RESUMEN
The lectin from the seeds of Cratvlia mollis shows strong binding to human malignant cancerous tissues, particularly those from many glands, uterus, rectum and brain. The C. mollis lectin has been crystallized using the hanging-drop method with polyethylene glycol 6000 as a precipitant. Two different crystal forms were grown from the same drops and they belong to space groups I222 and P2(1)2(1)2(1), respectively. The cell parameters obtained were a = 63.26 (4), b = 77.45 (8) and c = 105.22 (8) A, for the I222 form, and a = 88.83 (5), b = 183.24 (9) and c = 61.70 (2) A for the P2(1)2(1)2(1) crystals. The solution of both structures is currently being attempted by means of molecular replacement techniques.
RESUMEN
Substantia nigra (SN) is known to play an important role in seizure generalization. Both excitatory and inhibitory neurotransmitters can modulate this role of SN. Previous studies have shown that GABA as well as aspartate and glutamate participate in seizure regulation through this site. Evidence for such a role comes from studies on the genetically epilepsy-prone rat (GEPR) and other seizure models. In the GEPR, bilateral microinjections of NMDA receptor antagonists in SN block or reduce seizure severity. In order to further evaluate which neurotransmitters are specifically involved at the SN level of seizure regulation in the GEPR, we undertook a microdialysis study of K+ stimulated release of amino acids in the SN of GEPR-9s- and non-epileptic controls. A 1 mm loop-type microdialysis probe was inserted through pre-implanted guides into the SN of awake and freely moving rats (seven GEPR-9s and four non-epileptic controls), and used to perfuse a 100 mM K+ (high K+) solution for 2 h. Four 30 microliters samples were collected prior to high K+ stimulation (basal release), during high K+ perfusion, and after high K+ infusion. After precolumn derivatization with phenylisothiocyanate, levels of aspartic (ASP) and glutamic (GLU) acids, glycine (GLY), taurine (TAU) and GABA were measured by reversed phase high performance liquid chromatography. Two hours after the initiation of high K+ infusion, the increases relative to basal were, for non-epileptic controls, 35%, 74%, 68%, 847% and 283% respectively for ASP, GLU, GLY, TAU and GABA. Corresponding increases for GEPR-9s were 14%, 10%, 41%, 505% and 123% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Aminoácidos/metabolismo , Epilepsia/metabolismo , Espacio Extracelular/metabolismo , Convulsiones/fisiopatología , Sustancia Negra/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Epilepsia/genética , Masculino , Microdiálisis , Potasio/farmacología , Ratas , Ratas Endogámicas , Espectrofotometría Ultravioleta , Sustancia Negra/anatomía & histología , Taurina/metabolismoRESUMEN
In a prospective investigation of 17 children with severe croup, we analyzed the effect of epinephrine inhalations and mild sedation with chloral hydrate on transcutaneous carbon dioxide pressure (tcPCO2), pulse oximetry measurements, and croup scores. There was a highly significant reduction (p less than 0.001) in the tcPCO2 values and croup scores after inhalation of epinephrine. The changes in the tcPCO2 values correlated with the clinical findings. Mild sedation also significantly improved the croup scores but failed to influence the tcPCO2 values. There was not statistically significant difference in pulse oximetry saturation, fraction of administered oxygen, heart rate, or respiratory rate before and after inhalation of epinephrine or chloral hydrate administration. Monitoring tcPCO2 appears to be a reliable and objective tool for managing patients with upper airway obstruction, whereas croup scores may be misleading.
Asunto(s)
Monitoreo de Gas Sanguíneo Transcutáneo , Dióxido de Carbono/sangre , Crup/diagnóstico , Preescolar , Hidrato de Cloral/administración & dosificación , Crup/tratamiento farmacológico , Crup/fisiopatología , Epinefrina/administración & dosificación , Frecuencia Cardíaca , Humanos , Lactante , Oximetría , Presión , Estudios Prospectivos , Respiración , Terapia RespiratoriaRESUMEN
The association between platelet counts and mechanical ventilation was assessed in 61 newborn infants with respiratory distress syndrome, 10 infants with congenital diaphragmatic hernia, and 10 infants with tracheoesophageal fistula. A significant decrease in platelet counts was observed during mechanical ventilation: (mean +/- SD) reduction of 39% +/- 5%, 42% +/- 5.6%, and 11.9% +/- 5.4% in the three groups, respectively, independent of other causes. In the group with congenital diaphragmatic hernia, there was a significant correlation between mean airway pressure and the reduction in platelet counts. In a subsequent series of experiments, platelet counts were recorded before and during ventilation in rabbits. A significant mean decrease of 37.3% in platelet counts was associated with ventilation with either air or pure oxygen. Results of these studies indicate that mechanical ventilation itself may cause a major decrease in platelet count in newborn infants.