Long-Term Potentiation in the CA1 Hippocampus Malinow, Roberto; Mainen, Zachary F.; Siegelbaum, Steven A. ...
Science (American Association for the Advancement of Science),
03/1996, Letnik:
271, Številka:
5255
Journal Article
Recenzirano
Odprti dostop
Malinow and Mainen discuss the work of Siegelbaum and Bolshakov regarding the locus of the modification responsible for the enhancement of synaptic transmission during long-term potentiation in CA1 ...hoppocampus. Siegelbaum and Bolshakov respond.
There is a keen interest in identifying the effects of Aβ on synapses. Here we review some of the published work on its effects on excitatory synaptic transmission and plasticity. We also provide new ...information indicating that activity-induced release of Aβ from either pre- or postsynaptic neurons can block structural plasticity.
The Asthma Control Test (ACT) questionnaire has been widely used and validated in various ethnic groups, showing an adequate correlation with physician assessment of asthma control. We sought to ...evaluate the relationship between ACT-defined asthma control and peak flow measures in subjects living in Puerto Rico.
A retrospective evaluation of data collected by a mobile asthma clinic in 2 cities in Puerto Rico was conducted. The participants completed an asthma and rhinitis survey. Self-reported asthmatics answered the age-appropriate Spanish version of the ACT. Peak flows (PEF) were measured. Subjects were skin-tested against the common local aeroallergens. The study was approved by the University of Puerto Rico's IRB.
We evaluated data from 70 subjects aged 4 to 68. Of them, 82.85% were 12 years old or older, 64.3% reported having a history of asthma, 57.14% reported that they still suffered from asthma, 81.4% reported that they suffered from rhinitis, and 78.57% were sensitized to at least 1 antigen. The mean ACT score of current asthmatics was 18.97, while that of past asthmatics was 23.83 (p = 6.6e-6). The variability of PEF increased as the ACT score increased. Age had no impact on asthma control (p > 0.25), while the effect of PEF on the control of asthma was tied to gender. Rhinitis was also associated with poor asthma control as defined by the ACT score. No other covariate was found to be statistically significant (p < 0.05).
Our study supports the use of the ACT to evaluate asthma control in asthmatics living in Puerto Rico. Research into factors associated with poor asthma control, and the importance of rhinitis with regard to such control, is needed.
Hyperhomocyst(e)inemia (HH) is an established independent risk factor for coronary, cerebral and peripheral vascular diseases. Recent studies have indicated that certain cardiovascular risk factors, ...including diabetes and hypercholesterolemia, impair expression of vascular endothelial growth factor (VEGF) and endogenous angiogenesis. In this study, we investigate the impact of moderate HH on angiogenesis and VEGF pathway in a mouse model of hindlimb ischemia. Upon induction of unilateral hindlimb ischemia, endogenous angiogenesis, expression of VEGF, and phosphorylation of the VEGF receptor Flk-1 were evaluated in mice heterozygous for a deletion of the cystathionine -synthase gene (CBS) and compared with those observed in CBS/mice. CBS/mice exhibit moderate HH, as demonstrated by measuring plasma total homocyst(e)ine (tHcy) levels, which were significantly higher in these animals compared with CBS/mice (4.77 0.82 vs 2.10 0.28, p 0.01). Twenty-eight days after induction of ischemia, hindlimb blood flow was significantly reduced in CBS/mice compared with CBS/animals (0.49 0.03, n 12 vs 0.71 0.09, n 10; p 0.05). In addition, there was a significant negative correlation between plasma homocyst(e)ine levels and the laser Doppler perfusion ratio in CBS/mice (p 0.0087, r 0.7171). While VEGF expression and Flk-1 phosphorylation were not impaired in the ischemic muscles of CBS/mice, phosphorylation of the endothelial cell survival factor Akt was significantly inhibited by homocyst(e)ine in a dose-dependent manner in human umbilical vein endothelial cell (HUVECs) in vitro. In conclusion, our findings demonstrate that endogenous angiogenesis is inversely related to plasma levels of homocyst(e)ine in genetically engineered, heterozygous mice with moderate HH. This impairment, however, is not dependent on reduced expression of VEGF or impaired phosphorylation of its receptor Flk-1. In contrast, our data suggest that impaired Akt phosphorylation mediates the impairment of angiogenesis associated with HH.
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