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1.
Paramecium calcium channels are blocked by a family of calmodulin antagonists. 总被引:3,自引:0,他引:3
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B E Ehrlich A R Jacobson R Hinrichsen L M Sayre M A Forte 《Proceedings of the National Academy of Sciences of the United States of America》1988,85(15):5718-5722
Although the voltage-sensitive Ca channel present in Paramecium has been subjected to detailed physiological and genetic analysis, no organic ligands have been described that block this channel with high affinity and that ultimately can be used to identify channel components. Based on a previous observation that the naphthalene sulfonamide calmodulin antagonist W-7 can block Paramecium Ca channels at high concentration, we have synthesized analogs of W-7 that block these channels at concentrations of less than 1 microM. The effectiveness of these compounds was tested both by a sensitive behavioral assay and on Ca channels that had been incorporated into planar lipid bilayers. Despite the fact that these compounds are effective Paramecium calmodulin antagonists, two independent lines of evidence suggest that W-7 and its analogs block the Ca channel by a mechanism that is independent of their action on calmodulin. In addition, the sensitivity to W-7 or dihydropyridines of Ca channels present in a number of eukaryotic phyla has been used to identify similarities in Ca channels from widely diverse organisms. It appears that the pharmacological specificity provides a means to group Ca channels. 相似文献
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Effect of total parenteral nutrition with intravenous fat on lipids and high density lipoprotein heterogeneity in neonates 总被引:1,自引:0,他引:1
T M Forte O Genzel-Boroviczeny M A Austin L C Kao C Scott J J Albers A E D'Harlingue 《JPEN. Journal of parenteral and enteral nutrition》1989,13(5):490-500
Plasma lipid concentrations and high density lipoprotein (HDL) subclass distributions were evaluated in 22 newborn infants nourished with intravenous (iv)-fat. The majority of infants were premature with respiratory distress syndrome. Based on baseline (prior to iv-fat) HDL subclass profiles determined by gradient gel electrophoresis (GGE), infants fell into two classes, one with two or more pronounced peaks within the normal HDL spectrum (group I, 17 subjects) and the other with highly unusual HDL distribution (group II, five subjects). Total plasma cholesterol increased in both groups during low and high fat intravenous feeding. HDL-cholesterol, however, did not change with iv-fat where mean values for groups I and II at baseline, iv-low fat and -high fat were: group I, 31.2 +/- 7.1, 30.0 +/- 8.8, and 36.6 +/- 16.7 mg/dl, respectively; and group II, 20.0 +/- 7.8, 20.2 +/- 7.4, and 19.8 +/- 8.8 mg/dl, respectively. Unlike HDL-cholesterol levels that remained constant with iv-fat, apolipoprotein (apo) AI concentrations increased significantly: group I, 73.0 +/- 11.0, 88.3 +/- 15.9, and 93.1 +/- 21.9 mg/dl, respectively; and group II, 31.8 +/- 10.5, 41.0 +/- 12.8, and 59.3 +/- 18.5 mg/dl, respectively. In group I infants, iv-fat is associated with an increase in larger-sized particles, particularly in the (HDL2b)gge range; in group II there is an increase in (HDL3b)gge and (HDL3c)gge components and a disappearance of particles that fall outside of the size range of normal HDL. In both groups, enteral feeding is associated with a further normalization of HDL subclass distribution. The aberrant GGE profiles and very low apoAI levels of group II infants at baseline were associated with unusual HDL morphology determined by electron microscopy where discoidal structures were prominent. With iv-fat, discoidal particles decline in number while normal spherical structures increase. Prevalence of discoidal HDL at baseline was associated with low concentrations of lecithin:cholesterol acyltransferase (LCAT) (1.12 +/- 0.5 micrograms/ml); with iv-fat this enzyme rose to 1.61 +/- 0.18 micrograms/ml. Increased LCAT is associated with the normalization of HDL morphology. It is likely that iv-fat improves the nutritional status of premature infants, thereby stimulating increased liver synthesis of important proteins, including apoAI and LCAT, associated with HDL metabolism. 相似文献
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M.A. Pajares J.A. Margarit C. García-Camacho J. García-Suarez E. Mateo M. Castaño C. López Forte J. López Menéndez M. Gómez M.J. Soto S. Veiras E. Martín B. Castaño S. López Palanca T. Gabaldón J. Acosta J. Fernández Cruz A.R. Fernández López R. Vicente 《Revista espa?ola de anestesiología y reanimación》2021,68(4):183-231
The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved. 相似文献
6.
Soleto Martín J Rodríguez Durántez JA González López JL Cervera Bravo P Cubillo Martín A López Valverde S García-Trevijano Forte JL Navascués del Río JA 《Cirugía pediátrica : organo oficial de la Sociedad Espa?ola de Cirugía Pediátrica》1999,12(3):119-121
Obstetrical sciatic palsy have been frequently seen in our hospital, but bibliography about this subject is rare, not only in Spanish but also in other languages. We review our experience about this pathology, and if it is possible, to contribute to prevent its occurrence. 相似文献
7.
Mapping of residues forming the voltage sensor of the voltage-dependent anion-selective channel. 总被引:3,自引:0,他引:3
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L Thomas E Blachly-Dyson M Colombini M Forte 《Proceedings of the National Academy of Sciences of the United States of America》1993,90(12):5446-5449
Voltage-gated ion-channel proteins contain "voltage-sensing" domains that drive the conformational transitions between open and closed states in response to changes in transmembrane voltage. We have used site-directed mutagenesis to identify residues affecting the voltage sensitivity of a mitochondrial channel, the voltage-dependent anion-selective channel (VDAC). Although charge changes at many sites had no effect, at other sites substitutions that increased positive charge also increased the steepness of voltage dependence and substitutions that decreased positive charge decreased voltage dependence by an appropriate amount. In contrast to the plasma membrane K+ and Na+ channels, these residues are distributed over large parts of the VDAC protein. These results have been used to define the conformational transitions that accompany voltage gating of an ion channel. This gating mechanism requires the movement of large portions of the VDAC protein through the membrane. 相似文献
8.
Forte L Migliaccio G Sanchez M Migliaccio AR Passarelli AM Amadori S 《Annali dell'Istituto superiore di sanità》2000,36(3):333-342
The small volume of placental/umbilical cord blood (PUCB) collectable restricts the use of these stem cells to pediatric transplantation. To extend the use of PUCB to adult recipients, many laboratories are investigating the feasibility of ex vivo PUCB expansion. The present study analyses the effects that PUCB banking cell manipulations (cell sedimentation, cryopreservation and thawing, mononuclear and CD34+ cell isolation) have on the number, viability and ex vivo expansion potential of PUCB cells. The results presented indicate the necessity of an open discussion on whether procedures used for handling the cells in PUCB banks can be extrapolated or not as such to the clinical use of ex vivo expanded PUCB. 相似文献
9.
X. Lu A.J. Forte R. Sawh-Martinez R. Wu R. Cabrejo D.M. Steinbacher M. Alperovich N. Alonso J.A. Persing 《The British journal of oral & maxillofacial surgery》2018,56(9):864-869
Bony malformations of the orbit and alterations to the soft tissue in Apert syndrome contribute to ophthalmic dysfunction. Recognised structural malformation of the sphenoid and ethmoid sinuses, together with corresponding deformities in the anterior and middle cranial base, are characteristic. Our aim was to explore the underlying structural components of disfigurement and the consequent development of the orbit in patients with Apert syndrome over time by studying 18 preoperative computed tomographic (CT) scans of affected patients and 36 scans from controls. Cephalometric measurements related to the orbit were collected, and analysed with Materialise software. The patients with Apert syndrome had larger than normal external orbital horizontal angles between the ages of 6 months and 2 years. The inside horizontal angle was narrower at 16.36° before 6 months, and continued to decrease into adulthood. The ethmoid and sphenoid side angles in affected patients consistently increased, starting at 7.93% and 14.68% of the external horizontal angle, respectively, during the first 6 months of age, and becoming 20.55% and 11.69%, respectively, in adulthood. In unaffected patients, both angles were less than 3% of the external horizontal angle overall. The orbital vertical angle also changed synchronously, with increasingly wide lateral orbits and shortened anteroposterior orbits. The anterior protrusion of the lateral orbital wall resulted from superior and posterior rotation of a curved, greater wing of the sphenoid, while the widened median orbital wall was caused by the widened ethmoid sinus. These resulted in bony deformities of the orbit, which predisposed to the visual impairments of Apert syndrome. 相似文献
10.
Studies on the role of cells in physiological and pathological processes generally require isolation of some populations, such as neutrophils. In the literature, several methods used for isolating neutrophils are described; however, there is no consensus on the best technique to be used in cell functional studies. The present study compares the efficiency and impact on the chemotactic and phagocytic activity of neutrophils isolated from blood by three different methods: Percoll and Ficoll density centrifugation gradients and spontaneous sedimentation technique. The neutrophil chemotaxis, stimulated with lipopolysaccharide (LPS), autologous serum or homologous serum, was determined by using Boyden chambers. The phagocytic capacity was assessed by ingestion of zimosan particles, and digestion phase was analyzed by nitroblue tetrazolium test (NBT). The results obtained from neutrophil isolation by Percoll and Ficoll density gradients, as compared to spontaneous sedimentation technique, showed similar degrees of cell yields and higher purity; however, these methods affected neutrophil responsiveness, accompanied by elevated chemotaxis and reduced chemotactic capacity to respond to subsequent stimulation. Neutrophil isolation by spontaneous sedimentation, in contrast, did not affect cellular activity and resulted in cell preparation with high number of neutrophils. Although neutrophil phagocytosis results were similar between the different methods, digestion phase of phagocytosis was significantly enhanced after LPS-stimulation, only in the neutrophils isolated by spontaneous sedimentation technique. In conclusion, the present study shows that isolation of blood neutrophils by the spontaneous sedimentation technique is appropriate for the assessment of cellular activity, since it neither primes or activates the neutrophils nor does it affect their functional responsiveness. 相似文献