RESUMEN
Women's health throughout the world is adversely affected by low status and literacy, poor nutrition, environmental toxins, violence, and other social, cultural, and economic factors. The majority of maternal deaths and disability occur in the developing nations of the world, such as Africa, where being born female is often a tragedy. The International Confederation of Midwives and the American College of Nurse-Midwives have nearly a century of commitment to making pregnancies and births safer and women's lives better. The shared vision of women as persons who are due full human rights guides the efforts of nurses and midwives in their global efforts of working with women and childbearing families and promoting health for all.
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Área sin Atención Médica , Partería/organización & administración , Países en Desarrollo , Femenino , Humanos , Cooperación Internacional , Embarazo , Sociedades de Enfermería , Salud de la MujerRESUMEN
OBJECTIVE: Partial liquid ventilation with the perfluorochemical, perflubron, has been shown to improve lung mechanics and enhance gas exchange in the treatment of severe acute lung injury. However, the most effective strategy to provide optimal intrapulmonary distribution of perflubron has not been fully accessed. The objective of this study was to examine the effect of body position (supine vs. rotational) and mode of ventilation (conventional mechanical ventilation [CMV] vs. high-frequency oscillatory ventilation [HFOV]) on perflubron distribution and oxygenation improvement. DESIGN: Prospective, randomized, animal trial. SETTING: Research laboratory at a university medical center. SUBJECTS: Twenty healthy piglets (4.5-6.6 kg). INTERVENTIONS: Subjects underwent repetitive saline lavage to achieve a uniform degree of lung injury and then were randomized to either CMV or were converted to HFOV. Within each ventilator group, animals were randomized to supine positioning (S) or rotational positioning with alternation between supine and prone position (R) during incremental dosing of three 5-mL/kg doses of perflubron. MEASUREMENTS AND MAIN RESULTS: Arterial blood gas tensions, hemodynamic variables, and the oxygenation index were recorded after each dose of 5 mL/kg. Lateral cinefluoroscopic images after each dose were digitized for computer analysis of density. A density index was calculated for a 2-cm2 window in three dorsal and three ventral lung regions. Uniformity of distribution was calculated by comparing the mean density among the six regions. Oxygenation improvements were compared between groups. There were no significant differences in hemodynamic variables or gas exchange after lung injury in the four groups. Rotational positioning produced significantly more uniform perflubron distribution during both CMV and HFOV. This effect was independent of the mode of ventilation. The mean ventral density index was affected by rotating position and HFOV mode of ventilation after 10 mL/kg of perflubron, and rotating position was affected only after 15 mL/kg of perflubron. There was a significant reduction in the oxygenation index from baseline to end lavage in both CMV groups, as well as all of the animals that were rotated. CONCLUSION: Perflubron is more uniformly dispersed when dosed in a rotational fashion with alternation between supine and prone position during incremental dosing. This effect is independent of mode of ventilation. There was no relationship between oxygenation improvements and nondependent perflubron distribution. CMV and rotating dosing both led to a significant decrease in the oxygenation index after a 15 mL/kg dose of perflubron. This information has important impact on the future development of dosing strategies and clinical trial design.
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Modelos Animales de Enfermedad , Monitoreo de Drogas , Fluorocarburos/farmacocinética , Fluoroscopía , Ventilación de Alta Frecuencia/métodos , Ventilación Liquida/métodos , Posición Prona , Respiración Artificial/métodos , Síndrome de Dificultad Respiratoria/diagnóstico por imagen , Síndrome de Dificultad Respiratoria/terapia , Posición Supina , Animales , Análisis de los Gases de la Sangre , Evaluación Preclínica de Medicamentos , Monitoreo de Drogas/métodos , Fluorocarburos/administración & dosificación , Fluoroscopía/métodos , Hemodinámica/efectos de los fármacos , Humanos , Estudios Prospectivos , Intercambio Gaseoso Pulmonar/efectos de los fármacos , Distribución Aleatoria , Síndrome de Dificultad Respiratoria/inducido químicamente , Síndrome de Dificultad Respiratoria/metabolismo , Síndrome de Dificultad Respiratoria/fisiopatología , Mecánica Respiratoria/efectos de los fármacos , Cloruro de Sodio , Porcinos , Irrigación Terapéutica , Distribución TisularRESUMEN
Thirteen major volatiles of the carnation flower fragrance signature have been identified by GC/MS. Of these, ten, hexanal, (2E)-hexenal, 1-hexanol, 2-hexanol, 3-hexen-1-ol, nonanal, benzaldehyde, benzyl alcohol, benzyl benzoate and caryophyllene, were quantified. The steady-state levels of these ten volatiles change independently as the flowers develop and senesce, suggesting that their synthesis is developmentally regulated. In addition, the chemical composition of the fragrance signature in naturally senesced flowers proved to be very different from that for flowers that had been induced to senesce prematurely by treatment with ethylene. Thus, senescence-related changes in carnation floral scent appear not to be directly regulated by ethylene. From cellular fractionation studies, it is evident that all of the volatiles, except 2-hexanol, are present in both membranous and cytosolic compartments, suggesting that their synthesis is membrane-associated and that they subsequently partition into the cytosol in accordance with partition coefficients.
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Magnoliopsida/crecimiento & desarrollo , Odorantes/análisis , Alcoholes/análisis , Aldehídos/análisis , Cromatografía de Gases y Espectrometría de Masas , Magnoliopsida/químicaRESUMEN
Full-length cDNA clones encoding deoxyhypusine synthase (DHS) and eucaryotic initiation factor 5A (eIF-5A) have been isolated from a cDNA expression library prepared from tomato leaves (Lycopersicon esculentum, cv. Match) exposed to environmental stress. DHS mediates the first of two enzymatic reactions that activate eIF-5A by converting a conserved lysine to the unusual amino acid, deoxyhypusine. Recombinant protein obtained by expressing tomato DHS cDNA in Escherichia coli proved capable of carrying out the deoxyhypusine synthase reaction in vitro in the presence of eIF-5A. Of particular interest is the finding that DHS mRNA and eIF-5A mRNA show a parallel increase in abundance in senescing tomato flowers, senescing tomato fruit, and environmentally stressed tomato leaves exhibiting programmed cell death. Western blot analyses indicated that DHS protein also increases at the onset of senescence. It is apparent from previous studies with yeast and mammalian cells that hypusine-modified eIF-5A facilitates the translation of a subset of mRNAs mediating cell division. The present study provides evidence for senescence-induced DHS and eIF-5A in tomato tissues that may facilitate the translation of mRNA species required for programmed cell death.
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Regulación de la Expresión Génica de las Plantas , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Factores de Iniciación de Péptidos/genética , Proteínas de Unión al ARN , Solanum lycopersicum/enzimología , Solanum lycopersicum/genética , Envejecimiento , Secuencia de Aminoácidos , Archaea/genética , Secuencia de Bases , Secuencia Conservada , ADN Complementario , Hongos/genética , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Biblioteca de Genes , Humanos , Solanum lycopersicum/crecimiento & desarrollo , Lisina , Datos de Secuencia Molecular , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Factores de Iniciación de Péptidos/metabolismo , Hojas de la Planta/metabolismo , Tallos de la Planta/metabolismo , Plantas/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Factor 5A Eucariótico de Iniciación de TraducciónRESUMEN
Distinguishable populations of lipid particles isolated from chloroplasts of yellow wax bean (Phaseolus vulgaris L. cv Kinghorn Wax) leaves have been found to contain plastid-lipid-associated protein (J. Pozueta-Romero, F. Rafia, G. Houlné, C. Cheniclet, J.P. Carde, M.-L. Schantz, R. Schantz [1997] Plant Physiol 115: 1185-1194). One population is comprised of plastoglobuli obtained from sonicated chloroplasts by flotation centrifugation. Higher density lipid-protein particles isolated from chloroplast stroma by ultrafiltration constitute a second population. Inasmuch as the stromal lipid-protein particles contain plastid-lipid-associated protein, but are distinguishable from plastoglobuli in terms of their lipid and protein composition, they appear to be plastoglobuli-like particles. Of particular interest is the finding that plastoglobuli and the higher density lipid-protein particles both contain catabolites of the thylakoid protein, cytochrome f. These observations support the view that there are distinguishable populations of plastoglobuli-like particles in chloroplasts. They further suggest that the formation of these particles may allow removal of protein catabolites from the thylakoid membrane that are destined for degradation as part of normal thylakoid turnover.
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Citocromos/metabolismo , Fabaceae/metabolismo , Metabolismo de los Lípidos , Proteínas de Plantas/metabolismo , Plantas Medicinales , Plastidios/metabolismo , Secuencia de Aminoácidos , Western Blotting , Fraccionamiento Celular , Cloroplastos/química , Cloroplastos/metabolismo , Cromatografía en Gel , Citocromos f , Electroforesis en Gel de Poliacrilamida , Fabaceae/química , Lípidos/aislamiento & purificación , Datos de Secuencia Molecular , Proteínas de Plantas/aislamiento & purificación , Plastidios/química , Fracciones Subcelulares/química , Fracciones Subcelulares/metabolismo , Tilacoides/química , Tilacoides/metabolismoRESUMEN
Neutral xyloglucan was purified from the cell walls of suspension-cultured rose (Rosa sp. 'Paul's Scarlet') cells by alkali extraction, ethanol precipitation and anion-exchange chromatography on 'Q-Sepharose FastFlow'. The procedure recovered 70% of the total xyloglucan at about 95% purity in the neutral fraction. The remaining 30% of the xyloglucan was anionic, as demonstrated both by anion-exchange chromatography at pH 4.7 and by high-voltage electrophoresis at pH 6.5. Alkali did not cause neutral xyloglucan to become anionic, indicating that the anionic nature of the rose xyloglucan was not an artefact of the extraction procedure. Pre-incubation of neutral [3H]xyloglucan with any of ten non-radioactive acidic polysaccharides did not cause the radioactive material to become anionic as judged by electrophoresis, indicating that stable complexes between neutral xyloglucan and acidic polysaccharides were not readily formed in vitro. The anionic xyloglucan did not lose its charge in the presence of 8 M urea or after a second treatment with NaOH, indicating that its anionic nature was not due to hydrogen-bonding of xyloglucan to an acidic polymer. Proteinase did not affect the anionic xyloglucan, indicating that it was not associated with an acidic protein. Cellulase converted the anionic xyloglucan to the expected neutral nonasaccharide and heptasaccharide, indicating that the repeatunits of the xyloglucan did not contain acidic residues. Endo-polygalacturonase converted about 40% of the anionic xyloglucan to neutral material. Arabinanase and galactanase also converted appreciable proportions of the anionic xyloglucan to neutral material. These results show that about 30% of the xyloglucan in the cell walls of suspension-cultured rose cells exists in covalently-linked complexes with acidic pectins.
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Glucanos , Pectinas/metabolismo , Polisacáridos/metabolismo , Rosales/citología , Xilanos , Arabinosa/metabolismo , Artefactos , Pared Celular/fisiología , Células Cultivadas , Celulasa , Celulosa/metabolismo , Cromatografía por Intercambio Iónico , Electroforesis en Papel , Endopeptidasas , Oligosacáridos/química , Oligosacáridos/aislamiento & purificación , Pectinas/química , Pectinas/aislamiento & purificación , Poligalacturonasa , Polisacáridos/química , Polisacáridos/aislamiento & purificación , Técnica de Dilución de Radioisótopos , Rosales/fisiología , TritioRESUMEN
OBJECTIVE: The purpose of our study was to compare the ability of MR spectroscopy with that of standard presurgical methods to accurately lateralize the abnormal hippocampus in a group of patients with complex partial seizures. SUBJECTS AND METHODS: Ten healthy volunteers (five male, five female) without a history of seizures, significant head trauma, or other neurologic abnormalities were chosen to participate in the study. Twelve consecutive patients (three male, nine female) having intractable temporal lobe epilepsy and undergoing presurgical evaluation for temporal lobectomy were chosen to participate in the study. The condition of all patients was refractory to medications. All patients underwent presurgical examination with interictal and video ictal electroencephalography, ictal single-photon emission computed tomography, interictal positron emission tomography, MR imaging, and neuropsychologic testing. When noninvasive data were inconclusive, depth or grid recordings were performed. The results of MR spectroscopy were also compared with postsurgical seizure control as defined by the Engel classification. RESULTS: Nine (90%) of 10 control subjects showed no significant difference in N-acetyl aspartate. One control subject showed 16% asymmetry in N-acetyl aspartate between sides. The control group showed no statistically significant differences in ratios of N-acetyl aspartate:creatine, N-acetyl aspartate:choline, or creatine:choline when comparing sides (p < .05). All 12 patients showed clearly lateralizing values identified by the index of asymmetry in N-acetyl aspartate (range, 24-93%), with a mean difference of 51% (SD, 22) (p = .01). Additionally, as a group, statistically significant indexes of asymmetry (p = .01) were seen in ratios of N-acetyl aspartate:choline (mean, 42; SD, 22%), N-acetyl aspartate:creatine (mean, 41; SD, 27), and N-acetyl aspartate:creatine + choline (mean, 42; SD, 22). Using an N-acetyl aspartate index of asymmetry of greater than 15%, which represents the mean index of asymmetry of the control subjects +/- two SDs, as our cutoff level for lateralization, the correct side was identified in all patients. When comparing both hippocampi using an asymmetry index of 15% for N-acetyl aspartate:choline + creatine, 11 (92%) of 12 were correctly lateralized. When comparing the unaffected temporal lobes between patients and control subjects, no statistically significant differences were detected in any metabolites or ratios. CONCLUSION: Our study agrees with others in showing decreased N-acetyl aspartate in the hippocampus of seizure patients when compared with control subjects. Using N-acetyl aspartate, N-acetyl aspartate:creatine, N-acetyl aspartate:choline, and N-acetyl aspartate:creatine + choline as our parameters, patients with mesial temporal lobe epilepsy were correctly lateralized with MR spectroscopy when compared with clinical consensus criteria. We consider MR spectroscopy to be complementary to MR imaging. Both studies can be performed as a single integrated examination.
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Epilepsia del Lóbulo Temporal/metabolismo , Hipocampo/metabolismo , Espectroscopía de Resonancia Magnética , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/análisis , Colina/análisis , Creatina/análisis , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Hipocampo/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Temporal/cirugíaRESUMEN
PURPOSE: To describe the MR imaging findings in five children with proved L-carnitine deficiency. METHODS: MR imaging studies (five without contrast, two with contrast) were obtained in five children (mean age, 9 years) who presented with stroke symptoms and who proved to have L-carnitine deficiency as established by serum levels. RESULTS: In three of five patients, infarctions were confined to arterial distributions; one patient had a hemorrhagic infarction in one frontoparietal region; and one patient had only nonspecific periventricular white matter T2 hyper-intensities. Serum L-carnitine levels normalized after correction; sequelae included seizures in two patients, hemiparesis in one patient, normal outcome in one patient, and death in one patient. CONCLUSION: L-Carnitine deficiency is a rare metabolic disorder leading to cerebral infarctions, as seen in our five patients, and should be considered in the differential diagnosis of children who have had a stroke, particularly when associated with hypoglycemia and myopathy.
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Carnitina/deficiencia , Infarto Cerebral/diagnóstico , Imagen por Resonancia Magnética , Adolescente , Carnitina/sangre , Causas de Muerte , Hemorragia Cerebral/diagnóstico , Ventrículos Cerebrales/patología , Medios de Contraste , Diagnóstico Diferencial , Femenino , Lóbulo Frontal/patología , Hemiplejía/etiología , Humanos , Aumento de la Imagen , Lactante , Recién Nacido , Masculino , Lóbulo Parietal/patología , Convulsiones/etiologíaRESUMEN
The incidence of neonatal extracorporeal membrane oxygenation (ECMO) is decreasing nationally. This decrease is presumed to be a result of the emergence of alternative technologies such as high-frequency oscillatory ventilation (HFOV), nitric oxide (NO), and surfactant therapy as well as others. The purposes of the present report were to determine just how rapidly the demographics of ECMO are changing and to determine the impact of competing technologies on ECMO use. The authors reviewed their entire ECMO experience of 455 cases (370 neonatal, 38 pediatric, and 47 cardiac). The neonatal cases also were separated into diagnostic groups: MAS (meconium aspiration syndrome), PPHN (persistent pulmonary hypertension of the newborn), RDS (respiratory distress syndrome), and sepsis. To allow statistical comparison, the patients were divided into four chronological groups, of equal 3-year duration, spanning the 12 years that ECMO has been available. The results of the analysis demonstrated four principle findings. (1) The total number of patients receiving ECMO per year was declining (P = .0001). This decline was attributable to a reduction in the total number of neonatal patients, with the exception of cases of congenital diaphragmatic hernia. (2) The complexity of each ECMO run was increasing, as evidenced by substantial increases in mean ECMO duration per patient and an increase in the incidence of patient complications on ECMO (P = .0001). (3) There has been a significant decrease in the overall survival rate for patients treated with ECMO (P = .0001). (4) The ECMO population mix has shifted away from straightforward neonatal cases and toward the more complex pediatric and cardiac cases. This demographic shift has occurred as a result of improvements in pre-ECMO management of neonatal patients, and is primarily responsible for the findings noted above. However, there also has been a worsening of condition severity within each diagnostic group, which also is partly responsible for the changes noted. If these trends continue, pediatric, cardiac, and CDH patients will likely account for the majority of ECMO patients. Consequently, existing ECMO centers must be prepared to adapt to the changing demographics by evolving programs that support pediatric, cardiac, and adult patients, in addition to neonates. Furthermore, the complexity associated with transporting these unstable older patients and the likelihood that the number of active ECMO centers will decline may require remaining ECMO centers to develop long-distance ECMO transport capabilities.
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Oxigenación por Membrana Extracorpórea/tendencias , Adulto , Niño , Oxigenación por Membrana Extracorpórea/efectos adversos , Oxigenación por Membrana Extracorpórea/estadística & datos numéricos , Ventilación de Alta Frecuencia , Humanos , Incidencia , Recién Nacido , Óxido Nítrico/uso terapéutico , Selección de Paciente , Surfactantes Pulmonares/uso terapéutico , Análisis de Regresión , Análisis de Supervivencia , Evaluación de la Tecnología Biomédica , Resultado del TratamientoRESUMEN
Non-sedimentable microvesicles, termed deteriosomes, have been isolated from the cytosol of bean cotyledons by ultrafiltration, and found to be enzymatically active. Specifically, they possess proteinase activity that is able to catabolize exogenous proteins as well as deteriosome proteins. The proteolytic activity is inhibited by heat-denaturation and known proteinase inhibitors (iodoacetate and phenylmethylsulfonyl fluoride), and the pattern of deteriosome-associated proteinase activity changes with advancing senescence of the cotyledon tissue. Deteriosomes are formed by blebbing from membranes. The finding that they possess proteinase activity is consistent with an earlier proposal [(1991) Proc. Natl. Acad. Sci. USA 88, 2269-2273] that they are involved in membrane turnover and serve as a vehicle for moving bilayer-destabilizing phospholipid and protein catabolites out of membranes into the cytosol for further processing. The data also indicate that a significant proportion of the proteinase activity traditionally considered to be cytosolic is associated with deteriosomes.
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Membrana Celular/enzimología , Endopeptidasas/metabolismo , Electroforesis en Gel de Poliacrilamida , Fabaceae/enzimología , Concentración de Iones de Hidrógeno , Cinética , Plantas Medicinales , Albúmina Sérica Bovina/metabolismo , Solubilidad , Ácido Tricloroacético/metabolismoRESUMEN
Antibiotic treatment of biliary tract infections is widely accepted. An open, prospective, randomized, multicenter trial comparing cefepime (2 grams every 12 hours) with gentamicin (1.5 milligrams per kilograms every eight hours) plus mezlocillin (3 grams every four hours) for a minimum of five days was undertaken. Of the 149 patients enrolled, 120 were evaluable; 80 were randomized to receive cefepime and 40 were randomized to receive gentamicin plus mezlocillin (two to one randomization schedule). The diagnosis was acute cholecystitis in 101 patients and acute cholangitis in the remainder. There were no differences between the two treatment groups with regard to gender, age, disease, signs and symptoms, admitting temperature or laboratory values. All patients (100 percent) treated with gentamicin and mezlocillin were cured of the infection, as were 78 (97.5 percent) of the patients treated with cefepime (difference not significant). The incidence and spectrum of adverse events and complications were similar between the two groups (8.8 percent for cefepime versus 10 percent for gentamicin and mezlocillin). Our data show that the efficacy and safety of cefepime administered every 12 hours is equivalent to that of gentamicin and mezlocillin combination for treating patients with acute infections of the biliary tract. In addition, twice-daily administration of cefepime may be more cost-effective than the aminoglycoside-based combination.
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Infecciones Bacterianas/tratamiento farmacológico , Enfermedades de las Vías Biliares/tratamiento farmacológico , Cefalosporinas/uso terapéutico , Quimioterapia Combinada/uso terapéutico , Adulto , Infecciones Bacterianas/microbiología , Enfermedades de las Vías Biliares/microbiología , Cefepima , Cefalosporinas/administración & dosificación , Esquema de Medicación , Quimioterapia Combinada/administración & dosificación , Femenino , Gentamicinas/uso terapéutico , Humanos , Masculino , Mezlocilina/uso terapéutico , Persona de Mediana Edad , Estudios Prospectivos , Resultado del TratamientoRESUMEN
The data from this study indicate that cefoxitin was effective and generally well tolerated in the management of gangrenous and/or perforated appendicitis. No strong correlation was identified between in vitro susceptibility testing results and clinical outcome.
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Apendicitis/tratamiento farmacológico , Cefoxitina/uso terapéutico , Ceftizoxima/uso terapéutico , Apendicitis/complicaciones , Apendicitis/microbiología , Bacteroides fragilis/efectos de los fármacos , Método Doble Ciego , Gangrena , Humanos , Perforación Intestinal/etiología , Pruebas de Sensibilidad Microbiana , Estudios Prospectivos , Rotura EspontáneaRESUMEN
The first direct evidence is provided for the presence of unconventional lipids in a particular subcellular membrane system of a sponge. Spherulous cells were isolated from the variety of cell types present in the marine sponge Aplysina fistularis by density gradient centrifugation. Spherulous cell plasma membrane was subsequently isolated by cell rupture followed by differential centrifugation and sucrose, or Percoll, density gradient ultracentrifugation. Plasma membrane isolates were identified and assessed for purity using [3H]concanavalin A plasma membrane marker, sodium dodecyl sulfate polyacrylamide gel electrophoresis and ratios of protein, sterol and phosphate. Plasma membrane isolates could not be assessed for purity by traditional enzymatic means. Spherulous cell plasma membrane was found to contain unusual lipids, including long-chain (C24-C30) fatty acids (16.8-27.2%) and unconventional 26-alkylated sterols (66.4-72.6%), in addition to more conventional fatty acids and sterols. Spherulous cell intracellular membranes were also found to contain long-chain fatty acids and unconventional sterols, although the relative importance of these unusual lipids apparently varies between intracellular membranes, with some containing approximately 50% long-chain acids.
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Ácidos Grasos/metabolismo , Poríferos/metabolismo , Esteroles/metabolismo , Animales , Fraccionamiento Celular/métodos , Membrana Celular/metabolismo , Membranas Intracelulares/metabolismo , Lípidos de la Membrana/metabolismo , Poríferos/citologíaRESUMEN
Exposing guinea pigs to toluene diisocyanate (TDI) causes an acute increase in airway responsiveness to inhaled acetylcholine. The mechanism of this increase in airway responsiveness is unknown. Capsaicin-sensitive afferent nerves and the tachykinins they release upon activation are important in controlling bronchomotor tone in guinea pigs. To determine whether tachykinins are important in TDI-induced airway hyperresponsiveness, we studied the effects of tachykinin depletion, using capsaicin, and competitive tachykinin antagonism, using (D-Arg1, D-Pro2, D-Trp7.9, Leu11) substance P, on TDI-induced airway hyperresponsiveness. In 9 of 9 untreated animals, TDI exposure caused a large and significant increase in airway responsiveness to acetylcholine. The mean concentration of acetylcholine required to decrease specific airway conductance by 50% below baseline (the PD50) was 1.51% before TDI exposure and 0.17% after TDI exposure (p less than 0.0005). Capsaicin treatment had no effect on the PD50 but prevented the TDI-induced increase in airway responsiveness in 10 of 12 animals. (The PD50 was 1.03% before TDI and 1.27% after TDI exposure.) Treatment with the tachykinin antagonist (D-Arg1, D-Pro2, D-Trp7.9, Leu11) substance P also abolished the TDI-induced increase in airway responsiveness in all 5 animals treated. Although TDI exposure also causes airway edema, the effect of capsaicin treatment on TDI-induced airway hyperresponsiveness did not result from prevention of airway edema. TDI exposure caused a marked increase in tracheal extravasation of intravenously administered Evans blue dye that was not prevented by capsaicin treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Resistencia de las Vías Respiratorias/efectos de los fármacos , Cianatos/farmacología , Neuropéptidos/fisiología , 2,4-Diisocianato de Tolueno/farmacología , Acetilcolina/farmacología , Animales , Capsaicina/farmacología , Capsaicina/uso terapéutico , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Azul de Evans/metabolismo , Extravasación de Materiales Terapéuticos y Diagnósticos/metabolismo , Cobayas , Masculino , Neuropéptidos/antagonistas & inhibidores , Edema Pulmonar/inducido químicamente , Edema Pulmonar/tratamiento farmacológico , Receptores de Neurotransmisores/efectos de los fármacos , Receptores de Taquicininas , Sustancia P/análogos & derivados , Sustancia P/farmacología , Taquicininas , Tráquea/metabolismoAsunto(s)
Códigos de Ética , Ética en Enfermería , Ética Profesional , Enfermeras Obstetrices , Teoría Ética , Humanos , Partería , Obligaciones MoralesRESUMEN
The lipid microviscosity of microsomal membranes from senescing cut carnation (Dianthus caryophyllus L. cv. White Sim) flowers rises with advancing senescence. The increase in membrane microviscosity is initiated within 3 to 4 days of cutting the flowers and coincides temporally with petal-inrolling denoting the climacteric-like rise in ethylene production. Treatment of young cut flowers with aminoethoxyvinylglycine prevented the appearance of petal-inrolling and delayed the rise in membrane microviscosity until day 9 after cutting. When freshly cut flowers or aminoethoxyvinylglycine-treated flowers were exposed to exogenous ethylene (1 microliter per liter), the microviscosity of microsomal membranes rose sharply within 24 hours, and inrolling of petals was clearly evident. Thus, treatment with ethylene accelerates membrane rigidification. Silver thiosulphate, a potent anti-ethylene agent, delayed the rise in microsomal membrane microviscosity even when the flowers were exposed to exogenous ethylene. Membrane rigidification in both naturally senescing and ethylene-treated flowers was accompanied by an increased sterol:phospholipid ratio reflecting the selective loss of membrane phospholipid that accompanies senescence. The results collectively indicate that the climacteric-like surge in ethylene production during senescence of carnation flowers facilitates physical changes in membrane lipids that presumably lead to loss of membrane function.