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1.
Atmos Environ (1994) ; 244: 117834, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32895604

RESUMEN

Global aviation operations contribute to anthropogenic climate change via a complex set of processes that lead to a net surface warming. Of importance are aviation emissions of carbon dioxide (CO2), nitrogen oxides (NOx), water vapor, soot and sulfate aerosols, and increased cloudiness due to contrail formation. Aviation grew strongly over the past decades (1960-2018) in terms of activity, with revenue passenger kilometers increasing from 109 to 8269 billion km yr-1, and in terms of climate change impacts, with CO2 emissions increasing by a factor of 6.8 to 1034 Tg CO2 yr-1. Over the period 2013-2018, the growth rates in both terms show a marked increase. Here, we present a new comprehensive and quantitative approach for evaluating aviation climate forcing terms. Both radiative forcing (RF) and effective radiative forcing (ERF) terms and their sums are calculated for the years 2000-2018. Contrail cirrus, consisting of linear contrails and the cirrus cloudiness arising from them, yields the largest positive net (warming) ERF term followed by CO2 and NOx emissions. The formation and emission of sulfate aerosol yields a negative (cooling) term. The mean contrail cirrus ERF/RF ratio of 0.42 indicates that contrail cirrus is less effective in surface warming than other terms. For 2018 the net aviation ERF is +100.9 milliwatts (mW) m-2 (5-95% likelihood range of (55, 145)) with major contributions from contrail cirrus (57.4 mW m-2), CO2 (34.3 mW m-2), and NOx (17.5 mW m-2). Non-CO2 terms sum to yield a net positive (warming) ERF that accounts for more than half (66%) of the aviation net ERF in 2018. Using normalization to aviation fuel use, the contribution of global aviation in 2011 was calculated to be 3.5 (4.0, 3.4) % of the net anthropogenic ERF of 2290 (1130, 3330) mW m-2. Uncertainty distributions (5%, 95%) show that non-CO2 forcing terms contribute about 8 times more than CO2 to the uncertainty in the aviation net ERF in 2018. The best estimates of the ERFs from aviation aerosol-cloud interactions for soot and sulfate remain undetermined. CO2-warming-equivalent emissions based on global warming potentials (GWP* method) indicate that aviation emissions are currently warming the climate at approximately three times the rate of that associated with aviation CO2 emissions alone. CO2 and NOx aviation emissions and cloud effects remain a continued focus of anthropogenic climate change research and policy discussions.

2.
Cephalalgia ; 31(16): 1634-41, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22116943

RESUMEN

INTRODUCTION: Deep brain stimulation (DBS) of the posterior hypothalamus has been found to be effective in the treatment of refractory chronic cluster headache (CCH). METHODS: We report the long-term outcomes of five patients with refractory CCH on whom stimulation of a modified target of approximately 3 mm in radius, which included the posterolateral hypothalamus, the fasciculus mammillotegmentalis, the fasciculus mammillothalamicus and the fasciculus medialis telencephali, was performed. The stereotaxic coordinates were 4 mm from the third ventricle wall, 2 mm from behind the mid-intercommissural point and 5 mm from under the intercommissural line. RESULTS: All patients became pain-free for 1-2 weeks after the procedure, but then needed an average of 54 days to optimize stimulation parameters. After a mean follow-up of 33 months, two remain pain-free, two have an excellent response (>90% decrease in attack frequency) and in one the attacks have been reduced by half. There were no serious adverse events. Permanent myosis and euphoria/well-being feeling were seen in three patients. Other adverse events, such as diplopia, dizziness, global headache of cervical dystonia, were seen transiently related to an increase in stimulation parameters. Attacks reappeared transiently in two patients as a result of cable rupture and when the stimulator was disconnected. CONCLUSIONS: Our results supports the efficacy of DBS in very refractory CCH with a slightly modified hypothalamic target conceived to avoid the lateral ventricle wall so as to extend the stimulated brain area and to decrease the morbidity of potential haemorrhagic complications.


Asunto(s)
Cefalalgia Histamínica/terapia , Estimulación Encefálica Profunda/métodos , Hipotálamo/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad
3.
Environ Sci Technol ; 45(9): 4145-50, 2011 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-21480609

RESUMEN

To manage artificial recharge systems, it is necessary to understand the inactivation process of microorganisms within aquifers so that requirements regarding storage times and treatment strategies for ground and surface waters can be developed and modeled to improve water management practices. This study was designed to investigate the survival of representative adenoviruses in surface- and groundwaters using a cell culture plaque assay with human lung carcinoma cells (A549) to enumerate surviving viruses. Adenovirus types 2 (Ad2) and 41 (Ad41) were seeded into 50 mL of three sterilized surface waters and groundwaters, and incubated at 10 and 19 °C for up to 301 days. Concentrations of Ad2 and Ad41 were relatively stable in all waters at 10 °C for at least 160 days and in some instances up to 301 days. At 19 °C, virus concentrations were reduced by 99.99% (4 log) after 301 days in surface water. There was approximately 90% (1 log) reduction of both viruses at 19 °C after 160 days of incubation in groundwater samples. There was no overall difference in survival kinetics in surface waters compared to groundwaters. The relatively high stability and long-term survival of adenoviruses in environmental waters at elevated temperatures should be considered in risk assessment models and drinking water management strategies.


Asunto(s)
Adenoviridae/fisiología , Agua Dulce/virología , Microbiología del Agua , Abastecimiento de Agua , Infecciones por Adenoviridae/virología , Línea Celular Tumoral , Humanos , Temperatura , Ensayo de Placa Viral
4.
Int J Gynaecol Obstet ; 99 Suppl 2: S190-3, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17961568

RESUMEN

The frequency of intrauterine fetal death (IUFD) with retained fetus varies, but is estimated to occur in 1% of all pregnancies. The vast majority of women will spontaneously labor and deliver within three weeks of the intrauterine death. The complexity in medical management increases significantly when the cervix is unripe or unfavorable, or when the woman develops disseminated intravascular coagulation. Misoprostol regimens for the induction of labor for second and third trimester IUFDs, range from 50 to 400 microg every 3 to 12 h, and are all clinically effective. Nevertheless, the current scientific evidence supports vaginal misoprostol dosages, which are adjusted to gestational age: between 13-17 weeks, 200 microg 6-hourly; between 18-26 weeks, 100 microg 6-hourly; and more than 27 weeks, 25-50 microg 4-hourly. In women with a previous cesarean, lower doses should be used and doubling of doses should not occur. Clinical monitoring should continue after delivery or expulsion because of the risk of postpartum atony and/or placenta retention.


Asunto(s)
Abortivos no Esteroideos/administración & dosificación , Aborto Retenido/tratamiento farmacológico , Muerte Fetal/terapia , Misoprostol/administración & dosificación , Administración Intravaginal , Esquema de Medicación , Femenino , Humanos , Embarazo , Trimestres del Embarazo/efectos de los fármacos
5.
Int J Gynaecol Obstet ; 99 Suppl 2: S182-5, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17961567

RESUMEN

Missed abortion in the first trimester is characterized by the arrest of embryonic or fetal development. The cervix is closed and there is no or only slight bleeding. Ultrasound examination shows an empty gestational sac or an embryo/fetus without cardiac activity. Based on a review of the published literature a single dose of 800 microg vaginal misoprostol may be offered as an effective, safe, and acceptable alternative to the traditional surgical treatment for this indication. Alternatively, 600 microg misoprostol can be administered sublingually. After administration of misoprostol, hospitalization is not necessary and the time to expulsion varies considerably. Bleeding may last for more than 14 days with additional days of light bleeding or spotting. The woman should be advised to contact a provider in case of heavy bleeding or signs of infection. A follow-up is recommended after 1 to 2 weeks.


Asunto(s)
Abortivos no Esteroideos/administración & dosificación , Aborto Retenido/tratamiento farmacológico , Misoprostol/administración & dosificación , Abortivos no Esteroideos/efectos adversos , Administración Intravaginal , Administración Sublingual , Esquema de Medicación , Femenino , Humanos , Misoprostol/efectos adversos , Embarazo , Primer Trimestre del Embarazo , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
6.
Int J Gynaecol Obstet ; 99 Suppl 2: S178-81, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17961566

RESUMEN

A combination of mifepristone and misoprostol is the regimen of choice for termination of pregnancy between 13 to 26 weeks. In many countries, mifepristone is still not available, and misoprostol has to be used alone. Many misoprostol-alone regimens have been reported in the literature with apparently good results. Most of the trials were conducted in pregnancies between 13 and 22 weeks. For this gestational period, we recommend the regimen of 400 microg of vaginal misoprostol every 3 h up to 5 doses, as it appears to be effective without excessive side effects or complications. There is inadequate data to recommend a regimen for the gestational period of 23 to 26 weeks but it is advisable to reduce the dose and frequency of administration of misoprostol. Common side effects of misoprostol-induced termination of pregnancy include gastrointestinal side effects, abdominal cramps, bleeding, fever and chills. Complications may include infection or rarely rupture of uterus.


Asunto(s)
Abortivos no Esteroideos/administración & dosificación , Aborto Terapéutico/métodos , Misoprostol/administración & dosificación , Administración Intravaginal , Esquema de Medicación , Femenino , Humanos , Embarazo , Segundo Trimestre del Embarazo , Resultado del Tratamiento
7.
Rev. méd. Panamá ; 42(1): 10-10, mayo 2022.
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1371949

RESUMEN

Objetivos: Estimar la necesidad insatisfecha de planificación familiar con métodos modernos identificando factores relacionados en hombres de Colombia, Guatemala, Haití, Honduras y Panamá. Métodos: Este estudio transversal utilizó datos de encuestas representativas a nivel nacional en Colombia, Guatemala, Haití, Honduras y Panamá para analizar entrevistados casados/unidos de 15-59 años con necesidades de planificación familiar. La relación de factores con la necesidad insatisfecha se probó mediante regresión logística multivariable. Resultados: La necesidad insatisfecha era mayor en Haití (46.5%), seguido por Panamá (43.0%), Guatemala (36.8%), Honduras (21.3%) y Colombia (12.4%). Las oportunidades relativas ajustadas de necesidad insatisfecha aumentaron con la edad en todos los países; eran mayores en pertenecientes a pueblos indígenas de Colombia, Guatemala, Honduras y Panamá; en quienes vivían en hogares con menor bienestar en Guatemala, Honduras y Panamá; y en quienes informaron uniones formales en Guatemala y Honduras. Las oportunidades de necesidad insatisfecha disminuyeron con mayor escolaridad en Haití; con mayor conocimiento de métodos modernos en Guatemala y Honduras; si discutieron sobre planificación familiar con algún profesional/trabajador de salud en Haití y Panamá; y si recibieron información sobre planificación familiar en medios de comunicación en Colombia. Conclusiones: Existen factores demográficos, socioeconómicos, de acceso a información y comportamiento relacionados con la necesidad insatisfecha. Incluir a los hombres en los programas de planificación familiar y en el desarrollo de intervenciones culturalmente aceptadas contribuiría a acelerar el logro del ejercicio responsable y voluntario del derecho a decidir si reproducirse, cuándo y con qué frecuencia. (provisto por Infomedic International)


Objectives: To estimate unmet need for family planning with modern methods, identifying related factors, in men from Colombia, Guatemala, Haiti, Honduras, and Panama. Methods: This cross-sectional study used data from nationally representative surveys in Colombia, Guatemala, Haiti, Honduras, and Panama to analyze 15-59 years old married or cohabiting men in need of family planning. The relationship of factors with unmet need was tested using multivariate logistic regression. Results: The unsatisfied need was higher in Haiti (46.5%), followed by Panama (43.0%), Guatemala (36.8%), Honduras (21.3%), and Colombia (12.4%). The adjusted odds ratio for unmet need increased with age in all countries and were greater in men from indigenous people of Colombia, Guatemala, Honduras, and Panama; in those who were living in households with less well-being in Guatemala, Honduras, and Panama; and in those who reported formal cohabiting in Guatemala and Honduras. The adjusted odds ratio for unsatisfied need diminished with increasing education in Haiti; with greater knowledge of modern methods in Guatemala and Honduras; if they discussed family planning with a health professional or worker in Haiti and Panama; and if they received information on family planning in the media in Colombia. Conclusions: There are demographic, socioeconomic, access to information, and behavioral factors related to unsatisfied need. Including men in family planning programs and in the development of culturally accepted interventions would help accelerate the achievement of the responsible and voluntary exercise of the right to decide whether, when, and how often to reproduce. (provided by Infomedic International)

8.
Cardiovasc Res ; 19(5): 264-9, 1985 May.
Artículo en Inglés | MEDLINE | ID: mdl-3995522

RESUMEN

The aim of the present study was to determine whether the diversion of blood flow away from a collapsed pulmonary lobe is due to hypoxic pulmonary vasoconstriction alone, or whether hypercapnia and mechanical factors also contribute. Hypoxic pulmonary vasoconstriction was tested in a canine pulmonary left lower lobe. Alveolar hypoxia was produced by absorption collapse or by ventilation with 7% oxygen, which has previously been shown to produce an end-pulmonary capillary pO2 similar to mixed venous pO2. The proportion of the cardiac output flowing to the lobe was reduced in both hypoxic states but was significantly lower during collapse than during ventilation hypoxia. The beta 1-adrenergic agonist dobutamine hydrochloride (30 micrograms X kg-1 X min-1 iv) produced a significant increase in the proportion of the cardiac output flowing to the lobe during collapse but no significant change during ventilation hypoxia. It is concluded that changes in local pCO2 during collapse may account for the greater diversion of blood flow from the lobe when compared with ventilation hypoxia.


Asunto(s)
Pulmón/irrigación sanguínea , Atelectasia Pulmonar/fisiopatología , Vasoconstricción , Animales , Dobutamina/farmacología , Perros , Hemodinámica , Hipoxia/complicaciones , Pulmón/efectos de los fármacos , Atelectasia Pulmonar/complicaciones , Flujo Sanguíneo Regional
9.
J Appl Phys ; 117(3): 034306, 2015 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-25641981

RESUMEN

In this work, we report the fabrication of self-assembled zinc oxide nanorods grown on pentagonal faces of silver nanowires by using microwaves irradiation. The nanostructures resemble a hierarchal nanoantenna and were used to study the far and near field electrical metal-semiconductor behavior from the electrical radiation pattern resulting from the phase map reconstruction obtained using off-axis electron holography. As a comparison, we use electric numerical approximations methods for a finite number of ZnO nanorods on the Ag nanowires and show that the electric radiation intensities maps match closely the experimental results obtained with electron holography. The time evolution of the radiation pattern as generated from the nanostructure was recorded under in-situ radio frequency signal stimulation, in which the generated electrical source amplitude and frequency were varied from 0 to 5 V and from 1 to 10 MHz, respectively. The phase maps obtained from electron holography show the change in the distribution of the electric radiation pattern for individual nanoantennas. The mapping of this electrical behavior is of the utmost importance to gain a complete understanding for the metal-semiconductor (Ag/ZnO) heterojunction that will help to show the mechanism through which these receiving/transmitting structures behave at nanoscale level.

10.
Immunol Lett ; 51(3): 157-61, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8832284

RESUMEN

In anuran metamorphosis, histoincompatible adult cells arise within an immunocompetent larval body. However, the larvae are unresponsive to these altered-self cells. The basis for this tolerance is an issue of considerable interest. While a loss of tolerance in mammalian pregnancy may initiate localized abortion, since the entire metamorphic amphibian is involved, there is the potential for total body self-destruction. Metamorphosing Xenopus laevis, the South African clawed toad, produce an internal corticosterone environment that induces T-cell anergy. This impairment may save the animal from immune self-destruction. Here we examine the capacity of recombinant gene produced human interleukin 2 (IL-2) to substitute for, or restore the level of autologous IL-2, as a further test of whether the altered-self tolerance found during metamorphosis may rely on corticosteroid-induced anergy. We find that the capacity of rIL-2 to break this tolerance and stimulate mortality is low, unless it is accompanied by antigenic co-stimulation. A study of sections of experimental and control animals revealed lymphocyte and mast cell increases within the kidney, particularly in the region of the coelomoduct, perhaps reflecting autoimmune reactivity responsible for the mortality.


Asunto(s)
Interleucina-2/farmacología , Longevidad/inmunología , Metamorfosis Biológica/efectos de los fármacos , Xenopus laevis/crecimiento & desarrollo , Xenopus laevis/inmunología , Animales , Larva/efectos de los fármacos , Larva/inmunología
11.
Am J Med Genet ; 30(4): 925-8, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2973234

RESUMEN

This is the second reported case of a child with holoprosencephaly and trisomy 21. The first case was born to a diabetic woman; in our case, there was no evidence of diabetes in the mother. Most of the distinctive facial features of Down syndrome were obscured by the presence of cyclopia and a supraorbital proboscis in this infant. The relevance of chromosome analysis in cases with holoprosencephaly is discussed.


Asunto(s)
Anomalías Múltiples/genética , Encéfalo/anomalías , Síndrome de Down/complicaciones , Síndrome de Down/genética , Femenino , Humanos , Recién Nacido , Masculino , Nariz/anomalías , Órbita/anomalías , Embarazo , Embarazo en Diabéticas
12.
Menopause ; 8(5): 353-60, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11528362

RESUMEN

OBJECTIVE: To assess the serum concentrations of estradiol (E2), estrone (E1), gonadotrophins, sex hormone-binding globulin, and lipids, and to determine degree of symptom relief after subcutaneous implantation of 25 mg estradiol in postmenopausal Mexican women. DESIGN: Fifteen postmenopausal, hysterectomized women participated in an open, observational study. Blood samples were obtained before implantation and at regular intervals during a study period of 24 weeks. Climacteric symptoms were evaluated by means of the Greene climacteric scale. Wilcoxon's test was performed on the paired results of pre-and postimplantation values. RESULTS: Serum concentrations of E2 obtained after implantation were fairly constant, remaining within the early follicular range for the entire study period of 24 weeks, and were associated with significant symptom relief. A physiological, premenopausal E2:E1 ratio was achieved. No significant metabolic changes occurred. Side effects were estrogenic in nature and no removal of implant was required. CONCLUSIONS: Subcutaneous implantation of 25 mg estradiol results in physiological, premenopausal estrogen concentrations in most women and is associated with considerable symptom relief without inducing significant adverse metabolic effects.


Asunto(s)
Estradiol/farmacología , Estradiol/farmacocinética , Terapia de Reemplazo de Estrógeno , Posmenopausia/efectos de los fármacos , Estradiol/administración & dosificación , Estradiol/sangre , Estrona/sangre , Femenino , Hormona Folículo Estimulante/sangre , Humanos , Hormona Luteinizante/sangre , México , Persona de Mediana Edad , Posmenopausia/fisiología , Prótesis e Implantes , Globulina de Unión a Hormona Sexual/análisis
13.
J Neurotrauma ; 9 Suppl 1: S119-28, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1588602

RESUMEN

The neural circuitry of the lumbar spinal cord can generate alternating extension and flexion of the hindlimbs. The hindlimbs of adult cats with complete transection of the spinal cord at a low thoracic level (T12-T13) can perform full weight-supporting locomotion on a treadmill belt moving at a range of speeds. Some limitations in the locomotor capacity can be associated with a deficit in the recruitment level of the fast extensors during the stance phase and the flexors during the swing phase of a step cycle. The level of locomotor performance, however, can be enhanced by daily training on a treadmill while emphasizing full weight-support stepping and by providing appropriately timed sensory stimulation, loading, and/or pharmacologic stimulation of the hindlimb neuromuscular apparatus. Furthermore, there appears to be an interactive effect of these interventions. For example, the maximum treadmill speed that a spinal adult cat can attain and maintain is significantly improved with daily full weight-supporting treadmill training, but progressive recruitment of fast extensors becomes apparent only when the hindlimbs are loaded by gently pulling down on the tail during the stepping. Stimulation of the sural nerve at the initiation of the flexion phase of the step cycle can likewise markedly improve the locomotor capability. Administration of clonidine, in particular in combination with an elevated load, resulted in the most distinct and consistent alternating bursts of electromyographic activity during spinal stepping. These data indicate that the spinal cord has the ability to execute alternating activation of the extensor and flexor musculature of the hindlimbs (stepping) and that this ability can be improved by several interventions such as training, sensory stimulation, and use of some pharmacologic agents. Thus, it appears that the spinal cord, without supraspinal input, is highly plastic and has the potential to "learn," that is, to acquire and improve its ability to execute full weight-supporting locomotion on a treadmill belt.


Asunto(s)
Locomoción/fisiología , Actividad Motora/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Médula Espinal/fisiología , Animales , Gatos , Clonidina/farmacología , Electromiografía , Femenino , Músculos/efectos de los fármacos , Músculos/fisiología , Médula Espinal/fisiopatología , Factores de Tiempo
14.
Intensive Care Med ; 15(3): 155-9, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2738219

RESUMEN

We have studied the effect of changing ventilatory frequency (VF) of high frequency oscillatory ventilation (HFOV) on fluid filtration rate (FFR) in twelve isolated rabbit lungs perfused at constant blood flow. Mean pulmonary artery pressure (Ppa), mean left atrial pressure (Pla), airway pressure (Paw), pulmonary vascular resistance (PVR), pH, O2 and CO2 partial arterial pressures (PaO2 and PaCO2) and plasma colloid osmotic pressure (COP), were measured. We ventilated the lungs with a modified Bird Mark 7 ventilator which could achieve HFOV (range 5-30 Hertz). In each experiment VF was randomly varied on ten different occasions, maintaining each variation for ten minutes. The first group of six rabbits was ventilated under normal haemodynamic conditions. The other six rabbits were ventilated after the production of hydrostatic lung oedema. Blood gas exchange in both groups of rabbits was satisfactory. There was no statistically significant correlation between VF and FFR. We conclude that variations in VF using HFOV does not alter lung fluid balance in normal and in hydrostatic oedema rabbit lungs.


Asunto(s)
Líquidos Corporales/fisiología , Ventilación de Alta Frecuencia , Pulmón/fisiopatología , Animales , Filtración , Edema Pulmonar/fisiopatología , Intercambio Gaseoso Pulmonar , Presión Esfenoidal Pulmonar , Conejos
15.
Intensive Care Med ; 16(2): 89-94, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2185291

RESUMEN

The influence of positive end expiratory pressure (PEEP) on the fluid filtration rate (FFR) in the pulmonary circulation has been the subject of considerable investigation but data are conflicting. We studied twenty-nine isolated rabbit lung preparations, FFR was sensed by a force transducer. Autologous blood was used to prime the perfusion circuit. Hydrostatic oedema was achieved by increasing the left atrial pressure to 16 mmHg. In order to bring about increased membrane permeability oleic acid was injected through the pulmonary artery. Increasing and decreasing levels of PEEP at 0, 5, 10 and 15 cm H2O were each used for ten minutes in each of three experimental models. The FFR, pH, mean pulmonary arterial pressure (MPAP), mean left atrial pressure (MLAP), PaO2, PaCO2 and oncotic pressure were measured in each experiment. There was a significant correlation between PEEP and FFR (+0.94) in non-oedema lungs. With no PEEP the FFR was 0 g/min and with 15 cm of PEEP it increased to 0.07 g/min, on removing the PEEP the FFR returned to 0 g/min. In the hydrostatic lung oedema model the correlation was also significant but negative (r = -0.94). With no PEEP the FFR was 0.33 g/min, with PEEP of 15 cm H2O it decreased to 0.08 g/min. No correlation between PEEP and FFR was found in the oleic acid preparation. In the normal lung PEEP increases capillary hydrostatic pressure and total lung vascular area and decreases interstitial pressure. It is by these mechanisms that PEEP causes an increase in FFR. In the hydrostatic oedema model PEEP decreases FFR by increasing the interstitial pressure and by decreasing the total lung vascular area. In the oleic acid preparation the coefficient of filtration is so large that small changes in pressure or vascular area do not modify the FFR. We suggest that PEEP may be beneficial by decreasing FFR in hydrostatic lung oedema, but it may increase the FFR in the normal lung, while having no effect in oleic acid lung injury.


Asunto(s)
Respiración con Presión Positiva , Circulación Pulmonar , Edema Pulmonar/fisiopatología , Resistencia de las Vías Respiratorias , Animales , Permeabilidad de la Membrana Celular , Modelos Animales de Enfermedad , Ácidos Oléicos/efectos adversos , Edema Pulmonar/inducido químicamente , Edema Pulmonar/terapia , Presión Esfenoidal Pulmonar , Conejos
16.
Brain Res ; 654(2): 241-50, 1994 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-7987674

RESUMEN

EMG activity was recorded from the vastus lateralis (VL, knee extensor), rectus femoris (RF, hip flexor and knee extensor), tibialis anterior (TA, ankle flexor and digit extensor) and either the lateral or medial gastrocnemius (LG, MG, knee flexors and ankle extensors) muscles of 7 adult rats during treadmill locomotion and swimming. Most flexors and extensors are activated as a single burst but each is known to be modulated differently during locomotion. For example, the extensor EMG bursts are shortened and amplitude elevated as speed increases, whereas little change occurs in the EMG duration and amplitude in flexors. The RF and VL displayed a double burst of EMG activity per cycle during treadmill locomotion and a single burst during swimming. Kinematic and EMG analyses showed that during running, one of these EMG bursts occurred primarily during swing while the other burst occurred primarily during stance. Modulation of the burst occurring during swing approximated a flexor pattern, while the second burst was modulated like a typical extensor when running over a range of speeds and grades on a treadmill. These data suggest that motoneurons within a motor pool of a uniarticular (VL) as well as a biarticular (RF) muscle can be modulated by more than one cyclical input, probably of central origin, and that under some conditions several motor pools may share the same central commands.


Asunto(s)
Actividad Motora , Desnervación Muscular , Músculos/fisiología , Ciclos de Actividad , Animales , Electromiografía , Miembro Posterior/fisiología , Locomoción , Masculino , Músculos/inervación , Ratas , Ratas Sprague-Dawley , Natación
17.
Int J Impot Res ; 14(1): 54-9; discussion 60, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11896479

RESUMEN

Oral therapy has become first line treatment for patients with mild to moderate erectile dysfunction (ED). Studies have shown that sildenafil may not be effective in all patients, and has been associated with a variety of adverse effects and an adverse interaction with nitrates and inhibitors of cytochrome P450 enzymes. The objective was to compare the efficacy and safety of three different oral combinations with the highest dose of sildenafil in men with moderate to severe ED. Randomized, double blind, unblinded active-controlled, Phase II study was carried out at three sites in Mexico. After a 4-week placebo run-in period, patients received all four of the following treatments using a 4-way cross-over design: 40 mg phentolamine (PM) +6 mg apomorphine (Apo); 40 mg PM +150 mg papaverine (Pap); 40 mg PM +6 mg Apo +150 mg Pap (Tricombo); 100 mg sildenafil (SC). With the exception of sildenafil tablets, all study medication was blinded. Moderate to severe ED was defined as a less than 50% vaginal penetration success rate during the placebo run-in period. A total of 44 patients were enrolled, of whom 36 completed all four treatment periods. All treatments produced a significant effect in primary efficacy variable (Sexual Encounter Profile) compared to baseline, however, no statistically significant differences were found between treatments. A significant period effect was observed. Also, the four treatments were found not to differ significantly in five out of six secondary efficacy variables. The lowest incidence of treatment-related adverse events (AE) occurred in the 40 mg PM +6 mg Apo group (9.8%), followed by 100 mg SC (15%), and the other two combinations (16.7 and 17.5%, respectively). Nasocongestion and headache were the most frequently reported AE. An oral combination of vasoactive agents may provide an alternative approach to sildenafil. Based on these results a combination of phentolamine and apomorphine warrants further clinical investigation.


Asunto(s)
Antagonistas Adrenérgicos alfa/administración & dosificación , Apomorfina/administración & dosificación , Disfunción Eréctil/tratamiento farmacológico , Papaverina/administración & dosificación , Fentolamina/administración & dosificación , Vasodilatadores/administración & dosificación , Antagonistas Adrenérgicos alfa/efectos adversos , Antagonistas Adrenérgicos alfa/uso terapéutico , Apomorfina/efectos adversos , Apomorfina/uso terapéutico , Estudios Cruzados , Método Doble Ciego , Combinación de Medicamentos , Disfunción Eréctil/fisiopatología , Humanos , Masculino , Papaverina/efectos adversos , Papaverina/uso terapéutico , Fentolamina/efectos adversos , Fentolamina/uso terapéutico , Piperazinas/uso terapéutico , Purinas , Seguridad , Índice de Severidad de la Enfermedad , Citrato de Sildenafil , Sulfonas , Resultado del Tratamiento , Vasodilatadores/efectos adversos , Vasodilatadores/uso terapéutico
18.
Toxicon ; 37(1): 173-80, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9920489

RESUMEN

It is well known that scorpion venom induces lung lesions and respiratory distress which are usually classified as pulmonary oedema (PO). Tityus discrepans is a scorpion that lives in the north-central area of Venezuela, is the most common source of human envenomation here and produces PO. We studied the action of the venom of Tityus discrepans on whole rabbits and on their isolated lungs perfused with Krebs saline with 1 g/l of bovine serum albumin (Krebs-BSA saline). Two milligram of venom were diluted in 250 ml of solution (approximately the rabbit's total blood volume) and used to perfuse isolated lungs. Lung oedema occurred in rabbits which received 1 mg/kg of scorpion venom i.p., heparin prevented the production of this lung oedema. T. discrepans venom produced PO, in rabbits pretreated with 15 mg/kg of ajoene. Yet, Tityus venom had no effects on isolated lungs perfused with citrated or heparinized blood, and in lungs perfused with Krebs-BSA with normal Ca2+. These result show that Tityus venom does not act directly on lungs. Otherwise, we have observed that abundant microthrombi occurred in all rabbit lungs exposed to venom in vivo, suggesting that these clotting alterations are fundamental to produce PO. The presence of intravascular microthrombi is not characteristic of the usual PO hinting that scorpion venom induced pulmonary alterations are a different clinical entity. We thus propose that the use of the term pulmonary oedema in scorpionism should abandoned in favor of scorpion venom respiratory distress syndrome.


Asunto(s)
Síndrome de Dificultad Respiratoria del Recién Nacido/inducido químicamente , Venenos de Escorpión/toxicidad , Presión del Aire , Animales , Presión Sanguínea , Líquido del Lavado Bronquioalveolar , Humanos , Técnicas In Vitro , Recién Nacido , Pulmón/patología , Pulmón/fisiopatología , Masculino , Arteria Pulmonar/fisiología , Edema Pulmonar/inducido químicamente , Edema Pulmonar/patología , Edema Pulmonar/fisiopatología , Conejos , Síndrome de Dificultad Respiratoria del Recién Nacido/patología , Síndrome de Dificultad Respiratoria del Recién Nacido/fisiopatología
19.
BMC Infect Dis ; 1: 23, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11737869

RESUMEN

BACKGROUND: The potential role of oral vaccination of dogs against rabies in the Philippines was investigated in terms of safety and efficacy. METHODS: Prior to the vaccination campaign, a house-to-house survey was carried out to collect data on the dog population in the study area, the coastal village of Mindoro. During the vaccination campaign all households were visited again, and all dogs encountered (>2 months old) were, if possible, vaccinated. Furthermore, 14 dogs vaccinated were bled on different occasions. RESULTS: During the survey, a total of 216 dogs were counted, and none of these animals had previously been vaccinated against rabies. Only 17 dogs could be restrained and subsequently vaccinated directly by the vaccinators. Another 126 dogs were offered a local-made boiled intestine bait, containing a capsule filled with 3.0 ml SAD B19 (107.9 FFU/ml). The bait acceptance rate of dogs offered a bait was 96.1%. The vaccination coverage of the dog population (> 2 months old) estimated by the number of animals vaccinated directly and the number of dogs that accepted a bait and subsequently punctured the vaccine container was 76%. Fifteen and 29 days after the vaccination campaign 6 and 10 dogs (n = 14) had rabies virus neutralizing antibody titres of >/= 0.5 IU/ml, respectively. No unintentional contacts of nontarget species, including humans, with the vaccine virus were reported. CONCLUSIONS: The results of the campaign show that oral vaccination of dogs against rabies is a promising supplementary method in dog rabies control in the Philippines.


Asunto(s)
Enfermedades de los Perros/prevención & control , Vacunas Antirrábicas/administración & dosificación , Rabia/prevención & control , Administración Oral , Animales , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/virología , Perros , Femenino , Masculino , Filipinas/epidemiología , Rabia/epidemiología , Vacunas Antirrábicas/efectos adversos , Medición de Riesgo , Resultado del Tratamiento
20.
Med Sci Sports Exerc ; 26(12): 1491-7, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7869884

RESUMEN

Progress toward restoring locomotor function in low thoracic spinal transected cats and the application of similar techniques to patients with spinal cord injury is reviewed. Complete spinal cord transection (T12-T13) in adult cats results in an immediate loss of locomotor function in the hindlimbs. Limited locomotor function returns after several months in cats that have not received specific therapies designed to restore hindlimb stepping. Training transected cats to step on a treadmill for 30 min.d-1 and 5 d.wk-1 greatly improves their stepping ability. The most successful outcome was in cats where training began early, i.e., 1 wk after spinal transection. Cats trained to stand instead of stepping had great difficulty using the hindlimbs for locomotion. These effects were reversible over a 20-month period such that cats unable to step as a result of standing training could be trained to step and, conversely, locomotion in stepping-trained cats could be abolished by standing training. These results indicate that the spinal cord is capable of learning specific motor tasks. It has not been possible to elicit locomotion in patients with clinically complete spinal injuries, but appropriately coordinated EMG activity has been demonstrated in musculature of the legs during assisted locomotion on a treadmill.


Asunto(s)
Destreza Motora/fisiología , Médula Espinal/fisiología , Animales , Gatos , Miembro Posterior/fisiología , Humanos , Locomoción/fisiología , Vértebras Lumbares , Mamíferos , Modalidades de Fisioterapia , Postura/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Vértebras Torácicas
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