias , Animais , Comportamento Animal , Ecolocação , Ruído , Oceano Pacífico , Espectrografia do Som , Vocalização Animal
13.
Invest Ophthalmol Vis Sci ; 36(5): 828-40, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7706031

RESUMO

PURPOSE: To characterize a model of contact lens-induced corneal inflammation in the closed eye, with respect to inflammatory parameters and the metabolism of arachidonic acid by homogenates of the corneal epithelium. METHODS: Rabbit eyes were fitted with extended wear etafilcon A (58% water) hydrogel contact lenses in stacked fashion (two lenses per eye), followed by a silk suture tarsorrhaphy of approximately 90%. The anterior surface was analyzed over a 9-day period for inflammatory events through slit lamp biomicroscopy, subjective inflammatory scoring, corneal pachymetry, and corneal epithelial [1-(14)C]-arachidonic acid metabolism. RESULTS: Hydrogel contact lens wear in the closed eye resulted in a progressive anterior surface inflammatory response correlated over time (r = 0.999). Central corneal thickness progressively increased and was also correlated to the inflammatory score (r = 0.995). [1-(14)C]-arachidonic acid metabolism by homogenates of the corneal epithelium resulted in the time-dependent formation of two major products, 12-hydroxyeicosatetraenoic acid (12-HETE) and 12-hydroxyeicosatrienoic acid (12-HETrE). Correlations were established between the synthesis of 12-HETE and 12-HETrE, the subjective inflammatory score (r = 0.963) and the progressive increase in corneal thickness (r = 0.971), over 9 days. CONCLUSIONS: With this model of contact lens wear, eicosanoid synthesizing capacity of the corneal epithelium showed a time-dependent increase in the production of 12-HETE and 12-HETrE strongly correlating to the in situ inflammatory response. The relationship between 12-HETE and 12-HETrE synthesis and the degree of anterior surface inflammation implicate these eicosanoids, among others, as mediators of the inflammatory response to hydrogel contact lens wear in the closed eye.


Assuntos
Córnea/metabolismo , Sistema Enzimático do Citocromo P-450/biossíntese , Pálpebras/cirurgia , Ácidos Hidroxieicosatetraenoicos/biossíntese , Ceratite/metabolismo , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico , Animais , Cromatografia Líquida de Alta Pressão , Lentes de Contato de Uso Prolongado/efeitos adversos , Córnea/patologia , Edema da Córnea/etiologia , Edema da Córnea/metabolismo , Edema da Córnea/patologia , Modelos Animais de Doenças , Epitélio/metabolismo , Epitélio/patologia , Ceratite/etiologia , Ceratite/patologia , Masculino , Coelhos , Fatores de Tempo
14.
Pacing Clin Electrophysiol ; 16(8): 1713-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7690940

RESUMO

To determine whether the magnitude of Beat-to-Beat variability in stroke volume (SV) during VVI pacing can predict hemodynamic benefit from DDD pacing, we undertook Doppler recordings of systolic and diastolic LV flow during VVI and DDD pacing in 20 patients (age 54 +/- 9 years) with DDD pacemakers implanted due to AV block. SV increased by 19% +/- 10% from VVI to DDD (P < 0.01). This increase was greater (29% +/- 9%) in patients with a ratio of early (E)/late (A) filling < 1 compared to those with E/A > 1 (10% +/- 9%) (P < 0.001). Beat-to-Beat variability in SV was greater in VVI (13% +/- 8%) compared to DDD (4% +/- 1%) (P < 0.001). Patients with E/A < 1 showed greater Beat-to-Beat variability in SV during VVI pacing (19 +/- 6%) compared to those with E/A > 1 (8% +/- 4%) (P < 0.001). Beat-to-Beat variability in SV during VVI pacing correlated with both percent change in SV from VVI to DDD (r = 0.89, P < 0.001) and E/A (r = -0.71, P < 0.001). In conclusion, patients with E/A < 1 derive greater hemodynamic benefit at rest from DDD pacing compared with E/A > 1. In addition, patients with complete AV block who show large variations in SV during VVI pacing may obtain greater hemodynamic benefit at rest from DDD pacing than patients with small variations.


Assuntos
Estimulação Cardíaca Artificial/métodos , Frequência Cardíaca/fisiologia , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Adolescente , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Débito Cardíaco/fisiologia , Ecocardiografia , Ecocardiografia Doppler , Feminino , Previsões , Bloqueio Cardíaco/fisiopatologia , Bloqueio Cardíaco/terapia , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/fisiopatologia , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologia
15.
J Helminthol ; 65(3): 234-8, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1719067

RESUMO

Acetic orcein stain may be dropped onto the specimen before applying a cover slip. This single reagent reveals cercarial and metacercarial structures that would otherwise be made visible only by complicated and time consuming procedures.


Assuntos
Oxazinas , Coloração e Rotulagem , Trematódeos/anatomia & histologia , Animais
16.
Health Care Manage Rev ; 14(1): 81-9, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2647673

RESUMO

Controversy prevails concerning the relative superiority of for-profit versus not-for-profit hospitals. Presented here are three variations to each of two basic theoretical models that contrast performance of for-profit and not-for-profit hospitals.


Assuntos
Economia Hospitalar , Hospitais com Fins Lucrativos/economia , Hospitais Filantrópicos/economia , Organização e Administração , Objetivos Organizacionais , Comportamento do Consumidor , Teoria da Decisão , Administração Financeira de Hospitais , Modelos Teóricos , Papel do Médico , Qualidade da Assistência à Saúde , Estados Unidos
17.
Pacing Clin Electrophysiol ; 11(6 Pt 1): 730-5, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2456553

RESUMO

Five patients with respiratory dependent rate responsive pacemakers (Biorate RDP3, Biotec) were studied using ambulatory telemetry to evaluate the sensitivity of this pacing system to nonrespiratory signals. In each case the pacemaker was implanted in the left infraclavicular position with an impedance sensing electrode inserted into the subcutaneous tissues of the anterior chest wall. The pacing rate was 73 +/- 2 beats per minute at rest and rose by 42 +/- 5 beats per minute when the patients were walking with both arms swinging (mean +/- SEM). Three of the five patients had sensing electrodes that extended across the midline. In this subgroup, pacing rate rose by 26 +/- 4 beats per minute when walking with arms held immobile and by 36 +/- 2 beats per minute during sustained voluntary hyperventilation. These same activities did not elicit any appreciable changes in pacing rate in the remaining two patients whose sensing electrodes were confined to the left hemithorax. Recordings taken from all five patients while they were standing upright and regularly swinging one upper limb showed an increase in pacing rate of 15 + 6 beats per minute with movement of the right arm and 46 + 8 with movement of the left. These observations establish that the Biorate RDP3 pacemaker is capable of responding both to changes in respiratory rate and to movement of the upper limbs. The sensitivity to limb movement is greatest when the chest wall impedance sensor does not extend across the midline and is most evident when the arm ipsilateral to the pacemaker is swung.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Marca-Passo Artificial , Respiração , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação
18.
Br Heart J ; 58(6): 613-6, 1987 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3322351

RESUMO

Atrial tracking pacemakers may improve exercise capacity and symptoms because they maintain atrioventricular synchrony and preserve the physiological response of heart rate to exercise. A rate responsive pacemaker which reacts to physical activity may be effective in patients with sinus node disease who are unsuitable for VDD pacing. At least three months after implant a double blind randomised short and long term crossover study was performed in ten patients with complete heart block: block was present at rest and during exercise on a modified Bruce protocol. Symptoms were assessed on a visual analogue scale and exercise capacity (maximal oxygen consumption and anaerobic threshold) was measured during rate responsive (peak rate 125/min) and conventional fixed rate (VVI) pacing (70/min). One month after randomisation treadmill exercise was performed. The mode was then changed to the other pacing mode and exercise was repeated three hours later. After another month the process was repeated but in the reverse order. During long term assessment there was subjective improvement in the sensation of breathlessness with rate responsive pacing. During short term assessment maximal oxygen consumption increased and the benefit was maintained during long term rate responsive compared with long term VVI pacing; oxygen consumption at the anaerobic threshold was similarly improved. Activity detecting rate responsive pacing is better than fixed rate ventricular pacing in patients with complete atrioventricular block.


Assuntos
Estimulação Cardíaca Artificial/métodos , Bloqueio Cardíaco/terapia , Marca-Passo Artificial , Esforço Físico , Adulto , Idoso , Ensaios Clínicos como Assunto , Método Duplo-Cego , Teste de Esforço , Humanos , Pessoa de Meia-Idade , Consumo de Oxigênio , Distribuição Aleatória , Respiração
20.
J Am Coll Cardiol ; 9(6): 1230-4, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2953772

RESUMO

Animal studies have established that there is a rapid increase in extracellular potassium concentration in myocardial tissue after the onset of ischemia. To study this phenomenon in humans, coronary sinus plasma potassium concentration was measured in five patients undergoing therapeutic coronary angioplasty. Recordings were obtained during a total of 22 coronary artery occlusions lasting between 5 and 50 seconds. Though little change was observed during angioplasty balloon inflation, all occlusions that lasted more than 15 seconds were followed by a transient elevation in coronary sinus potassium concentration of between 0.18 and 1.55 mmol X liter-1. The majority of occlusions (n = 17) were not accompanied by chest pain, electrocardiographic (ECG) changes or alteration of heart rate. The increase in coronary sinus potassium concentration after angioplasty balloon deflation is attributable to a washout of accumulated extracellular potassium during reperfusion. Redistribution of human myocardial potassium occurs within 15 seconds of the onset of myocardial ischemia and may be an important factor accounting for early electrophysiologic changes.


Assuntos
Doença das Coronárias/metabolismo , Miocárdio/metabolismo , Potássio/metabolismo , Doença Aguda , Angioplastia com Balão , Doença das Coronárias/fisiopatologia , Doença das Coronárias/terapia , Eletrocardiografia , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade
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