Time filter

Source Type

San Juan, Puerto Rico

The University of Puerto Rico, Río Piedras , also referred to as UPR-RP, is a public research university located on a 289-acre campus in Río Piedras, San Juan, Puerto Rico.UPR-RP serves more than 18,000 students, 20% graduate, and grants an average of over 3,000 degrees a year. It is recognized by the Carnegie Foundation for the Advancement of Teaching as an Intensive Doctoral/Research University. As a public comprehensive doctoral institution, its academic offerings range from the baccalaureate to the doctoral degree, through 70 undergraduate programs and 19 graduate degrees with 71 specializations in the basic disciplines and professional fields. UPR‐RP has consistently granted the largest number of doctorate degrees to Hispanics in the US.UPR-RP is the largest campus in terms of student population of the University of Puerto Rico System, and Puerto Rico's first public university. Wikipedia.

Melendez R.I.,University of Puerto Rico at San Juan
Alcoholism: Clinical and Experimental Research | Year: 2011

Background: Using adult C57BL/6J (B6) mice, we previously developed a procedure that causes a progressive increase in ethanol intake and preference (i.e., alcohol escalation effect) following weekly (intermittent) access to ethanol (Melendez et al., 2006). A limitation of this procedure is that it requires many weeks of testing, which limits its use to study ethanol escalation (i.e., binge-like drinking) during adolescence. Previous studies have shown that intermittent every-other-day (EOD) access to ethanol is sufficient to induce ethanol escalation in rats. The objective of this study was to verify whether EOD access is sufficient to induce escalated levels of ethanol intake and preference in adult and adolescent B6 mice. Methods: Male B6 mice received free-choice 24-hour access to 15% ethanol and water on an EOD or daily basis for 2weeks. Food and water were available at all times. Using adult mice, Experiment 1 characterized the induction of ethanol escalation following EOD access at 6 (i.e., drinking in the dark) and 24-hour intervals, whereas Experiment 2 determined whether daily drinking reverses escalation induced by EOD drinking. Experiment 3 compared ethanol-drinking capacity following daily versus EOD drinking in adolescent (P30-45) and adult (P70-85) mice. Results: Experiment 1 revealed that EOD drinking leads to a significant (nearly 2-fold) increase in ethanol intake and preference over mice given daily access. Experiment 2 demonstrated that EOD-elicited escalation is blocked and subsequently reversed following daily drinking. Experiment 3 revealed that ethanol drinking was greater in adolescent mice compared with adults following daily drinking and EOD (escalated) drinking. Although the escalated levels of ethanol intake were greater in adolescent mice, the rate or onset of escalation was comparable between both age-groups. Conclusions: This study is the first to demonstrate that EOD drinking leads to escalation of ethanol intake and preference in adolescent and adult mice. Moreover, our results indicate that daily ethanol reverses ethanol escalation induced by intermittent drinking. The study also revealed that adolescent mice have a greater capacity to drink ethanol under both daily (controlled) and EOD (escalated) conditions, which further supports the notion of adolescent's susceptibility to heavy drinking. © 2011 by the Research Society on Alcoholism. Source

Santiago-Casas Y.,University of Puerto Rico at San Juan
Arthritis care & research | Year: 2012

To determine the clinical manifestations and disease damage associated with discoid rash in a large multiethnic systemic lupus erythematosus (SLE) cohort. SLE patients (per American College of Rheumatology [ACR] criteria) ages ≥16 years with a disease duration of ≤10 years at enrollment and defined ethnicity (African American, Hispanic, or white) from a longitudinal cohort were studied. Socioeconomic-demographic features, clinical manifestations, and disease damage (per the Systemic Lupus International Collaborating Clinics/ACR Damage Index) were determined. The association of discoid lupus erythematosus (DLE) with clinical manifestations and disease damage was examined using multivariable logistic regression. A total of 2,228 SLE patients were studied. The mean ± SD age at diagnosis was 34.3 ± 12.8 years and the mean ± SD disease duration was 7.9 ± 6.0 years; 91.8% were women. DLE was observed in 393 patients with SLE (17.6%). In the multivariable analysis, patients with DLE were more likely to be smokers and of African American ethnicity and to have malar rash, photosensitivity, oral ulcers, leukopenia, and vasculitis. DLE patients were less likely to be of Hispanic (from Texas) ethnicity and to have arthritis, end-stage renal disease, and antinuclear, anti-double-stranded DNA, and antiphospholipid antibodies. Patients with DLE had more damage accrual, particularly chronic seizures, scarring alopecia, scarring of the skin, and skin ulcers. In this cohort of SLE patients, DLE was associated with several clinical features, including serious manifestations such as vasculitis and chronic seizures. Copyright © 2012 by the American College of Rheumatology. Source

Ayala-Pena S.,University of Puerto Rico at San Juan
Free Radical Biology and Medicine | Year: 2013

Huntington's disease (HD) is a neurodegenerative disorder with an autosomal dominant expression pattern and typically a late-onset appearance. HD is a movement disorder with a heterogeneous phenotype characterized by involuntary dance-like gait, bioenergetic deficits, motor impairment, and cognitive and psychiatric deficits. Compelling evidence suggests that increased oxidative stress and mitochondrial dysfunction may underlie HD pathogenesis. However, the exact mechanisms underlying mutant huntingtin-induced neurological toxicity remain unclear. The objective of this paper is to review recent literature regarding the role of oxidative DNA damage in mitochondrial dysfunction and HD pathogenesis. © 2013 Elsevier Inc. All rights reserved. Source

Kuffler D.P.,University of Puerto Rico at San Juan
Progress in Neurobiology | Year: 2014

Restoring neurological function to a damaged peripheral nerve separated by a gap requires axon regeneration (1) across the gap, no matter its length, and then (2) through the distal portion of the nerve, regardless of the time between the trauma and repair, and irrespective of animal or patient age. Sensory nerve grafts, the clinical "gold standard", and most alternative techniques for bridging nerve gaps, promote reliable axon regeneration only across nerve gaps <2. cm in length, and with few axons regenerating when nerve repairs are performed >2 months post-trauma or for patients >20 years of age. Three novel nerve repair techniques are discussed that induce axon regeneration and neurological recovery clinically under conditions where other techniques are ineffective: for nerve gaps up to cm long, repairs performed as late as 3.25 years post-trauma, and for patients up to 58 years old. The mechanisms by which these techniques may work are discussed. Although these techniques provide significant improvements in the extents of axon regeneration and neurological recovery, more extensive and reliable clinical recovery of neurological function is needed and will probably require the simultaneous application of multiple techniques. © 2014. Source

Agnarsson I.,University of Puerto Rico at San Juan
PloS one | Year: 2010

Combining high strength and elasticity, spider silks are exceptionally tough, i.e., able to absorb massive kinetic energy before breaking. Spider silk is therefore a model polymer for development of high performance biomimetic fibers. There are over 41,000 described species of spiders, most spinning multiple types of silk. Thus we have available some 200,000+ unique silks that may cover an amazing breadth of material properties. To date, however, silks from only a few tens of species have been characterized, most chosen haphazardly as model organisms (Nephila) or simply from researchers' backyards. Are we limited to 'blindly fishing' in efforts to discover extraordinary silks? Or, could scientists use ecology to predict which species are likely to spin silks exhibiting exceptional performance properties? We examined the biomechanical properties of silk produced by the remarkable Malagasy 'Darwin's bark spider' (Caerostris darwini), which we predicted would produce exceptional silk based upon its amazing web. The spider constructs its giant orb web (up to 2.8 m(2)) suspended above streams, rivers, and lakes. It attaches the web to substrates on each riverbank by anchor threads as long as 25 meters. Dragline silk from both Caerostris webs and forcibly pulled silk, exhibits an extraordinary combination of high tensile strength and elasticity previously unknown for spider silk. The toughness of forcibly silked fibers averages 350 MJ/m(3), with some samples reaching 520 MJ/m(3). Thus, C. darwini silk is more than twice tougher than any previously described silk, and over 10 times better than Kevlar®. Caerostris capture spiral silk is similarly exceptionally tough. Caerostris darwini produces the toughest known biomaterial. We hypothesize that this extraordinary toughness coevolved with the unusual ecology and web architecture of these spiders, decreasing the likelihood of bridgelines breaking and collapsing the web into the river. This hypothesis predicts that rapid change in material properties of silk co-occurred with ecological shifts within the genus, and can thus be tested by combining material science, behavioral observations, and phylogenetics. Our findings highlight the potential benefits of natural history-informed bioprospecting to discover silks, as well as other materials, with novel and exceptional properties to serve as models in biomimicry. Source

Discover hidden collaborations