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1.
Schweiz Arch Tierheilkd ; 158(11): 759-763, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27821380

RESUMEN

INTRODUCTION: This case report includes different diagnostic imaging methods for localization of textile foreign bodies in reptiles and shows the limitations and advantages of these methods. A six-year-old, male, green iguana was presented to our clinic after ingesting a sock 5 days earlier. Ultrasound, contrast x-ray, computed tomography and endoscopy were used to locate the foreign body before surgery. Attempts to remove the sock endoscopically failed. The sock was surgically removed via celiotomy and enterotomy.


Asunto(s)
Cuerpos Extraños/veterinaria , Iguanas , Textiles , Animales , Endoscopía/veterinaria , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía , Masculino , Tomografía Computarizada por Rayos X/veterinaria , Ultrasonografía/veterinaria
2.
Rev. med. vet. zoot ; 62(3): 75-92, sep.-dic. 2015. ilus, tab
Artículo en Español | LILACS-Express | LILACS | ID: lil-779686

RESUMEN

La distocia en reptiles es una patología caracterizada por la dificultad de llevar a cabo el proceso de parto u ovoposición, la literatura es escasa en lo que concierne a distocias en serpientes, por tanto, existen vacíos frente a este tema. Se describe el caso de una serpiente Coelognathus flavolineatus de 10 años de edad que presentaba dificultad en la ovoposición. Fueron evaluados parámetros sanguíneos, radiográficos y ecográficos, así como cultivo bacteriano y antibiograma, con el fin de identificar las posibles causas y complicaciones que desencadenaron el proceso de distocia en la serpiente. En cuanto al tratamiento de la distocia, se realizó una punción aspirativa del huevo a través de la cloaca extrayéndose su contenido, posteriormente se procedió a extraer los restos y se tomaron hisopados de la mucosa del tracto reproductivo. Las muestras seleccionadas fueron sometidas a cultivo, luego de lo cual, se aislaron cepas de Salmonella del grupo F-67 y Escherichia coli, y en menor proporción cepas de Morganella morganii, Pseudomona aeruginosa, Flavobacterium y Proteus, las cuales se atribuyen como agentes infecciosos involucrados en la distocia en la serpiente.


Dystocia in reptiles is a disease characterized by the difficulty of carrying out the process of calving or oviposition, literature is scarce in regard to dystocia in snakes, therefore, there are unsolved questions with this issue. A case of a snake Coelognathus flavolineatus of 10 years of age that had difficulty in the oviposition is described. The blood, radiographic and ultrasound parameters were evaluated as well as bacterial culture and antibiogram, in order to identify the possible causes and complications that the dystocia process causes in the snake. In regard to the treatment of dystocia, an aspiration of the egg through the cloaca was carried out. Its content was pulled out, then we proceeded to remove the remains and swabs were taken of the mucosa of the reproductive tract. The selected samples were tested by cultivation, where Salmonella was isolated from the F-67 group and Escherichia coli, and to a smaller proportion of strains Morganella morganii, Pseudomonas aeruginosa, Flavobacterium and Proteus, attributed as infectious agents involved in the dystocia in the snake.

3.
Artículo en Inglés | MEDLINE | ID: mdl-26105200

RESUMEN

OBJECTIVE: The cardiac anatomy in tortoises depicted on B-mode and color-Doppler should be better differentiated by additional contrast-echocardiography. MATERIAL AND METHODS: An intravenous contrast agent (INN-sulphur hexafluoride [SonoVue®]) was injected in four tortoises (three Testudo hermanni, one Agrionemys horsfieldii), via the coccygeal vein, with parallel B-mode echocardiographic examination. The results of the contrast-enhanced echocardiography were compared with the contrast-free B-mode recordings and color-Doppler ultrasound. RESULTS: The use of SonoVue® enabled clearer distinction of the cardiac structures, differentiation of the arising major arteries, identification of wash-out-shunts, and visualization of blood flow patterns throughout the tortoise heart. CONCLUSION AND CLINICAL RELEVANCE: This study enables the accurate depiction and differentiation of cardiac anatomy in tortoises through the use of a combination of B-mode, color-Doppler and contrast-echocardiography. Basic knowledge of blood flow in the reptile heart is essential to understand echocardiographic anatomy. Blood-flow-patterns and anatomy of the tortoise heart as found in this study will help to establish a basis for further echocardiographic examinations of these animals.


Asunto(s)
Ecocardiografía/métodos , Corazón/fisiología , Tortugas/fisiología , Animales , Fosfolípidos/uso terapéutico , Hexafluoruro de Azufre/uso terapéutico
4.
Artículo en Alemán | MEDLINE | ID: mdl-23765364

RESUMEN

In a 6-month-old, chronically inappetent Lawsons's Dragon (Pogona henrylawsonii) with stunted growth a hyperdense cardiac region was found using radiology and computed tomography. At necropsy a profound necrosis of the myocardium with dystrophic calcification was diagnosed. In contrast to the frequently seen metastatic mineralisation of soft tissues, mainly due to poor husbandry, primary tissue destruction is the cause for dystrophic calcification. In reptiles, this is a rarely described form of calcification. Possible causes are infectious processes, nutritional or metabolic insufficiencies, intoxications or genetic components. In the presented case the aetiology could not be determined. In conclusion, dystrophic calcifications should be considered as a differential diagnosis in reptiles with soft tissue mineralisation.


Asunto(s)
Calcinosis/veterinaria , Cardiomiopatías/veterinaria , Iguanas , Animales , Calcinosis/diagnóstico , Calcinosis/diagnóstico por imagen , Cardiomiopatías/diagnóstico , Cardiomiopatías/diagnóstico por imagen , Radiografía
6.
J Clin Microbiol ; 39(9): 3156-63, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11526144

RESUMEN

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to a herpesvirus associated with an upper respiratory tract disease in Mediterranean tortoises [spur-thighed tortoise (Testudo graeca) and Hermann's tortoise (Testudo hermanni)]. This serodiagnostic test was validated through a hyperimmunization study. The mean of the A(405) readings of the plasma samples collected at time zero of the hyperimmunization study plus three times the standard deviation was used as the cutoff for seropositivity in tortoises. ELISA results were compared to serum neutralization (SN) values for the same samples by using the McNemar test. The results obtained by SN and ELISA were not significantly different (P > 0.05). This new ELISA could be used as an important diagnostic tool for screening wild populations and private and zoo collections of Mediterranean tortoises.


Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por Herpesviridae/veterinaria , Herpesviridae/inmunología , Infecciones del Sistema Respiratorio/veterinaria , Tortugas , Animales , Antígenos Virales/análisis , Ensayo de Inmunoadsorción Enzimática , Infecciones por Herpesviridae/virología , Inmunización , Immunoblotting , Ratones , Pruebas de Neutralización , Conejos , Reproducibilidad de los Resultados , Infecciones del Sistema Respiratorio/virología
7.
Mol Cell Biol ; 19(1): 229-40, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9858547

RESUMEN

Genetic and biochemical studies have identified kinase suppressor of Ras (KSR) to be a conserved component of Ras-dependent signaling pathways. To better understand the role of KSR in signal transduction, we have initiated studies investigating the effect of phosphorylation and protein interactions on KSR function. Here, we report the identification of five in vivo phosphorylation sites of KSR. In serum-starved cells, KSR contains two constitutive sites of phosphorylation (Ser297 and Ser392), which mediate the binding of KSR to the 14-3-3 family of proteins. In the presence of activated Ras, KSR contains three additional sites of phosphorylation (Thr260, Thr274, and Ser443), all of which match the consensus motif (Px[S/T]P) for phosphorylation by mitogen-activated protein kinase (MAPK). Further, we find that treatment of cells with the MEK inhibitor PD98059 blocks phosphorylation of the Ras-inducible sites and that activated MAPK associates with KSR in a Ras-dependent manner. Together, these findings indicate that KSR is an in vivo substrate of MAPK. Mutation of the identified phosphorylation sites did not alter the ability of KSR to facilitate Ras signaling in Xenopus oocytes, suggesting that phosphorylation at these sites may serve other functional roles, such as regulating catalytic activity. Interestingly, during the course of this study, we found that the biological effect of KSR varied dramatically with the level of KSR protein expressed. In Xenopus oocytes, KSR functioned as a positive regulator of Ras signaling when expressed at low levels, whereas at high levels of expression, KSR blocked Ras-dependent signal transduction. Likewise, overexpression of Drosophila KSR blocked R7 photoreceptor formation in the Drosophila eye. Therefore, the biological function of KSR as a positive effector of Ras-dependent signaling appears to be dependent on maintaining KSR protein expression at low or near-physiological levels.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Proteínas Quinasas/metabolismo , Proteínas/metabolismo , Tirosina 3-Monooxigenasa , Proteínas ras/metabolismo , Proteínas 14-3-3 , Células 3T3 , Animales , Sitios de Unión , Línea Celular , Línea Celular Transformada , Drosophila melanogaster , Ratones , Mutación , Fosforilación , Unión Proteica , Proteínas Quinasas/genética , Conejos , Serina
8.
Aviat Space Environ Med ; 67(5): 467-73, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8725475

RESUMEN

We conducted an opinion survey to improve the characterization of medical risk during spaceflight, using a questionnaire designed to elicit space medicine experts' perceptions of the probability, health effect, and mission impact of selected medical events occurring during spaceflight missions of 30-90 d. This questionnaire was directed toward those events about which little data currently exist, therefore medical events that have occurred during spaceflights with some frequency, such as space motion sickness, were excluded from the questionnaire. The questionnaire was mailed to 99 clinical and research professionals involved with NASA medical programs; 65 responses were returned, of which 60 could be analyzed. The experts rated skin disorders as the most likely to occur, but which would have little effect on mission completion or astronaut health. Circulatory diseases were rated as having the lowest probability of occurrence, but the highest effect on the mission or on a crewmember's health. The results of this survey will be combined with data from analogous populations and existing astronaut health data to establish a data set to support decisions about allocation of health care resources.


Asunto(s)
Enfermedades Profesionales/epidemiología , Vuelo Espacial , Humanos , Medición de Riesgo , Encuestas y Cuestionarios
9.
Mol Cell Biol ; 15(6): 3390-7, 1995 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7760835

RESUMEN

Recent reports have demonstrated the in vivo association of Raf-1 with members of the 14-3-3 protein family. To address the significance of the Raf-1-14-3-3 interaction, we investigated the enzymatic activity and biological function of Raf-1 in the presence and absence of associated 14-3-3. The interaction between these two molecules was disrupted in vivo and in vitro with a combination of molecular and biochemical techniques. Biochemical studies demonstrated that the enzymatic activities of Raf-1 were equivalent in the presence and absence of 14-3-3. Furthermore, mixing of purified Raf-1 and 14-3-3 in vitro was not sufficient to activate Raf-1. With a molecular approach, Cys-165 and Cys-168 as well as Ser-259 were identified as residues of Raf-1 required for the interaction with 14-3-3. Cys-165 and Cys-168 are located within the conserved cysteine-rich region of the CR1 domain, and Ser-259 is a conserved site of serine phosphorylation found within the CR2 domain. Mutation of either Cys-165 and Cys-168 or Ser-259 prevented the stable interaction of Raf-1 with 14-3-3 in vivo. Consistent with the model in which a site of serine phosphorylation is involved in the Raf-1-14-3-3 interaction, dephosphorylated Raf-1 was unable to associate with 14-3-3 in vitro. Phosphorylation may represent a general mechanism mediating 14-3-3 binding, because dephosphorylation of the Bcr kinase (known to interact with 14-3-3) also eliminated its association with 14-3-3. Finally, mutant Raf-1 proteins unable to stably interact with 14-3-3 exhibited enhanced enzymatic activity in human 293 cells and Xenopus oocytes and were biologically activated, as demonstrated by their ability to induced meiotic maturation of Xenopus oocytes. However, in contrast to wild-type Raf-1, activation of these mutants was independent of Ras. Our results therefore indicate that interaction with 14-3-3 is not essential for Raf-1 function.


Asunto(s)
Proteínas Serina-Treonina Quinasas/química , Proteínas/metabolismo , Proteínas Proto-Oncogénicas/química , Tirosina 3-Monooxigenasa , Proteínas 14-3-3 , Animales , Línea Celular , Activación Enzimática , Humanos , Mutación , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-raf , Xenopus
10.
Biochem Genet ; 31(1-2): 29-50, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8471022

RESUMEN

The peptidase system in Drosophila melanogaster (dipeptidase-A, -B, and -C and leucine aminopeptidases G and P) was used as a model to study the effects of modifier genes on activity of enzymes with similar functions. A screen of X, second, and third chromosome substitution isogenic lines revealed the presence of activity modifiers for peptidases on all three chromosomes. Correlation analyses indicated that covariation between some of the peptidase activities is independent of genetic background, while others are associated with variable second chromosomes. Chromosome-specific effects on Km, Vmax, and specific activity of partially purified peptidases were also detected. Moreover, a repeatable technique using anion-exchange column chromatography allowed the characterization of possibly two putative peptidic enzymes, glycyl-L-isoleucine-ase and L-leucyl-L-proline-ase, whose kinetic properties differ from the dipeptidases and the leucine aminopeptidases. These findings confirm the existence of activity modifiers for peptidases, much like other enzymes in Drosophila melanogaster.


Asunto(s)
Cromosomas/fisiología , Dipeptidasas/metabolismo , Drosophila melanogaster/enzimología , Leucil Aminopeptidasa/metabolismo , Análisis de Varianza , Animales , Cromatografía por Intercambio Iónico , Dipeptidasas/genética , Dipeptidasas/aislamiento & purificación , Drosophila melanogaster/genética , Variación Genética , Leucil Aminopeptidasa/genética , Leucil Aminopeptidasa/aislamiento & purificación , Masculino , Cromosoma X/fisiología
11.
Artículo en Inglés | MEDLINE | ID: mdl-8149927

RESUMEN

Hemodynamic, cardiac, and hormonal responses to lower-body negative pressure (LBNP) were examined in 24 healthy men to test the hypothesis that responsiveness of reflex control of blood pressure during orthostatic challenge is associated with interactions between strength and aerobic power. Subjects underwent treadmill tests to determine peak oxygen uptake (VO2max) and isokinetic dynamometer tests to determine knee extensor strength. Based on predetermined criteria, subjects were classified into one of four fitness profiles of six subjects each, matched for age, height, and body mass: (a) low strength/average aerobic fitness, (b) low strength/high aerobic fitness, (c) high strength/average aerobic fitness, and (d) high strength/high aerobic fitness. Following 90 min of 0.11 rad (6 degrees) head-down tilt (HDT), each subject underwent graded LBNP to -6.7 kPa or presyncope, with maximal duration 15 min, while hemodynamic, cardiac, and hormonal responses were measured. All groups exhibited typical hemodynamic, hormonal, and fluid shift responses during LBNP, with no intergroup differences between high and low strength characteristics. Subjects with high aerobic power exhibited greater (P < 0.05) stroke volume and lower (P < 0.05) heart rate, vascular peripheral resistance, and mean arterial pressure during rest, HDT, and LBNP. Seven subjects, distributed among the four fitness profiles, became presyncopal. These subjects showed greatest reduction in mean arterial pressure during LBNP, had greater elevations in vasopressin, and lesser increases in heart rate and peripheral resistance. Neither VO2max nor leg strength were associated with fall in arterial pressure or with syncopal episodes. We conclude that interactions between aerobic and strength fitness characteristics do not influence responses to LBNP challenge.


Asunto(s)
Epinefrina/sangre , Hemodinámica/fisiología , Presión Negativa de la Región Corporal Inferior , Contracción Muscular/fisiología , Norepinefrina/sangre , Aptitud Física/fisiología , Adulto , Presión Sanguínea/fisiología , Humanos , Masculino , Consumo de Oxígeno/fisiología , Postura/fisiología , Renina/sangre , Resistencia Vascular/fisiología
12.
Biochem Genet ; 30(11-12): 603-24, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1296574

RESUMEN

Dip-A, Dip-B, and Dip-C constitute structural genes for three peptidic enzymes in Drosophila melanogaster distinct from the leucine aminopeptidases. Their ontogenetic and tissue distributions of activities suggest the involvement of these enzymes in a general metabolic role, such as the regulation of amino acid and oligopeptide pools to make amino acids available for protein synthesis. Screening of chromosome substitution isogenic lines for DIP-C activity indicated that, like DIP-A and DIP-B, unlinked activity modifiers exist for Dip-C. The developmental profiles of dipeptidase activities are very similar, except in the pupal stage, during which DIP-C activity is markedly low compared to the other two enzymes. Intercorrelations of dipeptidase activities vary ontogenetically, which is consistent with the need for coordinate expression of these enzymes during certain developmental stages. Tissue-specific expression of dipeptidases in larvae and adults are also similar, although the relative levels of DIP-A activity differ from those of DIP-B and DIP-C in certain organs and body parts. Some of the differences among chromosome substitution lines for dipeptidase activities appear to be systemic, while others are developmental stage-specific and tissue-specific. Second- and third-chromosome variants for DIP-C activity differed in their tissue distribution. This is consistent with the presence of temporal and spatial variants in natural populations for other Drosophila enzymes.


Asunto(s)
Dipeptidasas/genética , Drosophila melanogaster/genética , Isoenzimas/genética , Animales , Dipeptidasas/biosíntesis , Drosophila melanogaster/enzimología , Drosophila melanogaster/crecimiento & desarrollo , Femenino , Regulación Enzimológica de la Expresión Génica , Genes , Isoenzimas/biosíntesis , Larva , Masculino , Especificidad de Órganos , Pupa
13.
Genetics ; 131(3): 625-42, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1628808

RESUMEN

The peptidase system in Drosophila melanogaster, consisting of dipeptidase-A, dipeptidase-B, dipeptidase-C and the leucine aminopeptidases, was used as a model to study the adaptive significance of enzyme activity variation. The involvement of the peptidases in osmoregulation has been suggested from the ubiquitous distribution of peptidase activities in nearly all tissues and the high concentration of amino acids and oligopeptides in the hemolymph. Under this hypothesis, larvae counteract increases in environmental osmotic stress by hydrolyzing peptides into amino acids both intra- and extracellularly to increase physiological osmotic concentration. The expression of the peptidases was studied by assaying for peptidase activities in third instar larvae of isogenic lines, which were reared under increasing levels of environmental osmotic stress using either D-mannitol or NaCl. Second and third chromosome substitution isogenic lines were used to assess the relative contribution of regulatory and structural genes in enzyme activity variation. Results indicate that: (1) genetic variation exists for peptidase activities, (2) the effect of osmotic stress is highly variable among peptidases, (3) changes in peptidase activities in response to osmotic stress depend on both genetic background and osmotic effector and (4) peptidase activities are correlated with each other, but these phenotypic correlations depend on genetic background, osmotic effector, and level of osmotic stress. Osmotic concentration in the larval hemolymph is correlated with leucine aminopeptidase activity, but changes in hemolymph osmotic concentration in response to environmental osmotic stress depend on the osmotic effector in the environment. Although these findings suggest that genetic and environmental factors contribute significantly toward the expression of enzymes with similar functions, a relative larval viability study of genotypes that differed significantly in dipeptidase-B (DIP-B) activity revealed that low DIP-B activity did not confer any measurable reduction in larval viability under increasing levels of environmental osmotic stress. These negative results suggest that, either DIP-B does not play a major role in osmoregulation or differential osmoregulation is not related to egg to adult viability in these tests.


Asunto(s)
Dipeptidasas/biosíntesis , Drosophila melanogaster/enzimología , Leucil Aminopeptidasa/biosíntesis , Animales , Dipeptidasas/genética , Dipeptidasas/metabolismo , Drosophila melanogaster/genética , Ambiente , Femenino , Hemolinfa/enzimología , Larva/crecimiento & desarrollo , Leucil Aminopeptidasa/genética , Leucil Aminopeptidasa/metabolismo , Masculino , Presión Osmótica
14.
Ecotoxicol Environ Saf ; 20(2): 197-202, 1990 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2276364

RESUMEN

Since 1980 the German Ministry of Research has sponsored a number of ecotoxicological research projects aimed at the analysis of effects of environmental chemicals on terrestrial ecosystems. Some of these field studies were conducted by using a baseline-ecosystem approach, the theoretical framework of which is given. It is demonstrated by the baseline ecosystem derived from a ruderal site. The results from the German ecotoxicology program concerning some features of structural and functional responses of ecosystems to chemicals are summarized. Many effects observed in "real nature" could be attributed to the substances under study as side effects due to the integrative approach. This means that without knowledge of the structure and function of a biogeocoenosis reliable predictions of chemically induced changes at the ecosystem level will not be possible.


Asunto(s)
Ecología , Toxicología/métodos , Modelos Biológicos , Proyectos de Investigación
15.
Aviat Space Environ Med ; 60(7): 653-8, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2764848

RESUMEN

The purpose of these experiments was to test the hypothesis that reduced size of the leg muscle compartment following exposure to long-duration microgravity would be associated with increased leg compliance. Eight men, 31-45 years of age, were measured for vascular compliance of the calf and serial circumferences of the thigh and calf before, during and after 30 d of continuous 6 degrees head-down bedrest. Cross-sectional areas (CSA) of muscle, fat, and bone compartments in the thigh and calf were determined pre- and post-bedrest by computed tomography. Calculated leg volumes decreased (p less than 0.05) in the calf by 9.9% and in the thigh by 4.5% from pre- to post-bedrest. Muscle compartment CSA also decreased (p less than 0.05) in both calf (-4.8%) and thigh (-8.1%); leg compliance (vol%/mm Hg x 100) increased (p less than 0.05) from 3.9 +/- 0.7 to 4.9 +/- 0.5. Calf compliance measured before and after bedrest was inversely related to calf muscle compartment CSA (r = -0.61, p less than 0.05) and the percent decrease in calf muscle compartment CSA from pre- to post-bedrest was inversely correlated with an increase in calf compliance (r = -0.72, p less than 0.05). Increased leg compliance following long-duration spaceflight is associated with reduced size of the leg muscle compartment.


Asunto(s)
Pierna/patología , Ingravidez/efectos adversos , Tejido Adiposo/diagnóstico por imagen , Tejido Adiposo/patología , Adulto , Huesos/diagnóstico por imagen , Huesos/patología , Humanos , Pierna/irrigación sanguínea , Pierna/fisiopatología , Masculino , Persona de Mediana Edad , Músculos/diagnóstico por imagen , Músculos/patología , Músculos/fisiopatología , Flujo Sanguíneo Regional , Vuelo Espacial , Factores de Tiempo , Tomografía Computarizada por Rayos X , Pérdida de Peso
16.
Aviat Space Environ Med ; 58(12): 1149-52, 1987 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3426487

RESUMEN

High aerobic fitness may be associated with impaired responsiveness to orthostatic challenge. This could be detrimental to astronauts returning from spaceflight. Thus, we examined the cardiovascular responses of a group of 45 healthy women to graded lower body negative pressure (LBNP) through 5 min at -50 mm Hg or until they become presyncopal. The ages (range = 23-43 years, mean = 30.4) and peak aerobic capacities (range = 23.0-55.3 ml.kg-1.min-1, mean = 37.8) of these subjects paralleled those of the women astronauts. We monitored heart rate, stroke volume, cardiac output, Heather index of contractility, arterial pressure, peripheral resistance, change in calf circumference, and thoracic impedance (ZO)--a measure of fluid in the chest. The women in this study exhibited the same response pattern to LBNP as previously reported for male subjects. VO2peak of the six subjects who became presyncopal was not different from VO2peak of the tolerant subjects. At rest, only systolic and mean arterial pressures were significantly correlated with VO2peak. Percent changes in calf circumference (i.e. fluid accumulation in the legs) at -30 and -40 mm Hg were the only responses to LBNP significantly related to VO2peak. The greater pooling of blood in the legs during LBNP by women with higher aerobic fitness, and lower percent body fat may be related to more muscle tissue and vasculature in the legs of the more fit subjects. These data indicated that orthostatic tolerance is not related to aerobic capacity in women, and orthostatic tolerance need not be a concern to aerobically fit women astronauts.


Asunto(s)
Descompresión/efectos adversos , Presión Negativa de la Región Corporal Inferior/efectos adversos , Aptitud Física , Adaptación Fisiológica , Adulto , Aerobiosis , Líquidos Corporales/fisiología , Femenino , Humanos , Consumo de Oxígeno , Vuelo Espacial , Síncope/etiología
17.
Aviat Space Environ Med ; 57(6): 531-8, 1986 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3718376

RESUMEN

Lower body negative pressure (LBNP) has provided a method for studying cardiovascular responses in men while simulating a return to the stresses of 1-G following space flight. In this study, we have monitored responses of women to the stresses provided by LBNP. There were 20 women, 23-43 years, each tested in the follicular and luteal phases of the menstrual cycle. Variables were recorded during supine control; at -30, -40, -50 mm Hg LBNP; immediately after pressure release; and after 5 min recovery. There were no significant differences in response to LBNP between the two menstrual phases. During LBNP calf circumference was enlarged; transthoracic impedance was increased; stroke volume, left ventricular ejection time, the Heather Index of contractility and systolic pressure were reduced; total peripheral resistance was elevated; and cardiac output fell despite a rise in heart rate. Differences in cardiovascular variables between 0 mm Hg LBNP and -50 mm Hg LBNP were generally similar to reported differences between supine and standing. The responses of these women to LBNP were qualitatively similar to those reported for the Apollo astronauts and other male subjects. These women appeared to compensate with a greater heart rate response; however, the net cardiovascular compensation as determined from arterial pressure appears to be similar in men and women.


Asunto(s)
Descompresión , Hemodinámica , Presión Negativa de la Región Corporal Inferior , Ciclo Menstrual , Adulto , Presión Sanguínea , Gasto Cardíaco , Femenino , Fase Folicular , Frecuencia Cardíaca , Humanos , Fase Luteínica , Contracción Miocárdica , Postura , Volumen Sistólico , Resistencia Vascular
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