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1.
Nanoscale Adv ; 5(9): 2508-2516, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37143794

RESUMEN

Metal halide perovskites represent an intriguing class of materials, and a very promising approach to tune the properties of optoelectronic devices and improve their performance involves the implementation of architectures based on mixed 3D and 2D perovskites. In this work, we investigated the use of a corrugated 2D Dion-Jacobson perovskite as an additive to a classical 3D MAPbBr3 perovskite for applications in light-emitting diodes. Taking advantage of the properties of this emerging class of materials, we studied the effect of a 2D 2-(dimethylamino)ethylamine (DMEN)-based perovskite on the morphological, photophysical, and optoelectronic properties of 3D perovskite thin films. We used α-DMEN perovskite both in a mixture with MAPbBr3 creating mixed 2D/3D phases and as a passivating thin layer deposited on the top of a 3D perovskite polycrystalline film. We observed a beneficial modulation of the thin film surface, a blue shift in the emission spectrum, and enhanced device performance.

2.
Eur Rev Med Pharmacol Sci ; 23(9): 4052-4063, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31115035

RESUMEN

With our study, we searched the medical literature to find magnesium (Mg) correlation with Emergency situations or its use in Emergency Medicine. Our aim is to fill the gap that we find in our daily routine between Mg studies on its role in Emergency and the real conception that doctors have of it in medical practice. We searched the literature for terms as magnesium or magnesium sulphate, magnesium in emergency, eclampsia, arrhythmias, acute asthma exacerbation, magnesium, and pediatric population. After a thorough research, we divided our discoveries into chapters to sort out a large amount often discordant articles.


Asunto(s)
Arritmias Cardíacas/tratamiento farmacológico , Asma/tratamiento farmacológico , Sulfato de Magnesio/uso terapéutico , Arritmias Cardíacas/patología , Asma/patología , Enfermedades Cardiovasculares/tratamiento farmacológico , Eclampsia/tratamiento farmacológico , Eclampsia/patología , Servicio de Urgencia en Hospital , Femenino , Paro Cardíaco/etiología , Humanos , Enfermedades Pulmonares/tratamiento farmacológico , Enfermedades Pulmonares/patología , Sulfato de Magnesio/efectos adversos , Sulfato de Magnesio/sangre , Embarazo
3.
Chem Commun (Camb) ; 50(90): 13904-6, 2014 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-25266064

RESUMEN

We here report the implementation of poly[(3-N-methylimidazoliumpropyl)methylsiloxane-co-dimethylsiloxane]iodides as suitable polymeric hosts for a novel class of in situ cross-linkable iodine/iodide-based gel-electrolytes for dye-sensitized solar cells. The polymers are first partially quaternized and then subjected to a thermal cross-linking which allows the formation of a 3D polymeric network which is accompanied by a dramatic enhancement of the ionic conductivity.


Asunto(s)
Reactivos de Enlaces Cruzados/química , Geles/química , Hidrocarburos Yodados/química , Siloxanos/química , Colorantes/química , Conductividad Eléctrica , Electrólitos/química , Energía Solar
4.
ACS Appl Mater Interfaces ; 6(9): 6425-33, 2014 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-24694230

RESUMEN

We implemented a low-temperature approach to fabricate efficient photoanodes for dye-sensitized solar cells, which combines three different nanoarchitectures, namely, a highly conductive and highly transparent AZO film, a thin TiO2-blocking layer, and a mesoporous TiO2 nanorod-based working electrode. All the components were processed at T≤200°C. Both the AZO and the TiO2 blocking layers were deposited by reactive sputtering, whereas the TiO2 nanorods were synthesized by surfactant-assisted wet-chemical routes and processed into photoelectrodes in which the native geometric features assured uniform mesoporous structure with effective nanocrystal interconnectivity suitable to maximize light harvesting and electron diffusion. Because of the optimized structure of the TiO2-blocking/AZO bilayer, and thanks to the good adhesion of the TiO2 nanorods over it, a significant enhancement of the charge recombination resistance was demonstrated, this laying on the basis of the outstanding power conversion efficiency achievable through the use of this photoanode's architecture: a value of 4.6% (N719) was achieved with a 4-µm-thick electrode processed at T=200°C. This value noticeably overcomes the current literature limit got on AZO-based cells (N719), which instead use Nb-doped and thicker blocking layers, and thicker nanostructured photoanodes, which have been even sintered at higher temperatures (450-500°C).

5.
Eur Rev Med Pharmacol Sci ; 17 Suppl 1: 65-85, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23436669

RESUMEN

BACKGROUND: In this Part II psychiatric disorders coexisting with organic diseases are discussed. "Comorbidity phenomenon" defines the not univocal interrelation between medical illnesses and psychiatric disorders, each other negatively influencing morbidity and mortality. Most severe psychiatric disorders, such as schizophrenia, bipolar disorder and depression, show increased prevalence of cardiovascular disease, related to poverty, use of psychotropic medication, and higher rate of preventable risk factors such as smoking, addiction, poor diet and lack of exercise. Moreover, psychiatric and organic disorders can develop together in different conditions of toxic substance and prescription drug use or abuse, especially in the emergency setting population. Different combinations with mutual interaction of psychiatric disorders and substance use disorders are defined by the so called "dual diagnosis". The hypotheses that attempt to explain the psychiatric disorders and substance abuse relationship are examined: (1) common risk factors; (2) psychiatric disorders precipitated by substance use; (3) psychiatric disorders precipitating substance use (self-medication hypothesis); and (4) synergistic interaction. Diagnostic and therapeutic difficulty concerning the problem of dual diagnosis, and legal implications, are also discussed. Substance induced psychiatric and organic symptoms can occur both in the intoxication and withdrawal state. Since ancient history, humans selected indigene psychotropic plants for recreational, medicinal, doping or spiritual purpose. After the isolation of active principles or their chemical synthesis, higher blood concentrations reached predispose to substance use, abuse and dependence. Abuse substances have specific molecular targets and very different acute mechanisms of action, mainly involving dopaminergic and serotoninergic systems, but finally converging on the brain's reward pathways, increasing dopamine in nucleus accumbens. The most common substances producing an addiction status may be assembled in depressants (alcohol, benzodiazepines, opiates), stimulants (cocaine, amphetamines, nicotine, caffeine, modafinil), hallucinogens (mescaline, LSD, ecstasy) and other substances (cannabis, dissociatives, inhalants). Anxiety disorders can occur in intoxication by stimulants, as well as in withdrawal syndrome, both by stimulants and sedatives. Substance induced mood disorders and psychotic symptoms are as much frequent conditions in ED, and the recognition of associated organic symptoms may allow to achieve diagnosis. Finally, psychiatric and organic symptoms may be caused by prescription and doping medications, either as a direct effect or after withdrawal. Adverse drug reactions can be divided in type A, dose dependent and predictable, including psychotropic drugs and hormones; and type B, dose independent and unpredictable, usually including non psychotropic drugs, more commonly included being cardiovascular, antibiotics, anti-inflammatory and antineoplastic medications.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Servicio de Urgencia en Hospital , Servicios de Urgencia Psiquiátrica , Trastornos Mentales/diagnóstico , Escalas de Valoración Psiquiátrica , Trastornos Relacionados con Sustancias/diagnóstico , Comorbilidad , Diagnóstico Dual (Psiquiatría) , Interacciones Farmacológicas , Urgencias Médicas , Humanos , Trastornos Mentales/epidemiología , Trastornos Mentales/fisiopatología , Trastornos Mentales/psicología , Valor Predictivo de las Pruebas , Pronóstico , Factores de Riesgo , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/fisiopatología , Trastornos Relacionados con Sustancias/psicología
6.
Eur Rev Med Pharmacol Sci ; 17 Suppl 1: 86-99, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23436670

RESUMEN

An exhaustive review on the organic illnesses presenting with psychiatric manifestations, properly defined pseudopsychiatric emergencies, is presented. A systematic classification of the numerous organic causes of psychiatric disorders, based on authors' experience and literature revision, is carefully analysed, and their suitable diagnostic management in emergency setting is proposed. Moreover, the role of bedside ultrasonography in Emergency Department is emphasized. The underlying pathogenetic mechanisms are separately discussed. A particular significance is given to "neuropsychological studies", displaying the complex connection between the central nervous system and the endocrine system. The role of immune system in influencing the central nervous system, explaining the model of "sickness behaviour" in inflammatory disease, is also described, according to recent reports of "psychoneuroimmunology". Moreover, the immune-mediated mechanism explaining how neoplasm can influence brain function in the "paraneoplastic syndromes" is shown. In order to facilitate the teaching method, organic illnesses presenting with acute psychic manifestations or mimicking specific psychiatric disorders are subdivided into three groups: (1) Endocrine and metabolic disorders and deficiency states; (2) Internal diseases; (3) Neurologic disorders.


Asunto(s)
Servicio de Urgencia en Hospital , Servicios de Urgencia Psiquiátrica , Conducta de Enfermedad , Trastornos Mentales/diagnóstico , Escalas de Valoración Psiquiátrica , Comorbilidad , Urgencias Médicas , Humanos , Trastornos Mentales/epidemiología , Trastornos Mentales/fisiopatología , Trastornos Mentales/psicología , Sistemas de Atención de Punto , Valor Predictivo de las Pruebas , Pronóstico , Factores de Riesgo
7.
Eur Rev Med Pharmacol Sci ; 17 Suppl 1: 55-64, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23436668

RESUMEN

Psychiatric emergencies are conditions that mostly destabilize the already frenetic activity of the Emergency Department. Sometimes the emergency is clearly referable to primitive psychiatric illness. Other times, psychiatric and organic symptoms can independently coexist (comorbidity), or develop together in different conditions of substance abuse, including alcohol and prescription drugs. Differentiating between substance induced and pre-existing psychiatric disorder (dual diagnosis) may be difficult, other than controversial issue. Finally, an organic disease can hide behind a psychiatric disorder (pseudopsychiatric emergency). In this review (part I), psychiatric disorders that occur with organic symptoms are discussed. They include: (1) anxiety, conversion and psychosomatic disorders, and (2) simulated diseases. The physiologic mechanisms of the stress reaction, divided into a dual neuro-hormonal response, are reviewed in this section: (1) activation of the sympathetic nervous system and adrenal medulla with catecholamine production (rapid response), and (2) activation of the hypothalamic-pituitary-adrenal axis with cortisol production (slow response). The concept of the fight-or-flight response, its adaptive significance and the potential evolution in paralyzing response, well showing by Yerkes-Dodson curve, is explained. Abnormal short- and long-term reactions to stress evolving toward well codified cluster of trauma and stressor-related disorders, including acute stress disorder, adjustment disorder and post-traumatic stress disorder, are examined. A brief review of major psychiatric disorder and related behaviour abnormalities, vegetative symptoms and cognitive impairment, according to DMS IV-TR classification, are described. Finally, the reactive psychic symptoms and behavioral responses to acute or chronic organic disease, so called "somatopsychic disorders", commonly occurring in elderly and pediatric patients, are presented. The specific conditions of post-operative and intensive care unit patients, and cancer and HIV positive population are emphasized.


Asunto(s)
Servicio de Urgencia en Hospital , Servicios de Urgencia Psiquiátrica , Trastornos Mentales/diagnóstico , Escalas de Valoración Psiquiátrica , Comorbilidad , Diagnóstico Dual (Psiquiatría) , Urgencias Médicas , Humanos , Trastornos Mentales/epidemiología , Trastornos Mentales/fisiopatología , Trastornos Mentales/psicología , Valor Predictivo de las Pruebas , Pronóstico , Factores de Riesgo , Estrés Psicológico , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/fisiopatología , Trastornos Relacionados con Sustancias/psicología
8.
Eur Rev Med Pharmacol Sci ; 14(7): 629-34, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20707253

RESUMEN

INTRODUCTION: The management of pain in polytrauma patients is mandatory. While non-steroidal anti-inflammatory drugs (NSAIDs) represent the most used drugs in polytrauma patients, their use may be associated with an increased risk of haemorrhage. Opioids may represent a valid alternative to NSAIDs either alone or in combination with acetaminophen. Whether their efficacy is comparable to that produced by NSAIDs in polytrauma patients has never been studied. PATIENTS AND METHODS: 60 polytrauma patients were enrolled for this study. 30 patients were treated with acetaminophen 1000 mg plus codeine 60 mg tid for 24 hours (Group A), while the remaining 30 with ketorolac 10 mg qid for 24 hours (Group B). Pain intensity has been evaluated using an analogical visual scale (VAS) ranging from 0 (no pain) to 10 (very severe pain). The level of pain was valuated at enrolment (TO) as well as after 2 (T2), 12 (T12) and 24 (T24) hours from the starting of the analgesic therapy. Results obtained by the group A were compared with those reported by the group B. RESULTS: T0: Group A mean score was 6.4 +/- 1.5 compared with 6.6 +/- 1.5 of Group B (p= ns); T2: Group A mean score was 3.4 +/- 2.8, compared with 3.5 +/- 2.4 of group B (p = ns); T12: Group A mean score was 3.4 +/- 3.4, compared with 3.5 +/- 3 of Gorup B (p = ns); T24: Group A mean score was 2.9 +/- 1.5, compared to 3.0 +/- 1.6 of Group B (p = ns). All those drugs determined a significant reduction of pain intensity during the course of therapy. CONCLUSIONS: Acetaminophen plus codeine is effective in pain control in polytrauma patients at least in our series. It may represent a valid alternative to NSAIDs, especially in patients with a documented haemorrhage or with a high hemorrhagic risk.


Asunto(s)
Acetaminofén/uso terapéutico , Codeína/uso terapéutico , Ketorolaco/uso terapéutico , Dolor/tratamiento farmacológico , Acetaminofén/administración & dosificación , Acetaminofén/efectos adversos , Adulto , Anciano , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/efectos adversos , Analgésicos no Narcóticos/uso terapéutico , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/efectos adversos , Analgésicos Opioides/uso terapéutico , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/uso terapéutico , Codeína/administración & dosificación , Codeína/efectos adversos , Combinación de Medicamentos , Femenino , Hemorragia/etiología , Hemorragia/prevención & control , Humanos , Ketorolaco/efectos adversos , Masculino , Persona de Mediana Edad , Traumatismo Múltiple/complicaciones , Dolor/etiología , Dimensión del Dolor , Factores de Riesgo , Factores de Tiempo
9.
Eur Rev Med Pharmacol Sci ; 14(2): 77-88, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20329565

RESUMEN

BACKGROUND AND OBJECTIVE: Guidelines on cardiac arrest (CA) recommend the prompt beginning of cardio-pulmonary resuscitation (CPR) and the identification and correction of reversible causes. This article deals with the application of clinical ultrasonography (US) in resuscitation, presenting a simple codified US protocol usable during CPR to recognize reversible causes of CA. EVIDENCE ON US IN CA AND STATE OF THE ART: Emergency US is a bedside, point-of-care, focused diagnostic procedure with aim to complete the physical examination. It is performed by emergency physician everywhere to answer briefly important clinical questions. Several trials recently experimented US employment during advanced life support, demonstrating its feasibility without delaying CPR. PERSPECTIVES: The PEA Protocol: We propose a simplified US protocol for non-shockable rhythms, called "PEA protocol" to remember the applications of the study (CA in Pulseless Electrical Activity, PEA) and the US scan sequence: Pulmonary scans to depict pneumothorax and pleural effusion and to differentiate wet or dry lung; Epigastric for pericardial effusion, left and right ventricular sides and motion, IVC filling; Abdominal and other scans for aortic aneurism and dissection, peritoneal effusion, bowel occlusion or perforation, deep venous thrombosis. The PEA protocol could be performed both during CA in PEA and during periarrest conditions. CONCLUSIONS: Clinical US, using a well codified protocol, could effectively help to identify reversible causes in CA, even improving patients outcome.


Asunto(s)
Paro Cardíaco/diagnóstico por imagen , Algoritmos , Reanimación Cardiopulmonar , Servicios Médicos de Urgencia , Paro Cardíaco/etiología , Paro Cardíaco/fisiopatología , Humanos , Hipovolemia/diagnóstico por imagen , Neumotórax/diagnóstico por imagen , Embolia Pulmonar/diagnóstico por imagen , Ultrasonografía
10.
J Ultrasound ; 12(1): 38-40, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23397000

RESUMEN

We report a case in which ultrasonography (US) examination was used in the Emergency Department to reveal and diagnose gas contamination of a penetrating wound. Air microbubbles are extremely small and their typical distribution and movement are like those of "sparkling-wine microbubbles". US assessment of spontaneous disappearance of the air bubbles can distinguish a harmless traumatic nature of the wound from a life-threatening gas-producing bacterial infection.

11.
Biol Neonate ; 85(1): 68-72, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-14631170

RESUMEN

Neonatal status epilepticus (SE) is very rare and, to date, very little information exists on SE in preterm infants. Here, we report recurrent SE as a result of hypoxic-ischemic encephalopathy in an extremely low birth weight (ELBW) infant, who had favorable neurodevelopment at a corrected age of 2 years. This clinical observation seems to indicate that recurrent SE does not exclude normal long-term neurodevelopment, even in ELBW infants.


Asunto(s)
Hipoxia-Isquemia Encefálica/complicaciones , Recien Nacido Prematuro , Recién Nacido de muy Bajo Peso , Sistema Nervioso/crecimiento & desarrollo , Estado Epiléptico/etiología , Peso al Nacer , Cesárea , Electroencefalografía , Femenino , Sufrimiento Fetal , Estudios de Seguimiento , Edad Gestacional , Humanos , Recién Nacido , Embarazo , Complicaciones del Embarazo , Recurrencia , Estado Epiléptico/fisiopatología , Incompetencia del Cuello del Útero
12.
Pediatr Med Chir ; 21(3): 115-7, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10687159

RESUMEN

OBJECTIVES: This study was carried out to verify whether during neonatal stage gastroesophageal scintigraphy, may be useful not only to diagnose gastroesophageal reflux (GER), but also to detect pulmonary aspiration, at times responsible for respiratory symptoms frequently associated with GER. PATIENTS AND METHODS: Gastroesophageal scintigraphy was performed on 50 newborns admitted to NICU of Brindisi in the last two years who presented symptoms as cyanosis, apnoea, bradycardia, laringeal stridor, wheezing, not related to respiratory or cardiac problems, but suspected to be clinical suggestive symptoms of "pathological" GER. After administration of 99mTC mixed with the usual meal formula, we obtained a recording period of 60-90 minutes and a later recording at 4 and 24 hours to document radioactive material in lungs. RESULTS: Scintigraphy showed GER in 40/50 cases and despite frequent observation of respiratory symptoms (39/40 cases) in these newborns never radiation in pulmonary fields. CONCLUSIONS: Our results could indicate that scintigraphy, noninvasive and low in radiation, may be considered effective and reliable to diagnose GER in newborns. The absence of radiation in pulmonary fields could indicate that respiratory symptoms frequently associated with GER could depend on involuntary mechanism of vagal type and not on pulmonary aspiration.


Asunto(s)
Reflujo Gastroesofágico/diagnóstico por imagen , Bradicardia/etiología , Bradicardia/prevención & control , Cianosis/etiología , Cianosis/prevención & control , Reflujo Gastroesofágico/complicaciones , Humanos , Recién Nacido , Neumonía por Aspiración/etiología , Neumonía por Aspiración/prevención & control , Cintigrafía , Ruidos Respiratorios/etiología
13.
Artículo en Inglés | MEDLINE | ID: mdl-8318618

RESUMEN

After first adventurous attempts to apply perfusion techniques to the treatment of liver diseases, more extensive experiences have been acquired in the last twenty years, not only in acute hepatic failure but also in some chronic liver diseases (mainly in CAH:chronic active hepatitis, and in primary biliary cirrhosis) and in a severe complication of them, that is cryoglobulinemia. Some experiences on this field that are found in literature, using both plasma exchange and hemoperfusion, are reviewed and some personal data are reported: 15 patients with acute viral liver failure (survival rate: 33%) and 5 patients with a CAH-linked (3 viral and 2 autoimmune) cryoglobulinemia, in whom a good control of the disease parameters was obtained.


Asunto(s)
Crioglobulinemia/terapia , Hemoperfusión , Cirrosis Hepática Biliar/terapia , Fallo Hepático Agudo/terapia , Intercambio Plasmático , Adulto , Anciano , Enfermedad Crónica , Femenino , Hepatitis Viral Humana/complicaciones , Humanos , Persona de Mediana Edad , Proyectos Piloto
14.
J Surg Res ; 51(5): 417-24, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1758175

RESUMEN

Advances in the understanding of the pathophysiology of traumatic brain injury have implicated a number of cellular events as fundamental to the evolution of neurologic dysfunction in this process. Following the primary biomechanical insult, a highly complex series of biochemical changes occur, some of which are reversible. The development of fluid percussion injury as an in vivo model for traumatic brain injury has greatly improved our ability to study this disease. However, a comparable in vitro model of biomechanical injury which would enable investigators to study the response to injury in isolated cell types has not been described. We have developed a model of transient barotrauma in cell culture to examine the effects of this form of injury on cell metabolism. This model employs the same fluid percussion device commonly used in in vivo brain injury studies. The effect of this injury was evaluated in monolayers of human glial cells. Cell viability by trypan blue exclusion and the production of leukotrienes following increasing barotrauma was investigated. This model provided a reproducible method of subjecting cells in culture to forces similar to those currently used in animal experimental head injury.


Asunto(s)
Lesiones Encefálicas/fisiopatología , Modelos Biológicos , Barotrauma , Fenómenos Biomecánicos , Calibración , Células Cultivadas , Humanos , Neuroglía/metabolismo , Percusión , SRS-A/biosíntesis
15.
Clin Ter ; 135(5): 347-53, 1990 Dec 15.
Artículo en Italiano | MEDLINE | ID: mdl-2150364

RESUMEN

Cystic fibrosis, a hereditary chronically evolving disease, is characterized by special predisposition to bronchial infections, especially by Pseudomonas strains. In the present open noncomparative study, the therapeutic efficacy of cefoperazone in respiratory infections by Pseudomonas aeruginosa in 25 children suffering from cystic fibrosis has been evaluated. Results were favorable, since both the specific symptoms of the infection and the general condition of the patients was markedly improved although the eradication of Pseudomonas was not achieved.


Asunto(s)
Bronconeumonía/tratamiento farmacológico , Cefoperazona/uso terapéutico , Fibrosis Quística/complicaciones , Infecciones por Pseudomonas/tratamiento farmacológico , Adolescente , Bronconeumonía/etiología , Niño , Preescolar , Enfermedad Crónica , Fibrosis Quística/tratamiento farmacológico , Evaluación de Medicamentos , Femenino , Humanos , Lactante , Masculino , Infecciones por Pseudomonas/etiología
16.
Artículo en Inglés | MEDLINE | ID: mdl-1965273

RESUMEN

Elevated intracranial pressure and acute cerebrovascular changes following head injury remain the principle challenge in the management of traumatic brain injury. Recent work has demonstrated that leukotrienes can induce increases in blood brain barrier permeability and alter cerebrovascular dynamics. We investigated whether human astroglia in culture: 1. generate specific leukotrienes; 2. how they metabolize leukotrienes, and; 3. if astroglia generate leukotrienes in response to barotraumatic injury. Human astroglial cultures established from normal human brain obtained at surgery were exposed to either ionophore, exogenous 3H-LTC4, or barotraumatic injury. Supernatants were assayed for specific leukotrienes by one of three methods: HPLC, radioimmunoassay, or enzyme-immunoassay. Glial cells exposed to exogenous LTC4 metabolized nearly all of the LTC4 to LTD4 and LTE4 within 20 minutes. Glial cells stimulated with ionophore produced mostly LTC4 at five minutes after stimulation and LTD4 and LTE4 at fifteen minutes after stimulation. Glial cells subject to barotraumatic injury produced LTC4 in concentrations of 40-200 pg/ml 15 minutes after injury. These results demonstrate that human astroglial cells are capable of rapidly generating and degrading LTC4 and this capability of glial cells may play an important role in the pathophysiology of cerebrovascular changes following head injury.


Asunto(s)
Leucotrienos/metabolismo , Neuroglía/metabolismo , Calcimicina/farmacología , Cromatografía Líquida de Alta Presión , Humanos , Leucotrieno E4 , Radioinmunoensayo , SRS-A/análogos & derivados , SRS-A/metabolismo , Factores de Tiempo
17.
J Trauma ; 29(9): 1203-10, 1989 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2504938

RESUMEN

Acute cerebrovascular changes which occur following traumatic brain injury represent a highly complex, multifactorial pathophysiologic process which is poorly understood. It is now recognized that, under normal conditions, the brain is a source of a variety of arachidonic acid metabolites which are synthesized by both cyclooxygenase and lipoxygenase. The specific cellular source of these highly vasoactive substances remains controversial. Recent work has demonstrated that lipoxygenase products were detected by immunosensitive assay in whole brain samples from a gerbil concussive injury model, yet the production of leukotrienes could not be accounted for by cerebral vessels and their contents alone. It has been theorized that the probable source for these metabolites is the cortical neuron. We sought to elucidate whether cultured human glial cells, obtained from specimens removed at the time of surgery, are a significant source of lipoxygenase products as measured by high performance liquid chromatography (HPLC). We observed that these cells consistently produced 5, 12, and 15-HETE class eicosanoids despite failure to produce significant cyclooxygenase products. These preliminary findings are of considerable interest because these lipoxygenase products are known to be highly vasoactive as well as potent mediators of increased vascular permeability. Since it is known that mechanical perturbation of cell membranes stimulates the release of arachidonic acid from membrane phospholipids, it is conceivable that the production of these eicosanoids following traumatic brain injury could account for local cerebrovascular changes including both vasospasm and interstitial edema formation.


Asunto(s)
Ácidos Hidroxieicosatetraenoicos/biosíntesis , Lipooxigenasa/metabolismo , Neuroglía/metabolismo , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/fisiopatología , Calcimicina/farmacología , Células Cultivadas , Circulación Cerebrovascular , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Humanos , Neuroglía/efectos de los fármacos
19.
Biochim Biophys Acta ; 939(2): 343-8, 1988 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-3355822

RESUMEN

Osmotic permeability coefficients, PF, for water in isolated calf pulmonary artery endothelial cells determined over the temperature range 41 to 20 degrees C are 311.10(-5) cm.s-1 at 37 degrees C and 159.10(-5) cm.s-1 at 20 degrees C. The value at 37 degrees C is close to that reported earlier for the diffusional permeability coefficient, PD. The PF/PD ratio is 1.0 at 37 degrees C. The PF values are within the range of values extrapolated for filtration permeability in pulmonary endothelium. The temperature dependence expressed as the activation energy is 7.2 kcal.mol-1. The product of hydraulic conductivity, Lp (or PF) and of viscosity changes in water is not constant from 37 to 20 degrees C. These results can be interpreted to indicate a similar pathway for water whether under diffusional or osmotic gradients.


Asunto(s)
Permeabilidad de la Membrana Celular , Endotelio Vascular/metabolismo , Animales , Bovinos , Células Cultivadas , Concentración Osmolar , Ósmosis , Arteria Pulmonar/metabolismo , Temperatura , Termodinámica , Viscosidad , Agua/metabolismo
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