San Diego State University

About: San Diego State University is a education organization based out in San Diego, California, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 12418 authors who have published 27950 publications receiving 1192375 citations. The organization is also known as: SDSU & San Diego State College.

Loss of MCL-1 leads to impaired autophagy and rapid development of heart failure

Abstract: Myeloid cell leukemia-1 (MCL-1) is an anti-apoptotic BCL-2 protein that is up-regulated in several human cancers. MCL-1 is also highly expressed in myocardium, but its function in myocytes has not been investigated. We generated inducible, cardiomyocyte-specific Mcl-1 knockout mice and found that ablation of Mcl-1 in the adult heart led to rapid cardiomyopathy and death. Although MCL-1 is known to inhibit apoptosis, this process was not activated in MCL-1-deficient hearts. Ultrastructural analysis revealed disorganized sarcomeres and swollen mitochondria in myocytes. Mitochondria isolated from MCL-1-deficient hearts exhibited reduced respiration and limited Ca(2+)-mediated swelling, consistent with opening of the mitochondrial permeability transition pore (mPTP). Double-knockout mice lacking MCL-1 and cyclophilin D, an essential regulator of the mPTP, exhibited delayed progression to heart failure and extended survival. Autophagy is normally induced by myocardial stress, but induction of autophagy was impaired in MCL-1-deficient hearts. These data demonstrate that MCL-1 is essential for mitochondrial homeostasis and induction of autophagy in the heart. This study also raises concerns about potential cardiotoxicity for chemotherapeutics that target MCL-1.

Age-structured and two-delay models for erythropoiesis

Abstract: An age-structured model is developed for erythropoiesis and is reduced to a system of threshold-type differential delay equations using the method of characteristics. Under certain assumptions, this model can be reduced to a system of delay differential equations with two delays. The parameters in the system are estimated from experimental data, and the model is simulated for a normal human subject following a loss of blood. The characteristic equation of the two-delay equation is analyzed and shown to exhibit Hopf bifurcations when the destruction rate of erythrocytes is increased. A numerical study for a rabbit with autoimmune hemolytic anemia is performed and compared with experimental data.

Task effectiveness and word learning in a second language: The involvement load hypothesis on trial:

Abstract: This study tests the claim that word learning and retention in a second language are contingent upon a task's involvement load (i.e. the amount of need, search, and evaluation it imposes), as proposed by Laufer and Hulstijn (2001). Seventy-nine beginning learners of Spanish completed one of three vocabulary learning tasks that varied in the amount of involvement (i.e. mental effort) they induced: reading comprehension (no effort), reading comprehension plus target word suppliance (moderate effort), and sentence writing (strong effort). Passive and active knowledge of the target words was assessed immediately after treatment and two weeks later. In line with the predictions of the Involvement Load Hypothesis, retention was highest in the sentence writing task, lower in the reading plus fill-in task, and lowest in the reading comprehension task. However, when time on task was considered, the benefit associated with more involving tasks faded. The results are discussed in light of form-focused vocabulary ins...

Unawareness of Smell Loss in Normal Aging and Alzheimer's Disease: Discrepancy between Self-Reported and Diagnosed Smell Sensitivity

Abstract: Awareness of loss in smell sensitivity was assessed in 80 normal elderly subjects, 80 patients with probable Alzheimer's disease (AD), and 80 patients with sinusitis by comparing measured smell sensitivity to questionnaire-based, self-reported sensitivity. Both AD patients and sinusitis patients had significantly poorer diagnosed smell sensitivity than the normal elderly. Both patient groups had thresholds which on average were about nine times more concentrated than those of the normal elderly. However, 74% of the AD patients and 77% of the normal elderly with smell loss reported normal smell sensitivity. In contrast, only 8% of the sinusitis patients with loss reported normal smell sensitivity.